home-automation/frontend/src/energy/MeterManager.test.tsx

/**
 * Tests for MeterManager component.
 *
 * Coverage:
 * 1. Loading state rendering.
 * 2. Error state rendering.
 * 3. Empty state when no meters exist.
 * 4. Meter timeline list rendering (label, dates, active badge, reason).
 * 5. "Declare New Meter" button opens form modal.
 * 6. Declare meter — form submit calls POST /api/energy/meters.
 * 7. Declare meter — 422 (倒挂) error is displayed.
 * 8. Edit button opens edit form modal.
 * 9. Edit meter — saves label/note via PATCH /api/energy/meters/{meter_id}.
 * 10. Edit meter — retroactive started_at triggers recompute notice.
 */

import { describe, it, expect, vi, beforeEach } from 'vitest'
import { screen, waitFor } from '@testing-library/react'
import userEvent from '@testing-library/user-event'
import { renderWithProviders } from '../test-utils'
import { MeterManager } from './MeterManager'

// ---------------------------------------------------------------------------
// Mock apiClient
// ---------------------------------------------------------------------------

const mockGet = vi.fn()
const mockPost = vi.fn()
const mockPatch = vi.fn()

vi.mock('../api/client', () => ({
  default: {
    GET: (...args: unknown[]) => mockGet(...args),
    POST: (...args: unknown[]) => mockPost(...args),
    PATCH: (...args: unknown[]) => mockPatch(...args),
    DELETE: vi.fn(),
  },
  ApiError: class ApiError extends Error {
    status: number
    body: unknown
    constructor(status: number, body: unknown) {
      super(`API error ${status}`)
      this.name = 'ApiError'
      this.status = status
      this.body = body
    }
  },
  registerLoginRedirect: vi.fn(),
}))

// ---------------------------------------------------------------------------
// Fixtures
// ---------------------------------------------------------------------------

const ACTIVE_METER = {
  id: 1,
  label: 'Initial 2G meter',
  commodity: 'electricity',
  started_at: '2024-01-15T00:00:00Z',
  ended_at: null,
  reason: 'initial',
  note: null,
  created_at: '2024-01-15T00:00:00Z',
  bindings: [],
}

const CLOSED_METER = {
  id: 2,
  label: 'Old 4G meter',
  commodity: 'electricity',
  started_at: '2023-06-01T00:00:00Z',
  ended_at: '2024-01-15T00:00:00Z',
  reason: 'meter_swap',
  note: 'Replaced by grid company',
  created_at: '2023-06-01T00:00:00Z',
}

const METERS_RESPONSE = {
  items: [CLOSED_METER, ACTIVE_METER],
  total: 2,
}

// ---------------------------------------------------------------------------
// Tests
// ---------------------------------------------------------------------------

describe('MeterManager — loading / error / empty states', () => {
  // M8 keeps the existing Modbus-facing meter regressions alongside commodity additions.
  beforeEach(() => vi.clearAllMocks())

  it('renders loading state initially', () => {
    mockGet.mockImplementation(() => new Promise(() => {}))

    renderWithProviders(<MeterManager />)

    expect(screen.getByTestId('meters-loading')).toBeInTheDocument()
  })

  it('renders error state when GET fails', async () => {
    mockGet.mockRejectedValue(new Error('Network error'))

    renderWithProviders(<MeterManager />)

    await waitFor(() => {
      expect(screen.getByTestId('meters-load-error')).toBeInTheDocument()
    })
  })

  it('renders empty state when no meters exist', async () => {
    mockGet.mockResolvedValue({ data: { items: [], total: 0 } })

    renderWithProviders(<MeterManager />)

    await waitFor(() => {
      expect(screen.getByTestId('meters-empty')).toBeInTheDocument()
    })
  })
})

describe('MeterManager — binding switch safety', () => {
  beforeEach(() => vi.clearAllMocks())
  it('does not offer switching for a closed meter epoch', async () => {
    mockGet.mockResolvedValue({ data: { items: [CLOSED_METER], total: 1 } })
    renderWithProviders(<MeterManager />)
    await waitFor(() => expect(screen.getByTestId('meters-table')).toBeInTheDocument())
    expect(screen.queryByRole('button', { name: 'Transfer source' })).not.toBeInTheDocument()
  })
  it('closes an active meter with one atomic close request and local datetime payload', async () => {
    const user = userEvent.setup()
    mockGet.mockResolvedValue({ data: { items: [ACTIVE_METER], total: 1 } })
    mockPost.mockResolvedValue({ data: { ...ACTIVE_METER, ended_at: '2026-08-24T10:00:00Z' } })
    renderWithProviders(<MeterManager />)
    await user.click(await screen.findByRole('button', { name: 'Close meter' }))
    expect(await screen.findByText(/Every open binding/)).toBeInTheDocument()
    await user.click(screen.getAllByRole('button', { name: 'Close meter' })[1])
    await waitFor(() => expect(mockPost).toHaveBeenCalledWith(
      '/api/energy/meters/{meter_id}/close',
      expect.objectContaining({ params: { path: { meter_id: ACTIVE_METER.id } }, body: expect.objectContaining({ ended_at: expect.not.stringMatching(/Z$/) }) }),
    ))
  })

  it('offers atomic stranded-binding recovery to the adjacent active meter and warns about a gap', async () => {
    const user = userEvent.setup()
    const stranded = {
      ...CLOSED_METER,
      ended_at: '2024-01-10T00:00:00Z',
      bindings: [{ uuid: 'stranded-binding', source_uuid: 'dsmr', source_channel_uuid: 'dsmr-total', started_at: '2023-06-01T00:00:00Z', ended_at: null }],
    }
    mockGet.mockImplementation((path: string) => {
      if (path === '/api/energy/meters') return Promise.resolve({ data: { items: [stranded, ACTIVE_METER], total: 2 } })
      if (path === '/api/energy/sources') return Promise.resolve({ data: { items: [{ uuid: 'dsmr', name: 'DSMR' }], total: 1 } })
      return Promise.resolve({ data: { items: [] } })
    })
    renderWithProviders(<MeterManager />)
    await user.click(await screen.findByRole('button', { name: 'Recover binding' }))
    expect(await screen.findByText(/one atomic Transfer request/)).toBeInTheDocument()
    expect(screen.getByText(/defaults to the new meter start/)).toBeInTheDocument()
    const effectiveAt = screen.getByTestId('transfer-effective-at')
    await user.clear(effectiveAt)
    await user.type(effectiveAt, '2024-01-16T12:00')
    expect(screen.getByText(/leaves an unbound gap/)).toBeInTheDocument()
  })

  it('does not offer recovery when another epoch overlaps the source or target timeline', async () => {
    const stranded = {
      ...CLOSED_METER,
      ended_at: '2024-01-10T00:00:00Z',
      bindings: [{ uuid: 'stranded-binding', source_uuid: 'dsmr', source_channel_uuid: 'dsmr-total', started_at: '2023-06-01T00:00:00Z', ended_at: null }],
    }
    const ambiguous = { ...CLOSED_METER, id: 3, started_at: '2024-01-12T00:00:00Z', ended_at: '2024-01-20T00:00:00Z' }
    mockGet.mockResolvedValue({ data: { items: [stranded, ambiguous, ACTIVE_METER], total: 3 } })
    renderWithProviders(<MeterManager />)
    await waitFor(() => expect(screen.getByTestId('meters-table')).toBeInTheDocument())
    expect(screen.queryByRole('button', { name: 'Recover binding' })).not.toBeInTheDocument()
  })

})

describe('MeterManager — meter list', () => {
  beforeEach(() => vi.clearAllMocks())

  it('renders meter timeline with label, dates, status badge, reason', async () => {
    mockGet.mockResolvedValue({ data: METERS_RESPONSE })

    renderWithProviders(<MeterManager />)

    await waitFor(() => {
      expect(screen.getByTestId('meters-table')).toBeInTheDocument()
    })

    // Labels
    expect(screen.getByText('Initial 2G meter')).toBeInTheDocument()
    expect(screen.getByText('Old 4G meter')).toBeInTheDocument()

    // Status badges
    expect(screen.getByTestId(`meter-status-${ACTIVE_METER.id}`)).toHaveTextContent('active')
    expect(screen.getByTestId(`meter-status-${CLOSED_METER.id}`)).toHaveTextContent('closed')

    // Reason badges
    expect(screen.getByText('initial')).toBeInTheDocument()
    expect(screen.getByText('meter_swap')).toBeInTheDocument()
  })

  it('renders every binding timeline segment with source, channel, and half-open boundaries', async () => {
    const meterWithBindings = {
      ...ACTIVE_METER,
      bindings: [
        { uuid: 'binding-closed', source_uuid: 'source-old', source_channel_uuid: 'channel-old', started_at: '2025-01-01T00:00:00Z', ended_at: '2025-02-01T00:00:00Z' },
        { uuid: 'binding-active', source_uuid: 'source-new', source_channel_uuid: 'channel-new', started_at: '2025-02-01T00:00:00Z', ended_at: null },
      ],
    }
    mockGet.mockImplementation((path: string) => {
      if (path === '/api/energy/meters') return Promise.resolve({ data: { items: [meterWithBindings], total: 1 } })
      if (path === '/api/energy/sources') return Promise.resolve({ data: { items: [
        { uuid: 'source-old', name: 'Old source' }, { uuid: 'source-new', name: 'New source' },
      ], total: 2 } })
      if (path === '/api/energy/sources/{source_uuid}/channels') return Promise.resolve({ data: { items: [
        { uuid: 'channel-old', label: 'Old channel', unit: 'kWh' }, { uuid: 'channel-new', label: 'New channel', unit: 'kWh' },
      ], total: 2 } })
      return Promise.resolve({ data: { items: [] } })
    })
    renderWithProviders(<MeterManager />)
    const closed = await screen.findByTestId('binding-timeline-binding-closed')
    await waitFor(() => expect(closed).toHaveTextContent('Old source → Old channel'))
    const active = screen.getByTestId('binding-timeline-binding-active')
    expect(closed).toHaveTextContent('Old source → Old channel')
    expect(closed).toHaveTextContent('[1/1/2025, 00:00:00, 2/1/2025, 00:00:00) (closed)')
    expect(active).toHaveTextContent('New source → New channel')
    expect(active).toHaveTextContent('[2/1/2025, 00:00:00, open-ended) (active)')
    expect(closed).not.toHaveTextContent('source-old')
    expect(active).not.toHaveTextContent('channel-new')
  })

  it('uses UUID-free honest binding fallbacks while source details load or fail', async () => {
    const meter = { ...ACTIVE_METER, bindings: [{ uuid: 'binding-visible-id-only', source_uuid: 'private-source-id', source_channel_uuid: 'private-channel-id', started_at: '2025-01-01T00:00:00Z', ended_at: null }] }
    mockGet.mockImplementation((path: string) => {
      if (path === '/api/energy/meters') return Promise.resolve({ data: { items: [meter], total: 1 } })
      if (path === '/api/energy/sources') return new Promise(() => {})
      return Promise.resolve({ data: { items: [] } })
    })
    renderWithProviders(<MeterManager />)
    const timeline = await screen.findByTestId('binding-timeline-binding-visible-id-only')
    expect(timeline).toHaveTextContent('Loading source details… → Channel details unavailable')
    expect(timeline).not.toHaveTextContent('private-source-id')
    expect(timeline).not.toHaveTextContent('private-channel-id')
  })

  it('keeps meter row actions in the shared light, xs order', async () => {
    const binding = { uuid: 'ordered-binding', source_uuid: 'source-1', source_channel_uuid: 'channel-1', started_at: '2024-01-15T00:00:00Z', ended_at: null }
    mockGet.mockImplementation((path: string) => {
      if (path === '/api/energy/meters') return Promise.resolve({ data: { items: [{ ...ACTIVE_METER, bindings: [binding] }], total: 1 } })
      if (path === '/api/energy/sources') return Promise.resolve({ data: { items: [{ uuid: 'source-1', name: 'DSMR' }], total: 1 } })
      if (path === '/api/energy/sources/{source_uuid}/channels') return Promise.resolve({ data: { items: [{ uuid: 'channel-1', label: 'Total import', unit: 'kWh' }], total: 1 } })
      return Promise.resolve({ data: { items: [] } })
    })
    renderWithProviders(<MeterManager />)
    const row = await screen.findByTestId(`meter-row-${ACTIVE_METER.id}`)
    const buttons = Array.from(row.querySelectorAll('button'))
    expect(buttons.map((button) => button.textContent)).toEqual(['Edit', 'Transfer source', 'Unbind', 'Close meter'])
    expect(buttons).toHaveLength(4)
  })

  it('renders "Declare New Meter" button', async () => {
    mockGet.mockResolvedValue({ data: METERS_RESPONSE })

    renderWithProviders(<MeterManager />)

    await waitFor(() => {
      expect(screen.getByTestId('meter-declare-button')).toBeInTheDocument()
    })
  })
})

describe('MeterManager — declare new meter', () => {
  beforeEach(() => vi.clearAllMocks())

  it('opens declare modal when "Declare New Meter" is clicked', async () => {
    const user = userEvent.setup()
    mockGet.mockResolvedValue({ data: { items: [], total: 0 } })

    renderWithProviders(<MeterManager />)

    await waitFor(() => expect(screen.getByTestId('meter-declare-button')).toBeInTheDocument())

    await user.click(screen.getByTestId('meter-declare-button'))

    await waitFor(() => {
      expect(screen.getByTestId('declare-meter-modal')).toBeInTheDocument()
    })
    expect(screen.getByTestId('declare-meter-form')).toBeInTheDocument()
  })

  it('calls POST /api/energy/meters with correct payload including local-midnight naive datetime', async () => {
    const user = userEvent.setup()
    mockGet.mockResolvedValue({ data: { items: [], total: 0 } })
    mockPost.mockResolvedValue({ data: ACTIVE_METER })

    renderWithProviders(<MeterManager />)

    await waitFor(() => expect(screen.getByTestId('meter-declare-button')).toBeInTheDocument())
    await user.click(screen.getByTestId('meter-declare-button'))

    await waitFor(() => expect(screen.getByTestId('declare-meter-form')).toBeInTheDocument())

    // Fill form
    await user.type(screen.getByTestId('meter-label'), 'New meter label')
    await user.type(screen.getByTestId('meter-started-at'), '2026-01-01')

    // Select reason via the combobox (Mantine Select renders a combobox)
    await user.click(screen.getByTestId('meter-reason'))
    await waitFor(() => screen.getByText('Initial installation'))
    await user.click(screen.getByText('Initial installation'))

    await user.click(screen.getByTestId('declare-meter-submit'))

    await waitFor(() => {
      expect(mockPost).toHaveBeenCalledWith(
        '/api/energy/meters',
        expect.objectContaining({
          body: expect.objectContaining({
            label: 'New meter label',
            // FU10 local-midnight naive convention: no Z suffix
            started_at: '2026-01-01T00:00:00',
            reason: 'initial',
            commodity: 'electricity',
          }),
        }),
      )
    })
  })

  it('offers a channel with closed history and one current old-meter binding for a safe swap', async () => {
    const user = userEvent.setup()
    mockGet.mockImplementation((path: string) => {
      if (path === '/api/energy/meters') return Promise.resolve({ data: { items: [{
        ...CLOSED_METER,
        bindings: [{
          uuid: 'binding-history', source_channel_uuid: 'handoff-channel', source_uuid: 'source-1',
          started_at: '2023-06-01T00:00:00Z', ended_at: '2024-01-15T00:00:00Z',
        }],
      }, {
        ...ACTIVE_METER,
        bindings: [{
          uuid: 'binding-current', source_channel_uuid: 'handoff-channel', source_uuid: 'source-1',
          started_at: '2024-01-15T00:00:00Z', ended_at: null,
        }],
      }], total: 2 } })
      if (path === '/api/energy/sources') return Promise.resolve({ data: { items: [{ uuid: 'source-1', name: 'DSMR' }] } })
      if (path === '/api/energy/sources/{source_uuid}/channels') {
        return Promise.resolve({ data: { items: [
          { uuid: 'handoff-channel', label: 'Current total', unit: 'kWh', binding_count: 2, bound_meter_ids: [CLOSED_METER.id, ACTIVE_METER.id] },
          { uuid: 'occupied-channel', label: 'Other total', unit: 'kWh', binding_count: 1, bound_meter_ids: [999] },
        ] } })
      }
      return Promise.resolve({ data: { items: [] } })
    })
    mockPost.mockResolvedValue({ data: ACTIVE_METER })

    renderWithProviders(<MeterManager />)
    await user.click(await screen.findByTestId('meter-declare-button'))
    await user.type(screen.getByTestId('meter-label'), 'Replacement meter')
    await user.type(screen.getByTestId('meter-started-at'), '2026-01-01')
    await user.click(screen.getByTestId('meter-reason'))
    await user.click(await screen.findByText('Meter swap (same address)'))
    await user.click(screen.getAllByLabelText('Bind source (optional)')[0])
    await user.click(await screen.findByText('DSMR'))
    await user.click((await screen.findAllByLabelText('Compatible source channel (optional)'))[0])

    expect(await screen.findByText('Current total (kWh) — hand off from current meter')).toBeInTheDocument()
    // Its historical count alone does not make it unavailable: eligibility is
    // derived from actual open intervals, not lifetime binding_count.
    expect(screen.getByRole('option', { name: 'Other total (kWh)' })).not.toHaveAttribute('data-combobox-disabled')
    await user.click(screen.getByText('Current total (kWh) — hand off from current meter'))
    await user.click(screen.getByTestId('declare-meter-submit'))

    await waitFor(() => expect(mockPost).toHaveBeenCalledWith(
      '/api/energy/meters',
      expect.objectContaining({ body: expect.objectContaining({ source_channel_uuid: 'handoff-channel' }) }),
    ))
  })

  it('keeps a channel disabled when its current open binding is ambiguous', async () => {
    const user = userEvent.setup()
    const competingMeter = {
      ...ACTIVE_METER,
      id: 999,
      label: 'Competing meter',
      bindings: [{
        uuid: 'binding-competing', source_channel_uuid: 'handoff-channel', source_uuid: 'source-1',
        started_at: '2025-01-01T00:00:00Z', ended_at: null,
      }],
    }
    mockGet.mockImplementation((path: string) => {
      if (path === '/api/energy/meters') return Promise.resolve({ data: { items: [{
        ...ACTIVE_METER,
        bindings: [{
          uuid: 'binding-current', source_channel_uuid: 'handoff-channel', source_uuid: 'source-1',
          started_at: '2024-01-15T00:00:00Z', ended_at: null,
        }],
      }, competingMeter], total: 2 } })
      if (path === '/api/energy/sources') return Promise.resolve({ data: { items: [{ uuid: 'source-1', name: 'DSMR' }] } })
      if (path === '/api/energy/sources/{source_uuid}/channels') {
        return Promise.resolve({ data: { items: [
          { uuid: 'handoff-channel', label: 'Current total', unit: 'kWh', binding_count: 2, bound_meter_ids: [ACTIVE_METER.id, competingMeter.id] },
        ] } })
      }
      return Promise.resolve({ data: { items: [] } })
    })

    renderWithProviders(<MeterManager />)
    await user.click(await screen.findByTestId('meter-declare-button'))
    await user.type(screen.getByTestId('meter-label'), 'Replacement meter')
    await user.type(screen.getByTestId('meter-started-at'), '2026-01-01')
    await user.click(screen.getByTestId('meter-reason'))
    await user.click(await screen.findByText('Meter swap (same address)'))
    await user.click(screen.getAllByLabelText('Bind source (optional)')[0])
    await user.click(await screen.findByText('DSMR'))
    await user.click((await screen.findAllByLabelText('Compatible source channel (optional)'))[0])

    expect(await screen.findByRole('option', { name: /Current total \(kWh\).*ambiguous/ })).toHaveAttribute(
      'data-combobox-disabled',
    )
  })

  it('disables an equal handoff boundary with a reason and fails closed on submit', async () => {
    const user = userEvent.setup()
    mockGet.mockImplementation((path: string) => {
      if (path === '/api/energy/meters') return Promise.resolve({ data: { items: [{
        ...ACTIVE_METER,
        bindings: [{
          uuid: 'binding-1', source_channel_uuid: 'handoff-channel', source_uuid: 'source-1',
          started_at: '2024-01-15T00:00:00Z', ended_at: null,
        }],
      }], total: 1 } })
      if (path === '/api/energy/sources') return Promise.resolve({ data: { items: [{ uuid: 'source-1', name: 'DSMR' }] } })
      if (path === '/api/energy/sources/{source_uuid}/channels') {
        return Promise.resolve({ data: { items: [
          { uuid: 'handoff-channel', label: 'Current total', unit: 'kWh', binding_count: 1, bound_meter_ids: [ACTIVE_METER.id] },
        ] } })
      }
      return Promise.resolve({ data: { items: [] } })
    })
    mockPost.mockResolvedValue({ data: ACTIVE_METER })

    renderWithProviders(<MeterManager />)
    await user.click(await screen.findByTestId('meter-declare-button'))
    await user.type(screen.getByTestId('meter-label'), 'Replacement meter')
    await user.type(screen.getByTestId('meter-started-at'), '2024-01-15')
    await user.click(screen.getByTestId('meter-reason'))
    await user.click(await screen.findByText('Meter swap (same address)'))
    await user.click(screen.getAllByLabelText('Bind source (optional)')[0])
    await user.click(await screen.findByText('DSMR'))
    const channelInput = screen.getAllByLabelText('Compatible source channel (optional)')[0]
    await user.click(channelInput)
    const disabled = await screen.findByText(/handoff boundary must be strictly after the current binding start/)
    expect(disabled.closest('[role="option"]')).toHaveAttribute('data-combobox-disabled', 'true')
    await user.keyboard('{Escape}')
    await user.click(screen.getByTestId('declare-meter-submit'))
    expect(screen.getByTestId('declare-meter-error')).toHaveTextContent('Handoff boundary must be strictly after')
    expect(mockPost).not.toHaveBeenCalled()
  })

  it('submits an explicitly selected handoff strictly after its binding start', async () => {
    vi.stubEnv('TZ', 'Europe/Amsterdam')
    try {
      const user = userEvent.setup()
      mockGet.mockImplementation((path: string) => {
        if (path === '/api/energy/meters') return Promise.resolve({ data: { items: [{
          ...ACTIVE_METER,
          bindings: [{
            uuid: 'binding-1', source_channel_uuid: 'handoff-channel', source_uuid: 'source-1',
            started_at: '2024-01-15T00:00:00Z', ended_at: null,
          }],
        }], total: 1 } })
        if (path === '/api/energy/sources') return Promise.resolve({ data: { items: [{ uuid: 'source-1', name: 'DSMR' }] } })
        if (path === '/api/energy/sources/{source_uuid}/channels') {
          return Promise.resolve({ data: { items: [
            { uuid: 'handoff-channel', label: 'Current total', unit: 'kWh', binding_count: 1, bound_meter_ids: [ACTIVE_METER.id] },
          ] } })
        }
        return Promise.resolve({ data: { items: [] } })
      })
      mockPost.mockResolvedValue({ data: ACTIVE_METER })

      renderWithProviders(<MeterManager />)
      await user.click(await screen.findByTestId('meter-declare-button'))
      await user.type(screen.getByTestId('meter-label'), 'Replacement meter')
      await user.type(screen.getByTestId('meter-started-at'), '2024-01-16')
      await user.click(screen.getByTestId('meter-reason'))
      await user.click(await screen.findByText('Meter swap (same address)'))
      await user.click(screen.getAllByLabelText('Bind source (optional)')[0])
      await user.click(await screen.findByText('DSMR'))
      await user.click((await screen.findAllByLabelText('Compatible source channel (optional)'))[0])
      await user.click(await screen.findByText('Current total (kWh) — hand off from current meter'))

      const startedAt = screen.getByTestId('meter-started-at')
      await user.clear(startedAt)
      await user.type(startedAt, '2024-01-16')
      const channelInput = screen.getAllByLabelText('Compatible source channel (optional)')[0]
      await user.click(channelInput)
      await user.click(await screen.findByText('Current total (kWh) — hand off from current meter'))
      await waitFor(() => expect(channelInput).toHaveValue('Current total (kWh) — hand off from current meter'))
      await user.click(screen.getByTestId('declare-meter-submit'))

      await waitFor(() => expect(mockPost).toHaveBeenCalledWith(
        '/api/energy/meters',
        expect.objectContaining({ body: expect.objectContaining({ source_channel_uuid: 'handoff-channel', started_at: '2024-01-16T00:00:00' }) }),
      ))
      expect(mockPost).toHaveBeenCalledTimes(1)
    } finally {
      vi.unstubAllEnvs()
    }
  })

  it.each([
    ['equal boundary', '2024-01-15', false],
    ['strictly later boundary', '2024-01-16', true],
  ])('handles an implicit auto-handoff at the %s with another commodity open', async (_name, date, submits) => {
    const user = userEvent.setup()
    const electricity = {
      ...ACTIVE_METER,
      bindings: [{
        uuid: 'electricity-open', source_uuid: 'dsmr-source', source_channel_uuid: 'electricity-kwh',
        started_at: '2024-01-15T00:00:00Z', ended_at: null,
      }],
    }
    const heating = {
      ...ACTIVE_METER,
      id: 2,
      label: 'Heating meter',
      commodity: 'heating',
      started_at: '2024-01-01T00:00:00Z',
      bindings: [{
        uuid: 'heating-open', source_uuid: 'warmtelink-source', source_channel_uuid: 'heating-gj',
        started_at: '2024-01-01T00:00:00Z', ended_at: null,
      }],
    }
    mockGet.mockImplementation((path: string) => {
      if (path === '/api/energy/meters') return Promise.resolve({ data: { items: [electricity, heating], total: 2 } })
      if (path === '/api/energy/sources') return Promise.resolve({ data: { items: [], total: 0 } })
      return Promise.resolve({ data: { items: [] } })
    })
    mockPost.mockResolvedValue({ data: ACTIVE_METER })
    renderWithProviders(<MeterManager />)
    await user.click(await screen.findByTestId('meter-declare-button'))
    await user.type(screen.getByTestId('meter-label'), 'Replacement meter')
    await user.type(screen.getByTestId('meter-started-at'), date)
    await user.click(screen.getByTestId('meter-reason'))
    await user.click(await screen.findByText('Meter swap (same address)'))
    await user.click(screen.getByTestId('declare-meter-submit'))

    if (!submits) {
      expect(screen.getByTestId('declare-meter-error')).toHaveTextContent('Handoff boundary must be strictly after')
      expect(mockPost).not.toHaveBeenCalled()
      return
    }
    await waitFor(() => expect(mockPost).toHaveBeenCalledWith('/api/energy/meters', {
      body: {
        label: 'Replacement meter', started_at: '2024-01-16T00:00:00', reason: 'meter_swap',
        commodity: 'electricity',
      },
    }))
    expect(mockPost).toHaveBeenCalledTimes(1)
  })

  it('displays error when POST fails with 422 (倒挂 / validation error)', async () => {
    const user = userEvent.setup()
    mockGet.mockResolvedValue({ data: { items: [ACTIVE_METER], total: 1 } })

    const { ApiError } = await import('../api/client')
    mockPost.mockRejectedValue(
      new ApiError(422, { detail: 'started_at must be ≥ current active meter started_at' }),
    )

    renderWithProviders(<MeterManager />)

    await waitFor(() => expect(screen.getByTestId('meter-declare-button')).toBeInTheDocument())
    await user.click(screen.getByTestId('meter-declare-button'))
    await waitFor(() => expect(screen.getByTestId('declare-meter-form')).toBeInTheDocument())

    await user.type(screen.getByTestId('meter-label'), 'Bad meter')
    await user.type(screen.getByTestId('meter-started-at'), '2020-01-01')
    await user.click(screen.getByTestId('meter-reason'))
    await waitFor(() => screen.getByText('Meter swap (same address)'))
    await user.click(screen.getByText('Meter swap (same address)'))

    await user.click(screen.getByTestId('declare-meter-submit'))

    await waitFor(() => {
      expect(screen.getByTestId('declare-meter-error')).toBeInTheDocument()
    })
    expect(screen.getByTestId('declare-meter-error').textContent).toContain(
      'started_at must be ≥',
    )
  })

  it('cancel button closes the declare modal', async () => {
    const user = userEvent.setup()
    mockGet.mockResolvedValue({ data: { items: [], total: 0 } })

    renderWithProviders(<MeterManager />)

    await waitFor(() => expect(screen.getByTestId('meter-declare-button')).toBeInTheDocument())
    await user.click(screen.getByTestId('meter-declare-button'))
    await waitFor(() => expect(screen.getByTestId('declare-meter-modal')).toBeInTheDocument())

    await user.click(screen.getByTestId('declare-meter-cancel'))

    await waitFor(() => {
      expect(screen.queryByTestId('declare-meter-modal')).not.toBeInTheDocument()
    })
  })
})

describe('MeterManager — edit meter date initialisation', () => {
  beforeEach(() => vi.clearAllMocks())

  it('initialises date input from started_at (Z-suffix, UTC midnight → local date)', async () => {
    // ACTIVE_METER.started_at = '2024-01-15T00:00:00Z' (UTC midnight).
    // The test suite is pinned to TZ=UTC (via vite.config.ts test.env), so
    // the local date is deterministically '2024-01-15' on any CI runner.
    const user = userEvent.setup()
    mockGet.mockResolvedValue({ data: { items: [ACTIVE_METER], total: 1 } })

    renderWithProviders(<MeterManager />)

    await waitFor(() => expect(screen.getByTestId(`meter-edit-${ACTIVE_METER.id}`)).toBeInTheDocument())
    await user.click(screen.getByTestId(`meter-edit-${ACTIVE_METER.id}`))
    await waitFor(() => expect(screen.getByTestId('edit-meter-form')).toBeInTheDocument())

    const dateInput = screen.getByTestId('edit-meter-started-at') as HTMLInputElement
    expect(dateInput.value).toBe('2024-01-15')
  })

  it('initialises date input from started_at (naive, no tz marker)', async () => {
    // A naive timestamp without timezone marker — parseBackendTimestamp appends 'Z'
    // so it is treated as UTC. With TZ=UTC (pinned in vite.config.ts), the local date
    // equals the UTC date exactly.
    const naiveMeter = { ...ACTIVE_METER, started_at: '2024-03-20T00:00:00' }
    const user = userEvent.setup()
    mockGet.mockResolvedValue({ data: { items: [naiveMeter], total: 1 } })

    renderWithProviders(<MeterManager />)

    await waitFor(() => expect(screen.getByTestId(`meter-edit-${naiveMeter.id}`)).toBeInTheDocument())
    await user.click(screen.getByTestId(`meter-edit-${naiveMeter.id}`))
    await waitFor(() => expect(screen.getByTestId('edit-meter-form')).toBeInTheDocument())

    const dateInput = screen.getByTestId('edit-meter-started-at') as HTMLInputElement
    expect(dateInput.value).toBe('2024-03-20')
  })

  it('initialises date input from started_at with explicit UTC offset (+02:00) — regression for old buggy regex', async () => {
    // The old hand-written regex /[zZ+-]\d*$/ would fail to match '+02:00' (the ':00'
    // suffix broke the pattern) and would incorrectly append 'Z', producing an Invalid Date.
    // The new code uses parseBackendTimestamp which uses the correct TZ_MARKER_RE regex
    // and handles explicit offsets properly.
    const offsetMeter = { ...ACTIVE_METER, started_at: '2024-01-15T02:00:00+02:00' }
    // UTC equivalent: 2024-01-15T00:00:00Z → with TZ=UTC (pinned) local date = '2024-01-15'
    const user = userEvent.setup()
    mockGet.mockResolvedValue({ data: { items: [offsetMeter], total: 1 } })

    renderWithProviders(<MeterManager />)

    await waitFor(() => expect(screen.getByTestId(`meter-edit-${offsetMeter.id}`)).toBeInTheDocument())
    await user.click(screen.getByTestId(`meter-edit-${offsetMeter.id}`))
    await waitFor(() => expect(screen.getByTestId('edit-meter-form')).toBeInTheDocument())

    const dateInput = screen.getByTestId('edit-meter-started-at') as HTMLInputElement
    // Must not be empty (which would indicate Invalid Date from the old buggy path)
    expect(dateInput.value).not.toBe('')
    expect(dateInput.value).toBe('2024-01-15')
  })

  it('does not include started_at in PATCH body when date is unchanged (round-trip idempotence)', async () => {
    // Open the edit form and immediately submit without changing any fields except label.
    // The date should be considered unchanged → no started_at in the PATCH body.
    const user = userEvent.setup()
    mockGet.mockResolvedValue({ data: { items: [ACTIVE_METER], total: 1 } })
    mockPatch.mockResolvedValue({ data: { ...ACTIVE_METER, label: 'New label' } })

    renderWithProviders(<MeterManager />)

    await waitFor(() => expect(screen.getByTestId(`meter-edit-${ACTIVE_METER.id}`)).toBeInTheDocument())
    await user.click(screen.getByTestId(`meter-edit-${ACTIVE_METER.id}`))
    await waitFor(() => expect(screen.getByTestId('edit-meter-form')).toBeInTheDocument())

    // Change only label; leave date untouched
    const labelInput = screen.getByTestId('edit-meter-label')
    await user.clear(labelInput)
    await user.type(labelInput, 'New label')

    await user.click(screen.getByTestId('edit-meter-submit'))

    await waitFor(() => {
      expect(mockPatch).toHaveBeenCalled()
    })

    const patchBody = mockPatch.mock.calls[0][1].body
    expect(patchBody).not.toHaveProperty('started_at')
  })
})

describe('MeterManager — edit meter', () => {
  beforeEach(() => vi.clearAllMocks())

  it('opens edit modal when Edit button is clicked', async () => {
    const user = userEvent.setup()
    mockGet.mockResolvedValue({ data: METERS_RESPONSE })

    renderWithProviders(<MeterManager />)

    await waitFor(() => expect(screen.getByTestId(`meter-edit-${ACTIVE_METER.id}`)).toBeInTheDocument())

    await user.click(screen.getByTestId(`meter-edit-${ACTIVE_METER.id}`))

    await waitFor(() => {
      expect(screen.getByTestId('edit-meter-modal')).toBeInTheDocument()
    })
    expect(screen.getByTestId('edit-meter-form')).toBeInTheDocument()
  })

  it('calls PATCH /api/energy/meters/{meter_id} when label is changed', async () => {
    const user = userEvent.setup()
    mockGet.mockResolvedValue({ data: { items: [ACTIVE_METER], total: 1 } })
    mockPatch.mockResolvedValue({ data: { ...ACTIVE_METER, label: 'Renamed meter' } })

    renderWithProviders(<MeterManager />)

    await waitFor(() => expect(screen.getByTestId(`meter-edit-${ACTIVE_METER.id}`)).toBeInTheDocument())
    await user.click(screen.getByTestId(`meter-edit-${ACTIVE_METER.id}`))
    await waitFor(() => expect(screen.getByTestId('edit-meter-form')).toBeInTheDocument())

    // Clear label and type new one
    const labelInput = screen.getByTestId('edit-meter-label')
    await user.clear(labelInput)
    await user.type(labelInput, 'Renamed meter')

    await user.click(screen.getByTestId('edit-meter-submit'))

    await waitFor(() => {
      expect(mockPatch).toHaveBeenCalledWith(
        '/api/energy/meters/{meter_id}',
        expect.objectContaining({
          params: { path: { meter_id: ACTIVE_METER.id } },
          body: expect.objectContaining({ label: 'Renamed meter' }),
        }),
      )
    })
  })

  it('shows recompute notice when started_at is changed (retroactive correction)', async () => {
    const user = userEvent.setup()
    mockGet.mockResolvedValue({ data: { items: [ACTIVE_METER], total: 1 } })
    mockPatch.mockResolvedValue({ data: { ...ACTIVE_METER, started_at: '2024-02-01T00:00:00' } })

    renderWithProviders(<MeterManager />)

    await waitFor(() => expect(screen.getByTestId(`meter-edit-${ACTIVE_METER.id}`)).toBeInTheDocument())
    await user.click(screen.getByTestId(`meter-edit-${ACTIVE_METER.id}`))
    await waitFor(() => expect(screen.getByTestId('edit-meter-form')).toBeInTheDocument())

    // Change the date field
    const dateInput = screen.getByTestId('edit-meter-started-at')
    await user.clear(dateInput)
    await user.type(dateInput, '2024-02-01')

    await user.click(screen.getByTestId('edit-meter-submit'))

    await waitFor(() => {
      expect(screen.getByTestId('meter-recompute-notice')).toBeInTheDocument()
    })
  })

  it('displays error when PATCH fails', async () => {
    const user = userEvent.setup()
    mockGet.mockResolvedValue({ data: { items: [ACTIVE_METER], total: 1 } })

    const { ApiError } = await import('../api/client')
    mockPatch.mockRejectedValue(new ApiError(422, { detail: 'started_at conflict' }))

    renderWithProviders(<MeterManager />)

    await waitFor(() => expect(screen.getByTestId(`meter-edit-${ACTIVE_METER.id}`)).toBeInTheDocument())
    await user.click(screen.getByTestId(`meter-edit-${ACTIVE_METER.id}`))
    await waitFor(() => expect(screen.getByTestId('edit-meter-form')).toBeInTheDocument())

    // Change label so there's something to patch
    const labelInput = screen.getByTestId('edit-meter-label')
    await user.clear(labelInput)
    await user.type(labelInput, 'Different label')

    await user.click(screen.getByTestId('edit-meter-submit'))

    await waitFor(() => {
      expect(screen.getByTestId('edit-meter-error')).toBeInTheDocument()
    })
    expect(screen.getByTestId('edit-meter-error').textContent).toContain('started_at conflict')
  })
})

describe('MeterManager — declare channel interval boundaries', () => {
  beforeEach(() => vi.clearAllMocks())

  it.each([
    ['closed-history overlap', '2025-06-01', false, 'overlaps closed binding history; choose a time at or after it ends'],
    ['closed-history equal end', '2025-12-31', true, null],
  ])('treats Declare Meter %s as %s with the corresponding request state', async (_name, date, eligible, reason) => {
    const user = userEvent.setup()
    const source = { uuid: 'source-1', name: 'DSMR' }
    const channel = { uuid: 'channel-1', label: 'Total import', unit: 'kWh', binding_count: 1, bound_meter_ids: [8] }
    const history = { ...CLOSED_METER, id: 8, started_at: '2024-01-01T00:00:00Z', ended_at: '2026-01-01T00:00:00Z', bindings: [{ uuid: 'history', source_uuid: source.uuid, source_channel_uuid: channel.uuid, started_at: '2025-01-01T00:00:00Z', ended_at: '2025-12-31T00:00:00Z' }] }
    mockGet.mockImplementation((path: string) => {
      if (path === '/api/energy/meters') return Promise.resolve({ data: { items: [history], total: 1 } })
      if (path === '/api/energy/sources') return Promise.resolve({ data: { items: [source], total: 1 } })
      if (path === '/api/energy/sources/{source_uuid}/channels') return Promise.resolve({ data: { items: [channel], total: 1 } })
      return Promise.resolve({ data: { items: [] } })
    })
    mockPost.mockResolvedValue({ data: ACTIVE_METER })
    renderWithProviders(<MeterManager />)
    await user.click(await screen.findByTestId('meter-declare-button'))
    await user.type(screen.getByTestId('meter-label'), 'Boundary meter')
    await user.type(screen.getByTestId('meter-started-at'), date)
    await user.click(screen.getByTestId('meter-reason')); await user.click(await screen.findByText('Initial installation'))
    const sourceInput = screen.getAllByLabelText('Bind source (optional)').find((element) => element.tagName === 'INPUT')!
    await user.click(sourceInput); await user.click(await screen.findByText('DSMR'))
    const channelInput = screen.getAllByLabelText('Compatible source channel (optional)').find((element) => element.tagName === 'INPUT')!
    await user.click(channelInput)
    if (!eligible) {
      const disabled = await screen.findByText(new RegExp(reason!))
      expect(disabled.closest('[role="option"]')).toHaveAttribute('data-combobox-disabled', 'true')
      await user.keyboard('{Escape}')
      await user.click(screen.getByTestId('declare-meter-submit'))
      expect(mockPost).not.toHaveBeenCalled()
      return
    }
    await user.click(await screen.findByText('Total import (kWh)'))
    await user.click(screen.getByTestId('declare-meter-submit'))
    await waitFor(() => expect(mockPost).toHaveBeenCalledWith('/api/energy/meters', expect.objectContaining({
      body: expect.objectContaining({ source_channel_uuid: 'channel-1', started_at: '2025-12-31T00:00:00' }),
    })))
    expect(mockPost).toHaveBeenCalledTimes(1)
  })
})

// These are deliberately component-level tests: the important contract is that
// each lifecycle dialog sends one endpoint request, rather than a UI-only
// assertion which could still regress into a two-step switch.
describe('MeterManager — lifecycle modal submissions', () => {
  const source = { uuid: 'source-1', name: 'DSMR' }
  const channel = { uuid: 'channel-1', label: 'Total import', unit: 'kWh', binding_count: 0, bound_meter_ids: [] }
  const mockLifecycleReads = (items: unknown[], channels = [channel], sources = [source]) => {
    mockGet.mockImplementation((path: string) => {
      if (path === '/api/energy/meters') return Promise.resolve({ data: { items, total: items.length } })
      if (path === '/api/energy/sources') return Promise.resolve({ data: { items: sources, total: sources.length } })
      if (path === '/api/energy/sources/{source_uuid}/channels') return Promise.resolve({ data: { items: channels, total: channels.length } })
      return Promise.resolve({ data: { items: [] } })
    })
  }
  const chooseChannel = async (user: ReturnType<typeof userEvent.setup>) => {
    const labelledInput = (label: string) => screen.getAllByLabelText(label).find((element) => element.tagName === 'INPUT')!
    await user.click(labelledInput('Source'))
    await user.click(await screen.findByText('DSMR'))
    await user.click(labelledInput('Source channel'))
    await user.click(await screen.findByText('Total import (kWh)'))
  }

  beforeEach(() => vi.clearAllMocks())

  it('unbinds an active binding with one PATCH, keeps the dialog after FastAPI detail-array error, and retries', async () => {
    const user = userEvent.setup()
    const binding = { uuid: 'open-binding', source_uuid: 'source-1', source_channel_uuid: 'old-channel', started_at: '2024-01-15T00:00:00Z', ended_at: null }
    mockLifecycleReads([{ ...ACTIVE_METER, bindings: [binding] }])
    const { ApiError } = await import('../api/client')
    mockPatch.mockRejectedValueOnce(new ApiError(422, { detail: [{ msg: 'unbind must follow binding start' }] }))
    mockPatch.mockResolvedValueOnce({ data: { ...binding, ended_at: '2026-08-24T10:00:00' } })
    renderWithProviders(<MeterManager />)
    await user.click(await screen.findByRole('button', { name: 'Unbind' }))
    const input = screen.getByTestId('unbind-modal-open-binding').querySelector('input[type="datetime-local"]')!
    await user.clear(input); await user.type(input, '2026-08-24T10:00')
    const unbindButtons = screen.getAllByRole('button', { name: 'Unbind' })
    await user.click(unbindButtons[unbindButtons.length - 1])
    await waitFor(() => expect(mockPatch).toHaveBeenCalledWith('/api/energy/bindings/{binding_uuid}', expect.objectContaining({
      params: { path: { binding_uuid: 'open-binding' } }, body: { ended_at: '2026-08-24T10:00' },
    })))
    expect(await screen.findByText('unbind must follow binding start')).toBeInTheDocument()
    expect(screen.getByTestId('unbind-modal-open-binding')).toBeInTheDocument()
    const retryUnbindButtons = screen.getAllByRole('button', { name: 'Unbind' })
    await user.click(retryUnbindButtons[retryUnbindButtons.length - 1])
    await waitFor(() => expect(mockPatch).toHaveBeenCalledTimes(2))
  })

  it('binds an unbound active meter directly with local datetime and one create-binding request', async () => {
    const user = userEvent.setup()
    mockLifecycleReads([ACTIVE_METER])
    mockPost.mockResolvedValue({ data: {} })
    renderWithProviders(<MeterManager />)
    await user.click(await screen.findByRole('button', { name: 'Bind source' }))
    await chooseChannel(user)
    const start = screen.getByTestId(`direct-bind-modal-${ACTIVE_METER.id}`).querySelector('input[type="datetime-local"]')!
    await user.clear(start); await user.type(start, '2026-08-24T10:00')
    const bindButtons = screen.getAllByRole('button', { name: 'Bind source' })
    await user.click(bindButtons[bindButtons.length - 1])
    await waitFor(() => expect(mockPost).toHaveBeenCalledWith('/api/energy/meters/{meter_id}/bindings', expect.objectContaining({
      params: { path: { meter_id: ACTIVE_METER.id } }, body: { source_channel_uuid: 'channel-1', started_at: '2026-08-24T10:00' },
    })))
  })

  it('transfers on the same meter with one atomic request and excludes its source binding from channel eligibility', async () => {
    const user = userEvent.setup()
    const binding = { uuid: 'same-source', source_uuid: 'source-1', source_channel_uuid: 'channel-1', started_at: '2024-01-15T00:00:00Z', ended_at: null }
    mockLifecycleReads([{ ...ACTIVE_METER, bindings: [binding] }], [{ ...channel, binding_count: 1 }])
    mockPost.mockResolvedValue({ data: {} })
    renderWithProviders(<MeterManager />)
    await user.click(await screen.findByRole('button', { name: 'Transfer source' }))
    await chooseChannel(user)
    const effective = screen.getByTestId('transfer-effective-at')
    await user.clear(effective); await user.type(effective, '2026-08-24T10:00')
    await user.click(screen.getByRole('button', { name: 'Transfer binding' }))
    await waitFor(() => expect(mockPost).toHaveBeenCalledWith('/api/energy/meters/{meter_id}/bindings/transfer', expect.objectContaining({
      params: { path: { meter_id: ACTIVE_METER.id } }, body: { from_binding_uuid: 'same-source', to_source_channel_uuid: 'channel-1', effective_at: '2026-08-24T10:00' },
    })))
    expect(mockPost).toHaveBeenCalledTimes(1)
  })

  it('recovers a stranded binding to the unique later active meter in one transfer at its default start', async () => {
    const user = userEvent.setup()
    const stranded = { ...CLOSED_METER, ended_at: '2024-01-10T00:00:00Z', bindings: [{ uuid: 'stranded', source_uuid: 'source-1', source_channel_uuid: 'old-channel', started_at: '2023-06-01T00:00:00Z', ended_at: null }] }
    const target = { ...ACTIVE_METER, id: 7, started_at: '2024-01-15T00:00:00Z', bindings: [] }
    mockLifecycleReads([stranded, target])
    mockPost.mockResolvedValue({ data: {} })
    renderWithProviders(<MeterManager />)
    await user.click(await screen.findByRole('button', { name: 'Recover binding' }))
    expect(screen.getByTestId('transfer-effective-at')).toHaveValue('2024-01-15T00:00')
    await chooseChannel(user)
    await user.click(screen.getByRole('button', { name: 'Transfer binding' }))
    await waitFor(() => expect(mockPost).toHaveBeenCalledWith('/api/energy/meters/{meter_id}/bindings/transfer', expect.objectContaining({
      params: { path: { meter_id: 7 } }, body: { from_binding_uuid: 'stranded', to_source_channel_uuid: 'channel-1', effective_at: '2024-01-15T00:00' },
    })))
  })

  it('shows source loading and channel fetch failure without enabling a submit request', async () => {
    const user = userEvent.setup()
    mockGet.mockImplementation((path: string) => {
      if (path === '/api/energy/meters') return Promise.resolve({ data: { items: [ACTIVE_METER], total: 1 } })
      if (path === '/api/energy/sources') return new Promise(() => {})
      return Promise.reject(new Error('channel fetch failed'))
    })
    renderWithProviders(<MeterManager />)
    await user.click(await screen.findByRole('button', { name: 'Bind source' }))
    expect(await screen.findByText('Loading sources…')).toBeInTheDocument()
    expect(mockPost).not.toHaveBeenCalled()
  })

  it('shows a source error and an enabled channel-query loading or error state independently', async () => {
    const user = userEvent.setup()
    mockGet.mockImplementation((path: string) => {
      if (path === '/api/energy/meters') return Promise.resolve({ data: { items: [ACTIVE_METER], total: 1 } })
      if (path === '/api/energy/sources') return Promise.reject(new Error('source fetch failed'))
      return Promise.resolve({ data: { items: [] } })
    })
    renderWithProviders(<MeterManager />)
    await user.click(await screen.findByRole('button', { name: 'Bind source' }))
    expect(await screen.findByText('Could not load sources. Retry after the connection recovers.')).toBeInTheDocument()

    mockGet.mockImplementation((path: string) => {
      if (path === '/api/energy/meters') return Promise.resolve({ data: { items: [ACTIVE_METER], total: 1 } })
      if (path === '/api/energy/sources') return Promise.resolve({ data: { items: [source], total: 1 } })
      if (path === '/api/energy/sources/{source_uuid}/channels') return Promise.reject(new Error('channel fetch failed'))
      return Promise.resolve({ data: { items: [] } })
    })
    await user.click(screen.getAllByRole('button', { name: 'Cancel' })[0])
    await user.click(await screen.findByRole('button', { name: 'Bind source' }))
    await user.click((screen.getAllByLabelText('Source').find((element) => element.tagName === 'INPUT'))!)
    await user.click(await screen.findByText('DSMR'))
    expect(await screen.findByText('Could not load source channels. Choose another source or retry.')).toBeInTheDocument()
    expect(mockPost).not.toHaveBeenCalled()
  })

  it('clears a direct-bind selection that becomes a closed-history overlap and does not submit it', async () => {
    const user = userEvent.setup()
    const target = { ...ACTIVE_METER, bindings: [{ uuid: 'history', source_uuid: 'source-1', source_channel_uuid: 'channel-1', started_at: '2025-01-01T00:00:00Z', ended_at: '2025-12-31T00:00:00Z' }] }
    mockLifecycleReads([target])
    renderWithProviders(<MeterManager />)
    await user.click(await screen.findByRole('button', { name: 'Bind source' }))
    await chooseChannel(user)
    const start = screen.getByTestId(`direct-bind-modal-${ACTIVE_METER.id}`).querySelector('input[type="datetime-local"]')!
    await user.clear(start); await user.type(start, '2025-06-01T10:00')
    expect(screen.getAllByLabelText('Source channel').find((element) => element.tagName === 'INPUT')).toHaveValue('')
    const bindButtons = screen.getAllByRole('button', { name: 'Bind source' })
    await user.click(bindButtons[bindButtons.length - 1])
    expect(mockPost).not.toHaveBeenCalled()
  })

  it('keeps a direct-bind selection at the equal closed-history boundary and submits it', async () => {
    const user = userEvent.setup()
    const target = { ...ACTIVE_METER, bindings: [{ uuid: 'history', source_uuid: 'source-1', source_channel_uuid: 'channel-1', started_at: '2025-01-01T00:00:00Z', ended_at: '2025-12-31T00:00:00Z' }] }
    mockLifecycleReads([target]); mockPost.mockResolvedValue({ data: {} })
    renderWithProviders(<MeterManager />)
    await user.click(await screen.findByRole('button', { name: 'Bind source' })); await chooseChannel(user)
    const start = screen.getByTestId(`direct-bind-modal-${ACTIVE_METER.id}`).querySelector('input[type="datetime-local"]')!
    await user.clear(start); await user.type(start, '2025-12-31T00:00')
    const bindButtons = screen.getAllByRole('button', { name: 'Bind source' })
    await user.click(bindButtons[bindButtons.length - 1])
    await waitFor(() => expect(mockPost).toHaveBeenCalledWith('/api/energy/meters/{meter_id}/bindings', expect.objectContaining({ body: expect.objectContaining({ source_channel_uuid: 'channel-1', started_at: '2025-12-31T00:00' }) })))
  })

  it('clears a same-meter transfer selection that becomes earlier than its source and does not submit it', async () => {
    const user = userEvent.setup()
    const binding = { uuid: 'same-source', source_uuid: 'source-1', source_channel_uuid: 'old-channel', started_at: '2025-06-01T00:00:00Z', ended_at: null }
    mockLifecycleReads([{ ...ACTIVE_METER, bindings: [binding] }]); renderWithProviders(<MeterManager />)
    await user.click(await screen.findByRole('button', { name: 'Transfer source' })); await chooseChannel(user)
    const effective = screen.getByTestId('transfer-effective-at')
    await user.clear(effective); await user.type(effective, '2025-05-31T23:59')
    expect(screen.getAllByLabelText('Source channel').find((element) => element.tagName === 'INPUT')).toHaveValue('')
    await user.click(screen.getByRole('button', { name: 'Transfer binding' }))
    expect(mockPost).not.toHaveBeenCalled()
  })

  it('rejects a same-meter transfer exactly at its source start with a specific reason, but submits one minute later', async () => {
    const user = userEvent.setup()
    const binding = { uuid: 'same-source', source_uuid: 'source-1', source_channel_uuid: 'old-channel', started_at: '2025-06-01T00:00:00Z', ended_at: null }
    mockLifecycleReads([{ ...ACTIVE_METER, bindings: [binding] }])
    mockPost.mockResolvedValue({ data: {} })
    renderWithProviders(<MeterManager />)
    await user.click(await screen.findByRole('button', { name: 'Transfer source' }))
    await chooseChannel(user)
    const effective = screen.getByTestId('transfer-effective-at')
    await user.clear(effective); await user.type(effective, '2025-06-01T00:00')
    expect(screen.getAllByLabelText('Source channel').find((element) => element.tagName === 'INPUT')).toHaveValue('')
    await user.click(screen.getByRole('button', { name: 'Transfer binding' }))
    expect(mockPost).not.toHaveBeenCalled()
    expect(screen.getByText('Select a unit-compatible source channel.')).toBeInTheDocument()

    await user.click(screen.getAllByLabelText('Source channel').find((element) => element.tagName === 'INPUT')!)
    expect(await screen.findByText(/strictly after the source binding start/)).toBeInTheDocument()
    await user.clear(effective); await user.type(effective, '2025-06-01T00:01')
    await user.click(screen.getAllByLabelText('Source channel').find((element) => element.tagName === 'INPUT')!)
    await user.click(await screen.findByText('Total import (kWh)'))
    await user.click(screen.getByRole('button', { name: 'Transfer binding' }))
    await waitFor(() => expect(mockPost).toHaveBeenCalledWith('/api/energy/meters/{meter_id}/bindings/transfer', expect.objectContaining({
      params: { path: { meter_id: ACTIVE_METER.id } },
      body: { from_binding_uuid: 'same-source', to_source_channel_uuid: 'channel-1', effective_at: '2025-06-01T00:01' },
    })))
    expect(mockPost).toHaveBeenCalledTimes(1)
  })

  it('does not apply the same-meter source-start rule to legal cross-meter recovery', async () => {
    const user = userEvent.setup()
    // The transfer service closes this old binding at the closed Meter end.
    // Keep its start strictly earlier: [2025-05-31, 2025-06-01) is a real,
    // non-zero source interval while the two Meter epochs meet at the selected
    // effective boundary.
    const stranded = { ...CLOSED_METER, ended_at: '2025-06-01T00:00:00Z', bindings: [{ uuid: 'stranded', source_uuid: 'source-1', source_channel_uuid: 'old-channel', started_at: '2025-05-31T00:00:00Z', ended_at: null }] }
    const target = { ...ACTIVE_METER, id: 7, started_at: '2025-06-01T00:00:00Z', bindings: [] }
    mockLifecycleReads([stranded, target]); mockPost.mockResolvedValue({ data: {} })
    renderWithProviders(<MeterManager />)
    await user.click(await screen.findByRole('button', { name: 'Recover binding' }))
    expect(screen.getByTestId('transfer-effective-at')).toHaveValue('2025-06-01T00:00')
    await chooseChannel(user)
    await user.click(screen.getByRole('button', { name: 'Transfer binding' }))
    await waitFor(() => expect(mockPost).toHaveBeenCalledWith('/api/energy/meters/{meter_id}/bindings/transfer', expect.objectContaining({
      params: { path: { meter_id: 7 } },
      body: expect.objectContaining({ from_binding_uuid: 'stranded', effective_at: '2025-06-01T00:00' }),
    })))
  })

  it('fails closed for an anomalous cross recovery source interval that the server would reject', async () => {
    const stranded = { ...CLOSED_METER, ended_at: '2025-06-01T00:00:00Z', bindings: [{ uuid: 'bad-stranded', source_uuid: 'source-1', source_channel_uuid: 'old-channel', started_at: '2025-06-01T00:00:00Z', ended_at: null }] }
    const target = { ...ACTIVE_METER, id: 7, started_at: '2025-06-01T00:00:00Z', bindings: [] }
    mockLifecycleReads([stranded, target])
    renderWithProviders(<MeterManager />)
    await waitFor(() => expect(screen.getByTestId('meters-table')).toBeInTheDocument())
    expect(screen.queryByRole('button', { name: 'Recover binding' })).not.toBeInTheDocument()
    expect(screen.getByText(/Cannot recover: the source binding starts at or after this Meter ended/)).toBeInTheDocument()
    expect(mockPost).not.toHaveBeenCalled()
  })

  it('uses a closed meter end as the unbind default and sends it in the PATCH payload', async () => {
    const user = userEvent.setup()
    const binding = { uuid: 'closed-binding', source_uuid: 'source-1', source_channel_uuid: 'old-channel', started_at: '2024-01-01T00:00:00Z', ended_at: null }
    const closed = { ...CLOSED_METER, ended_at: '2024-02-02T03:04:00Z', bindings: [binding] }
    mockLifecycleReads([closed]); mockPatch.mockResolvedValue({ data: {} })
    renderWithProviders(<MeterManager />)
    await user.click(await screen.findByRole('button', { name: 'Unbind' }))
    expect(screen.getByTestId('unbind-modal-closed-binding').querySelector('input[type="datetime-local"]')).toHaveValue('2024-02-02T03:04')
    const unbindButtons = screen.getAllByRole('button', { name: 'Unbind' })
    await user.click(unbindButtons[unbindButtons.length - 1])
    await waitFor(() => expect(mockPatch).toHaveBeenCalledWith('/api/energy/bindings/{binding_uuid}', expect.objectContaining({
      params: { path: { binding_uuid: 'closed-binding' } }, body: { ended_at: '2024-02-02T03:04' },
    })))
  })

  it('shows channel loading only after source selection and never posts while loading', async () => {
    const user = userEvent.setup()
    mockGet.mockImplementation((path: string) => {
      if (path === '/api/energy/meters') return Promise.resolve({ data: { items: [ACTIVE_METER], total: 1 } })
      if (path === '/api/energy/sources') return Promise.resolve({ data: { items: [source], total: 1 } })
      if (path === '/api/energy/sources/{source_uuid}/channels') return new Promise(() => {})
      return Promise.resolve({ data: { items: [] } })
    })
    renderWithProviders(<MeterManager />)
    await user.click(await screen.findByRole('button', { name: 'Bind source' }))
    expect(screen.queryByText('Loading source channels…')).not.toBeInTheDocument()
    await user.click(screen.getAllByLabelText('Source').find((element) => element.tagName === 'INPUT')!)
    await user.click(await screen.findByText('DSMR'))
    expect(await screen.findByText('Loading source channels…')).toBeInTheDocument()
    expect(mockPost).not.toHaveBeenCalled()
  })

  it('clears a recovery transfer selection that moves before its target epoch and does not submit it', async () => {
    const user = userEvent.setup()
    const stranded = { ...CLOSED_METER, ended_at: '2025-01-01T00:00:00Z', bindings: [{ uuid: 'stranded', source_uuid: 'source-1', source_channel_uuid: 'old-channel', started_at: '2024-01-01T00:00:00Z', ended_at: null }] }
    const target = { ...ACTIVE_METER, id: 7, started_at: '2025-01-01T00:00:00Z', bindings: [] }
    mockLifecycleReads([stranded, target]); renderWithProviders(<MeterManager />)
    await user.click(await screen.findByRole('button', { name: 'Recover binding' })); await chooseChannel(user)
    const effective = screen.getByTestId('transfer-effective-at')
    await user.clear(effective); await user.type(effective, '2024-12-31T23:59')
    expect(screen.getAllByLabelText('Source channel').find((element) => element.tagName === 'INPUT')).toHaveValue('')
    await user.click(screen.getByRole('button', { name: 'Transfer binding' }))
    expect(mockPost).not.toHaveBeenCalled()
  })

  it('keeps Close Meter open after its own error and retries the close endpoint', async () => {
    const user = userEvent.setup(); const { ApiError } = await import('../api/client')
    mockLifecycleReads([ACTIVE_METER])
    mockPost.mockRejectedValueOnce(new ApiError(422, { detail: 'close must follow meter start' }))
    mockPost.mockResolvedValueOnce({ data: {} })
    renderWithProviders(<MeterManager />)
    await user.click(await screen.findByRole('button', { name: 'Close meter' }))
    const modal = screen.getByTestId(`close-meter-modal-${ACTIVE_METER.id}`)
    const input = modal.querySelector('input[type="datetime-local"]')!
    await user.clear(input); await user.type(input, '2026-08-24T10:00')
    await user.click(screen.getAllByRole('button', { name: 'Close meter' })[1])
    await waitFor(() => expect(mockPost).toHaveBeenCalledWith('/api/energy/meters/{meter_id}/close', expect.objectContaining({
      params: { path: { meter_id: ACTIVE_METER.id } }, body: { ended_at: '2026-08-24T10:00' },
    })))
    expect(await screen.findByText('close must follow meter start')).toBeInTheDocument()
    expect(screen.getByTestId(`close-meter-modal-${ACTIVE_METER.id}`)).toBeInTheDocument()
    await user.click(screen.getAllByRole('button', { name: 'Close meter' })[1])
    await waitFor(() => expect(mockPost).toHaveBeenCalledTimes(2))
  })

  it('keeps Direct Bind open after its own error and retries the create endpoint', async () => {
    const user = userEvent.setup(); const { ApiError } = await import('../api/client')
    mockLifecycleReads([ACTIVE_METER])
    mockPost.mockRejectedValueOnce(new ApiError(422, { detail: 'binding conflict' }))
    mockPost.mockResolvedValueOnce({ data: {} })
    renderWithProviders(<MeterManager />)
    await user.click(await screen.findByRole('button', { name: 'Bind source' })); await chooseChannel(user)
    const bindButtons = screen.getAllByRole('button', { name: 'Bind source' })
    await user.click(bindButtons[bindButtons.length - 1])
    expect(await screen.findByText('binding conflict')).toBeInTheDocument()
    expect(screen.getByTestId(`direct-bind-modal-${ACTIVE_METER.id}`)).toBeInTheDocument()
    const retryButtons = screen.getAllByRole('button', { name: 'Bind source' })
    await user.click(retryButtons[retryButtons.length - 1])
    await waitFor(() => expect(mockPost).toHaveBeenCalledTimes(2))
  })

  it.each([
    ['same', false],
    ['cross recovery', true],
  ])('keeps %s Transfer open after failure, states no partial save, and retries', async (_name, recovery) => {
    const user = userEvent.setup()
    const binding = { uuid: 'transfer-source', source_uuid: 'source-1', source_channel_uuid: 'old-channel', started_at: recovery ? '2024-01-01T00:00:00Z' : '2024-02-01T00:00:00Z', ended_at: null }
    const sourceMeter = recovery
      ? { ...CLOSED_METER, ended_at: '2025-01-01T00:00:00Z', bindings: [binding] }
      : { ...ACTIVE_METER, bindings: [binding] }
    const target = recovery ? { ...ACTIVE_METER, id: 7, started_at: '2025-01-01T00:00:00Z', bindings: [] } : undefined
    mockLifecycleReads(target ? [sourceMeter, target] : [sourceMeter])
    mockPost.mockRejectedValueOnce(new Error('network failure'))
    mockPost.mockResolvedValueOnce({ data: {} })
    renderWithProviders(<MeterManager />)
    await user.click((await screen.findAllByRole('button', { name: recovery ? 'Recover binding' : 'Transfer source' }))[0])
    await chooseChannel(user); await user.click(screen.getByRole('button', { name: 'Transfer binding' }))
    await waitFor(() => expect(mockPost).toHaveBeenCalledTimes(1))
    expect(await screen.findByText('Transfer failed. No partial source switch was saved.')).toBeInTheDocument()
    expect(screen.getByText(/No partial source switch was saved/)).toBeInTheDocument()
    expect(screen.getByTestId('transfer-modal-transfer-source')).toBeInTheDocument()
    await user.click(screen.getByRole('button', { name: 'Transfer binding' }))
    await waitFor(() => expect(mockPost).toHaveBeenCalledTimes(2))
  })

  it.each(['close', 'unbind', 'direct bind', 'same-meter transfer', 'cross-meter recovery'])(
    'submits %s with Enter once while pending, disables its button, and ignores a second click and Enter',
    async (entry) => {
      const user = userEvent.setup()
      let release!: () => void
      const pending = new Promise((resolve) => { release = () => resolve({ data: {} }) })
      const binding = { uuid: 'pending-source', source_uuid: 'source-1', source_channel_uuid: 'old-channel', started_at: '2024-02-01T00:00:00Z', ended_at: null }
      const stranded = { ...CLOSED_METER, ended_at: '2025-01-01T00:00:00Z', bindings: [binding] }
      const target = { ...ACTIVE_METER, id: 7, started_at: '2025-01-01T00:00:00Z', bindings: [] }
      mockLifecycleReads(entry === 'close' || entry === 'direct bind' ? [ACTIVE_METER] : entry === 'cross-meter recovery' ? [stranded, target] : [{ ...ACTIVE_METER, bindings: [binding] }])
      if (entry === 'unbind') mockPatch.mockReturnValue(pending)
      else mockPost.mockReturnValue(pending)
      renderWithProviders(<MeterManager />)

      let input: HTMLInputElement
      let submit: HTMLElement
      if (entry === 'close') {
        await user.click(await screen.findByRole('button', { name: 'Close meter' }))
        input = screen.getByTestId(`close-meter-modal-${ACTIVE_METER.id}`).querySelector('input[type="datetime-local"]')!
        submit = screen.getAllByRole('button', { name: 'Close meter' })[1]
      } else if (entry === 'unbind') {
        await user.click(await screen.findByRole('button', { name: 'Unbind' }))
        input = screen.getByTestId('unbind-modal-pending-source').querySelector('input[type="datetime-local"]')!
        submit = screen.getAllByRole('button', { name: 'Unbind' })[1]
      } else {
        await user.click(await screen.findByRole('button', { name: entry === 'direct bind' ? 'Bind source' : entry === 'same-meter transfer' ? 'Transfer source' : 'Recover binding' }))
        await chooseChannel(user)
        input = entry === 'direct bind'
          ? screen.getByTestId(`direct-bind-modal-${ACTIVE_METER.id}`).querySelector('input[type="datetime-local"]')!
          : screen.getByTestId('transfer-effective-at')
        const submitButtons = screen.getAllByRole('button', { name: entry === 'direct bind' ? 'Bind source' : 'Transfer binding' })
        submit = submitButtons[submitButtons.length - 1]
      }
      await user.type(input, '{Enter}')
      await waitFor(() => expect(entry === 'unbind' ? mockPatch : mockPost).toHaveBeenCalledTimes(1))
      expect(submit).toBeDisabled()
      if (entry === 'unbind') expect(mockPatch).toHaveBeenCalledWith('/api/energy/bindings/{binding_uuid}', expect.objectContaining({ params: { path: { binding_uuid: 'pending-source' } } }))
      else if (entry === 'close') expect(mockPost).toHaveBeenCalledWith('/api/energy/meters/{meter_id}/close', expect.objectContaining({ params: { path: { meter_id: ACTIVE_METER.id } } }))
      else expect(mockPost).toHaveBeenCalledWith(entry === 'direct bind' ? '/api/energy/meters/{meter_id}/bindings' : '/api/energy/meters/{meter_id}/bindings/transfer', expect.objectContaining({ params: { path: { meter_id: entry === 'cross-meter recovery' ? 7 : ACTIVE_METER.id } } }))
      await user.click(submit)
      await user.type(input, '{Enter}')
      expect(entry === 'unbind' ? mockPatch : mockPost).toHaveBeenCalledTimes(1)
      release()
    },
  )

  it('rejects an empty Direct Bind datetime without a request', async () => {
    const user = userEvent.setup(); mockLifecycleReads([ACTIVE_METER])
    renderWithProviders(<MeterManager />)
    await user.click(await screen.findByRole('button', { name: 'Bind source' })); await chooseChannel(user)
    const start = screen.getByTestId(`direct-bind-modal-${ACTIVE_METER.id}`).querySelector('input[type="datetime-local"]')!
    await user.clear(start)
    const bindButtons = screen.getAllByRole('button', { name: 'Bind source' })
    await user.click(bindButtons[bindButtons.length - 1])
    expect(mockPost).not.toHaveBeenCalled()
    expect(screen.getByText(/valid binding start time|Select a genuinely unbound/)).toBeInTheDocument()
  })

  it.each(['close', 'unbind', 'direct', 'same', 'cross'])(
    'keeps the %s required-form empty case as a separate no-request regression',
    async (entry) => {
      const user = userEvent.setup()
      const binding = { uuid: 'empty-regression-source', source_uuid: 'source-1', source_channel_uuid: 'old-channel', started_at: '2024-02-01T00:00:00Z', ended_at: null }
      const stranded = { ...CLOSED_METER, ended_at: '2025-01-01T00:00:00Z', bindings: [binding] }
      const target = { ...ACTIVE_METER, id: 7, started_at: '2025-01-01T00:00:00Z', bindings: [] }
      mockLifecycleReads(entry === 'close' || entry === 'direct' ? [ACTIVE_METER] : entry === 'cross' ? [stranded, target] : [{ ...ACTIVE_METER, bindings: [binding] }])
      renderWithProviders(<MeterManager />)
      if (entry === 'close') {
        await user.click(await screen.findByRole('button', { name: 'Close meter' }))
        const input = screen.getByTestId(`close-meter-modal-${ACTIVE_METER.id}`).querySelector('input')!
        await user.clear(input); await user.click(screen.getAllByRole('button', { name: 'Close meter' })[1])
      } else if (entry === 'unbind') {
        await user.click(await screen.findByRole('button', { name: 'Unbind' }))
        const input = screen.getByTestId('unbind-modal-empty-regression-source').querySelector('input')!
        await user.clear(input); await user.click(screen.getAllByRole('button', { name: 'Unbind' })[1])
      } else {
        await user.click(await screen.findByRole('button', { name: entry === 'direct' ? 'Bind source' : entry === 'same' ? 'Transfer source' : 'Recover binding' }))
        await chooseChannel(user)
        const input = entry === 'direct'
          ? screen.getByTestId(`direct-bind-modal-${ACTIVE_METER.id}`).querySelector('input[type="datetime-local"]')!
          : screen.getByTestId('transfer-effective-at')
        await user.clear(input)
        const submits = screen.getAllByRole('button', { name: entry === 'direct' ? 'Bind source' : 'Transfer binding' })
        await user.click(submits[submits.length - 1])
      }
      expect(mockPost).not.toHaveBeenCalled(); expect(mockPatch).not.toHaveBeenCalled()
    },
  )

  it.each([
    ['unit mismatch', { ...channel, unit: 'GJ' }, 'unit mismatch: GJ'],
    ['retained anomaly: open occupancy', channel, 'occupied by an open binding'],
    ['retained anomaly: ambiguity', channel, 'ambiguous: channel has overlapping binding history'],
  ])('shows Direct Bind %s reason and sends no request', async (_name, selected, reason) => {
    const user = userEvent.setup()
    const selectedSource = selected.unit === 'GJ'
      ? { uuid: 'warmtelink-source', name: 'WarmteLink', kind: 'warmtelink_serial' }
      : source
    const conflicts = selected.unit === 'kWh' ? [{ ...ACTIVE_METER, id: 9, bindings: [
      { uuid: 'conflict-a', source_channel_uuid: 'channel-1', started_at: '2024-02-01T00:00:00Z', ended_at: null },
      ...(_name.includes('ambiguity') ? [{ uuid: 'conflict-b', source_channel_uuid: 'channel-1', started_at: '2024-03-01T00:00:00Z', ended_at: null }] : []),
    ] }] : []
    mockLifecycleReads([ACTIVE_METER, ...conflicts], [selected], [selectedSource])
    renderWithProviders(<MeterManager />)
    await user.click(await screen.findByRole('button', { name: 'Bind source' }))
    const sourceInput = screen.getAllByLabelText('Source').find((element) => element.tagName === 'INPUT')!
    await user.click(sourceInput); await user.click(await screen.findByText(selectedSource.name))
    const channelInput = screen.getAllByLabelText('Source channel').find((element) => element.tagName === 'INPUT')!
    await user.click(channelInput)
    const disabled = await screen.findByText(new RegExp(reason))
    expect(disabled.closest('[role="option"]')).toHaveAttribute('data-combobox-disabled', 'true')
    await user.keyboard('{Escape}')
    const submits = screen.getAllByRole('button', { name: 'Bind source' })
    await user.click(submits[submits.length - 1])
    expect(mockPost).not.toHaveBeenCalled()
  })

  it('offers recovery only to the unique latest predecessor in a multi-generation timeline', async () => {
    const user = userEvent.setup()
    const older = { ...CLOSED_METER, id: 2, started_at: '2023-01-01T00:00:00Z', ended_at: '2024-01-01T00:00:00Z', bindings: [{ uuid: 'older', source_channel_uuid: 'older-channel', started_at: '2023-01-01T00:00:00Z', ended_at: null }] }
    const binding = { uuid: 'predecessor', source_uuid: 'source-1', source_channel_uuid: 'old-channel', started_at: '2024-01-01T00:00:00Z', ended_at: null }
    const predecessor = { ...CLOSED_METER, id: 3, started_at: '2024-01-01T00:00:00Z', ended_at: '2025-01-01T00:00:00Z', bindings: [binding] }
    const target = { ...ACTIVE_METER, id: 7, started_at: '2025-01-01T00:00:00Z', bindings: [] }
    mockLifecycleReads([older, predecessor, target]); mockPost.mockResolvedValue({ data: {} })
    renderWithProviders(<MeterManager />)
    expect(await screen.findByRole('button', { name: 'Recover binding' })).toBeInTheDocument()
    await user.click(screen.getByRole('button', { name: 'Recover binding' })); await chooseChannel(user)
    await user.click(screen.getByRole('button', { name: 'Transfer binding' }))
    await waitFor(() => expect(mockPost).toHaveBeenCalledWith('/api/energy/meters/{meter_id}/bindings/transfer', expect.objectContaining({
      params: { path: { meter_id: 7 } },
      body: { from_binding_uuid: 'predecessor', to_source_channel_uuid: 'channel-1', effective_at: '2025-01-01T00:00' },
    })))
    expect(mockPost).toHaveBeenCalledTimes(1)
  })

  it.each([
    ['two equally recent predecessors', [
      { ...CLOSED_METER, id: 3, ended_at: '2025-01-01T00:00:00Z', bindings: [{ uuid: 'a', source_channel_uuid: 'old-channel', started_at: '2024-01-01T00:00:00Z', ended_at: null }] },
      { ...CLOSED_METER, id: 4, ended_at: '2025-01-01T00:00:00Z', bindings: [{ uuid: 'b', source_channel_uuid: 'old-channel', started_at: '2024-01-01T00:00:00Z', ended_at: null }] },
    ]],
    ['a non-predecessor stranded meter', [
      { ...CLOSED_METER, id: 3, ended_at: '2024-12-31T00:00:00Z', bindings: [{ uuid: 'old', source_channel_uuid: 'old-channel', started_at: '2024-01-01T00:00:00Z', ended_at: null }] },
      { ...CLOSED_METER, id: 4, ended_at: '2025-01-01T00:00:00Z', bindings: [] },
    ]],
  ])('fails closed for recovery with %s', async (_name, closed) => {
    mockLifecycleReads([...closed, { ...ACTIVE_METER, id: 7, started_at: '2025-01-01T00:00:00Z', bindings: [] }])
    renderWithProviders(<MeterManager />)
    await waitFor(() => expect(screen.getByTestId('meters-table')).toBeInTheDocument())
    expect(screen.queryByRole('button', { name: 'Recover binding' })).not.toBeInTheDocument()
    expect(mockPost).not.toHaveBeenCalled()
  })

  it.each([
    ['Close Meter equal to meter start', 'close', '2024-01-15T00:00', 'Close time must be strictly after the meter start.'],
    ['Unbind equal to binding start', 'unbind', '2024-02-01T00:00', 'Unbind time must be strictly after the binding start.'],
    ['Direct Bind in the future', 'direct', '2099-01-01T00:00', 'future binding start times are not allowed'],
    ['same-Meter Transfer equal to source start', 'same', '2024-02-01T00:00', 'same-meter transfer must be strictly after the source binding start'],
    ['cross-Meter Recovery before target epoch', 'cross', '2024-12-31T23:59', 'effective time must be within the target meter epoch'],
  ])('rejects %s expressible datetime boundary with a reason and no request', async (_name, entry, replacement, reason) => {
    const user = userEvent.setup()
    const binding = { uuid: 'empty-source', source_uuid: 'source-1', source_channel_uuid: 'old-channel', started_at: '2024-02-01T00:00:00Z', ended_at: null }
    const stranded = { ...CLOSED_METER, ended_at: '2025-01-01T00:00:00Z', bindings: [binding] }
    const target = { ...ACTIVE_METER, id: 7, started_at: '2025-01-01T00:00:00Z', bindings: [] }
    mockLifecycleReads(entry === 'close' || entry === 'direct' ? [ACTIVE_METER] : entry === 'unbind' || entry === 'same'
      ? [{ ...ACTIVE_METER, bindings: [binding] }] : [stranded, target])
    renderWithProviders(<MeterManager />)
    if (entry === 'close') {
      await user.click(await screen.findByRole('button', { name: 'Close meter' }))
      const input = screen.getByTestId(`close-meter-modal-${ACTIVE_METER.id}`).querySelector('input')!
      await user.clear(input); await user.type(input, replacement); await user.click(screen.getAllByRole('button', { name: 'Close meter' })[1])
    } else if (entry === 'unbind') {
      await user.click(await screen.findByRole('button', { name: 'Unbind' }))
      const input = screen.getByTestId('unbind-modal-empty-source').querySelector('input')!
      await user.clear(input); await user.type(input, replacement); await user.click(screen.getAllByRole('button', { name: 'Unbind' })[1])
    } else {
      await user.click(await screen.findByRole('button', { name: entry === 'direct' ? 'Bind source' : entry === 'same' ? 'Transfer source' : 'Recover binding' }))
      await chooseChannel(user)
      const input = entry === 'direct'
        ? screen.getByTestId(`direct-bind-modal-${ACTIVE_METER.id}`).querySelector('input[type="datetime-local"]')!
        : screen.getByTestId('transfer-effective-at')
      await user.clear(input); await user.type(input, replacement)
      if (entry === 'direct' || entry === 'same' || entry === 'cross') {
        expect(screen.getAllByLabelText('Source channel').find((element) => element.tagName === 'INPUT')).toHaveValue('')
        await user.click(screen.getAllByLabelText('Source channel').find((element) => element.tagName === 'INPUT')!)
        const disabled = await screen.findByText(new RegExp(reason))
        expect(disabled.closest('[role="option"]')).toHaveAttribute(
          'data-combobox-disabled',
          'true',
        )
      }
      const submitButtons = screen.getAllByRole('button', { name: entry === 'direct' ? 'Bind source' : 'Transfer binding' })
      await user.click(submitButtons[submitButtons.length - 1])
    }
    if (entry === 'close' || entry === 'unbind') expect(await screen.findByText(reason)).toBeInTheDocument()
    expect(mockPost).not.toHaveBeenCalled(); expect(mockPatch).not.toHaveBeenCalled()
  })

  it.each([
    ['before closed history', '2024-12-31T23:59', 'overlaps closed binding history; choose a time at or after it ends'],
    ['inside closed history', '2025-06-01T00:00', 'overlaps closed binding history; choose a time at or after it ends'],
    ['at target epoch start', '2023-12-31T23:59', 'binding start must be within this meter epoch'],
    ['future', '2099-01-01T00:00', 'future binding start times are not allowed'],
  ])('shows Direct Bind %s reason, clears selection, and sends no request', async (_name, value, reason) => {
    const user = userEvent.setup()
    const target = { ...ACTIVE_METER, bindings: [{ uuid: 'closed-history', source_channel_uuid: 'channel-1', started_at: '2025-01-01T00:00:00Z', ended_at: '2025-12-31T00:00:00Z' }] }
    mockLifecycleReads([target]); renderWithProviders(<MeterManager />)
    await user.click(await screen.findByRole('button', { name: 'Bind source' })); await chooseChannel(user)
    const input = screen.getByTestId(`direct-bind-modal-${ACTIVE_METER.id}`).querySelector('input[type="datetime-local"]')!
    await user.clear(input); await user.type(input, value)
    expect(screen.getAllByLabelText('Source channel').find((element) => element.tagName === 'INPUT')).toHaveValue('')
    await user.click(screen.getAllByLabelText('Source channel').find((element) => element.tagName === 'INPUT')!)
    const disabled = await screen.findByText(new RegExp(reason))
    expect(disabled.closest('[role="option"]')).toHaveAttribute('data-combobox-disabled', 'true')
    await user.keyboard('{Escape}')
    const submits = screen.getAllByRole('button', { name: 'Bind source' })
    await user.click(submits[submits.length - 1])
    expect(mockPost).not.toHaveBeenCalled()
  })

  it.each([
    ['same target channel early', false, '2023-12-31T23:59', 'effective time must be within the target meter epoch'],
    ['same source equality', false, '2025-06-01T00:00', 'same-meter transfer must be strictly after the source binding start'],
    ['same future', false, '2099-01-01T00:00', 'future effective times are not allowed'],
    ['cross target epoch early', true, '2024-12-31T23:59', 'effective time must be within the target meter epoch'],
    ['cross target channel overlap', true, '2025-01-02T00:00', 'overlaps closed binding history; choose a time at or after it ends'],
    ['cross target channel unit mismatch', true, '2025-01-02T00:00', 'unit mismatch: GJ; target needs kWh'],
    ['cross retained anomaly: target channel open occupancy', true, '2025-01-02T00:00', 'occupied by an open binding; close or transfer it first'],
    ['cross retained anomaly: target channel ambiguity', true, '2025-01-02T00:00', 'ambiguous: channel has overlapping binding history; resolve it first'],
    ['cross future', true, '2099-01-01T00:00', 'future effective times are not allowed'],
  ])('shows %s reason, clears selection, and sends no transfer request', async (_name, recovery, value, reason) => {
    const user = userEvent.setup()
    const sourceBinding = { uuid: 'matrix-source', source_uuid: 'source-1', source_channel_uuid: 'old-channel', started_at: recovery ? '2024-01-01T00:00:00Z' : '2025-06-01T00:00:00Z', ended_at: null }
    const sourceMeter = recovery ? { ...CLOSED_METER, ended_at: '2025-01-01T00:00:00Z', bindings: [sourceBinding] } : { ...ACTIVE_METER, bindings: [sourceBinding] }
    const target = recovery ? { ...ACTIVE_METER, id: 7, started_at: '2025-01-01T00:00:00Z', bindings: [] } : sourceMeter
    const targetStart = recovery ? '2025-01-01T00:00:00Z' : '2024-01-15T00:00:00Z'
    const conflictBindings = _name.includes('overlap') ? [{ uuid: 'history', source_channel_uuid: 'channel-1', started_at: recovery ? '2025-01-01T00:00:00Z' : '2025-01-01T00:00:00Z', ended_at: '2025-12-31T00:00:00Z' }] :
      _name.includes('open occupancy') ? [{ uuid: 'bad-stranded-open', source_channel_uuid: 'channel-1', started_at: targetStart, ended_at: null }] :
      _name.includes('ambiguity') ? [{ uuid: 'bad-stranded-a', source_channel_uuid: 'channel-1', started_at: targetStart, ended_at: null }, { uuid: 'bad-stranded-b', source_channel_uuid: 'channel-1', started_at: targetStart, ended_at: null }] : []
    const targetWithConflict = { ...target, bindings: [...(target.bindings ?? []), ...conflictBindings] }
    const selected = _name.includes('unit mismatch') ? { ...channel, unit: 'GJ' } : channel
    const selectedSource = selected.unit === 'GJ'
      ? { uuid: 'warmtelink-source', name: 'WarmteLink', kind: 'warmtelink_serial' }
      : source
    mockLifecycleReads(recovery ? [sourceMeter, targetWithConflict] : [targetWithConflict], [selected], [selectedSource])
    renderWithProviders(<MeterManager />)
    await user.click((await screen.findAllByRole('button', { name: recovery ? 'Recover binding' : 'Transfer source' }))[0])
    const sourceInput = screen.getAllByLabelText('Source').find((element) => element.tagName === 'INPUT')!
    await user.click(sourceInput); await user.click(await screen.findByText(selectedSource.name))
    const channelInput = screen.getAllByLabelText('Source channel').find((element) => element.tagName === 'INPUT')!
    // Rows that begin eligible exercise a real selection before the invalid
    // time edit; initially invalid rows instead prove their disabled option.
    if (!_name.includes('unit mismatch') && !_name.includes('open occupancy') && !_name.includes('ambiguity')) {
      await user.click(channelInput); await user.click(await screen.findByText(/Total import \(kWh\)/))
    }
    const effective = screen.getByTestId('transfer-effective-at'); await user.clear(effective); await user.type(effective, value)
    await user.click(channelInput)
    const disabled = await screen.findByText(new RegExp(reason))
    expect(disabled.closest('[role="option"]')).toHaveAttribute('data-combobox-disabled', 'true')
    expect(channelInput).toHaveValue('')
    await user.keyboard('{Escape}')
    const submits = screen.getAllByRole('button', { name: 'Transfer binding' })
    await user.click(submits[submits.length - 1])
    expect(mockPost).not.toHaveBeenCalled()
  })

  it('treats cross-Meter target-channel history before its start as overlap and its equal end as a valid recovery transfer', async () => {
      const user = userEvent.setup()
      const sourceBinding = { uuid: 'target-history-source', source_uuid: 'source-1', source_channel_uuid: 'old-channel', started_at: '2024-01-01T00:00:00Z', ended_at: null }
      const sourceMeter = { ...CLOSED_METER, id: 3, ended_at: '2025-01-01T00:00:00Z', bindings: [sourceBinding] }
      const target = { ...ACTIVE_METER, id: 7, started_at: '2025-01-01T00:00:00Z', bindings: [] }
      // A same-Meter target-history positive is backend-unreachable: its open
      // source occupies the target Meter until now.  Cross-Meter history is
      // legal and exercises the actual target-channel interval boundary.
      const targetWithHistory = {
        ...target,
        bindings: [...(target.bindings ?? []), {
          uuid: 'target-history', source_channel_uuid: 'channel-1',
          started_at: '2025-01-02T00:00:00Z', ended_at: '2025-01-03T00:00:00Z',
        }],
      }
      const early = '2025-01-01T00:00'
      const equalEnd = '2025-01-03T00:00'
      mockLifecycleReads([sourceMeter, targetWithHistory])
      mockPost.mockResolvedValue({ data: {} })
      renderWithProviders(<MeterManager />)
      await user.click(await screen.findByRole('button', { name: 'Recover binding' }))
      const effective = screen.getByTestId('transfer-effective-at')
      // Select while the target channel is valid, then prove a time edit
      // clears that real selection and disables the now-conflicting option.
      await user.clear(effective); await user.type(effective, equalEnd)
      const sourceInput = screen.getAllByLabelText('Source').find((element) => element.tagName === 'INPUT')!
      await user.click(sourceInput); await user.click(await screen.findByText('DSMR'))
      const channelInput = screen.getAllByLabelText('Source channel').find((element) => element.tagName === 'INPUT')!
      await user.click(channelInput); await user.click(await screen.findByText(/Total import \(kWh\)/))
      await user.clear(effective); await user.type(effective, early)
      expect(channelInput).toHaveValue('')
      await user.click(channelInput)
      const reason = await screen.findByText(/overlaps closed binding history; choose a time at or after it ends/)
      expect(reason.closest('[role="option"]')).toHaveAttribute('data-combobox-disabled', 'true')
      await user.keyboard('{Escape}')
      await user.click(screen.getByRole('button', { name: 'Transfer binding' }))
      expect(mockPost).not.toHaveBeenCalled()

      await user.clear(effective); await user.type(effective, equalEnd)
      await user.click(channelInput); await user.click(await screen.findByText(/Total import \(kWh\)/))
      expect(channelInput).toHaveValue('Total import (kWh)')
      await user.click(screen.getByRole('button', { name: 'Transfer binding' }))
      await waitFor(() => expect(mockPost).toHaveBeenCalledWith('/api/energy/meters/{meter_id}/bindings/transfer', expect.objectContaining({
        params: { path: { meter_id: 7 } },
        body: { from_binding_uuid: 'target-history-source', to_source_channel_uuid: 'channel-1', effective_at: equalEnd },
      })))
      expect(mockPost).toHaveBeenCalledTimes(1)
    })

  it.each([
    ['recovery gap', '2025-01-02T00:00', true],
    ['recovery target equal boundary', '2025-01-01T00:00', false],
  ])('submits %s with the selected target time and exact transfer endpoint', async (_name, effectiveAt, warns) => {
    const user = userEvent.setup()
    const sourceBinding = { uuid: 'recovery-source', source_uuid: 'source-1', source_channel_uuid: 'old-channel', started_at: '2024-01-01T00:00:00Z', ended_at: null }
    const sourceMeter = { ...CLOSED_METER, ended_at: '2025-01-01T00:00:00Z', bindings: [sourceBinding] }
    const target = { ...ACTIVE_METER, id: 7, started_at: '2025-01-01T00:00:00Z', bindings: [] }
    mockLifecycleReads([sourceMeter, target]); mockPost.mockResolvedValue({ data: {} }); renderWithProviders(<MeterManager />)
    await user.click(await screen.findByRole('button', { name: 'Recover binding' })); await chooseChannel(user)
    const input = screen.getByTestId('transfer-effective-at'); await user.clear(input); await user.type(input, effectiveAt)
    if (warns) expect(screen.getByText(/leaves an unbound gap/)).toBeInTheDocument()
    await user.click(screen.getByRole('button', { name: 'Transfer binding' }))
    await waitFor(() => expect(mockPost).toHaveBeenCalledWith('/api/energy/meters/{meter_id}/bindings/transfer', expect.objectContaining({
      params: { path: { meter_id: 7 } }, body: { from_binding_uuid: 'recovery-source', to_source_channel_uuid: 'channel-1', effective_at: effectiveAt },
    })))
    expect(mockPost).toHaveBeenCalledTimes(1)
  })
})