"""add modbus_device and modbus_reading tables

Revision ID: 20260622_09_modbus_tables
Revises: 20260621_08_totp
Create Date: 2026-06-22 00:00:00.000000
"""

from typing import Sequence, Union

import sqlalchemy as sa
from alembic import op


revision: str = "20260622_09_modbus_tables"
down_revision: Union[str, None] = "20260621_08_totp"
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    # modbus_device — deployment/configurable metadata for each polled device.
    op.create_table(
        "modbus_device",
        sa.Column("id", sa.Integer(), autoincrement=True, nullable=False),
        sa.Column("uuid", sa.String(length=36), nullable=False),
        sa.Column("friendly_name", sa.String(length=255), nullable=False),
        sa.Column("transport", sa.String(length=16), nullable=False),
        sa.Column("host", sa.String(length=255), nullable=False),
        sa.Column("port", sa.Integer(), nullable=False),
        sa.Column("unit_id", sa.Integer(), nullable=False),
        sa.Column("profile", sa.String(length=64), nullable=False),
        sa.Column("poll_interval_s", sa.Integer(), nullable=False),
        sa.Column("enabled", sa.Boolean(), nullable=False),
        sa.Column("last_poll_at", sa.DateTime(timezone=True), nullable=True),
        sa.Column("last_poll_ok", sa.Boolean(), nullable=True),
        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False),
        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=False),
        sa.PrimaryKeyConstraint("id"),
        sa.UniqueConstraint("uuid", name="uq_modbus_device_uuid"),
    )

    # modbus_reading — generic telemetry, one row per device per poll cycle.
    op.create_table(
        "modbus_reading",
        sa.Column("id", sa.Integer(), autoincrement=True, nullable=False),
        sa.Column("device_id", sa.Integer(), nullable=False),
        sa.Column("recorded_at", sa.DateTime(timezone=True), nullable=False),
        sa.Column("payload", sa.JSON(), nullable=False),
        sa.ForeignKeyConstraint(
            ["device_id"],
            ["modbus_device.id"],
            ondelete="RESTRICT",
        ),
        sa.PrimaryKeyConstraint("id"),
    )

    # Individual index on recorded_at (from the ORM-level index=True).
    op.create_index(
        "ix_modbus_reading_recorded_at",
        "modbus_reading",
        ["recorded_at"],
        unique=False,
    )

    # Composite index for efficient time-range queries per device.
    op.create_index(
        "ix_modbus_reading_device_recorded",
        "modbus_reading",
        ["device_id", "recorded_at"],
        unique=False,
    )


def downgrade() -> None:
    # Drop the reading table first (it has a FK referencing modbus_device).
    op.drop_index("ix_modbus_reading_device_recorded", table_name="modbus_reading")
    op.drop_index("ix_modbus_reading_recorded_at", table_name="modbus_reading")
    op.drop_table("modbus_reading")

    # Drop the device table.
    op.drop_table("modbus_device")