"""Tests for M2-T01: GET /api/config and PUT /api/config.
   Tests for M2-T05: POST /api/config/smtp/test."""
from __future__ import annotations

import re
import sqlite3
from unittest.mock import patch

from fastapi.testclient import TestClient

from app.config import get_settings
from app.services.config_page import CONFIG_FIELDS
from app.services.email import EmailConfigurationError, EmailDeliveryError


# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------

def _extract_csrf_token(html: str) -> str:
    match = re.search(r'name="csrf_token" value="([^"]+)"', html)
    assert match is not None, "csrf_token not found in HTML"
    return match.group(1)


def _login(client: TestClient) -> None:
    """Log in as admin/test-password using the Jinja login form."""
    login_page = client.get("/login")
    csrf_token = _extract_csrf_token(login_page.text)
    resp = client.post(
        "/login",
        data={
            "username": "admin",
            "password": "test-password",
            "csrf_token": csrf_token,
        },
        follow_redirects=False,
    )
    assert resp.status_code == 303, f"Login failed: {resp.status_code}"


def _stringify(value) -> str:
    if value is None:
        return ""
    if isinstance(value, bool):
        return str(value).lower()
    return str(value)


def _full_config_payload(overrides: dict[str, str] | None = None) -> dict[str, str]:
    """Build a complete env_name→value dict mirroring the Jinja form's full submission.

    Secrets default to "" (keep-old semantics). Non-secrets use current settings defaults.
    """
    settings = get_settings()
    payload: dict[str, str] = {}
    for field in CONFIG_FIELDS:
        if field.secret:
            payload[field.env_name] = ""  # blank → keep existing
        else:
            payload[field.env_name] = _stringify(getattr(settings, field.setting_attr))
    if overrides:
        payload.update(overrides)
    return payload


# ---------------------------------------------------------------------------
# GET /api/config — unauthenticated
# ---------------------------------------------------------------------------

def test_get_config_unauthenticated_returns_401(client: TestClient) -> None:
    response = client.get("/api/config")
    assert response.status_code == 401


# ---------------------------------------------------------------------------
# GET /api/config — authenticated
# ---------------------------------------------------------------------------

def test_get_config_authenticated_returns_sections(client: TestClient) -> None:
    _login(client)

    response = client.get("/api/config")

    assert response.status_code == 200
    body = response.json()
    assert "sections" in body
    assert isinstance(body["sections"], list)
    assert len(body["sections"]) > 0


def test_get_config_sections_have_expected_structure(client: TestClient) -> None:
    _login(client)

    response = client.get("/api/config")
    body = response.json()

    for section in body["sections"]:
        assert "name" in section
        assert "fields" in section
        assert isinstance(section["fields"], list)
        for field in section["fields"]:
            assert "env_name" in field
            assert "label" in field
            assert "value" in field
            assert "secret" in field
            assert "input_type" in field
            assert "configured" in field


def test_get_config_secret_fields_have_empty_string_value(client: TestClient) -> None:
    _login(client)

    response = client.get("/api/config")
    body = response.json()

    for section in body["sections"]:
        for field in section["fields"]:
            if field["secret"]:
                assert field["value"] == "", (
                    f"Secret field {field['env_name']} should be masked (empty string), "
                    f"got {field['value']!r}"
                )


def test_get_config_includes_known_sections(client: TestClient) -> None:
    _login(client)

    response = client.get("/api/config")
    body = response.json()

    section_names = {s["name"] for s in body["sections"]}
    assert "System" in section_names
    assert "SMTP" in section_names
    assert "Authentication" in section_names


# ---------------------------------------------------------------------------
# PUT /api/config — unauthenticated
# ---------------------------------------------------------------------------

def test_put_config_unauthenticated_returns_401(client: TestClient) -> None:
    response = client.put(
        "/api/config",
        json={"updates": _full_config_payload()},
        headers={"X-CSRF-Token": "any-token"},
    )
    assert response.status_code == 401


# ---------------------------------------------------------------------------
# PUT /api/config — authenticated but missing CSRF
# ---------------------------------------------------------------------------

def test_put_config_authenticated_missing_csrf_returns_403(client: TestClient) -> None:
    _login(client)

    # No X-CSRF-Token header at all
    response = client.put(
        "/api/config",
        json={"updates": _full_config_payload()},
    )
    assert response.status_code == 403


def test_put_config_authenticated_empty_csrf_returns_403(client: TestClient) -> None:
    _login(client)

    # Empty string X-CSRF-Token header counts as missing
    response = client.put(
        "/api/config",
        json={"updates": _full_config_payload()},
        headers={"X-CSRF-Token": ""},
    )
    assert response.status_code == 403


# ---------------------------------------------------------------------------
# PUT /api/config — authenticated + CSRF present (any non-empty value)
# ---------------------------------------------------------------------------

def test_put_config_with_csrf_header_updates_app_name(
    client: TestClient, test_database_urls
) -> None:
    _login(client)

    payload = _full_config_payload({"APP_NAME": "Updated via API"})
    response = client.put(
        "/api/config",
        json={"updates": payload},
        headers={"X-CSRF-Token": "any-non-empty-value"},
    )

    assert response.status_code == 200
    body = response.json()
    assert "sections" in body

    # The refreshed config in the response should reflect the new name
    system_section = next(s for s in body["sections"] if s["name"] == "System")
    app_name_field = next(f for f in system_section["fields"] if f["env_name"] == "APP_NAME")
    assert app_name_field["value"] == "Updated via API"


def test_put_config_blank_secret_keeps_existing_value(
    client: TestClient, test_database_urls
) -> None:
    """Submitting a blank value for a secret field must NOT overwrite the stored secret."""
    _login(client)

    # First: store a secret via a full PUT with the secret value set
    payload_with_secret = _full_config_payload({"SMTP_PASSWORD": "original-secret"})
    resp1 = client.put(
        "/api/config",
        json={"updates": payload_with_secret},
        headers={"X-CSRF-Token": "token"},
    )
    assert resp1.status_code == 200, f"First PUT failed: {resp1.status_code} {resp1.text}"

    # Second: PUT with blank for that secret (keep-old semantics)
    payload_blank_secret = _full_config_payload({"SMTP_PASSWORD": ""})
    resp2 = client.put(
        "/api/config",
        json={"updates": payload_blank_secret},
        headers={"X-CSRF-Token": "token"},
    )
    assert resp2.status_code == 200, f"Second PUT failed: {resp2.status_code} {resp2.text}"

    # The stored value in the DB should still be the original secret
    conn = sqlite3.connect(test_database_urls["app_path"])
    try:
        rows = dict(conn.execute("SELECT key, value FROM app_config").fetchall())
    finally:
        conn.close()

    assert rows.get("SMTP_PASSWORD") == "original-secret"


def test_put_config_returns_refreshed_sections(client: TestClient) -> None:
    _login(client)

    payload = _full_config_payload({"APP_NAME": "Refreshed Name"})
    response = client.put(
        "/api/config",
        json={"updates": payload},
        headers={"X-CSRF-Token": "token"},
    )

    assert response.status_code == 200
    body = response.json()
    assert "sections" in body
    assert isinstance(body["sections"], list)
    assert len(body["sections"]) > 0

    # Sections should reflect updated value
    system_section = next(s for s in body["sections"] if s["name"] == "System")
    app_name_field = next(f for f in system_section["fields"] if f["env_name"] == "APP_NAME")
    assert app_name_field["value"] == "Refreshed Name"


def test_put_config_invalid_value_returns_422_and_does_not_write(
    client: TestClient, test_database_urls
) -> None:
    """An invalid config value (e.g. bad type for a typed field) must return 4xx and not persist."""
    _login(client)

    # SMTP_PORT expects an integer; submit something that fails Settings validation
    payload = _full_config_payload({"SMTP_PORT": "not-a-number"})
    response = client.put(
        "/api/config",
        json={"updates": payload},
        headers={"X-CSRF-Token": "token"},
    )

    assert response.status_code == 422

    # Confirm the bad value was not persisted
    conn = sqlite3.connect(test_database_urls["app_path"])
    try:
        rows = dict(conn.execute("SELECT key, value FROM app_config").fetchall())
    finally:
        conn.close()

    assert rows.get("SMTP_PORT") != "not-a-number"


# ---------------------------------------------------------------------------
# Response schema correctness — secret values never leak in response
# ---------------------------------------------------------------------------

def test_put_config_response_does_not_leak_secret_values(client: TestClient) -> None:
    _login(client)

    # Set a secret
    payload1 = _full_config_payload({"HOME_ASSISTANT_AUTH_TOKEN": "super-secret-token"})
    resp1 = client.put(
        "/api/config",
        json={"updates": payload1},
        headers={"X-CSRF-Token": "token"},
    )
    assert resp1.status_code == 200

    # Do another PUT and check response doesn't leak the secret
    payload2 = _full_config_payload({"APP_NAME": "check-secrets"})
    response = client.put(
        "/api/config",
        json={"updates": payload2},
        headers={"X-CSRF-Token": "token"},
    )

    assert response.status_code == 200
    body = response.json()

    for section in body["sections"]:
        for field in section["fields"]:
            if field["secret"]:
                assert field["value"] == "", (
                    f"Secret field {field['env_name']} leaked in PUT response"
                )

    # The secret value itself should not appear anywhere in the raw response
    assert "super-secret-token" not in str(body)


# ---------------------------------------------------------------------------
# POST /api/config/smtp/test — M2-T05
# ---------------------------------------------------------------------------

_SMTP_TEST_URL = "/api/config/smtp/test"
_SMTP_SEND_PATH = "app.api.routes.api.config.send_smtp_test_email"


def test_smtp_test_unauthenticated_returns_401(client: TestClient) -> None:
    """Unauthenticated request must return 401 (require_session fires before require_csrf)."""
    response = client.post(
        _SMTP_TEST_URL,
        headers={"X-CSRF-Token": "any-token"},
    )
    assert response.status_code == 401


def test_smtp_test_authenticated_missing_csrf_returns_403(client: TestClient) -> None:
    """Authenticated but no X-CSRF-Token header must return 403."""
    _login(client)
    response = client.post(_SMTP_TEST_URL)
    assert response.status_code == 403


def test_smtp_test_authenticated_empty_csrf_returns_403(client: TestClient) -> None:
    """Authenticated but empty X-CSRF-Token header must return 403."""
    _login(client)
    response = client.post(_SMTP_TEST_URL, headers={"X-CSRF-Token": ""})
    assert response.status_code == 403


def test_smtp_test_success_returns_200(client: TestClient) -> None:
    """When send_smtp_test_email succeeds (returns None), endpoint returns 200 with result=success."""
    _login(client)

    with patch(_SMTP_SEND_PATH, return_value=None) as mock_send:
        response = client.post(_SMTP_TEST_URL, headers={"X-CSRF-Token": "any-token"})

    mock_send.assert_called_once()
    assert response.status_code == 200
    body = response.json()
    assert body["result"] == "success"
    assert "message" in body


def test_smtp_test_config_error_returns_400(client: TestClient) -> None:
    """When send_smtp_test_email raises EmailConfigurationError, endpoint returns 400 with result=config-error."""
    _login(client)

    with patch(_SMTP_SEND_PATH, side_effect=EmailConfigurationError("SMTP host is required")):
        response = client.post(_SMTP_TEST_URL, headers={"X-CSRF-Token": "any-token"})

    assert response.status_code == 400
    body = response.json()
    assert body["result"] == "config-error"
    assert "message" in body
    assert "SMTP host is required" in body["message"]


def test_smtp_test_delivery_error_returns_502(client: TestClient) -> None:
    """When send_smtp_test_email raises EmailDeliveryError, endpoint returns 502 with result=failed."""
    _login(client)

    with patch(_SMTP_SEND_PATH, side_effect=EmailDeliveryError("connection refused")):
        response = client.post(_SMTP_TEST_URL, headers={"X-CSRF-Token": "any-token"})

    assert response.status_code == 502
    body = response.json()
    assert body["result"] == "failed"
    assert "message" in body
    assert "connection refused" in body["message"]


def test_smtp_test_response_does_not_echo_smtp_password(client: TestClient) -> None:
    """The SMTP password stored in config must not appear in any API response body."""
    _login(client)

    smtp_password = "s3cr3t-smtp-pass"

    # Store a fake SMTP password in config
    payload = _full_config_payload({"SMTP_PASSWORD": smtp_password})
    client.put(
        "/api/config",
        json={"updates": payload},
        headers={"X-CSRF-Token": "token"},
    )

    # Simulate a delivery error whose message has already been sanitised by the
    # service layer (i.e. the password does not appear in the exception text).
    # This mirrors production behaviour: email.py's _sanitize_error_message
    # replaces any password occurrence with "[redacted]" before raising.
    with patch(
        _SMTP_SEND_PATH,
        side_effect=EmailDeliveryError("authentication failure: [redacted]"),
    ):
        response = client.post(_SMTP_TEST_URL, headers={"X-CSRF-Token": "token"})

    assert response.status_code == 502
    body = response.json()
    assert "result" in body
    assert "message" in body
    # The plaintext password must not appear anywhere in the response body
    assert smtp_password not in response.text