"""Tests for database engine configuration."""

from unittest.mock import AsyncMock, MagicMock, patch

import pytest

from meshcore_hub.common.database import (
    DatabaseManager,
    _resolve_pg_schema,
    _to_async_url,
    create_database_engine,
)


class TestAsyncUrlMapping:
    """Map sync URLs to their asyncpg equivalents for the async engine."""

    @pytest.mark.parametrize(
        "sync_url,expected",
        [
            ("postgresql://u:p@h/db", "postgresql+asyncpg://u:p@h/db"),
            ("postgres://u:p@h/db", "postgresql+asyncpg://u:p@h/db"),
            # config assembles +psycopg2; the async engine must still use asyncpg
            ("postgresql+psycopg2://u:p@h/db", "postgresql+asyncpg://u:p@h/db"),
            ("postgresql+asyncpg://u:p@h/db", "postgresql+asyncpg://u:p@h/db"),
        ],
    )
    def test_to_async_url(self, sync_url: str, expected: str) -> None:
        assert _to_async_url(sync_url) == expected


class TestSchemaResolution:
    """search_path schema resolution (explicit arg vs DATABASE_SCHEMA env)."""

    def test_explicit_schema_wins(self) -> None:
        assert _resolve_pg_schema("prod") == "prod"

    def test_falls_back_to_env(self, monkeypatch: pytest.MonkeyPatch) -> None:
        monkeypatch.setenv("DATABASE_SCHEMA", "stg")
        assert _resolve_pg_schema(None) == "stg"

    def test_none_when_no_env(self, monkeypatch: pytest.MonkeyPatch) -> None:
        monkeypatch.delenv("DATABASE_SCHEMA", raising=False)
        assert _resolve_pg_schema(None) is None


class TestPostgresSessionTimezone:
    """Verify Postgres connections are pinned to UTC at the engine level.

    func.date(<timestamptz>) truncates on the session timezone's day boundary.
    The collector writes UTC, so the session must be UTC for day buckets to
    line up with those writes.
    """

    def test_sync_engine_sets_timezone_utc_without_schema(
        self, monkeypatch: pytest.MonkeyPatch
    ) -> None:
        """Postgres engine without a schema still pins timezone=UTC."""
        monkeypatch.delenv("DATABASE_SCHEMA", raising=False)
        with patch("meshcore_hub.common.database.create_engine") as mock_create:
            create_database_engine("postgresql://u:p@h/db")
        _, kwargs = mock_create.call_args
        assert kwargs["connect_args"]["options"] == "-ctimezone=UTC"

    def test_sync_engine_timezone_utc_with_schema(self) -> None:
        """Postgres engine with a schema sets both search_path and timezone."""
        with patch("meshcore_hub.common.database.create_engine") as mock_create:
            create_database_engine("postgresql://u:p@h/db", schema="meshcorehub")
        _, kwargs = mock_create.call_args
        options = kwargs["connect_args"]["options"]
        assert "-csearch_path=meshcorehub" in options
        assert "-ctimezone=UTC" in options

    def test_sync_engine_always_sizes_the_pool(self) -> None:
        """Pool sizing is unconditional (sized above the Starlette threadpool)."""
        with patch("meshcore_hub.common.database.create_engine") as mock_create:
            create_database_engine("postgresql://u:p@h/db")
        _, kwargs = mock_create.call_args
        assert kwargs["pool_size"] == 20
        assert kwargs["max_overflow"] == 30
        assert kwargs["pool_pre_ping"] is True

    def test_async_engine_sets_server_settings_timezone_utc(
        self, monkeypatch: pytest.MonkeyPatch
    ) -> None:
        """asyncpg engine gets server_settings with timezone=UTC."""
        monkeypatch.delenv("DATABASE_SCHEMA", raising=False)
        manager = DatabaseManager.__new__(DatabaseManager)
        manager.database_url = "postgresql://u:p@h/db"
        manager._echo = False
        manager._schema = None
        manager._async_engine = None
        manager._async_session_factory = None

        with patch("meshcore_hub.common.database.create_async_engine") as mock_async:
            manager._ensure_async_engine()
        _, kwargs = mock_async.call_args
        assert kwargs["connect_args"]["server_settings"] == {"timezone": "UTC"}

    def test_async_engine_sets_server_settings_with_schema(self) -> None:
        """asyncpg engine with schema gets both search_path and timezone."""
        manager = DatabaseManager.__new__(DatabaseManager)
        manager.database_url = "postgresql://u:p@h/db"
        manager._echo = False
        manager._schema = "meshcorehub"
        manager._async_engine = None
        manager._async_session_factory = None

        with patch("meshcore_hub.common.database.create_async_engine") as mock_async:
            manager._ensure_async_engine()
        _, kwargs = mock_async.call_args
        server_settings = kwargs["connect_args"]["server_settings"]
        assert server_settings["timezone"] == "UTC"
        assert server_settings["search_path"] == "meshcorehub"

    def test_async_engine_gets_pool_pre_ping_and_sizing(self) -> None:
        """Async engine mirrors the sync engine's pool config."""
        manager = DatabaseManager.__new__(DatabaseManager)
        manager.database_url = "postgresql://u:p@h/db"
        manager._echo = False
        manager._schema = None
        manager._async_engine = None
        manager._async_session_factory = None

        with patch("meshcore_hub.common.database.create_async_engine") as mock_async:
            manager._ensure_async_engine()
        _, kwargs = mock_async.call_args
        assert kwargs["pool_pre_ping"] is True
        assert kwargs["pool_size"] == 20
        assert kwargs["max_overflow"] == 30

    async def test_adispose_closes_async_engine(self) -> None:
        """adispose awaits the async engine dispose and clears it."""
        manager = DatabaseManager.__new__(DatabaseManager)
        manager.database_url = "postgresql://u:p@h/db"
        manager._echo = False
        manager._schema = None
        mock_async_engine = AsyncMock()
        manager._async_engine = mock_async_engine
        manager._async_session_factory = object()
        manager.engine = MagicMock()

        await manager.adispose()

        mock_async_engine.dispose.assert_awaited_once()
        manager.engine.dispose.assert_called_once()
        assert manager._async_engine is None
        assert manager._async_session_factory is None

    def test_dispose_sync_context_closes_async_engine_via_temp_loop(self) -> None:
        """Outside a running loop, dispose() drains the async engine too."""
        manager = DatabaseManager.__new__(DatabaseManager)
        manager.database_url = "postgresql://u:p@h/db"
        manager._echo = False
        manager._schema = None
        disposed = []

        async def _fake_async_dispose() -> None:
            disposed.append(True)

        mock_async_engine = MagicMock()
        mock_async_engine.dispose = _fake_async_dispose
        manager._async_engine = mock_async_engine
        manager._async_session_factory = object()
        manager.engine = MagicMock()

        manager.dispose()

        assert disposed == [True]
        manager.engine.dispose.assert_called_once()
        assert manager._async_engine is None