"""Tests for CacheManager."""

import pytest
from unittest.mock import AsyncMock, MagicMock, patch

from exchange_data_manager.cache.manager import CacheManager
from exchange_data_manager.config import DatabaseConfig
from exchange_data_manager.candles.models import Candle, CandleRequest


class MockConnector:
    """Mock exchange connector for testing."""

    def __init__(self):
        self.fetch_candles = AsyncMock(return_value=[])


@pytest.fixture
def cache_manager():
    """Create a cache manager for testing (sync mode)."""
    return CacheManager(use_async_db=False)


class TestCacheManagerColdCache:
    """Tests for cold-cache / limit-only requests."""

    @pytest.mark.asyncio
    async def test_limit_only_request_fetches_from_exchange(self, cache_manager):
        """Test that limit-only requests (no start/end) fetch from exchange."""
        # Setup mock connector
        mock_connector = MockConnector()
        expected_candles = [
            Candle(time=1709337600, open=50000.0, high=50100.0, low=49900.0, close=50050.0, volume=10.0),
            Candle(time=1709337660, open=50050.0, high=50200.0, low=50000.0, close=50150.0, volume=15.0),
        ]
        mock_connector.fetch_candles.return_value = expected_candles
        cache_manager.register_exchange("binance", mock_connector)

        # Request with limit but no start/end (cold cache scenario)
        request = CandleRequest(
            exchange="binance",
            symbol="BTC/USDT",
            timeframe="1m",
            start=None,
            end=None,
            limit=100,
        )

        result = await cache_manager.get_candles(request)

        # Should have fetched from exchange
        mock_connector.fetch_candles.assert_called_once_with(
            symbol="BTC/USDT",
            timeframe="1m",
            limit=100,
        )
        assert len(result) == 2
        assert result[0].time == 1709337600

    @pytest.mark.asyncio
    async def test_limit_only_no_connector_returns_empty(self, cache_manager):
        """Test limit-only request with no connector returns empty list."""
        request = CandleRequest(
            exchange="unknown_exchange",
            symbol="BTC/USDT",
            timeframe="1m",
            start=None,
            end=None,
            limit=100,
        )

        result = await cache_manager.get_candles(request)

        assert result == []

    @pytest.mark.asyncio
    @patch("exchange_data_manager.cache.memory.time.time")
    async def test_limit_only_caches_result(self, mock_time, cache_manager):
        """Test that limit-only results are cached in memory."""
        # Mock time to be close to test candle timestamps (prevents freshness check)
        mock_time.return_value = 1709337660  # Just after the candle

        mock_connector = MockConnector()
        expected_candles = [
            Candle(time=1709337600, open=50000.0, high=50100.0, low=49900.0, close=50050.0, volume=10.0),
        ]
        mock_connector.fetch_candles.return_value = expected_candles
        cache_manager.register_exchange("binance", mock_connector)

        request = CandleRequest(
            exchange="binance",
            symbol="BTC/USDT",
            timeframe="1m",
            start=None,
            end=None,
            limit=100,
        )

        # First call - fetches from exchange
        result1 = await cache_manager.get_candles(request)
        assert mock_connector.fetch_candles.call_count == 1
        assert len(result1) == 1

        # Second call - memory cache has data, so doesn't need to fetch again
        result2 = await cache_manager.get_candles(request)
        assert mock_connector.fetch_candles.call_count == 1  # Still 1 - used cache
        assert len(result2) == 1


class TestCacheManagerStats:
    """Tests for cache manager stats."""

    @pytest.mark.asyncio
    async def test_stats_returns_all_components(self, cache_manager):
        """Test that stats returns memory, database, and exchanges."""
        stats = await cache_manager.stats()

        assert "memory" in stats
        assert "database" in stats
        assert "registered_exchanges" in stats
        assert isinstance(stats["registered_exchanges"], list)


class TestCacheManagerSources:
    """Tests for source reporting and per-request connector overrides."""

    @pytest.mark.asyncio
    @patch("exchange_data_manager.cache.memory.time.time")
    async def test_get_candles_with_source_reports_memory(self, mock_time, cache_manager):
        """Memory-only responses should report memory source."""
        # Mock time to be close to test candle timestamps (prevents freshness check)
        mock_time.return_value = 1709337720  # Just after the second candle

        candles = [
            Candle(time=1709337600, open=50000.0, high=50100.0, low=49900.0, close=50050.0, volume=10.0),
            Candle(time=1709337660, open=50050.0, high=50200.0, low=50000.0, close=50150.0, volume=15.0),
        ]
        cache_manager.memory.put("binance:BTC/USDT:1m", candles)

        request = CandleRequest(
            exchange="binance",
            symbol="BTC/USDT",
            timeframe="1m",
            limit=2,
        )

        result, source = await cache_manager.get_candles_with_source(request)

        assert len(result) == 2
        assert source == "memory"

    @pytest.mark.asyncio
    async def test_get_candles_with_source_uses_connector_override(self, cache_manager):
        """A session-scoped connector override should be used when provided."""
        override_connector = MockConnector()
        override_connector.fetch_candles.return_value = [
            Candle(time=1709337600, open=50000.0, high=50100.0, low=49900.0, close=50050.0, volume=10.0),
        ]

        request = CandleRequest(
            exchange="binance",
            symbol="BTC/USDT",
            timeframe="1m",
            limit=1,
        )

        result, source = await cache_manager.get_candles_with_source(
            request,
            connector_override=override_connector,
        )

        assert len(result) == 1
        assert source == "exchange"
        override_connector.fetch_candles.assert_called_once_with(
            symbol="BTC/USDT",
            timeframe="1m",
            limit=1,
        )


class TestCacheManagerDatabaseConfig:
    """Tests for database config wiring."""

    def test_async_database_pool_config_is_wired(self):
        """CacheManager should pass pool config into AsyncDatabaseCache."""
        manager = CacheManager(
            database_config=DatabaseConfig(
                path="./data/test-pool.db",
                pool_size=7,
                max_overflow=3,
            ),
            use_async_db=True,
        )

        assert manager.database._pool_size == 7
        assert manager.database._max_overflow == 3


class TestCacheManagerExchangeRegistration:
    """Tests for exchange connector registration."""

    def test_register_exchange(self, cache_manager):
        """Test registering an exchange connector."""
        mock_connector = MockConnector()

        cache_manager.register_exchange("test_exchange", mock_connector)

        assert cache_manager.get_exchange("test_exchange") is mock_connector

    def test_get_exchange_case_insensitive(self, cache_manager):
        """Test that exchange lookup is case insensitive."""
        mock_connector = MockConnector()

        cache_manager.register_exchange("TestExchange", mock_connector)

        assert cache_manager.get_exchange("testexchange") is mock_connector
        assert cache_manager.get_exchange("TESTEXCHANGE") is mock_connector

    def test_get_nonexistent_exchange_returns_none(self, cache_manager):
        """Test that getting a non-existent exchange returns None."""
        result = cache_manager.get_exchange("nonexistent")
        assert result is None