"""
UsageService 测试

测试用量统计服务的核心功能：
- 成本计算
- 配额检查
- 用量统计查询
"""

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

from src.services.usage.service import UsageService


class TestCostCalculation:
    """测试成本计算"""

    def test_calculate_cost_basic(self) -> None:
        """测试基础成本计算"""
        # 价格：输入 $3/1M, 输出 $15/1M
        result = UsageService.calculate_cost(
            input_tokens=1000,
            output_tokens=500,
            input_price_per_1m=3.0,
            output_price_per_1m=15.0,
        )

        input_cost, output_cost, cache_creation_cost, cache_read_cost, cache_cost, request_cost, total_cost = result

        # 1000 tokens * $3 / 1M = $0.003
        assert abs(input_cost - 0.003) < 0.0001
        # 500 tokens * $15 / 1M = $0.0075
        assert abs(output_cost - 0.0075) < 0.0001
        # Total = $0.003 + $0.0075 = $0.0105
        assert abs(total_cost - 0.0105) < 0.0001

    def test_calculate_cost_with_cache(self) -> None:
        """测试带缓存的成本计算"""
        result = UsageService.calculate_cost(
            input_tokens=1000,
            output_tokens=500,
            input_price_per_1m=3.0,
            output_price_per_1m=15.0,
            cache_creation_input_tokens=200,
            cache_read_input_tokens=300,
            cache_creation_price_per_1m=3.75,  # 1.25x input price
            cache_read_price_per_1m=0.3,  # 0.1x input price
        )

        (
            input_cost,
            output_cost,
            cache_creation_cost,
            cache_read_cost,
            cache_cost,
            request_cost,
            total_cost,
        ) = result

        # 验证缓存成本被计算
        assert cache_creation_cost > 0
        assert cache_read_cost > 0
        assert cache_cost == cache_creation_cost + cache_read_cost

    def test_calculate_cost_with_request_price(self) -> None:
        """测试按次计费"""
        result = UsageService.calculate_cost(
            input_tokens=1000,
            output_tokens=500,
            input_price_per_1m=3.0,
            output_price_per_1m=15.0,
            price_per_request=0.01,
        )

        (
            input_cost,
            output_cost,
            cache_creation_cost,
            cache_read_cost,
            cache_cost,
            request_cost,
            total_cost,
        ) = result

        assert request_cost == 0.01
        # Total 包含 request_cost
        assert total_cost == input_cost + output_cost + request_cost

    def test_calculate_cost_zero_tokens(self) -> None:
        """测试零 token 的成本计算"""
        result = UsageService.calculate_cost(
            input_tokens=0,
            output_tokens=0,
            input_price_per_1m=3.0,
            output_price_per_1m=15.0,
        )

        (
            input_cost,
            output_cost,
            cache_creation_cost,
            cache_read_cost,
            cache_cost,
            request_cost,
            total_cost,
        ) = result

        assert input_cost == 0
        assert output_cost == 0
        assert total_cost == 0


class TestQuotaCheck:
    """测试配额检查"""

    def test_check_user_quota_sufficient(self) -> None:
        """测试配额充足"""
        mock_user = MagicMock()
        mock_user.quota_usd = 100.0
        mock_user.used_usd = 30.0
        mock_user.role = MagicMock()
        mock_user.role.value = "user"

        mock_api_key = MagicMock()
        mock_api_key.is_standalone = False

        mock_db = MagicMock()

        is_ok, message = UsageService.check_user_quota(mock_db, mock_user, api_key=mock_api_key)

        assert is_ok is True

    def test_check_user_quota_exceeded(self) -> None:
        """测试配额超限（当有预估成本时）"""
        mock_user = MagicMock()
        mock_user.quota_usd = 100.0
        mock_user.used_usd = 99.0  # 接近配额上限
        mock_user.role = MagicMock()
        mock_user.role.value = "user"

        mock_api_key = MagicMock()
        mock_api_key.is_standalone = False

        mock_db = MagicMock()

        # 当预估成本超过剩余配额时应该返回 False
        is_ok, message = UsageService.check_user_quota(
            mock_db, mock_user, estimated_cost=5.0, api_key=mock_api_key
        )

        assert is_ok is False
        assert "配额" in message

    def test_check_user_quota_no_limit(self) -> None:
        """测试无配额限制（None）"""
        mock_user = MagicMock()
        mock_user.quota_usd = None
        mock_user.used_usd = 1000.0
        mock_user.role = MagicMock()
        mock_user.role.value = "user"

        mock_api_key = MagicMock()
        mock_api_key.is_standalone = False

        mock_db = MagicMock()

        is_ok, message = UsageService.check_user_quota(mock_db, mock_user, api_key=mock_api_key)

        assert is_ok is True

    def test_check_user_quota_admin_bypass(self) -> None:
        """测试管理员绕过配额检查"""
        from src.models.database import UserRole

        mock_user = MagicMock()
        mock_user.quota_usd = 0.0
        mock_user.used_usd = 1000.0
        mock_user.role = UserRole.ADMIN

        mock_api_key = MagicMock()
        mock_api_key.is_standalone = False

        mock_db = MagicMock()

        is_ok, message = UsageService.check_user_quota(mock_db, mock_user, api_key=mock_api_key)

        assert is_ok is True

    def test_check_standalone_api_key_balance(self) -> None:
        """测试独立 API Key 余额检查"""
        mock_user = MagicMock()
        mock_user.quota_usd = 0.0
        mock_user.used_usd = 0.0
        mock_user.role = MagicMock()
        mock_user.role.value = "user"

        mock_api_key = MagicMock()
        mock_api_key.is_standalone = True
        mock_api_key.current_balance_usd = 50.0
        mock_api_key.balance_used_usd = 10.0

        mock_db = MagicMock()

        is_ok, message = UsageService.check_user_quota(mock_db, mock_user, api_key=mock_api_key)

        assert is_ok is True

    def test_check_standalone_api_key_insufficient_balance(self) -> None:
        """测试独立 API Key 余额不足"""
        mock_user = MagicMock()
        mock_user.quota_usd = 100.0
        mock_user.used_usd = 0.0
        mock_user.role = MagicMock()
        mock_user.role.value = "user"

        mock_api_key = MagicMock()
        mock_api_key.is_standalone = True
        mock_api_key.current_balance_usd = 10.0
        mock_api_key.balance_used_usd = 9.0  # 剩余 $1

        mock_db = MagicMock()

        # 需要 mock ApiKeyService.get_remaining_balance
        with patch(
            "src.services.user.apikey.ApiKeyService.get_remaining_balance",
            return_value=1.0,
        ):
            # 预估成本 $5 超过剩余余额 $1
            is_ok, message = UsageService.check_user_quota(
                mock_db, mock_user, estimated_cost=5.0, api_key=mock_api_key
            )

        assert is_ok is False


class TestUsageStatistics:
    """测试用量统计查询

    注意：get_usage_summary 方法内部使用了数据库方言特定的日期函数，
    需要真实数据库或更复杂的 mock。这里只测试方法存在性。
    """

    def test_get_usage_summary_exists(self) -> None:
        """测试 get_usage_summary 方法存在"""
        assert hasattr(UsageService, "get_usage_summary")
        assert callable(getattr(UsageService, "get_usage_summary"))


class TestHelperMethods:
    """测试辅助方法"""

    @pytest.mark.asyncio
    async def test_get_rate_multiplier_and_free_tier_default(self) -> None:
        """测试默认费率倍数"""
        mock_db = MagicMock()
        # 模拟未找到 provider_api_key
        mock_db.query.return_value.filter.return_value.first.return_value = None

        rate_multiplier, is_free_tier = await UsageService._get_rate_multiplier_and_free_tier(
            mock_db, provider_api_key_id=None, provider_id=None
        )

        assert rate_multiplier == 1.0
        assert is_free_tier is False

    @pytest.mark.asyncio
    async def test_get_rate_multiplier_from_provider_api_key(self) -> None:
        """测试从 ProviderAPIKey 获取费率倍数"""
        mock_provider_api_key = MagicMock()
        mock_provider_api_key.rate_multiplier = 0.8

        mock_endpoint = MagicMock()
        mock_endpoint.provider_id = "provider-123"

        mock_provider = MagicMock()
        mock_provider.billing_type = "standard"

        mock_db = MagicMock()
        # 第一次查询返回 provider_api_key
        mock_db.query.return_value.filter.return_value.first.side_effect = [
            mock_provider_api_key,
            mock_endpoint,
            mock_provider,
        ]

        rate_multiplier, is_free_tier = await UsageService._get_rate_multiplier_and_free_tier(
            mock_db, provider_api_key_id="pak-123", provider_id=None
        )

        assert rate_multiplier == 0.8
        assert is_free_tier is False