"""
Test LLM Service

Tests for LLM integration and service functionality.
"""

from unittest.mock import Mock, patch

import pytest
import requests

from src.llm.llm_service import LLMConfig, LLMResponse, LLMService


class TestLLMConfig:
    """Test LLMConfig dataclass."""

    def test_llm_config_creation(self):
        """Test basic LLMConfig creation."""
        config = LLMConfig(
            provider="openrouter",
            api_key="test-key",
            model_name="test-model",
            base_url="https://test.com",
        )

        assert config.provider == "openrouter"
        assert config.api_key == "test-key"
        assert config.model_name == "test-model"
        assert config.base_url == "https://test.com"
        assert config.max_tokens == 1000  # Default value
        assert config.temperature == 0.1  # Default value


class TestLLMResponse:
    """Test LLMResponse dataclass."""

    def test_llm_response_creation(self):
        """Test basic LLMResponse creation."""
        response = LLMResponse(
            content="Test response",
            provider="openrouter",
            model="test-model",
            usage={"tokens": 100},
            response_time=1.5,
            success=True,
        )

        assert response.content == "Test response"
        assert response.provider == "openrouter"
        assert response.model == "test-model"
        assert response.usage == {"tokens": 100}
        assert response.response_time == 1.5
        assert response.success is True
        assert response.error_message is None


class TestLLMService:
    """Test LLMService functionality."""

    def test_initialization_with_configs(self):
        """Test LLMService initialization with configurations."""
        config = LLMConfig(
            provider="openrouter",
            api_key="test-key",
            model_name="test-model",
            base_url="https://test.com",
        )

        service = LLMService([config])

        assert len(service.configs) == 1
        assert service.configs[0] == config
        assert service.current_config_index == 0

    def test_initialization_empty_configs_raises_error(self):
        """Test that empty configs raise ValueError."""
        with pytest.raises(ValueError, match="At least one LLM configuration must be provided"):
            LLMService([])

    @patch.dict("os.environ", {"OPENROUTER_API_KEY": "test-openrouter-key"})
    def test_from_environment_with_openrouter_key(self):
        """Test creating service from environment with OpenRouter key."""
        service = LLMService.from_environment()

        assert len(service.configs) >= 1
        openrouter_config = next(
            (config for config in service.configs if config.provider == "openrouter"),
            None,
        )
        assert openrouter_config is not None
        assert openrouter_config.api_key == "test-openrouter-key"

    @patch.dict("os.environ", {"GROQ_API_KEY": "test-groq-key"})
    def test_from_environment_with_groq_key(self):
        """Test creating service from environment with Groq key."""
        service = LLMService.from_environment()

        assert len(service.configs) >= 1
        groq_config = next((config for config in service.configs if config.provider == "groq"), None)
        assert groq_config is not None
        assert groq_config.api_key == "test-groq-key"

    @patch.dict("os.environ", {}, clear=True)
    def test_from_environment_no_keys_raises_error(self):
        """Test that no environment keys raise ValueError."""
        with pytest.raises(ValueError, match="No LLM API keys found in environment"):
            LLMService.from_environment()

    @patch("requests.post")
    def test_successful_response_generation(self, mock_post):
        """Test successful response generation."""
        # Mock successful API response
        mock_response = Mock()
        mock_response.status_code = 200
        mock_response.json.return_value = {
            "choices": [{"message": {"content": "Test response content"}}],
            "usage": {"prompt_tokens": 50, "completion_tokens": 20},
        }
        mock_response.raise_for_status = Mock()
        mock_post.return_value = mock_response

        config = LLMConfig(
            provider="openrouter",
            api_key="test-key",
            model_name="test-model",
            base_url="https://api.openrouter.ai/api/v1",
        )
        service = LLMService([config])

        result = service.generate_response("Test prompt")

        assert result.success is True
        assert result.content == "Test response content"
        assert result.provider == "openrouter"
        assert result.model == "test-model"
        assert result.usage == {"prompt_tokens": 50, "completion_tokens": 20}
        assert result.response_time > 0

        # Verify API call
        mock_post.assert_called_once()
        args, kwargs = mock_post.call_args
        assert args[0] == "https://api.openrouter.ai/api/v1/chat/completions"
        assert kwargs["json"]["model"] == "test-model"
        assert kwargs["json"]["messages"][0]["content"] == "Test prompt"

    @patch("requests.post")
    def test_api_error_handling(self, mock_post):
        """Test handling of API errors."""
        # Mock API error
        mock_post.side_effect = requests.exceptions.RequestException("API Error")

        config = LLMConfig(
            provider="openrouter",
            api_key="test-key",
            model_name="test-model",
            base_url="https://api.openrouter.ai/api/v1",
        )
        service = LLMService([config])

        result = service.generate_response("Test prompt")

        assert result.success is False
        assert "API Error" in result.error_message
        assert result.content == ""
        assert result.provider == "none"  # When all providers fail, provider is "none"

    @patch("requests.post")
    def test_fallback_to_second_provider(self, mock_post):
        """Test fallback to second provider when first fails."""
        # Mock first provider failing 3 times (1 attempt + 2 retries), second succeeding
        first_error = requests.exceptions.RequestException("First provider error")

        second_response = Mock()
        second_response.status_code = 200
        second_response.json.return_value = {
            "choices": [{"message": {"content": "Second provider response"}}],
            "usage": {},
        }
        second_response.raise_for_status = Mock()

        # First provider fails 3 times, then second provider succeeds
        mock_post.side_effect = [first_error, first_error, first_error, second_response]

        config1 = LLMConfig(
            provider="openrouter",
            api_key="key1",
            model_name="model1",
            base_url="https://api1.com",
        )
        config2 = LLMConfig(
            provider="groq",
            api_key="key2",
            model_name="model2",
            base_url="https://api2.com",
        )

        service = LLMService([config1, config2])
        result = service.generate_response("Test prompt")

        assert result.success is True
        assert result.content == "Second provider response"
        assert result.provider == "groq"
        assert mock_post.call_count == 4  # 3 failed attempts on first provider + 1 success on second

    @patch("requests.post")
    def test_all_providers_fail(self, mock_post):
        """Test when all providers fail."""
        mock_post.side_effect = requests.exceptions.RequestException("All providers down")

        config1 = LLMConfig(provider="provider1", api_key="key1", model_name="model1", base_url="url1")
        config2 = LLMConfig(provider="provider2", api_key="key2", model_name="model2", base_url="url2")

        service = LLMService([config1, config2])
        result = service.generate_response("Test prompt")

        assert result.success is False
        assert "All providers failed" in result.error_message
        assert result.provider == "none"
        assert result.model == "none"

    @patch("requests.post")
    def test_retry_logic(self, mock_post):
        """Test retry logic for failed requests."""
        # First call fails, second succeeds
        first_response = Mock()
        first_response.side_effect = requests.exceptions.RequestException("Temporary error")

        second_response = Mock()
        second_response.status_code = 200
        second_response.json.return_value = {
            "choices": [{"message": {"content": "Success after retry"}}],
            "usage": {},
        }
        second_response.raise_for_status = Mock()

        mock_post.side_effect = [first_response.side_effect, second_response]

        config = LLMConfig(
            provider="openrouter",
            api_key="test-key",
            model_name="test-model",
            base_url="https://api.openrouter.ai/api/v1",
        )
        service = LLMService([config])

        result = service.generate_response("Test prompt", max_retries=1)

        assert result.success is True
        assert result.content == "Success after retry"
        assert mock_post.call_count == 2

    def test_get_available_providers(self):
        """Test getting list of available providers."""
        config1 = LLMConfig(provider="openrouter", api_key="key1", model_name="model1", base_url="url1")
        config2 = LLMConfig(provider="groq", api_key="key2", model_name="model2", base_url="url2")

        service = LLMService([config1, config2])
        providers = service.get_available_providers()

        assert providers == ["openrouter", "groq"]

    @patch("requests.post")
    def test_health_check(self, mock_post):
        """Test health check functionality."""
        # Mock successful health check
        mock_response = Mock()
        mock_response.status_code = 200
        mock_response.json.return_value = {
            "choices": [{"message": {"content": "OK"}}],
            "usage": {},
        }
        mock_response.raise_for_status = Mock()
        mock_post.return_value = mock_response

        config = LLMConfig(
            provider="openrouter",
            api_key="test-key",
            model_name="test-model",
            base_url="https://api.openrouter.ai/api/v1",
        )
        service = LLMService([config])

        health_status = service.health_check()

        assert "openrouter" in health_status
        assert health_status["openrouter"]["status"] == "healthy"
        assert health_status["openrouter"]["model"] == "test-model"
        assert health_status["openrouter"]["response_time"] > 0

    @patch("requests.post")
    def test_openrouter_specific_headers(self, mock_post):
        """Test that OpenRouter-specific headers are added."""
        mock_response = Mock()
        mock_response.status_code = 200
        mock_response.json.return_value = {
            "choices": [{"message": {"content": "Test"}}],
            "usage": {},
        }
        mock_response.raise_for_status = Mock()
        mock_post.return_value = mock_response

        config = LLMConfig(
            provider="openrouter",
            api_key="test-key",
            model_name="test-model",
            base_url="https://api.openrouter.ai/api/v1",
        )
        service = LLMService([config])

        service.generate_response("Test")

        # Check headers
        args, kwargs = mock_post.call_args
        headers = kwargs["headers"]
        assert "HTTP-Referer" in headers
        assert "X-Title" in headers
        assert headers["HTTP-Referer"] == "https://github.com/sethmcknight/msse-ai-engineering"