import pytest
from unittest.mock import patch, MagicMock

from app.services.llm import (
    LLMProvider,
    ModelTier,
    detect_provider,
    get_chat_model,
    _resolve_model_name,
    _DEFAULTS,
)


class TestDetectProvider:
    def test_anthropic_preferred_when_both_keys_set(self):
        with patch("app.services.llm.get_settings") as mock:
            mock.return_value = MagicMock(
                anthropic_api_key="sk-ant-xxx", openai_api_key="sk-xxx"
            )
            assert detect_provider() == LLMProvider.ANTHROPIC

    def test_anthropic_when_only_anthropic_key(self):
        with patch("app.services.llm.get_settings") as mock:
            mock.return_value = MagicMock(anthropic_api_key="sk-ant-xxx", openai_api_key="")
            assert detect_provider() == LLMProvider.ANTHROPIC

    def test_openai_when_only_openai_key(self):
        with patch("app.services.llm.get_settings") as mock:
            mock.return_value = MagicMock(anthropic_api_key="", openai_api_key="sk-xxx")
            assert detect_provider() == LLMProvider.OPENAI

    def test_raises_when_no_keys(self):
        with patch("app.services.llm.get_settings") as mock:
            mock.return_value = MagicMock(anthropic_api_key="", openai_api_key="")
            with pytest.raises(RuntimeError, match="No LLM API key configured"):
                detect_provider()


class TestResolveModelName:
    def test_defaults_anthropic_fast(self):
        with patch("app.services.llm.get_settings") as mock:
            mock.return_value = MagicMock(llm_fast_model="", llm_strong_model="")
            name = _resolve_model_name(LLMProvider.ANTHROPIC, ModelTier.FAST)
            assert name == _DEFAULTS[LLMProvider.ANTHROPIC][ModelTier.FAST]

    def test_defaults_openai_strong(self):
        with patch("app.services.llm.get_settings") as mock:
            mock.return_value = MagicMock(llm_fast_model="", llm_strong_model="")
            name = _resolve_model_name(LLMProvider.OPENAI, ModelTier.STRONG)
            assert name == _DEFAULTS[LLMProvider.OPENAI][ModelTier.STRONG]

    def test_override_fast_model(self):
        with patch("app.services.llm.get_settings") as mock:
            mock.return_value = MagicMock(llm_fast_model="custom-fast", llm_strong_model="")
            name = _resolve_model_name(LLMProvider.ANTHROPIC, ModelTier.FAST)
            assert name == "custom-fast"

    def test_override_strong_model(self):
        with patch("app.services.llm.get_settings") as mock:
            mock.return_value = MagicMock(llm_fast_model="", llm_strong_model="custom-strong")
            name = _resolve_model_name(LLMProvider.OPENAI, ModelTier.STRONG)
            assert name == "custom-strong"


class TestGetChatModel:
    @patch("app.services.llm.get_settings")
    def test_returns_anthropic_model(self, mock_settings):
        mock_settings.return_value = MagicMock(
            anthropic_api_key="sk-ant-xxx",
            openai_api_key="",
            llm_fast_model="",
            llm_strong_model="",
        )
        model = get_chat_model(tier=ModelTier.STRONG)
        assert type(model).__name__ == "ChatAnthropic"

    @patch("app.services.llm.get_settings")
    def test_returns_openai_model(self, mock_settings):
        mock_settings.return_value = MagicMock(
            anthropic_api_key="",
            openai_api_key="sk-xxx",
            llm_fast_model="",
            llm_strong_model="",
        )
        model = get_chat_model(tier=ModelTier.FAST)
        assert type(model).__name__ == "ChatOpenAI"

    @patch("app.services.llm.get_settings")
    def test_explicit_provider_override(self, mock_settings):
        mock_settings.return_value = MagicMock(
            anthropic_api_key="sk-ant-xxx",
            openai_api_key="sk-xxx",
            llm_fast_model="",
            llm_strong_model="",
        )
        model = get_chat_model(tier=ModelTier.FAST, provider=LLMProvider.OPENAI)
        assert type(model).__name__ == "ChatOpenAI"

    @patch("app.services.llm.get_settings")
    def test_custom_temperature(self, mock_settings):
        mock_settings.return_value = MagicMock(
            anthropic_api_key="sk-ant-xxx",
            openai_api_key="",
            llm_fast_model="",
            llm_strong_model="",
        )
        model = get_chat_model(tier=ModelTier.STRONG, temperature=0.7)
        assert model.temperature == 0.7