"""Tests for the AI provider abstraction layer."""

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

from app.core.ai_provider import (
    AIProvider,
    AnthropicProvider,
    GeminiProvider,
    get_ai_provider,
)
from app.core.config import settings


class TestGetAIProvider:
    """Tests for the get_ai_provider factory function."""

    def test_returns_gemini_when_configured(self):
        original_provider = settings.AI_PROVIDER
        original_key = settings.GOOGLE_AI_API_KEY
        try:
            settings.AI_PROVIDER = "gemini"
            settings.GOOGLE_AI_API_KEY = "test-gemini-key"
            provider = get_ai_provider()
            assert isinstance(provider, GeminiProvider)
        finally:
            settings.AI_PROVIDER = original_provider
            settings.GOOGLE_AI_API_KEY = original_key

    def test_returns_anthropic_when_configured(self):
        original_provider = settings.AI_PROVIDER
        original_key = settings.ANTHROPIC_API_KEY
        try:
            settings.AI_PROVIDER = "anthropic"
            settings.ANTHROPIC_API_KEY = "test-anthropic-key"
            provider = get_ai_provider()
            assert isinstance(provider, AnthropicProvider)
        finally:
            settings.AI_PROVIDER = original_provider
            settings.ANTHROPIC_API_KEY = original_key

    def test_fallback_to_anthropic_when_gemini_key_missing(self):
        original_provider = settings.AI_PROVIDER
        original_gemini_key = settings.GOOGLE_AI_API_KEY
        original_anthropic_key = settings.ANTHROPIC_API_KEY
        try:
            settings.AI_PROVIDER = "gemini"
            settings.GOOGLE_AI_API_KEY = None
            settings.ANTHROPIC_API_KEY = "test-anthropic-key"
            provider = get_ai_provider()
            assert isinstance(provider, AnthropicProvider)
        finally:
            settings.AI_PROVIDER = original_provider
            settings.GOOGLE_AI_API_KEY = original_gemini_key
            settings.ANTHROPIC_API_KEY = original_anthropic_key

    def test_fallback_to_gemini_when_anthropic_key_missing(self):
        original_provider = settings.AI_PROVIDER
        original_gemini_key = settings.GOOGLE_AI_API_KEY
        original_anthropic_key = settings.ANTHROPIC_API_KEY
        try:
            settings.AI_PROVIDER = "anthropic"
            settings.ANTHROPIC_API_KEY = None
            settings.GOOGLE_AI_API_KEY = "test-gemini-key"
            provider = get_ai_provider()
            assert isinstance(provider, GeminiProvider)
        finally:
            settings.AI_PROVIDER = original_provider
            settings.GOOGLE_AI_API_KEY = original_gemini_key
            settings.ANTHROPIC_API_KEY = original_anthropic_key

    def test_raises_when_no_provider_configured(self):
        original_provider = settings.AI_PROVIDER
        original_gemini_key = settings.GOOGLE_AI_API_KEY
        original_anthropic_key = settings.ANTHROPIC_API_KEY
        try:
            settings.AI_PROVIDER = "gemini"
            settings.GOOGLE_AI_API_KEY = None
            settings.ANTHROPIC_API_KEY = None
            with pytest.raises(RuntimeError, match="No AI provider configured"):
                get_ai_provider()
        finally:
            settings.AI_PROVIDER = original_provider
            settings.GOOGLE_AI_API_KEY = original_gemini_key
            settings.ANTHROPIC_API_KEY = original_anthropic_key


class TestAnthropicProvider:
    """Tests for AnthropicProvider.generate_json."""

    @pytest.mark.asyncio
    async def test_generate_json(self):
        provider = AnthropicProvider(
            api_key="test-key", model="claude-haiku-4-5-20251001", timeout=30
        )

        mock_response = MagicMock()
        mock_response.content = [MagicMock(type="text", text='{"result": "ok"}')]
        mock_response.stop_reason = "end_turn"
        mock_response.usage = MagicMock(input_tokens=100, output_tokens=50)

        mock_client = AsyncMock()
        mock_client.messages.create = AsyncMock(return_value=mock_response)

        with patch("anthropic.AsyncAnthropic", return_value=mock_client):
            text, input_tokens, output_tokens = await provider.generate_json(
                system_prompt="You are a helper.",
                messages=[{"role": "user", "content": "Hello"}],
                max_tokens=1024,
            )

        assert text == '{"result": "ok"}'
        assert input_tokens == 100
        assert output_tokens == 50

        mock_client.messages.create.assert_called_once_with(
            model="claude-haiku-4-5-20251001",
            max_tokens=1024,
            system="You are a helper.",
            messages=[{"role": "user", "content": "Hello"}],
        )

    @pytest.mark.asyncio
    async def test_generate_json_skips_non_text_blocks(self):
        """A leading non-text block (e.g. thinking) is skipped; the first
        text block's text is returned instead of content[0].text."""
        from app.core import ai_provider

        ai_provider._anthropic_clients.clear()

        provider = AnthropicProvider(
            api_key="skip-key", model="claude-sonnet-4-6", timeout=31
        )

        thinking_block = MagicMock(type="thinking", thinking="hmm...")
        text_block = MagicMock(type="text", text='{"ok": 1}')
        mock_response = MagicMock()
        mock_response.content = [thinking_block, text_block]
        mock_response.stop_reason = "end_turn"
        mock_response.usage = MagicMock(input_tokens=10, output_tokens=5)

        mock_client = AsyncMock()
        mock_client.messages.create = AsyncMock(return_value=mock_response)

        with patch("anthropic.AsyncAnthropic", return_value=mock_client):
            text, _, _ = await provider.generate_json(
                system_prompt="You are a helper.",
                messages=[{"role": "user", "content": "Hi"}],
            )

        assert text == '{"ok": 1}'

    @pytest.mark.asyncio
    async def test_generate_json_raises_when_no_text_block(self):
        """A response with no text block (e.g. a bare refusal) raises a clear
        error instead of returning a non-text block's attributes."""
        from app.core import ai_provider

        ai_provider._anthropic_clients.clear()

        provider = AnthropicProvider(
            api_key="empty-key", model="claude-sonnet-4-6", timeout=32
        )

        mock_response = MagicMock()
        mock_response.content = [MagicMock(type="thinking", thinking="...")]
        mock_response.stop_reason = "refusal"
        mock_response.usage = MagicMock(input_tokens=10, output_tokens=0)

        mock_client = AsyncMock()
        mock_client.messages.create = AsyncMock(return_value=mock_response)

        with patch("anthropic.AsyncAnthropic", return_value=mock_client):
            with pytest.raises(ValueError, match="no text block"):
                await provider.generate_json(
                    system_prompt="You are a helper.",
                    messages=[{"role": "user", "content": "Hi"}],
                )

    @pytest.mark.asyncio
    async def test_generate_json_logs_warning_on_truncation(self, caplog):
        """When stop_reason is max_tokens, a warning is logged (truncation
        signal) and the partial text is still returned."""
        import logging

        from app.core import ai_provider

        ai_provider._anthropic_clients.clear()

        provider = AnthropicProvider(
            api_key="trunc-key", model="claude-sonnet-4-6", timeout=33
        )

        text_block = MagicMock(type="text", text='{"partial": tr')
        mock_response = MagicMock()
        mock_response.content = [text_block]
        mock_response.stop_reason = "max_tokens"
        mock_response.usage = MagicMock(input_tokens=10, output_tokens=4096)

        mock_client = AsyncMock()
        mock_client.messages.create = AsyncMock(return_value=mock_response)

        with patch("anthropic.AsyncAnthropic", return_value=mock_client):
            with caplog.at_level(logging.WARNING, logger="app.core.ai_provider"):
                text, _, _ = await provider.generate_json(
                    system_prompt="You are a helper.",
                    messages=[{"role": "user", "content": "Hi"}],
                )

        assert text == '{"partial": tr'
        truncation_records = [
            r for r in caplog.records if getattr(r, "stop_reason", None) == "max_tokens"
        ]
        assert truncation_records, "expected a warning record for max_tokens truncation"

    @pytest.mark.asyncio
    async def test_generate_json_passes_output_config_when_schema_given(self):
        """When a JSON schema is supplied, it is forwarded as
        output_config.format so the API constrains the response shape."""
        from app.core import ai_provider

        ai_provider._anthropic_clients.clear()

        provider = AnthropicProvider(
            api_key="schema-key", model="claude-sonnet-4-6", timeout=34
        )

        mock_response = MagicMock()
        mock_response.content = [MagicMock(type="text", text='{"title": "x"}')]
        mock_response.stop_reason = "end_turn"
        mock_response.usage = MagicMock(input_tokens=10, output_tokens=5)

        mock_client = AsyncMock()
        mock_client.messages.create = AsyncMock(return_value=mock_response)

        schema = {
            "type": "object",
            "properties": {"title": {"type": "string"}},
            "required": ["title"],
            "additionalProperties": False,
        }

        with patch("anthropic.AsyncAnthropic", return_value=mock_client):
            await provider.generate_json(
                system_prompt="You are a helper.",
                messages=[{"role": "user", "content": "Hi"}],
                max_tokens=512,
                schema=schema,
            )

        mock_client.messages.create.assert_called_once_with(
            model="claude-sonnet-4-6",
            max_tokens=512,
            system="You are a helper.",
            messages=[{"role": "user", "content": "Hi"}],
            output_config={"format": {"type": "json_schema", "schema": schema}},
        )

    @pytest.mark.asyncio
    async def test_generate_json_no_output_config_when_schema_none(self):
        """With no schema, output_config is not sent (backward compatible)."""
        from app.core import ai_provider

        ai_provider._anthropic_clients.clear()

        provider = AnthropicProvider(
            api_key="noschema-key", model="claude-sonnet-4-6", timeout=35
        )

        mock_response = MagicMock()
        mock_response.content = [MagicMock(type="text", text="{}")]
        mock_response.stop_reason = "end_turn"
        mock_response.usage = MagicMock(input_tokens=1, output_tokens=1)

        mock_client = AsyncMock()
        mock_client.messages.create = AsyncMock(return_value=mock_response)

        with patch("anthropic.AsyncAnthropic", return_value=mock_client):
            await provider.generate_json(
                system_prompt="You are a helper.",
                messages=[{"role": "user", "content": "Hi"}],
            )

        _, call_kwargs = mock_client.messages.create.call_args
        assert "output_config" not in call_kwargs


class TestGeminiProvider:
    """Tests for GeminiProvider.generate_json."""

    @pytest.mark.asyncio
    async def test_generate_json(self):
        provider = GeminiProvider(api_key="test-key", model="gemini-2.5-flash")

        mock_usage = MagicMock()
        mock_usage.prompt_token_count = 80
        mock_usage.candidates_token_count = 40

        mock_response = MagicMock()
        mock_response.text = '{"answer": 42}'
        mock_response.usage_metadata = mock_usage

        mock_client = MagicMock()
        mock_client.aio.models.generate_content = AsyncMock(
            return_value=mock_response
        )

        mock_genai_module = MagicMock()
        mock_genai_module.Client.return_value = mock_client

        mock_types = MagicMock()
        mock_types.Content.side_effect = lambda **kw: kw
        mock_types.Part.side_effect = lambda **kw: kw
        mock_types.GenerateContentConfig.side_effect = lambda **kw: kw

        mock_google = MagicMock()
        mock_google.genai = mock_genai_module
        mock_genai_module.types = mock_types

        with patch.dict(sys.modules, {
            "google": mock_google,
            "google.genai": mock_genai_module,
            "google.genai.types": mock_types,
        }):
            text, input_tokens, output_tokens = await provider.generate_json(
                system_prompt="Generate JSON.",
                messages=[
                    {"role": "user", "content": "Give me data"},
                    {"role": "assistant", "content": "Here it is"},
                    {"role": "user", "content": "More please"},
                ],
                max_tokens=2048,
            )

        assert text == '{"answer": 42}'
        assert input_tokens == 80
        assert output_tokens == 40

        mock_client.aio.models.generate_content.assert_called_once()

    @pytest.mark.asyncio
    async def test_generate_json_accepts_and_ignores_schema(self):
        """Gemini accepts the schema kwarg (interface parity) and still
        returns JSON; it does not error on the param."""
        provider = GeminiProvider(api_key="test-key", model="gemini-2.5-flash")

        mock_usage = MagicMock()
        mock_usage.prompt_token_count = 5
        mock_usage.candidates_token_count = 3

        mock_response = MagicMock()
        mock_response.text = '{"answer": 1}'
        mock_response.usage_metadata = mock_usage

        mock_client = MagicMock()
        mock_client.aio.models.generate_content = AsyncMock(return_value=mock_response)

        mock_genai_module = MagicMock()
        mock_genai_module.Client.return_value = mock_client

        mock_types = MagicMock()
        mock_types.Content.side_effect = lambda **kw: kw
        mock_types.Part.side_effect = lambda **kw: kw
        mock_types.GenerateContentConfig.side_effect = lambda **kw: kw

        mock_google = MagicMock()
        mock_google.genai = mock_genai_module
        mock_genai_module.types = mock_types

        with patch.dict(sys.modules, {
            "google": mock_google,
            "google.genai": mock_genai_module,
            "google.genai.types": mock_types,
        }):
            text, _, _ = await provider.generate_json(
                system_prompt="Generate JSON.",
                messages=[{"role": "user", "content": "data"}],
                schema={"type": "object"},
            )

        assert text == '{"answer": 1}'

    @pytest.mark.asyncio
    async def test_generate_json_handles_none_usage(self):
        """Token counts default to 0 when usage_metadata attributes are None."""
        provider = GeminiProvider(api_key="test-key", model="gemini-2.5-flash")

        mock_usage = MagicMock(spec=[])  # No attributes at all
        mock_response = MagicMock()
        mock_response.text = "{}"
        mock_response.usage_metadata = mock_usage

        mock_client = MagicMock()
        mock_client.aio.models.generate_content = AsyncMock(
            return_value=mock_response
        )

        mock_genai_module = MagicMock()
        mock_genai_module.Client.return_value = mock_client

        mock_types = MagicMock()
        mock_types.Content.side_effect = lambda **kw: kw
        mock_types.Part.side_effect = lambda **kw: kw
        mock_types.GenerateContentConfig.side_effect = lambda **kw: kw

        mock_google = MagicMock()
        mock_google.genai = mock_genai_module
        mock_genai_module.types = mock_types

        with patch.dict(sys.modules, {
            "google": mock_google,
            "google.genai": mock_genai_module,
            "google.genai.types": mock_types,
        }):
            text, input_tokens, output_tokens = await provider.generate_json(
                system_prompt="test",
                messages=[{"role": "user", "content": "test"}],
            )

        assert text == "{}"
        assert input_tokens == 0
        assert output_tokens == 0