from unittest.mock import AsyncMock, MagicMock, patch

import pytest
from fastapi import HTTPException

from api.dependencies import (
    cleanup_provider,
    get_provider,
    get_provider_for_type,
    get_settings,
)
from config.nim import NimSettings
from providers.lmstudio import LMStudioProvider
from providers.nvidia_nim import NvidiaNimProvider
from providers.open_router import OpenRouterProvider


def _make_mock_settings(**overrides):
    """Create a mock settings object with all required fields for get_provider()."""
    mock = MagicMock()
    mock.model = "nvidia_nim/meta/llama3"
    mock.provider_type = "nvidia_nim"
    mock.nvidia_nim_api_key = "test_key"
    mock.provider_rate_limit = 40
    mock.provider_rate_window = 60
    mock.provider_max_concurrency = 5
    mock.open_router_api_key = "test_openrouter_key"
    mock.lm_studio_base_url = "http://localhost:1234/v1"
    mock.nim = NimSettings()
    mock.http_read_timeout = 300.0
    mock.http_write_timeout = 10.0
    mock.http_connect_timeout = 2.0
    for key, value in overrides.items():
        setattr(mock, key, value)
    return mock


@pytest.fixture(autouse=True)
def reset_provider():
    """Reset the global _providers registry between tests."""
    import api.dependencies

    saved = api.dependencies._providers
    api.dependencies._providers = {}
    yield
    api.dependencies._providers = saved


@pytest.mark.asyncio
async def test_get_provider_singleton():
    with patch("api.dependencies.get_settings") as mock_settings:
        mock_settings.return_value = _make_mock_settings()

        p1 = get_provider()
        p2 = get_provider()

        assert isinstance(p1, NvidiaNimProvider)
        assert p1 is p2


@pytest.mark.asyncio
async def test_get_settings():
    settings = get_settings()
    assert settings is not None
    # Verify it calls the internal _get_settings
    with patch("api.dependencies._get_settings") as mock_get:
        get_settings()
        mock_get.assert_called_once()


@pytest.mark.asyncio
async def test_cleanup_provider():
    with patch("api.dependencies.get_settings") as mock_settings:
        mock_settings.return_value = _make_mock_settings()

        provider = get_provider()
        assert isinstance(provider, NvidiaNimProvider)
        provider._client = AsyncMock()

        await cleanup_provider()

        provider._client.aclose.assert_called_once()


@pytest.mark.asyncio
async def test_cleanup_provider_no_client():
    with patch("api.dependencies.get_settings") as mock_settings:
        mock_settings.return_value = _make_mock_settings()

        provider = get_provider()
        if hasattr(provider, "_client"):
            del provider._client

        await cleanup_provider()
        # Should not raise


@pytest.mark.asyncio
async def test_get_provider_open_router():
    """Test that provider_type=open_router returns OpenRouterProvider."""
    with patch("api.dependencies.get_settings") as mock_settings:
        mock_settings.return_value = _make_mock_settings(provider_type="open_router")

        provider = get_provider()

        assert isinstance(provider, OpenRouterProvider)
        assert provider._base_url == "https://openrouter.ai/api/v1"
        assert provider._api_key == "test_openrouter_key"


@pytest.mark.asyncio
async def test_get_provider_lmstudio():
    """Test that provider_type=lmstudio returns LMStudioProvider."""
    with patch("api.dependencies.get_settings") as mock_settings:
        mock_settings.return_value = _make_mock_settings(provider_type="lmstudio")

        provider = get_provider()

        assert isinstance(provider, LMStudioProvider)
        assert provider._base_url == "http://localhost:1234/v1"


@pytest.mark.asyncio
async def test_get_provider_lmstudio_uses_lm_studio_base_url():
    """LM Studio provider uses lm_studio_base_url from settings."""
    with patch("api.dependencies.get_settings") as mock_settings:
        mock_settings.return_value = _make_mock_settings(
            provider_type="lmstudio",
            lm_studio_base_url="http://custom:9999/v1",
        )

        provider = get_provider()

        assert isinstance(provider, LMStudioProvider)
        assert provider._base_url == "http://custom:9999/v1"


@pytest.mark.asyncio
async def test_get_provider_passes_http_timeouts_from_settings():
    """Provider receives http timeouts from settings when creating client."""
    with (
        patch("api.dependencies.get_settings") as mock_settings,
        patch("providers.openai_compat.AsyncOpenAI") as mock_openai,
    ):
        mock_settings.return_value = _make_mock_settings(
            http_read_timeout=600.0,
            http_write_timeout=20.0,
            http_connect_timeout=5.0,
        )
        provider = get_provider()
        assert isinstance(provider, NvidiaNimProvider)
        call_kwargs = mock_openai.call_args[1]
        timeout = call_kwargs["timeout"]
        assert timeout.read == 600.0
        assert timeout.write == 20.0
        assert timeout.connect == 5.0


@pytest.mark.asyncio
async def test_get_provider_nvidia_nim_missing_api_key():
    """NVIDIA NIM with empty API key raises HTTPException 503."""
    with patch("api.dependencies.get_settings") as mock_settings:
        mock_settings.return_value = _make_mock_settings(nvidia_nim_api_key="")

        with pytest.raises(HTTPException) as exc_info:
            get_provider()

        assert exc_info.value.status_code == 503
        assert "NVIDIA_NIM_API_KEY" in exc_info.value.detail
        assert "build.nvidia.com" in exc_info.value.detail


@pytest.mark.asyncio
async def test_get_provider_nvidia_nim_whitespace_only_api_key():
    """NVIDIA NIM with whitespace-only API key raises HTTPException 503."""
    with patch("api.dependencies.get_settings") as mock_settings:
        mock_settings.return_value = _make_mock_settings(nvidia_nim_api_key="   ")

        with pytest.raises(HTTPException) as exc_info:
            get_provider()

        assert exc_info.value.status_code == 503
        assert "NVIDIA_NIM_API_KEY" in exc_info.value.detail


@pytest.mark.asyncio
async def test_get_provider_open_router_missing_api_key():
    """OpenRouter with empty API key raises HTTPException 503."""
    with patch("api.dependencies.get_settings") as mock_settings:
        mock_settings.return_value = _make_mock_settings(
            provider_type="open_router",
            open_router_api_key="",
        )

        with pytest.raises(HTTPException) as exc_info:
            get_provider()

        assert exc_info.value.status_code == 503
        assert "OPENROUTER_API_KEY" in exc_info.value.detail
        assert "openrouter.ai" in exc_info.value.detail


@pytest.mark.asyncio
async def test_get_provider_unknown_type():
    """Test that unknown provider_type raises ValueError."""
    with patch("api.dependencies.get_settings") as mock_settings:
        mock_settings.return_value = _make_mock_settings(provider_type="unknown")

        with pytest.raises(ValueError, match="Unknown provider_type"):
            get_provider()


@pytest.mark.asyncio
async def test_cleanup_provider_aclose_raises():
    """cleanup_provider handles aclose() raising an exception."""
    with patch("api.dependencies.get_settings") as mock_settings:
        mock_settings.return_value = _make_mock_settings()

        provider = get_provider()
        assert isinstance(provider, NvidiaNimProvider)
        provider._client = AsyncMock()
        provider._client.aclose = AsyncMock(side_effect=RuntimeError("cleanup failed"))

        # Should propagate the error
        with pytest.raises(RuntimeError, match="cleanup failed"):
            await cleanup_provider()


# --- Provider Registry Tests ---


@pytest.mark.asyncio
async def test_get_provider_for_type_caches():
    """get_provider_for_type returns cached provider on second call."""
    with patch("api.dependencies.get_settings") as mock_settings:
        mock_settings.return_value = _make_mock_settings()

        p1 = get_provider_for_type("nvidia_nim")
        p2 = get_provider_for_type("nvidia_nim")

        assert p1 is p2
        assert isinstance(p1, NvidiaNimProvider)


@pytest.mark.asyncio
async def test_get_provider_for_type_different_types():
    """get_provider_for_type creates separate providers per type."""
    with patch("api.dependencies.get_settings") as mock_settings:
        mock_settings.return_value = _make_mock_settings()

        nim = get_provider_for_type("nvidia_nim")
        lmstudio = get_provider_for_type("lmstudio")

        assert isinstance(nim, NvidiaNimProvider)
        assert isinstance(lmstudio, LMStudioProvider)
        assert nim is not lmstudio


@pytest.mark.asyncio
async def test_get_provider_for_type_missing_key_raises_503():
    """get_provider_for_type raises HTTPException 503 for missing API key."""
    with patch("api.dependencies.get_settings") as mock_settings:
        mock_settings.return_value = _make_mock_settings(open_router_api_key="")

        with pytest.raises(HTTPException) as exc_info:
            get_provider_for_type("open_router")

        assert exc_info.value.status_code == 503
        assert "OPENROUTER_API_KEY" in exc_info.value.detail


@pytest.mark.asyncio
async def test_cleanup_provider_cleans_all():
    """cleanup_provider cleans up all providers in the registry."""
    with patch("api.dependencies.get_settings") as mock_settings:
        mock_settings.return_value = _make_mock_settings()

        nim = get_provider_for_type("nvidia_nim")
        lmstudio = get_provider_for_type("lmstudio")

        assert isinstance(nim, NvidiaNimProvider)
        assert isinstance(lmstudio, LMStudioProvider)

        nim._client = AsyncMock()
        lmstudio._client = AsyncMock()

        await cleanup_provider()

        nim._client.aclose.assert_called_once()
        lmstudio._client.aclose.assert_called_once()