"""Integration tests for RAG pipeline with OpenAI/GitHub Models API.

These tests validate the complete semantic search and MCP sampling flow using:
1. OpenAI embeddings for semantic search
2. MCP sampling for answer generation
3. Pre-indexed Nextcloud User Manual as the knowledge base

Environment Variables:
    OPENAI_API_KEY: OpenAI API key or GitHub token for models.github.ai
    OPENAI_BASE_URL: Base URL override (e.g., "https://models.github.ai/inference")
    OPENAI_EMBEDDING_MODEL: Embedding model (default: "text-embedding-3-small")
    OPENAI_GENERATION_MODEL: Generation model for sampling (default: "gpt-4o-mini")

For GitHub CI, set:
    OPENAI_API_KEY: ${{ secrets.GITHUB_TOKEN }}
    OPENAI_BASE_URL: https://models.github.ai/inference
    OPENAI_EMBEDDING_MODEL: openai/text-embedding-3-small
    OPENAI_GENERATION_MODEL: openai/gpt-4o-mini

Prerequisites:
    - Nextcloud User Manual indexed in Qdrant (via vector sync)
    - VECTOR_SYNC_ENABLED=true on the MCP server
"""

import json
import os
from pathlib import Path
from typing import Any, AsyncGenerator

import pytest
from mcp import ClientSession

from nextcloud_mcp_server.providers.openai import OpenAIProvider
from tests.conftest import create_mcp_client_session
from tests.integration.sampling_support import create_openai_sampling_callback

# Skip all tests if OpenAI API key not configured
pytestmark = [
    pytest.mark.integration,
    pytest.mark.skipif(
        not os.getenv("OPENAI_API_KEY"),
        reason="OPENAI_API_KEY not set - skipping OpenAI RAG tests",
    ),
]

# Ground truth fixture path
FIXTURES_DIR = Path(__file__).parent / "fixtures"
GROUND_TRUTH_FILE = FIXTURES_DIR / "nextcloud_manual_ground_truth.json"


@pytest.fixture(scope="module")
def ground_truth_qa():
    """Load ground truth Q&A pairs for the Nextcloud manual."""
    if not GROUND_TRUTH_FILE.exists():
        pytest.skip(f"Ground truth file not found: {GROUND_TRUTH_FILE}")

    with open(GROUND_TRUTH_FILE) as f:
        return json.load(f)


@pytest.fixture(scope="module")
async def openai_provider():
    """OpenAI provider configured from environment (embeddings only)."""
    api_key = os.getenv("OPENAI_API_KEY")
    base_url = os.getenv("OPENAI_BASE_URL")
    embedding_model = os.getenv("OPENAI_EMBEDDING_MODEL", "text-embedding-3-small")

    provider = OpenAIProvider(
        api_key=api_key,
        base_url=base_url,
        embedding_model=embedding_model,
        generation_model=None,  # Embeddings only
    )

    yield provider
    await provider.close()


@pytest.fixture(scope="module")
async def openai_generation_provider():
    """OpenAI provider configured for text generation (for sampling callback)."""
    api_key = os.getenv("OPENAI_API_KEY")
    base_url = os.getenv("OPENAI_BASE_URL")
    generation_model = os.getenv("OPENAI_GENERATION_MODEL", "gpt-4o-mini")

    # For GitHub Models API, use the prefixed model name
    if base_url and "models.github.ai" in base_url:
        if not generation_model.startswith("openai/"):
            generation_model = f"openai/{generation_model}"

    provider = OpenAIProvider(
        api_key=api_key,
        base_url=base_url,
        embedding_model=None,  # Generation only
        generation_model=generation_model,
    )

    yield provider
    await provider.close()


@pytest.fixture(scope="module")
async def nc_mcp_client_with_sampling(
    anyio_backend, openai_generation_provider
) -> AsyncGenerator[ClientSession, Any]:
    """MCP client with OpenAI-based sampling support.

    This fixture creates an MCP client that can handle sampling requests
    from the server using OpenAI for text generation.
    """
    sampling_callback = create_openai_sampling_callback(openai_generation_provider)

    async for session in create_mcp_client_session(
        url="http://localhost:8000/mcp",
        client_name="OpenAI Sampling MCP",
        sampling_callback=sampling_callback,
    ):
        yield session


async def test_openai_embeddings_work(openai_provider: OpenAIProvider):
    """Test that OpenAI embeddings can be generated."""
    embedding = await openai_provider.embed("test query about Nextcloud")

    assert isinstance(embedding, list)
    assert len(embedding) > 0
    assert all(isinstance(x, float) for x in embedding)
    # OpenAI embedding dimensions: 1536 (small) or 3072 (large)
    assert len(embedding) in [1536, 3072]


async def test_semantic_search_retrieval(nc_mcp_client, ground_truth_qa):
    """Test that semantic search retrieves relevant documents from the manual.

    This tests the retrieval component of RAG - ensuring that queries
    return relevant chunks from the indexed Nextcloud User Manual.
    """
    # Use first query from ground truth
    test_case = ground_truth_qa[0]  # 2FA question
    query = test_case["query"]
    expected_topics = test_case["expected_topics"]

    # Perform semantic search via MCP tool
    result = await nc_mcp_client.call_tool(
        "nc_semantic_search",
        arguments={
            "query": query,
            "limit": 5,
            "score_threshold": 0.0,
        },
    )

    assert result.isError is False, f"Tool call failed: {result}"
    data = result.structuredContent

    # Verify we got results
    assert data["success"] is True
    assert data["total_found"] > 0, f"No results for query: {query}"
    assert len(data["results"]) > 0

    # Check that at least one result contains expected topic keywords
    all_excerpts = " ".join([r["excerpt"].lower() for r in data["results"]])
    topic_found = any(topic.lower() in all_excerpts for topic in expected_topics)
    assert topic_found, (
        f"Expected topics {expected_topics} not found in results for query: {query}"
    )


async def test_semantic_search_answer_with_sampling(
    nc_mcp_client_with_sampling, ground_truth_qa
):
    """Test semantic search with MCP sampling for answer generation.

    This tests the full RAG pipeline:
    1. Semantic search retrieves relevant documents
    2. MCP sampling generates an answer from the retrieved context
    3. OpenAI generates the answer via the sampling callback

    Uses nc_mcp_client_with_sampling which has OpenAI-based sampling enabled.
    """
    # Use the 2FA question - has clear expected answer
    test_case = ground_truth_qa[0]
    query = test_case["query"]

    result = await nc_mcp_client_with_sampling.call_tool(
        "nc_semantic_search_answer",
        arguments={
            "query": query,
            "limit": 5,
            "score_threshold": 0.0,
            "max_answer_tokens": 300,
        },
    )

    assert result.isError is False, f"Tool call failed: {result}"
    data = result.structuredContent

    # Verify response structure
    assert data["success"] is True
    assert "query" in data
    assert "generated_answer" in data
    assert "sources" in data
    assert "search_method" in data

    # Check for either successful sampling or graceful fallback
    fallback_methods = {
        "semantic_sampling_unsupported",
        "semantic_sampling_user_declined",
        "semantic_sampling_timeout",
        "semantic_sampling_mcp_error",
        "semantic_sampling_fallback",
    }

    if data["search_method"] in fallback_methods:
        # Fallback mode - verify sources still returned
        assert len(data["sources"]) > 0, "Expected sources even in fallback mode"
        pytest.skip(
            f"MCP sampling not available (method: {data['search_method']}), "
            f"but retrieval succeeded with {len(data['sources'])} sources"
        )
    else:
        # Successful sampling - verify answer quality
        assert data["search_method"] == "semantic_sampling"
        assert data["generated_answer"] is not None
        assert len(data["generated_answer"]) > 50  # Non-trivial answer

        # Check answer contains relevant content
        answer_lower = data["generated_answer"].lower()
        assert any(
            keyword in answer_lower
            for keyword in ["two-factor", "2fa", "authentication", "password"]
        ), f"Answer doesn't seem relevant to query: {data['generated_answer'][:200]}"


@pytest.mark.parametrize(
    "qa_index,min_expected_results",
    [
        (0, 1),  # 2FA question
        (1, 1),  # File quotas question
        (2, 1),  # Linux installation question
        (3, 1),  # Windows requirements question
        (4, 1),  # Client apps with 2FA question
    ],
)
async def test_retrieval_quality_all_queries(
    nc_mcp_client, ground_truth_qa, qa_index, min_expected_results
):
    """Test retrieval quality for all ground truth queries.

    Validates that each query returns at least the minimum expected
    number of relevant results from the Nextcloud manual.
    """
    if qa_index >= len(ground_truth_qa):
        pytest.skip(f"Ground truth index {qa_index} not available")

    test_case = ground_truth_qa[qa_index]
    query = test_case["query"]

    result = await nc_mcp_client.call_tool(
        "nc_semantic_search",
        arguments={
            "query": query,
            "limit": 5,
            "score_threshold": 0.0,
        },
    )

    assert result.isError is False
    data = result.structuredContent

    assert data["total_found"] >= min_expected_results, (
        f"Query '{query}' returned {data['total_found']} results, "
        f"expected at least {min_expected_results}"
    )


async def test_no_results_for_unrelated_query(nc_mcp_client):
    """Test that completely unrelated queries return low/no scores.

    The Nextcloud manual shouldn't have relevant content for
    quantum physics queries.
    """
    result = await nc_mcp_client.call_tool(
        "nc_semantic_search",
        arguments={
            "query": "quantum entanglement hadron collider particle physics",
            "limit": 5,
            "score_threshold": 0.5,  # Higher threshold to filter irrelevant
        },
    )

    assert result.isError is False
    data = result.structuredContent

    # Should have few or no high-scoring results
    # Low score threshold means we might get some results, but they should be low quality
    if data["total_found"] > 0:
        # If results exist, they should have low scores
        max_score = max(r["score"] for r in data["results"])
        assert max_score < 0.8, f"Unexpected high score {max_score} for unrelated query"