"""
Pytest configuration and fixtures for local-context7 tests.

This module provides:
- Mocks for external dependencies (Qdrant, FastEmbed)
- Database fixtures for SQLite operations
- Common test utilities
"""
from unittest.mock import MagicMock, patch
import pytest
import os
import json
from pathlib import Path

from backend.app.db import init_db, upsert_library, insert_document_chunk, get_chunks_for_library, list_libraries, clear_library_documents, get_connection


# =============================================================================
# FIXTURES
# =============================================================================

@pytest.fixture(scope="function")
def test_database():
    """
    Create a fresh SQLite database for testing.
    
    Yields:
        Database connection with tables initialized
    """
    # Use an in-memory or temporary file database
    db_path = Path(__file__).parent.parent / "backend" / "data" / "test_db.sqlite"
    
    # Ensure data directory exists
    db_path.parent.mkdir(parents=True, exist_ok=True)
    
    # Remove existing test DB if present
    if db_path.exists():
        db_path.unlink()
    
    # Initialize database with tables
    result = init_db()
    assert result["success"], f"Failed to initialize test DB: {result.get('error')}"
    
    yield
    
    # Cleanup: remove test database after tests
    if db_path.exists():
        db_path.unlink()


@pytest.fixture(scope="function")
def sample_text():
    """Sample text for chunking tests."""
    return """# Introduction

This is the introduction section.

## Background

Background information goes here to make this longer and test chunking.

This paragraph has more content about the background topic.

### Details

Specific details about the background are provided in this subsection.

More details follow here to ensure we have enough text to properly test heading preservation.

## Conclusion

The conclusion wraps up everything nicely."""


# =============================================================================
# MOCKS
# =============================================================================

@pytest.fixture
def mock_embedding_model():
    """
    Mock FastEmbed model that returns dummy vectors.
    
    This avoids needing to download and load the actual embedding model.
    Returns 384-dimensional zero vectors for any input.
    """
    mock_model = MagicMock()
    
    # Mock embed method - returns list of lists with float values
    def mock_embed(texts):
        return [
            [0.0] * 384  # Zero vector placeholder
            for _ in texts
        ]
    
    mock_model.embed = mock_embed
    
    return mock_model


@pytest.fixture
def mock_qdrant_client():
    """
    Mock Qdrant client that returns empty or test results.
    
    Allows testing search logic without needing a running Qdrant server.
    """
    mock_client = MagicMock()
    
    # Mock search method
    def mock_search(collection_name, query_vector, limit=10, search_filter=None):
        # Return empty list (simulating no results)
        return []
    
    mock_client.search = mock_search
    
    # Mock delete_collection for cleanup
    mock_client.delete_collection = MagicMock(return_value=True)
    
    return mock_client


@pytest.fixture
def mock_embedding_model_batch():
    """
    Batch embedding model mock that returns deterministic fake vectors.
    
    Returns slightly different vectors for different input lengths/first chars,
    allowing tests to verify vector retrieval if needed.
    """
    def hash_text(text):
        # Simple hash-based pseudo-random vector generation
        text_hash = hash(text) % 1000000
        return [(hash_text(text) / 1000000 + (i * 0.001)) for i in range(384)]
    
    mock_model = MagicMock()
    mock_model.embed = lambda texts: [hash_text(t) for t in texts]
    
    return mock_model


# =============================================================================
# SETUP TEARDOWN FIXTURES
# =============================================================================

@pytest.fixture(autouse=True)
def clear_test_database(test_database):
    """
    Clear test database before and after each test function.
    
    Note: This fixture runs the teardown (cleanup) AFTER the test,
    so we manually clear at the end of the yield context.
    The db_path is cleaned up by the test_database fixture's yield block.
    """
    pass  # Cleanup handled in test_database fixture


@pytest.fixture
def empty_vector():
    """Empty/dummy embedding vector for tests."""
    return [0.0] * 384


@pytest.fixture
def fake_embeddings(sample_text):
    """Fake embedding vectors for sample text."""
    def hash_text(text):
        return [(hash(text) + len(text)) % 1000 / 10000 for _ in range(384)]
    
    return [hash_text(s) for s in sample_text.split("\n\n") if s.strip()]


# =============================================================================
# UTILITY FUNCTIONS
# =============================================================================

@pytest.fixture
def temp_file(tmp_path):
    """Create a temporary file and yield its path."""
    test_file = tmp_path / "test.txt"
    return test_file


# Register custom marker for slow tests (if needed)
def pytest_configure(config):
    config.addinivalue_line("markers", "slow: marks tests as slow (deselect with '-m \"not slow\"')")


def pytest_runtest_setup(item):
    """Add custom markers if needed."""
    pass