"""
Tests for document processor module.
"""

import pytest
import tempfile
from pathlib import Path
from unittest.mock import Mock, patch

import sys
sys.path.append(str(Path(__file__).parent.parent))

from src.document_processor import DocumentProcessor, DocumentChunk
from src.error_handler import DocumentProcessingError


@pytest.fixture
def sample_config():
    """Sample configuration for testing."""
    return {
        "app": {"max_upload_size": 50},
        "processing": {
            "chunk_size": 512,
            "chunk_overlap": 50,
            "min_chunk_size": 100,
            "max_chunks_per_doc": 1000,
            "supported_formats": ["pdf", "docx", "txt"]
        }
    }


@pytest.fixture
def doc_processor(sample_config):
    """Document processor instance."""
    return DocumentProcessor(sample_config)


class TestDocumentProcessor:
    """Test document processor functionality."""
    
    def test_init(self, sample_config):
        """Test processor initialization."""
        processor = DocumentProcessor(sample_config)
        assert processor.chunk_size == 512
        assert processor.chunk_overlap == 50
        assert processor.min_chunk_size == 100
    
    def test_process_text_file(self, doc_processor):
        """Test processing a simple text file."""
        # Create temporary text file
        with tempfile.NamedTemporaryFile(mode='w', suffix='.txt', delete=False) as f:
            f.write("This is a test document. " * 100)  # Make it long enough to chunk
            temp_file = f.name
        
        try:
            chunks = doc_processor.process_document(temp_file, "test.txt")
            
            assert len(chunks) > 0
            assert isinstance(chunks[0], DocumentChunk)
            assert chunks[0].content
            assert chunks[0].metadata["filename"] == "test.txt"
            assert chunks[0].metadata["file_type"] == ".txt"
            
        finally:
            Path(temp_file).unlink()
    
    def test_empty_file_error(self, doc_processor):
        """Test error handling for empty files."""
        with tempfile.NamedTemporaryFile(mode='w', suffix='.txt', delete=False) as f:
            f.write("")  # Empty file
            temp_file = f.name
        
        try:
            with pytest.raises(DocumentProcessingError):
                doc_processor.process_document(temp_file, "empty.txt")
        finally:
            Path(temp_file).unlink()
    
    def test_unsupported_file_type(self, doc_processor):
        """Test error for unsupported file types."""
        with tempfile.NamedTemporaryFile(suffix='.xyz', delete=False) as f:
            f.write(b"test content")
            temp_file = f.name
        
        try:
            with pytest.raises(DocumentProcessingError):
                doc_processor.process_document(temp_file, "test.xyz")
        finally:
            Path(temp_file).unlink()
    
    def test_chunk_creation(self, doc_processor):
        """Test chunk creation with overlaps."""
        # Create a longer text to ensure multiple chunks
        long_text = "This is sentence one. This is sentence two. " * 50
        
        with tempfile.NamedTemporaryFile(mode='w', suffix='.txt', delete=False) as f:
            f.write(long_text)
            temp_file = f.name
        
        try:
            chunks = doc_processor.process_document(temp_file, "long.txt")
            
            # Should create multiple chunks for long text
            if len(chunks) > 1:
                # Check that chunks have proper metadata
                for i, chunk in enumerate(chunks):
                    assert chunk.metadata["chunk_index"] == i
                    assert chunk.chunk_id is not None
                    
        finally:
            Path(temp_file).unlink()
    
    def test_document_stats(self, doc_processor):
        """Test document statistics generation."""
        with tempfile.NamedTemporaryFile(mode='w', suffix='.txt', delete=False) as f:
            f.write("Test document content. " * 20)
            temp_file = f.name
        
        try:
            chunks = doc_processor.process_document(temp_file, "stats_test.txt")
            stats = doc_processor.get_document_stats(chunks)
            
            assert stats["chunk_count"] == len(chunks)
            assert stats["total_chars"] > 0
            assert stats["avg_chunk_size"] > 0
            assert stats["source_file"] == "stats_test.txt"
            
        finally:
            Path(temp_file).unlink()


class TestDocumentChunk:
    """Test DocumentChunk functionality."""
    
    def test_chunk_creation(self):
        """Test chunk creation and ID generation."""
        content = "This is test content"
        metadata = {"source": "test.txt", "page": 1}
        
        chunk = DocumentChunk(content, metadata)
        
        assert chunk.content == content
        assert chunk.metadata == metadata
        assert chunk.chunk_id is not None
        assert len(chunk.chunk_id) > 0
    
    def test_chunk_to_dict(self):
        """Test chunk serialization."""
        content = "Test content"
        metadata = {"source": "test.txt"}
        
        chunk = DocumentChunk(content, metadata, "custom_id")
        chunk_dict = chunk.to_dict()
        
        assert chunk_dict["chunk_id"] == "custom_id"
        assert chunk_dict["content"] == content
        assert chunk_dict["metadata"] == metadata
    
    def test_chunk_id_generation(self):
        """Test automatic chunk ID generation."""
        chunk1 = DocumentChunk("Same content", {"source": "file1.txt"})
        chunk2 = DocumentChunk("Same content", {"source": "file1.txt"})
        chunk3 = DocumentChunk("Different content", {"source": "file1.txt"})
        
        # Same content should generate same ID
        assert chunk1.chunk_id == chunk2.chunk_id
        # Different content should generate different ID
        assert chunk1.chunk_id != chunk3.chunk_id


if __name__ == "__main__":
    pytest.main([__file__])