first commit - MVE Incrementables Parser microservice with FastAPI, JWT, Celery, Redis

app/services/pdf_text.py

@@ -0,0 +1,112 @@
+"""PDF text extraction service using PyMuPDF and pdfplumber."""
+import fitz  # PyMuPDF
+import pdfplumber
+import logging
+from typing import Tuple, Optional
+from io import BytesIO
+
+logger = logging.getLogger(__name__)
+
+
+class PDFExtractionError(Exception):
+    """Custom exception for PDF extraction errors."""
+    pass
+
+
+def extract_text_with_pymupdf(pdf_bytes: bytes) -> Tuple[str, int]:
+    """
+    Extract text from PDF using PyMuPDF (fitz).
+    
+    Args:
+        pdf_bytes: PDF file content as bytes
+        
+    Returns:
+        Tuple of (extracted_text, page_count)
+        
+    Raises:
+        PDFExtractionError: If extraction fails
+    """
+    try:
+        doc = fitz.open(stream=pdf_bytes, filetype="pdf")
+        
+        if doc.is_encrypted:
+            raise PDFExtractionError("PDF is encrypted and cannot be read")
+        
+        page_count = len(doc)
+        text_parts = []
+        
+        for page in doc:
+            text_parts.append(page.get_text())
+        
+        doc.close()
+        full_text = "\n".join(text_parts)
+        
+        logger.info(f"Extracted {len(full_text)} characters using PyMuPDF from {page_count} pages")
+        return full_text, page_count
+        
+    except Exception as e:
+        logger.warning(f"PyMuPDF extraction failed: {str(e)}")
+        raise PDFExtractionError(f"PyMuPDF extraction failed: {str(e)}")
+
+
+def extract_text_with_pdfplumber(pdf_bytes: bytes) -> Tuple[str, int]:
+    """
+    Extract text from PDF using pdfplumber (fallback method).
+    
+    Args:
+        pdf_bytes: PDF file content as bytes
+        
+    Returns:
+        Tuple of (extracted_text, page_count)
+        
+    Raises:
+        PDFExtractionError: If extraction fails
+    """
+    try:
+        with pdfplumber.open(BytesIO(pdf_bytes)) as pdf:
+            page_count = len(pdf.pages)
+            text_parts = []
+            
+            for page in pdf.pages:
+                page_text = page.extract_text()
+                if page_text:
+                    text_parts.append(page_text)
+            
+            full_text = "\n".join(text_parts)
+            
+            logger.info(f"Extracted {len(full_text)} characters using pdfplumber from {page_count} pages")
+            return full_text, page_count
+            
+    except Exception as e:
+        logger.error(f"pdfplumber extraction failed: {str(e)}")
+        raise PDFExtractionError(f"pdfplumber extraction failed: {str(e)}")
+
+
+def extract_text_from_pdf(pdf_bytes: bytes) -> Tuple[str, int, str]:
+    """
+    Extract text from PDF using available methods.
+    Tries PyMuPDF first, falls back to pdfplumber.
+    
+    Args:
+        pdf_bytes: PDF file content as bytes
+        
+    Returns:
+        Tuple of (extracted_text, page_count, method_used)
+        
+    Raises:
+        PDFExtractionError: If all extraction methods fail
+    """
+    # Try PyMuPDF first
+    try:
+        text, pages = extract_text_with_pymupdf(pdf_bytes)
+        return text, pages, "text"
+    except PDFExtractionError as e:
+        logger.warning(f"PyMuPDF failed, trying pdfplumber: {str(e)}")
+    
+    # Fallback to pdfplumber
+    try:
+        text, pages = extract_text_with_pdfplumber(pdf_bytes)
+        return text, pages, "text"
+    except PDFExtractionError as e:
+        logger.error(f"All extraction methods failed: {str(e)}")
+        raise PDFExtractionError("Failed to extract text from PDF using all available methods")