feat: add tiered fallback for pdf

_test_unstructured_client/unit/test_pdf_utils.py

@@ -5,7 +5,7 @@
 import pytest
 from pypdf import PdfReader
 
-from unstructured_client._hooks.custom.pdf_utils import check_pdf, PDFValidationError
+from unstructured_client._hooks.custom.pdf_utils import check_pdf, read_pdf, PDFValidationError
 from _test_unstructured_client.unit_utils import sample_docs_path
 
 
@@ -23,6 +23,7 @@ def test_check_pdf_with_valid_pdf():
     assert isinstance(result, PdfReader)
 
 
+# TODO(klaijan) - add pdf file when file is ready
 @pytest.mark.parametrize(
     ("pdf_name", "expected_error_message"),
     [
@@ -51,3 +52,15 @@ def test_check_pdf_raises_pdf_validation_error(
         check_pdf(pdf)
 
     assert exc_info.value.message == expected_error_message
+
+
+# TODO(klaijan) - uncomment when file is ready
+"""
+def test_check_read_pdf():
+    pdf_path = sample_docs_path(".pdf")
+    with open(pdf_path, "rb") as f:
+        pdf_content = f.read()
+    pdf = read_pdf(pdf_content)
+    result = check_pdf(pdf)
+    assert isinstance(result, PdfReader)
+"""

src/unstructured_client/_hooks/custom/pdf_utils.py

@@ -26,6 +26,43 @@ def __init__(self, message: str):
 
 
 def read_pdf(pdf_file: Union[BinaryIO, bytes]) -> Optional[PdfReader]:
+    reader = read_pdf_raw(pdf_file=pdf_file)
+    if reader:
+        return reader
+
+    # TODO(klaijan) - remove once debugged
+    pdf_logger.debug("Primary PdfReader parse failed, attempting multipart and raw extraction fallbacks.")
+
+    # Load raw bytes
+    # case bytes
+    if isinstance(pdf_file, bytes):
+        raw = pdf_file
+    # case BinaryIO
+    elif hasattr(pdf_file, "read"):
+        try:
+            pdf_file.seek(0)
+            raw = pdf_file.read()
+        except Exception as e:
+            raise IOError(f"Failed to read file stream: {e}") from e
+    else:
+        raise IOError("Expected bytes or a file-like object with 'read()' method")
+
+    # breakpoint()
+    # This looks for %PDF-
+    try:
+        start = raw.find(b"%PDF-")
+        end = raw.find(b"%%EOF") + len(b"%%EOF")
+        if start != -1:
+            sliced = raw[start:end]
+            pdf = PdfReader(io.BytesIO(sliced), strict=False)
+            return check_pdf(pdf)
+    except Exception as e:
+        pdf_logger.debug("%%PDF- slicing fallback failed: %s", e)
+
+    return None
+
+
+def read_pdf_raw(pdf_file: Union[BinaryIO, bytes]) -> Optional[PdfReader]:
     """Reads the given PDF file.
 
     Args:
@@ -34,13 +71,20 @@ def read_pdf(pdf_file: Union[BinaryIO, bytes]) -> Optional[PdfReader]:
     Returns:
         The PdfReader object if the file is a PDF, None otherwise.
     """
-
     try:
         if isinstance(pdf_file, bytes):
             content = cast(bytes, pdf_file)
             pdf_file = io.BytesIO(content)
-        return PdfReader(pdf_file, strict=False)
-    except (PdfReadError, UnicodeDecodeError):
+        reader = PdfReader(pdf_file, strict=False)
+        return check_pdf(reader)
+    except (PdfReadError, UnicodeDecodeError) as e:
+        pdf_logger.debug("Read pdf failed: %s", e)
+        return None
+    except PDFValidationError as e:
+        pdf_logger.debug("Check pdf failed: %s", e)
+        return None 
+    except Exception as e:
+        pdf_logger.debug("An unexpected error occurred: %s", e)
         return None