File size: 6,293 Bytes
d5ef46f
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
"""
Document Processing Utilities

This module provides utilities for extracting text from various document formats
including PDF, Word documents, and plain text files.
"""

import io

# Removed direct logging import - using unified config

# Import document processing libraries with availability checks
try:
    import PyPDF2

    PYPDF2_AVAILABLE = True
except ImportError:
    PYPDF2_AVAILABLE = False

try:
    import pdfplumber

    PDFPLUMBER_AVAILABLE = True
except ImportError:
    PDFPLUMBER_AVAILABLE = False

try:
    from docx import Document as DocxDocument

    DOCX_AVAILABLE = True
except ImportError:
    DOCX_AVAILABLE = False

from ..config.logfire_config import get_logger

logger = get_logger(__name__)


def extract_text_from_document(file_content: bytes, filename: str, content_type: str) -> str:
    """
    Extract text from various document formats.

    Args:
        file_content: Raw file bytes
        filename: Name of the file
        content_type: MIME type of the file

    Returns:
        Extracted text content

    Raises:
        ValueError: If the file format is not supported
        Exception: If extraction fails
    """
    try:
        extracted_text = ""
        # PDF files
        if content_type == "application/pdf" or filename.lower().endswith(".pdf"):
            extracted_text = extract_text_from_pdf(file_content)

        # Word documents
        elif content_type in [
            "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
            "application/msword",
        ] or filename.lower().endswith((".docx", ".doc")):
            extracted_text = extract_text_from_docx(file_content)

        # Text files (markdown, txt, etc.)
        elif content_type.startswith("text/") or filename.lower().endswith(
            (
                ".txt",
                ".md",
                ".markdown",
                ".rst",
            )
        ):
            extracted_text = file_content.decode("utf-8", errors="ignore")

        else:
            raise ValueError(f"Unsupported file format: {content_type} ({filename})")

        # Physical Hardening: Ensure final output is clean UTF-8 NFC and free of control chars
        import unicodedata

        # Keep newlines, tabs and printable chars, strip other control categories
        clean_text = "".join(
            ch
            for ch in unicodedata.normalize("NFC", extracted_text)
            if unicodedata.category(ch)[0] != "C" or ch in "\n\r\t"
        )
        return clean_text.strip()

    except Exception as e:
        logger.error(
            f"Document text extraction failed | filename={filename} | content_type={content_type} | error={str(e)}"
        )
        raise Exception(f"Failed to extract text from {filename}: {str(e)}") from e


def extract_text_from_pdf(file_content: bytes) -> str:
    """
    Extract text from PDF using both PyPDF2 and pdfplumber for best results.

    Args:
        file_content: Raw PDF bytes

    Returns:
        Extracted text content
    """
    if not PDFPLUMBER_AVAILABLE and not PYPDF2_AVAILABLE:
        raise Exception("No PDF processing libraries available. Please install pdfplumber and PyPDF2.")

    text_content = []

    # First try with pdfplumber (better for complex layouts)
    if PDFPLUMBER_AVAILABLE:
        try:
            with pdfplumber.open(io.BytesIO(file_content)) as pdf:
                for page_num, page in enumerate(pdf.pages):
                    try:
                        page_text = page.extract_text()
                        if page_text:
                            text_content.append(f"--- Page {page_num + 1} ---\n{page_text}")
                    except Exception as e:
                        logger.warning(f"pdfplumber failed on page {page_num + 1}: {e}")
                        continue

            # If pdfplumber got good results, use them
            if text_content and len("\n".join(text_content).strip()) > 100:
                return "\n\n".join(text_content)

        except Exception as e:
            logger.warning(f"pdfplumber extraction failed: {e}, trying PyPDF2")

    # Fallback to PyPDF2
    if PYPDF2_AVAILABLE:
        try:
            text_content = []
            pdf_reader = PyPDF2.PdfReader(io.BytesIO(file_content))

            for page_num, pdf_page in enumerate(pdf_reader.pages):
                try:
                    page_text = pdf_page.extract_text()
                    if page_text:
                        text_content.append(f"--- Page {page_num + 1} ---\n{page_text}")
                except Exception as e:
                    logger.warning(f"PyPDF2 failed on page {page_num + 1}: {e}")
                    continue

            if text_content:
                return "\n\n".join(text_content)
            else:
                raise Exception("No text could be extracted from PDF")

        except Exception as e:
            raise Exception(f"PyPDF2 failed to extract text: {str(e)}") from e

    # If we get here, no libraries worked
    raise Exception("Failed to extract text from PDF - no working PDF libraries available")


def extract_text_from_docx(file_content: bytes) -> str:
    """
    Extract text from Word documents (.docx).

    Args:
        file_content: Raw DOCX bytes

    Returns:
        Extracted text content
    """
    if not DOCX_AVAILABLE:
        raise Exception("python-docx library not available. Please install python-docx.")

    try:
        doc = DocxDocument(io.BytesIO(file_content))
        text_content = []

        for paragraph in doc.paragraphs:
            if paragraph.text.strip():
                text_content.append(paragraph.text)

        # Also extract text from tables
        for table in doc.tables:
            for row in table.rows:
                row_text = []
                for cell in row.cells:
                    if cell.text.strip():
                        row_text.append(cell.text.strip())
                if row_text:
                    text_content.append(" | ".join(row_text))

        if not text_content:
            raise Exception("No text content found in document")

        return "\n\n".join(text_content)

    except Exception as e:
        raise Exception(f"Failed to extract text from Word document: {str(e)}") from e