import re
import argparse
import fitz
import pytesseract
import cv2
import numpy as np

def redact_text(text, validators, ignored):
    redacted_text = text

    # Apply validators to redact sensitive information
    for validator_type, patterns in validators.items():
        for pattern, replacement in patterns:
            redacted_text = re.sub(pattern, replacement, redacted_text, flags=re.IGNORECASE)

    # Apply ignored patterns to exclude certain patterns from redaction
    for pattern in ignored:
        redacted_text = re.sub(pattern, '', redacted_text, flags=re.IGNORECASE)

    return redacted_text


def process_pdf(input_file, output_file, validators, ignored):
    doc = fitz.open(input_file)

    for page_index, page in enumerate(doc):
        pixmap = page.get_pixmap()

        # Convert the pixmap to a NumPy array
        image_np = np.frombuffer(pixmap.samples, dtype=np.uint8).reshape(pixmap.h, pixmap.w, pixmap.n)

        # Convert the image from BGR to RGB format
        image_rgb = cv2.cvtColor(image_np, cv2.COLOR_BGR2RGB)

        # Use Tesseract OCR to extract text from the image
        extracted_text = pytesseract.image_to_string(image_rgb)

        # Apply redaction on the extracted text
        redacted_text = redact_text(extracted_text, validators, ignored)

        # Print the extracted and redacted text for verification
        print(f"Page {page_index + 1} - Extracted Text:")
        print(extracted_text)
        print(f"Page {page_index + 1} - Redacted Text:")
        print(redacted_text)
        print("-----")

    doc.save(output_file)
    doc.close()

    print("Redacted PDF saved successfully!")

# Define the validators and ignored patterns
validators = {

    "Hong Kong Identity Card Number": [
        (r'\b[A-Z]\d{6}\([A-Z]\)', 'XXXXXXXXX'),
        (r'\b[A-Z]\d{6}\(\d\)', 'XXXXXXXXX')
    ],
    "Phone Numbers": [
        (r'\+\d{1,3}[-\s]?\d{1,4}[-\s]?\d{1,4}[-\s]?\d{1,9}', '+XXX XXXX XXXX'),
        (r'\d{1,4}[-\s]?\d{1,4}[-\s]?\d{1,9}', 'XXXX XXXX')
    ],
      "Credit Card Numbers": [
        (r'\b[0-9]{4}-[0-9]{4}-[0-9]{4}-[0-9]{4}\b', 'XXXX-XXXX-XXXX-XXXX')
    ],
    "Email Addresses": [
        (r'\b[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,}\b', 'XXXXX@XXXXX.XXX')
    ],

}

ignored = [
    r'0000[-\s]?0000[-\s]?0000[-\s]?0000',
    r'1111[-\s]?1111[-\s]?1111[-\s]?1111'
]

# Parse command-line arguments
parser = argparse.ArgumentParser(description='PDF Redaction Script')
parser.add_argument('input_file', help='Path to the input PDF file')
parser.add_argument('output_file', help='Path to the output PDF file')
args = parser.parse_args()

# Call the process_pdf function with input and output file paths, validators, and ignored patterns
process_pdf(args.input_file, args.output_file, validators, ignored)