#!/bin/bash
# extracts embedded files from all PDFs recursively to a $OUTPUT_DIR dir
#
# deps: pdfdetach (poppler utils)

OUTPUT_DIR="./extracted_attachments"
LOG_FILE="attachment_extraction.log"

mkdir -p "$OUTPUT_DIR"
> "$LOG_FILE"

echo "----------------------------------------"
echo "Starting attachment extraction scan..."
echo "Log: $LOG_FILE" 
echo "Output directory: $OUTPUT_DIR"
echo "----------------------------------------"

find . -type f -iname "*.pdf" | while read -r PDF_FILE; do
    REL_PATH="${PDF_FILE#./}"
    SAFE_NAME=$(echo "$REL_PATH" | tr '/' '_' | sed 's/\.pdf$//')
    FILE_OUTPUT_DIR="$OUTPUT_DIR/$SAFE_NAME"

    echo "Checking: $PDF_FILE" | tee -a "$LOG_FILE"

    ATTACHMENT_LIST=$(pdfdetach -list "$PDF_FILE" 2>/dev/null)

    if [ $? -eq 0 ] && [ -n "$ATTACHMENT_LIST" ]; then
        ATTACH_COUNT=$(echo "$ATTACHMENT_LIST" | tail -n +2 | wc -l)

        if [ "$ATTACH_COUNT" -gt 0 ]; then
            echo "  -> Found $ATTACH_COUNT attachment(s)" | tee -a "$LOG_FILE"

            mkdir -p "$FILE_OUTPUT_DIR"

            pdfdetach -saveall "$PDF_FILE" -o "$FILE_OUTPUT_DIR" 2>&1 | tee -a "$LOG_FILE"

            echo "--- Attachments in: $PDF_FILE ---" >> "$LOG_FILE"
            echo "$ATTACHMENT_LIST" >> "$LOG_FILE"
            echo "" >> "$LOG_FILE"
        fi
    fi
done

echo "----------------------------------------"
echo "Extraction complete. Check $LOG_FILE for details."