#!/bin/bash

###############################################################################
# Script Name: crop_images.sh
#
# Description:
#   Safely processes JPEG images in the current directory. If an image has a
#   width of 3546 pixels, the script:
#     1. Creates a cropped copy (2448x3264 from the top-left corner).
#     2. Saves the cropped image as *_c.jpg.
#     3. Renames the original image as *_u.jpg.
#
# Features:
#   - Processes only .jpg files.
#   - Handles filenames containing spaces.
#   - Verifies that ImageMagick is installed.
#   - Skips files that have already been processed.
#   - Uses ImageMagick's format output instead of parsing command output.
#
# Requirements:
#   - Bash
#   - ImageMagick (identify, convert)
#
# Usage:
#   chmod +x crop_images.sh
#   ./crop_images.sh
#
###############################################################################

set -euo pipefail

# Verify required commands exist
for cmd in identify convert; do
    command -v "$cmd" >/dev/null 2>&1 || {
        echo "Error: '$cmd' command not found. Install ImageMagick."
        exit 1
    }
done

# Process JPEG files only
for img in *.jpg *.JPG; do

    # Skip if no matching files exist
    [[ -f "$img" ]] || continue

    # Skip files already processed
    [[ "$img" =~ _c\.jpg$|_u\.jpg$ ]] && continue

    # Get image dimensions (e.g. 3546x4728)
    size=$(identify -format "%wx%h" "$img" 2>/dev/null) || {
        echo "Skipping invalid image: $img"
        continue
    }

    # Process only images whose width is exactly 3546 pixels
    if [[ "$size" == 3546x* ]]; then

        echo "Processing: $img ($size)"

        cropped="${img%.jpg}_c.jpg"
        original="${img%.jpg}_u.jpg"

        # Handle uppercase extension
        if [[ "$img" == *.JPG ]]; then
            cropped="${img%.JPG}_c.jpg"
            original="${img%.JPG}_u.jpg"
        fi

        # Create cropped image
        convert "$img" -crop 2448x3264+0+0 "$cropped"

        # Rename original image
        mv "$img" "$original"

        echo "  Created: $cropped"
        echo "  Renamed: $original"
    fi

done

echo "Done."