create rxdelta files from as hack dir to a nointro update dir and move the hacks there (overwriting the old matched rom) to make rhdndat-rn recognize some older softpatch romhacks as the newer nointro roms in new dats

merge-hacks.sh

#!/bin/bash

display_help() {
    cat << EOF
$(basename "$0") - NES Game Patch Processor & Merger
_
Usage: $(basename "$0") <patch_dir> <clean_zip_dir> <destination_dir>

A utility to identify differences between NES files and compressed
clean ROMs, generating delta patches for modified versions.
It is useful when no-intro updates because the generated rxdelta
makes my other tool rhdndat-rn consider the rom file the same as
the clean rom, because it can be restored with the patch.
I recommend rom hacks be in a different base directory as the clean
roms to make updating easier, so this tool does not support that.

ARGUMENTS:
  patch_dir        Directory containing subfolders with .nes and .bps/.ips files.
  clean_zip_dir    Directory containing clean ROMs in .zip format (named matching subfolders).
  destination_dir  Target directory where successfully processed game folders will be moved.

WHAT THIS SCRIPT DOES:
  1. Validates that all three paths are unique, accessible, and exist.
  2. Scans <patch_dir> for game subfolders with bps or ips files.
  3. Locates a matching ZIP file in <clean_zip_dir> for each subfolder.
  4. Compares the existing .nes file against the clean ZIP content.
  5. If they differ, it uses 'xdelta3' to create a new .rxdelta patch.
  6. Moves matched folders (from 3.) to the <destination_dir>.
  7. Prints a summary of processed games and the total number of patches created.

OPTIONS:
  -h, --help       Display this help message and exit.
EOF
    exit 0
}

# Check for help flags before running the main logic
if [[ "$1" == "-h" || "$1" == "--help" ]]; then
    display_help
fi

process_and_merge_games() {
    local patch_root=$(realpath -m "$1")
    local clean_root=$(realpath -m "$2")
    local dest_root=$(realpath -m "$3")
    if [[ ! -d "$patch_root" || ! -d "$clean_root" || ! -d "$dest_root" ]]; then
        echo "Error: One or more directories do not exist."
        return 1
    fi
    if [[ ! -r "$patch_root" || ! -r "$clean_root" || ! -w "$dest_root" ]]; then
        echo "Error: Insufficient permissions (Read required for sources, Write for destination)."
        return 1
    fi
    if [[ "$patch_root" == "$clean_root" ]] || [[ "$patch_root" == "$dest_root" ]] || [[ "$clean_root" == "$dest_root" ]]; then
        echo "Error: Source and destination directories must be unique."
        return 1
    fi

    local processed_dirs=()
    local patch_count=0

    for sub_path in "$patch_root"/*; do
        [[ -d "$sub_path" ]] || continue

        local dir_name=$(basename "$sub_path")
        local patch_subdir="$patch_root/$dir_name"
        local clean_subzip="$clean_root/$dir_name".zip

        # Check if the same named zip exists
        if [[ -f "$clean_subzip" ]]; then
            local patch_exists=false
            # Identify target games via patch files (.bps or .ips)
            for patch in "$patch_subdir"/*.bps "$patch_subdir"/*.ips; do
                [[ -e "$patch" ]] || continue
                patch_exists=true
                local base_name=$(basename "${patch%.*}")
                local nes_file="$patch_subdir/$base_name.nes"

                # If both files exist, we process them
                if [[ -f "$nes_file" ]]; then
                    if ! cmp -s "$nes_file" <(zcat "$clean_subzip"); then
                        # Files differ: Create the .rxdelta patch
                        xdelta3 -f -e -s "$nes_file" <(zcat "$clean_subzip") "$patch_subdir/$base_name.rxdelta"                                                       ((patch_count++))
                    fi
                fi
            done                                                                                                                                          if [ "$patch_exists" = "true" ]; then                                                                                                             processed_dirs+=("$patch_subdir")
            if [ "$patch_exists" = "true" ]; then
                processed_dirs+=("$patch_subdir")
            fi
        fi
    done
    if [[ ${#processed_dirs[@]} -gt 0 ]]; then
        mv -t "$dest_root" "${processed_dirs[@]}"
    fi
    echo -e "\n--- Process Summary ---"
    if [[ ${#processed_dirs[@]} -gt 0 ]]; then
        echo -e "Processed List:"
        for d in "${processed_dirs[@]}"; do echo " - $(basename "$d")"; done
    fi
    echo "Total .rxdelta patches generated: $patch_count"
}
process_and_merge_games "$1" "$2" "$3"