#!/bin/sh
# SPDX-License-Identifier: BSD-2-Clause

set -e
shopt -s nullglob

PROGPATH="$0"

usage() {
    echo "$PROGPATH <OPTIONS>"
    echo
    echo "Options:"
    echo "    -o: output dir"
    echo "    -1: first dir to compare"
    echo "    -2: second dir to compare"
    exit 1
}

error() {
    echo "error: $@" >&2
    exit 1
}

realpath() {
    python -c "import os; print(os.path.realpath('$1'))"
}

OUTPUT_DIR=
DIR1=
DIR2=

while :; do
    case $1 in
        -h|--help)
            usage
            ;;

        -o|--output)
            if [ -n "$2" ]; then OUTPUT_DIR="$2"; shift; else error "$1 requires an argument."; fi
            ;;

        -1)
            if [ -n "$2" ]; then DIR1="$2"; shift; else error "$1 requires an argument."; fi
            ;;

        -2)
            if [ -n "$2" ]; then DIR2="$2"; shift; else error "$1 requires an argument."; fi
            ;;

        --)
            shift
            break
            ;;

        -?*)
            error "unknown option: %s" "$1"
            ;;

        *)
            break
    esac
    shift
done

[ -z "$DIR1" ] && usage
[ -z "$DIR2" ] && usage
[ -z "$OUTPUT_DIR" ] && usage
[ ! -d "$DIR1" ] && error "$DIR1 is not a directory."
[ ! -d "$DIR2" ] && error "error: $DIR2 is not a directory."
[ "$DIR1" == "$DIR2" ] && error "error: it's the same directory."
[ ! -f "$DIR1/package.json" ] && error "error: package.json is not found in $DIR1."
[ ! -f "$DIR2/package.json" ] && error "error: package.json is not found in $DIR1."

[ -d "$OUTPUT_DIR" ] || mkdir "$OUTPUT_DIR"

DIR1=$(realpath $DIR1)
DIR2=$(realpath $DIR2)

# find differences across all files
# remember, diff returns 1 if differences were found
diff -qrN "$DIR1" "$DIR2" > "$OUTPUT_DIR/recursive.txt" || true

# loop through css and js
FILES=($DIR1/*.js)
FILES+=($DIR1/main/*.js)
FILES+=($DIR1/app/i18n/*.js)
FILES+=($DIR1/app/nt7/*.js)
FILES+=($DIR1/app/lib/*.js)
FILES+=($DIR1/dist/*.js)
FILES+=($DIR1/dist/*.css)

for f in "${FILES[@]}"; do
    # remove prefix $DIR1/ from $f
    _wo_path=${f#"$DIR1/"}
    _dirname=$(dirname $_wo_path)

    # compare files
    _md5_1=$(md5 -q "$DIR1/$_wo_path")
    _md5_2=$(md5 -q "$DIR2/$_wo_path")
    if [ "$_md5_1" == "$_md5_2" ]; then
        echo "no difference: $_wo_path"
        continue
    fi

    if [ "$_dirname" != "." ]; then
        mkdir -p "$OUTPUT_DIR/$_dirname"
    fi

    echo "processing: $_wo_path"

    # beautify files and generate diff
    if [[ $f == *.js ]]; then
        _beautify=js-beautify
        _ext=js
    elif [[ $f == *.css ]]; then
        _beautify=css-beautify
        _ext=css
    fi

    $_beautify "$DIR1/$_wo_path" > "$OUTPUT_DIR/${_wo_path/.$_ext/-1.$_ext}"
    $_beautify "$DIR2/$_wo_path" > "$OUTPUT_DIR/${_wo_path/.$_ext/-2.$_ext}"
    git diff "$OUTPUT_DIR/${_wo_path/.$_ext/-1.$_ext}" "$OUTPUT_DIR/${_wo_path/.$_ext/-2.$_ext}" > "$OUTPUT_DIR/$_wo_path.diff" || true
    rm "$OUTPUT_DIR/${_wo_path/.$_ext/-1.$_ext}" "$OUTPUT_DIR/${_wo_path/.$_ext/-2.$_ext}"
done

echo "done, saved to $OUTPUT_DIR"