#!/bin/bash
#
# rar2zip conversion script
# Based on: https://shkspr.mobi/blog/2016/12/converting-rar-to-zip-in-linux/
#
# Usage: rar2zip.sh file [file ...]

echo "Converting RARs to ZIPs"

# Use RAM disk for temporary files.
WORKDIR="/dev/shm/"

for INFILE in "$@"; do
    # Absolute path to old file
    OLDFILE=`realpath "${INFILE}"`

    # Get the file name without the extension
    BASENAME=`basename "${OLDFILE%.*}"`

    # Path for the file. The ".zip" file will be written there.
    DIRNAME=`dirname "$OLDFILE"`

    # Name of the .zip file
    NEWNAME="${DIRNAME}/$BASENAME.zip"

    if [ ! -e "${NEWNAME}" ]; then
        # Set name for the temp dir. This directory will be created under WORKDIR
        TEMPDIR=`mktemp -p "$WORKDIR" -d`

        # Create a temporary folder for unRARed files
        echo "Extracting $OLDFILE"
    
        rar x "$OLDFILE" "${TEMPDIR}/"

        # Zip the files with maximum compression
        7z a -tzip -mx=9 "$NEWNAME" "${TEMPDIR}/*"
        # Alternative. MUCH SLOWER, but better compression
        # 7z a -mm=Deflate -mfb=258 -mpass=15 -r "$NEWNAME" *

        # Preserve file modification time
        touch -r "$OLDFILE" "$NEWNAME"

        # Delete the temporary directory
        rm -r "$TEMPDIR"

        # OPTIONAL. Safe-remove the old file
        #gio trash "$OLDFILE"
    else
        echo "${NEWNAME}: File exists!"
    fi
done

echo "Conversion Done"