#!/bin/bash

# firefox_upgrade - program to upgrade firefox quantum

error_exit()
{
    echo "$1" 1>&2
    exit 1
}

firefox_path=""
firefox_file=""

# parsing path and filename
if [ $# -ne 1 ]; then
    error_exit "usage: $0 firefox_quantum_path"
else
    firefox_path="$1"
    firefox_file="${firefox_path##*/}"
fi

# checking if input is a valid file
if [ ! -f "$firefox_path" ]; then
    error_exit "Invalid file! Aborting."
fi

# removing previous install, if existent
firefox_bin="/opt/firefox"
if [ -e "$firefox_bin" ]; then
    rm -rf $firefox_bin
else
    echo "$firefox_bin doesn't exist."
fi

# removing previous symlink, if existent
firefox_link="/usr/bin/firefox-quantum"
if [ -f "$firefox_link" ]; then
    rm $firefox_link
else
    echo "$firefox_link doesn't exist."
fi

# copying the tar to /opt
rsync -ah --progress $firefox_path /opt/$firefox_file

# unpacking the tar if successfully changed directory
if cd /opt; then
    tar -jxvf $firefox_file
else
    error_exit "Could not change directory! Aborting."
fi

# if unpack was successful, set permissions, create symlink, and remove tar
if [ "$?" = "0" ]; then
    chmod 755 /opt/firefox
    ln -s /opt/firefox/firefox /usr/bin/firefox-quantum
    rm $firefox_file
else
    error_exit "Could not extract file! Aborting."
fi
exit 0