#!/bin/sh
#
# xcompmgr-autostart - activate or deactivate autostart of xcompmgr
#
# Copyright (c) 2010 <guido+opensuse.org@berhoerster.name>
#
# Permission to use, copy, modify, and distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# TORTIOUS ACTION, ARISING OUT OF
# PERFORMANCE OF THIS SOFTWARE.

PATH=/bin:/usr/bin
export PATH

error_msg () {
    printf "error: %s\n" "$@" >&2
}

usage () {
    printf "usage: xcompmgr-autostart [on|off]\n" >&2
}

has_xcompmgr_entry () {
    [ -r "${autostart_file}" ] || return 1
    grep "^X-Generated-By=xcompmgr-autostart$" "${autostart_file}" \
        >/dev/null 2>&1 || return 2
    grep "^Hidden=true$" "${autostart_file}" >/dev/null 2>&1 && return 1
    return 0
}

add_xcompmgr_entry () {
    has_xcompmgr_entry
    ret=$?
    if [ $ret -eq 0 ]; then
        return 0
    elif [ $ret -eq 2 ]; then
        error_msg "custom xcompmgr entry autostart found, aborting"
        return 1
    fi

    if [ ! -d "${xdg_autostart_dir}" ]; then
        if ! mkdir "${xdg_autostart_dir}"; then
            error_msg "could not create \"${xdg_autostart_dir}\""
            return 1
        fi
    fi
    cat >"${autostart_file}" <<EOF
[Desktop Entry]
Type=Application
Name=xcompmgr
GenericName=Composite Manager
TryExec=xcompmgr
Exec=xcompmgr -c -C
Hidden=false
X-Generated-By=xcompmgr-autostart

EOF
    ret=$?
    if [ $ret -ne 0 ]; then
        error_msg "could not create xcompmgr autostart entry"
        return 1
    fi
    printf "xcompmgr-autostart is on\n"
    return 0
}

remove_xcompmgr_entry () {
    has_xcompmgr_entry
    retval=$?
    if [ $retval -eq 1 ]; then
        return 0
    elif [ $retval -eq 2 ]; then
        error_msg "custom xcompmgr autostart entry found, aborting"
        return 1
    fi

    ed -- "${autostart_file}" >/dev/null 2>&1 <<EOF
,s/Hidden=false/Hidden=true/
w
q
EOF
    ret=$?
    if [ $ret -ne 0 ]; then
        error_msg "could not remove xcompmgr autostart entry"
        return 1
    fi
    printf "xcompmgr-autostart is off\n"
    return 0
}

xdg_autostart_dir="${XDG_CONFIG_HOME:+${XDG_CONFIG_HOME}/autostart}"
xdg_autostart_dir="${xdg_autostart_dir:=${HOME}/.config/autostart}"
autostart_file="${xdg_autostart_dir}/xcompmgr.desktop"

if [ $# -eq 0 ]; then
    has_xcompmgr_entry
    retval=$?
    if [ $retval -eq 0 ]; then
        printf "xcompmgr-autostart is on\n"
    elif [ $retval -eq 1 ]; then
        printf "xcompmgr-autostart is off\n"
    elif [ $retval -eq 2 ]; then
        printf "custom xcompmgr autostart entry found\n"
    fi
    exit 0
elif [ $# -eq 1 ]; then
    case "$1" in
        on)     add_xcompmgr_entry
                exit $?
                ;;
        off)    remove_xcompmgr_entry
                exit $?
                ;;
        *)      usage
                exit 1
                ;;
    esac
else
    usage
    exit 2
fi