#!/bin/bash
#      Copyright (C) 2010 Damjan Dimitrioski <damjandimitrioski at gmail dot com>
#
#      This program is free software; you can redistribute it and/or modify
#      it under the terms of the GNU General Public License as published by
#      the Free Software Foundation; either version 3 of the License, or
#      (at your option) any later version.
#
#      This program is distributed in the hope that it will be useful,
#      but WITHOUT ANY WARRANTY; without even the implied warranty of
#      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#      GNU General Public License for more details.
#
#      You should have received a copy of the GNU General Public License
#      along with this program; if not, write to the Free Software
#      Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
#      MA 02110-1301, USA.
#

# quick priority changer - program that will change the priority of "any"
# (almost) program by clicking on it's xwindow.

# USAGE:
#   add a global shortcut in your favourite DE or add 2 new desktop entri-
#   es.
#
# bugs:
#   not tested on remote xwindows.

# Returns the name of the program.
# arg $1 = process pid.
function progamName(){
    echo $(ps -p "$1" -o comm --no-headers);
}
# If the Desktop Session is unknown, invokes a custom gui dialog, made
# with zenity
# arg $1 = command to execute.
# arg $2 = command arguments.
function zcustomSudo(){
    echo "customSudo $1";
    cmd="$1 $2";
    zenity --entry --hide-text --title="Password" --text="enter sudo pasword for user: $USER." | sudo -S $cmd;
    sudo -k;
}
# Gets the priority of program by it's pid.
# arg $1 = process pid.
function getPriority(){
    echo $(ps -p "$1" -o nice --no-headers);
}
# Sets the priority of the program, if the niceness <0, than it invokes
# the sudo gui dialog.
# arg $1 = programs pid.
# arg $2 = new priority.
function setPriority(){
    #echo "the pid:"$1;
    if [[ $1 -gt -1 ]]; then
    #echo "new priority $2.";
    renice -n "$2" "$1";
    else
    $su "renice -n $2" "$1";
    fi;
}
# Sets the gui sudo dialog based on the running Desktop Session, if any.
function setSudoDialog(){
    case "$DESKTOP_SESSION" in
    kde)
        #if [[ -e "`which kdesu`" ]]; then alias su="kdesu"; fi;
        if [[ -e "`which kdesu`" ]]; then su="kdesu"; fi;
    ;;
    GNOME)
        #if [[ -e "`which gksudo`" ]]; then alias su="gksudo"; fi;
        if [[ -e "`which gksudo`" ]]; then su="gksudo"; fi;
    ;;
    *)
        su="zcustomSudo";
    esac
}
# Removes spaces from a given string.
# arg $1 = string to trim.
function trim(){
    echo $1 | sed -e 's/ //'
}
# Used to inform the user of an error.
# arg $1 = the case to jump to.
function inform(){
    case "$1" in
    *)
    zenity --error --title "Under construction" --text "Under construction.";
    esac
}
# Opens some sort of a gui dialog which ask's the user to choose a number
# from a range, defined by a minimum and a maximum.
# arg $1 = programs name.
# arg $2 = programs pid.
# TODO: A case switch that will open input prompt for the current DE.
function numberPrompt(){
    msg="Set a new priority to $1[$2], current [$value]"
    msgt="Set priority"

    zscale='--scale --min-value=-19 --max-value=19 '"--value=$value"
    empty=" " # to separate the strings :D.
    title="--title=$msgt"
    txtmsg="--text=$msg"

    # On cancel exits the script.
    echo $(zenity $zscale "$title" $empty "$txtmsg" || exit);
}

setSudoDialog # Sets the default gui sudo dialog.
# Gets the pid of the desired program.
pid="`xprop | grep "_NET_WM_PID(CARDINAL)" |\
awk -F= '{print $2}' | sed -e 's/ //'`" || exit; # TODO: if the xwindow
#coudn't be identified, than shows an error gui dialog.
pname=$(progamName $pid); # The name of the focused program.
value="`getPriority $pid`" # The current priority of the program.
# opens a gui dialog in which the user chooses a number
# for the new priority of the selected program.
priority=$(numberPrompt $pname $pid);
# Changes the programs priority to the number.
setPriority "$pid" "$priority"