#!/bin/sh
#
# vagalume-dbus: A shell script for easily managing some of the
# Vagalume features available via its D-Bus interface.
#
# Copyright (C) 2008 Mario Sanchez Prada <msanchez@igalia.com>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of version 2 of the GNU General Public
# License as published by the Free Software Foundation.
#
# 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., 59 Temple Place - Suite 330,
# Boston, MA 02111-1307, USA.
#
set -e

# Delay to be used in the 'ugly' sleep after starting Vagalume
# when it's not running yet. It helps (but not ensure) the command
# to be finally executed after Vagalume has started.
STARTUP_DELAY=25

# D-Bus basic parameters
DBUS_SERVICE='com.igalia.vagalume'
DBUS_OBJECT=/com/igalia/vagalume
DBUS_IFACE=com.igalia.vagalume

# Available D-Bus commands
DBUS_METHOD_PLAY="Play"
DBUS_METHOD_STOP="Stop"
DBUS_METHOD_SKIP="Skip"
DBUS_METHOD_PLAYURL="PlayUrl"
DBUS_METHOD_CLOSEAPP="CloseApp"
DBUS_METHOD_TOPAPP="top_application"

# Print the usage for this shell script
print_usage ()
{
    echo "Usage:"
    echo "  vagalume-dbus <COMMAND>"
    echo "     (Vagalume will be automatically started if not already running)"
    echo
    echo "  COMMAND:"
    echo "     play:              start playing the current radio"
    echo "     skip:              skip to the nex song in the current radio"
    echo "     stop:              stop playing the current radio"
    echo "     tag <TAG>:         change to a 'global tag' radio."
    echo "     artist <ARTIST>:   change to a 'similar artists' radio"
    echo "     group <GROUP>:     change to a 'last.fm group' radio"
    echo "     loved <USER>:      change to a 'loved' radio for a specific user"
    echo "     neighbours <USER>: change to a 'neighbours' radio for a specific user"
    echo "     pesonal <USER>:    change to a 'personal' radio for a specific user"
    echo "     playlist <USER>:   change to a 'playlist' radio for a specific user"
    echo "     playurl <URL>:     just play the specified URL on Vagalume"
    echo "     start:             start Vagalume (if not already running)"
    echo "     close:             close Vagalume (if not already closed)"
    echo "     help:              print this information"
    echo
    echo " It's REQUIRED to use 'double-quotes' when specifing parameters to some commands,"
    echo " such as TAG or ARTIST, because of the white spaces they might contain, e.g:"
    echo
    echo "     $ vagalume-dbus tag \"hard rock\""
    echo "     $ vagalume-dbus artist \"Led Zeppelin\""
    echo
}

# Invalid parameters: print usage and exit with error code
invalid_params ()
{
    print_usage;
    exit 1;
}

# Check number of parameteres
if [ $# -lt 1 ]; then
    invalid_params;
fi

# Check the command and execute it
COMMAND=${1}
if [ $# -eq 1 ]; then
  # Commands requiring no parameters
  case ${COMMAND} in
    "stop") DBUS_METHOD_CALL=${DBUS_METHOD_STOP};;
    "play") DBUS_METHOD_CALL=${DBUS_METHOD_PLAY};;
    "skip") DBUS_METHOD_CALL=${DBUS_METHOD_SKIP};;
    "start") DBUS_METHOD_CALL=${DBUS_METHOD_TOPAPP};;
    "close") DBUS_METHOD_CALL=${DBUS_METHOD_CLOSEAPP};;
    "help") print_usage; exit 0;;
    *) invalid_params;;
  esac
elif [ $# -eq 2 ]; then
  # Commands requiring a parameter
  ENCODED_PARAM=`echo ${2} | tr " " "+"`
  case ${COMMAND} in
    "tag") URL="lastfm://globaltags/"${ENCODED_PARAM};;
    "artist") URL="lastfm://artist/"${ENCODED_PARAM};;
    "group") URL="lastfm://group/"${ENCODED_PARAM};;
    "loved") URL="lastfm://user/"${ENCODED_PARAM}"/loved";;
    "neighbours") URL="lastfm://user/"${ENCODED_PARAM}"/neighbours";;
    "personal") URL="lastfm://user/"${ENCODED_PARAM};;
    "playlist") URL="lastfm://user/"${ENCODED_PARAM}"/playlist";;
    "playurl") URL=${ENCODED_PARAM};;
    *) invalid_params;;
  esac;
  DBUS_METHOD_CALL="playurl string:"${URL}
else
  invalid_params;
fi

# Check whether vagalume is or not already running
VAGALUME_RUNNING=`ps aux | grep -e vagalume | grep -v grep | grep -v vagalume-dbus > /dev/null ; echo $?`
if [ ${VAGALUME_RUNNING} -ne 0 ]; then
  if [ ${COMMAND} != "close" ] && [ ${COMMAND} != "start" ]; then
      echo "Vagalume not running: starting..."
      dbus-send --type=method_call \
          --dest=${DBUS_SERVICE} ${DBUS_OBJECT} ${DBUS_IFACE}.${DBUS_METHOD_TOPAPP}
      sleep ${STARTUP_DELAY}
  elif [ ${COMMAND} == "close" ]; then
      # Exit cleanly without executing the 'close' command when Vagalume is not running
      echo "Vagalume not running: no need to close it";
      exit 0;
  fi
elif [ ${COMMAND} == "start" ]; then
    echo "Vagalume already running.";
    exit 0;
fi

# At last, execute the command
dbus-send --type=method_call \
          --dest=${DBUS_SERVICE} ${DBUS_OBJECT} ${DBUS_IFACE}.${DBUS_METHOD_CALL}

echo "Command '"$COMMAND"' successfully executed"