#!/usr/bin/env python

# Simple media player with GStreamer
#
# Copyright (C) 2013  Antonio Ospite <ospite@studenti.unina.it>
#
# 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, see <http://www.gnu.org/licenses/>.

# References:
# http://pygstdocs.berlios.de/pygst-reference
# https://core.fluendo.com/gstreamer/svn/trunk/gst-fluendo-gdlsink/test/ismdplay.py

import sys
import os

import gobject
gobject.threads_init()

import gst

# The player window will have a fixed width and height.
# This is just to demonstrate the use of capabilities.
WIDTH = 640
HEIGHT = 300


class CustomVideoBin(gst.Bin):
    def __init__(self):
        gst.Bin.__init__(self, 'CustomVideoBin')

        queue = gst.element_factory_make('queue', 'vqueue')
        self.add(queue)

        caps = gst.Caps("video/x-raw-yuv,format=(fourcc)AYUV,width=%d,height=%d" % (WIDTH, HEIGHT))
        capsfilter = gst.element_factory_make("capsfilter", "filter")
        capsfilter.set_property("caps", caps)
        self.add(capsfilter)

        rescale = gst.element_factory_make("videoscale", "rescale")
        self.add(rescale)

        colorspace = gst.element_factory_make("colorspace", "colorspace")
        self.add(colorspace)

        videosink = gst.element_factory_make("autovideosink", "vidoesink")
        self.add(videosink)

        gst.element_link_many(queue, capsfilter, rescale, colorspace, videosink)
        sink = queue.get_pad('sink')
        self.add_pad(gst.GhostPad('sink', sink))


class CustomAudioBin(gst.Bin):
    def __init__(self):
        gst.Bin.__init__(self, 'CustomAudioBin')

        queue = gst.element_factory_make('queue', 'aqueue')
        self.add(queue)

        audioconvert = gst.element_factory_make("audioconvert", "audioconverter")
        self.add(audioconvert)

        audiosink = gst.element_factory_make("autoaudiosink", "audiosink")
        self.add(audiosink)

        gst.element_link_many(queue, audioconvert, audiosink)
        sink = queue.get_pad('sink')
        self.add_pad(gst.GhostPad('sink', sink))


class CustomPlayBin(gst.Pipeline):
    __gproperties__ = {
        'source': (gst.Element, "source", "Source element", gobject.PARAM_READABLE)
    }

    def __init__(self, uri=None):
        gst.Pipeline.__init__(self, 'CustomPlayBin')

        self._uri = uri

        self._playbin = gst.element_factory_make("playbin2", "playbin")
        self.add(self._playbin)

        self._playbin.set_property("uri", self._uri)
        self._playbin.set_property("video-sink", CustomVideoBin())
        self._playbin.set_property("audio-sink", CustomAudioBin())

    def set_uri(self, uri):
        self._uri = uri
        self._playbin.set_property("uri", self._uri)


class GstPlayer:
    def __init__(self):

        # The user can require some action at End Of Stream
        self.eos_cb = None

        self.pipeline = CustomPlayBin()

        bus = self.pipeline.get_bus()
        bus.add_signal_watch()
        bus.connect('message::eos', self.on_eos)
        bus.connect('message::tag', self.on_tag)
        bus.connect('message::error', self.on_error)
        bus.connect('message::state-changed', self.on_state_changed)

    def on_eos(self, bus, msg):
        print 'on_eos'
        self.stop()
        if self.eos_cb:
            self.eos_cb()

    def on_tag(self, bus, msg):
        print 'on_tag:'
        taglist = msg.parse_tag()
        for key in taglist.keys():
            print '\t%s = %s' % (key, taglist[key])

    def on_error(self, bus, msg):
        print 'on_error'
        error, debug = msg.parse_error()
        print "Error: %s" % error, debug
        self.stop()

    def on_state_changed(self, bus, msg):
        print 'on_state_changed'
        if msg.src != self.pipeline:
            return

        old_state, new_state, pending = msg.parse_state_changed()

    def set_location(self, location):
        self.pipeline.set_uri(location)

    def play(self):
        self.pipeline.set_state(gst.STATE_PLAYING)

    def pause(self):
        self.pipeline.set_state(gst.STATE_PAUSED)

    def stop(self):
        self.pipeline.set_state(gst.STATE_NULL)


class PlayerTUI():
    def __init__(self, location):

        self.player = GstPlayer()
        self.player.eos_cb = self.quit

        self.mainloop = gobject.MainLoop()

        self.player.set_location(location)
        self.player.play()

        gobject.io_add_watch(sys.stdin, gobject.IO_IN, self.on_stdin)

        try:
            self.mainloop.run()
        except KeyboardInterrupt:
            self.quit()

    def on_stdin(self, fd, event):
        # The user has to send a newline fo this to go on
        c = os.read(fd.fileno(), 1)

        if c == "q":
            self.quit()
        elif c == "s":
            self.player.pause()
        elif c == "r":
            self.player.play()

        return True

    def quit(self):
        self.player.stop()
        self.player = None
        self.mainloop.quit()


def main(args):
    def usage():
        sys.stdout.write("usage: %s <URI-OF-MEDIA-FILE>\n" % args[0])

    if len(args) != 2:
        usage()
        sys.exit(1)

    if not gst.uri_is_valid(args[1]):
        sys.stderr.write("Error: Invalid URI: %s\n" % args[1])
        sys.exit(1)

    tui = PlayerTUI(args[1])

if __name__ == '__main__':
    sys.exit(main(sys.argv))