#!/usr/bin/env python3

# Simple media player with GStreamer
#
# Copyright (C) 2013-2014  Antonio Ospite <ao2@ao2.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 gi
gi.require_version('Gst', '1.0')
from gi.repository import Gst
Gst.init(None)

from gi.repository import GLib
from gi.repository import GObject

# 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.ElementFactory.make('queue', 'vqueue')
        self.add(queue)

        rescale = Gst.ElementFactory.make("videoscale", "rescale")
        self.add(rescale)
        queue.link(rescale)

        caps = Gst.Caps("video/x-raw,format=(fourcc)AYUV,width=%d,height=%d,pixel-aspect-ratio=1/1" % (WIDTH, HEIGHT))
        capsfilter = Gst.ElementFactory.make("capsfilter", "filter")
        capsfilter.set_property("caps", caps)
        self.add(capsfilter)
        rescale.link(capsfilter)

        videoconvert = Gst.ElementFactory.make("videoconvert", "videoconvert")
        self.add(videoconvert)
        capsfilter.link(videoconvert)

        videosink = Gst.ElementFactory.make("autovideosink", "vidoesink")
        self.add(videosink)
        videoconvert.link(videosink)

        sink = queue.get_static_pad('sink')
        self.add_pad(Gst.GhostPad('sink', sink))


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

        queue = Gst.ElementFactory.make('queue', 'aqueue')
        self.add(queue)

        audioconvert = Gst.ElementFactory.make("audioconvert", "audioconverter")
        self.add(audioconvert)
        queue.link(audioconvert)

        audiosink = Gst.ElementFactory.make("autoaudiosink", "audiosink")
        self.add(audiosink)
        audioconvert.link(audiosink)

        sink = queue.get_static_pad('sink')
        self.add_pad(Gst.GhostPad('sink', sink))


class CustomPlayBin(Gst.Pipeline):
    __gproperties__ = {
        'source': (Gst.Element, "source", "Source element", GObject.ParamFlags.READABLE)
    }

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

        self._playbin = Gst.ElementFactory.make("playbin", "playbin")
        self.add(self._playbin)

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

        if uri:
            self.set_uri(uri)

    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()
        print('\t', taglist.to_string())

    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 = GLib.MainLoop()

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

        GLib.io_add_watch(sys.stdin, GLib.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)

    uri = Gst.filename_to_uri(args[1])

    tui = PlayerTUI(uri)

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