#!/usr/bin/python3
import sys
import gi
gi.require_version('Gst', '1.0')
from gi.repository import Gst
import time
import threading
import os
import stat

def mkfifo(fifo):
    if os.path.exists(fifo):
        if stat.S_ISFIFO(os.stat(fifo).st_mode):
            pass
        else:
            os.remove(fifo)
            os.mkfifo(fifo)
    else:
        os.mkfifo(fifo)

def control():
    global pads
    FIFO="/tmp/fifo"
    mkfifo(FIFO)

    idx = 0
    while True:
        with open(FIFO) as fifo:
            line=fifo.read().strip()
            if "=" not in line:
                print("Invalid line.")
                continue
            key = line.split("=")[0]
            val = line.split("=")[1]

            if key == "switch":
                idx = (idx+1) % len(pads)
                switch(idx)

def switch(idx):
    global pads
    global pipeline
    global switcher

    newpad = switcher.get_static_pad(pads[idx])
    pipeline.set_state(Gst.State.PAUSED)
    switcher.set_property('active-pad', newpad)
    pipeline.set_state(Gst.State.PLAYING)

if __name__ == "__main__":
    # initialization

    Gst.init(None)
    Gst.debug_set_active(True)
    Gst.debug_set_default_threshold(3)

    img = "multifilesrc name=img location=logo.png ! pngdec ! imagefreeze ! videobox border-alpha=0 top=-180 left=-10 ! mix."
    out = "x264enc ! mpegtsmux ! filesink location=out.mp4"
    out = "autovideosink sync=false "
    inputs = [
                "videotestsrc do-timestamp=true pattern=0 ! video/x-raw,width=800,height=600",
                "multifilesrc do-timestamp=true location=regret.png ! pngdec ! imagefreeze",
                "videotestsrc do-timestamp=true pattern=1 ! video/x-raw,width=800,height=600",
                "rtmpsrc      do-timestamp=true name=rtmp location=rtmp://192.168.2.120:1935/test/movie ! flvdemux ! decodebin ! videoconvert",
             ]

    p = "videomixer name=mix ! videoconvert ! " + out +  " ! in. ".join(inputs) + " ! in. input-selector sync-streams=true sync-mode=1 name=in ! mix. " + img
    print(p)
    pipeline = Gst.parse_launch (p)
    if pipeline == None:
        print ("Failed to create pipeline")
        sys.exit(0)

    # run
    switcher = pipeline.get_by_name('in')
    i = pipeline.get_by_name('img')
    #pads = [ p.get_name() for p in switch.pads if p.get_direction() == Gst.PadDirection.GST_PAD_SINK ]
    pads = [ p.get_name() for p in switcher.pads if p.get_name() != "src" ]

    pipeline.set_state(Gst.State.PLAYING)
    t = threading.Thread(target=control, daemon=True)
    t.start()

    while True:
        time.sleep(10)
    # cleanup
    pipeline.set_state(Gst.State.NULL)