#!/usr/bin/env python3

import subprocess
import pyinotify
import logging
import io
import time
import os
import shutil
import multiprocessing
import logging.handlers

indir = "upload/convert/"
outdir = "upload/"
faildir = "upload/fail/"

logf = "[%(name)s] %(levelname)s: %(message)s"
logging.basicConfig(format=logf)

class Worker(multiprocessing.Process):
    def __init__(self, path):
        super(Worker, self).__init__()

        self.path = path
        self.basename = path.rpartition("/")[-1].rpartition(".")[0]
        self.ext = path.rpartition(".")[-1]
        self.time = int(time.time())

        self.string = io.StringIO()
        self.logger = logging.getLogger("mp4conv")
        self.handler = logging.StreamHandler(self.string)
        self.logger.addHandler(self.handler)
        self.logger.setLevel(logging.DEBUG)

    def subprocess_logger(self, output):
        for line in io.TextIOWrapper(output, encoding="utf-8"):
            self.logger.debug("(ffmpeg - %s) %r" % (self.basename, line))

    def build_command(self):
        return ["ffmpeg", "-i", self.path, "-vcodec", "h264", "-acodec", "aac",
                "-strict", "-2", "%s/%s_%i.tmp.mp4" % (outdir, self.basename, 
                self.time), "-nostats", "-hide_banner"]

    def process(self):
        self.logger.info("Discovered file %s." % self.path)

        time.sleep(5)
        if not os.path.exists(self.path):
            self.logger.info("File %s disappeared." % self.path)
            return self.string

        self.logger.info("Starting to process %s." % self.path)

        try:
            sub = subprocess.Popen(self.build_command(), stdout=subprocess.PIPE,
                    stderr=subprocess.STDOUT)

            with sub.stdout as output:
                self.subprocess_logger(output)

            assert not sub.wait()

            os.rename("%s/%s_%i.tmp.mp4" % (outdir, self.basename, self.time),
                    "%s/%s_%i.mp4" % (outdir, self.basename, self.time))

            if os.path.exists(self.path):
                os.unlink(self.path)
        
        except Exception as e:
            self.logger.exception("Something went wrong. See the log file.")

            with open("%s/%s_%i.log" % (faildir, self.basename, 
                    self.time), "w+") as logfile:
                        self.string.seek(0)
                        shutil.copyfileobj(self.string, logfile)

            os.rename(self.path, "%s/%s_%i.%s" % (faildir, self.basename, 
                    self.time, self.ext))

        finally:
            return self.string

    def run(self):
        self.process()

class Handler(pyinotify.ProcessEvent):
    def process_IN_CLOSE_WRITE(self, event):
        Worker(event.pathname).start()

    def process_IN_MOVED_TO(self, event):
        self.process_IN_CLOSE_WRITE(event)


def runner():
    watch = pyinotify.WatchManager()
    event = pyinotify.IN_CLOSE_WRITE | pyinotify.IN_MOVED_TO

    notifier = pyinotify.ThreadedNotifier(watch, Handler())
    watch.add_watch(indir, event, rec=True)
    notifier.start()

if __name__ == "__main__":
    runner()