#! /usr/bin/env python3

import youtube_dl
import json
import ffmpeg
import subprocess
import glob
import sys
import argparse
import os

# bitrate recommendations as from https://developers.google.com/media/vp9/settings/vod
bitrateProfiles = {
	    "240": {"heigth":  240, "bitrate": "150k",   "minrate":   "75k", "maxrate":   "218k"},
	    "360": {"heigth":  360, "bitrate": "276k",   "minrate":  "138k", "maxrate":   "400k"},
	  "480LQ": {"heigth":  480, "bitrate": "512k",   "minrate":  "256k", "maxrate":   "742k"},
	  "480MQ": {"heigth":  480, "bitrate": "750k",   "minrate":  "375k", "maxrate":  "1088k"},
	 "720@30": {"heigth":  720, "bitrate": "1024k",  "minrate":  "512k", "maxrate":  "1485k"},
	 "720@60": {"heigth":  720, "bitrate": "1800k",  "minrate":  "900k", "maxrate":  "2610k"},
	"1080@30": {"heigth": 1080, "bitrate": "1800k",  "minrate":  "900k", "maxrate":  "2610k"},
	"1080@60": {"heigth": 1080, "bitrate": "3000k",  "minrate": "1500k", "maxrate":  "4350k"},
	"1440@30": {"heigth": 1440, "bitrate": "6000k",  "minrate": "3000k", "maxrate":  "8700k"},
	"1440@60": {"heigth": 1440, "bitrate": "9000k",  "minrate": "4500k", "maxrate": "13050k"},
	"2160@30": {"heigth": 2160, "bitrate": "12000k", "minrate": "6000k", "maxrate": "17400k"},
	"2160@60": {"heigth": 2160, "bitrate": "18000k", "minrate": "9000k", "maxrate": "26100k"},
}

config = {
	'vcodec': "vp9",
	'acodec': "libopus",
	'bitrateProfile': "480LQ",
	'quality': "best",
}

def generate_thumbnail(in_filename, out_filename, time, height):
    try:
        (
            ffmpeg
            .input(in_filename, ss=time)
            .filter('scale', -2, height)
            .output(out_filename, vframes=1)
            .overwrite_output()
            .run(capture_stdout=True, capture_stderr=True)
        )
    except ffmpeg.Error as e:
        print(e.stderr.decode(), file=sys.stderr)
        sys.exit(1)

# setting width and height from hardcoded defaults -> configured defaults -> clip
def getDimensions(config, clip, bitrateProfiles):
	# set width and height to a default
	w, h = -2, 480
	# set the height by the bitrateProfile
	try:
		h = bitrateProfiles[config['bitrateProfile']]['height']
	except:
		pass
	# overwrite it with the scaling
	if 'scale' in clip:
		h = clip['scale']['h'] if 'h' in clip['scale'] else h
		w = clip['scale']['w'] if 'w' in clip['scale'] else w

	return w, h

def twoPassEncode(inputFilename, clip):
	if os.path.isfile(clip['target']):
		print(f"{clip['target']} already existing! Skipping!")
		return
	# cutting
	kwArgs = {}
	if 'from' in clip:
		kwArgs['ss'] = clip['from']
	if 'to' in clip:
		kwArgs['to'] = clip['to']

	stream = ffmpeg.input( inputFilename, **kwArgs)

	video, audio = stream.video, stream.audio

	if 'crop' in clip:
		stream = ffmpeg.filter(stream, 
			"crop",
			x=clip['crop']['x'],
			y=clip['crop']['y'],
			w=clip['crop']['w'],
			h=clip['crop']['h']
		)

	stream = ffmpeg.output(stream, 
		# clip['target'], 
		"/dev/null",
		vcodec=config['vcodec'], 
		**{
			"an": None,
			"y": None, 
			"f": "null", 
			"pass": "1", 
			"b:v":     bitrateProfiles[config['bitrateProfile']]['bitrate'],
			"minrate": bitrateProfiles[config['bitrateProfile']]['minrate'],
			"maxrate": bitrateProfiles[config['bitrateProfile']]['maxrate'],
			"quality": config['quality'] if 'quality' in config else "best", 
		}
	)
	try:
		ffmpeg.run(stream)
	except:
		print(infoDict)


	if 'from' in clip and 'to' in clip:
		stream = ffmpeg.input(
			glob.glob(infoDict['id']+"*")[0], 
			ss=clip['from'], 
			to=clip['to'], 
		)
	else:
		stream = ffmpeg.input(
			glob.glob(infoDict['id']+"*")[0]
		)
	if 'crop' in clip:
		stream = ffmpeg.filter(stream, 
			"crop",
			x=clip['crop']['x'],
			y=clip['crop']['y'],
			w=clip['crop']['w'],
			h=clip['crop']['h']
		)

	h, w = getDimensions(config, clip, bitrateProfiles)

	stream = ffmpeg.output(stream, audio, 
		clip['target'], 
		vcodec=config['vcodec'], 
		**{
			"pass": "2", 
			"b:v":     bitrateProfiles[config['bitrateProfile']]['bitrate'],
			"minrate": bitrateProfiles[config['bitrateProfile']]['minrate'],
			"maxrate": bitrateProfiles[config['bitrateProfile']]['maxrate'],
			"quality": config['quality'] if 'quality' in config else "best", 
			"acodec": config['acodec'],
		}
	)
	try:
		ffmpeg.run(stream)
	except:
		print(infoDict)


argParser = argparse.ArgumentParser()

jsonFileName = sys.argv[1]

clipDict = {}
with open(jsonFileName) as jf:
	clipDict = json.load(jf)

ydl_opts = {"outtmpl": "%(id)s"}

for clip in clipDict:
	# create the directories so ffmpeg doesn't complain
	try:
		outputDir = os.path.dirname(clip['target'])
		os.makedirs(outputDir)
	except:
		print(f"Couldn't create {outputDir}")

	infoDict = None
	with youtube_dl.YoutubeDL(ydl_opts) as ydl:
		infoDict = ydl.extract_info(clip['source'], download=False)
		ydl.download([clip['source']])
		
	if infoDict is not None:
		# @todo This is a very bad hack because the outtmpl options doesn't seem to be working if the file gets reencoded
		inputFilename = glob.glob(infoDict['id']+"*")[0]

		w, h = getDimensions(config, clip, bitrateProfiles)

		# generate preview image for the video
		if 'poster' in clip:
			generate_thumbnail(inputFilename, os.path.splitext(clip['target'])[0]+".jpg", clip['poster']['timeIndex'], h )

		twoPassEncode(inputFilename, clip)