#!/usr/bin/python3
import math
import json
import os
import subprocess
import sys
import ox

def run(cmd):
    #print(' '.join('"%s"' % c for c in cmd))
    subprocess.call(cmd)


edit_json = sys.argv[1]
edit = json.load(open(edit_json))

render = './cache'
output = os.path.splitext(edit_json)[0] + '.mp4'
height = 480
aspect = 16/9
width = int(height * aspect)
width -= width % 2

if not os.path.exists(render):
    os.makedirs(render)

files = []
edit_duration = 0
subtitles = []
position = 0
for clip in edit:
    out = render + '/%s_%0.3f-%0.3f.ts' % (clip['oshash'], clip['in'], clip['out'])
    edit_duration += (clip['out']-clip['in'])
    files.append(out)
    if os.path.exists(out):
        duration = ox.avinfo(out)['duration']
        if clip['subtitles']:
            subtitles.append({
                'in': position,
                'out': position+duration,
                'value': clip['subtitles']
            })
        position += duration
        print(out, duration, (clip['out'] - clip['in']))
        continue
    clip_aspect = clip['resolution'][0] / clip['resolution'][1]
    if clip_aspect < aspect:
        x = width
        y = int(x / clip_aspect)
        y -= y % 2
    else:
        y = height
        x = int(y * clip_aspect)
        x -= x % 2
    vf = 'scale=%s:%s' % (x, y)
    if x != width:
        vf += ',crop=%s:%s' % (width, height)  # crop center
    elif y != height:
        offset = int(((y - height) / 3))
        vf += ',crop=w=%s:h=%s:x=0:y=%s' % (width, height, offset)
    options = [
        '-map_metadata', '-1',
        '-vf', vf,
        '-aspect', str(aspect),
        '-c:v', 'libx264',
        '-b:v', '2M',
        '-preset:v', 'medium', '-profile:v', 'high', '-level:v', '4.0',
        '-map', '0:0,0:0', '-map', '0:1,0:1',
        '-r', '25',
        '-c:a', 'aac',
        '-ar', '48000',
        '-ac', '2',
        '-b:a', '192k',
    ]
    clip_duration = math.ceil((clip['out'] - clip['in']) / (1/25)) * 1/25

    cmd = [
        'ffmpeg',
        '-nostats', '-loglevel', 'error',
        '-ss', str(clip['in']),
        '-i', clip['path']
    ] + options + [
        '-t', str(clip_duration),
        out
    ]
    run(cmd)
    duration = ox.avinfo(out)['duration']
    if clip['subtitles']:
        subtitles.append({
            'in': position,
            'out': position+duration,
            'value': clip['subtitles']
        })
    position += duration
    print(out, duration, (clip['out'] - clip['in']))

txt = output + '.txt'
with open(txt, 'w') as fd:
    fd.write('file ' + '\nfile '.join(files))
cmd = ['ffmpeg', '-y', '-f', 'concat', '-safe', '0', '-i', txt, '-c', 'copy', output]
run(cmd)
os.unlink(txt)

srt = output.replace('.mp4', '.srt')

with open(srt, 'wb') as fd:
    fd.write(ox.srt.encode(subtitles))

duration = ox.avinfo(output)['duration']
print('file is %d, edit should be %d' % (duration, edit_duration))