#!/usr/bin/python3
import json
import os
import subprocess
import sys
import time

import ox
from .pi import random
from .render_kdenlive import KDEnliveProject


def random_choice(seq, items, pop=False):
    n = n_ = len(items) - 1
    #print('len', n)
    if n == 0:
        if pop:
            return items.pop(n)
        return items[n]
    r = seq()
    base = 10
    while n > 10:
        n /= 10
        #print(r)
        r += seq()
        base += 10
    r = int(n_ * r / base)
    #print('result', r, items)
    if pop:
        return items.pop(r)
    return items[r]

def chance(seq, chance):
    return (seq() / 10) >= chance


def compose(clips, target=150, base=1024):
    length = 0
    scene = {
        'front': {
            'V1': [],
            'V2': [],
        },
        'back': {
            'V1': [],
            'V2': [],
        },
        'audio': {
            'A1': [],
            'A2': [],
            'A3': [],
            'A4': [],
        }
    }
    all_clips = clips.copy()
    seq = random(base)
    while target - length > 0 and clips:
        clip = random_choice(seq, clips, True)
        if not clips:
            clips = [c for c in all_clips if c != clip]
            if not clips:
                clips = all_clips.copy()
        if length + clip['duration'] > target:
            break
        length += clip['duration']

        fg = clip['foreground']
        if 'foreground2' in clip:
            if chance(seq, 0.5):
                fg = clip['foreground2']

        scene['front']['V1'].append({
            'duration': clip['duration'],
            'src': fg,
            "filter": {
                'transparency': seq() / 10,
            }
        })

        transparency = seq() / 10
        # coin flip which site is visible (50% chance)
        if chance(seq, 0.5):
            transparency_front = transparency
            transparency_back = 0
        else:
            transparency_back = transparency
            transparency_front = 0
        scene['front']['V2'].append({
            'duration': clip['duration'],
            'src': clip['background'],
            "filter": {
                'transparency': transparency_front
            }
        })
        scene['back']['V1'].append({
            'duration': clip['duration'],
            'src': clip['background'],
            "filter": {
                'transparency': transparency_back
            }
        })
        scene['back']['V2'].append({
            'duration': clip['duration'],
            'src': clip['original'],
            "filter": {
                'transparency': seq() / 10,
            }
        })
        # 50 % chance to blur original from 0 to 30
        if chance(seq, 0.5):
            blur = seq() * 3
            if blur:
                scene['back']['V2'][-1]['filter']['blur'] = blur
        scene['audio']['A1'].append({
            'duration': clip['duration'],
            'src': clip['original'],
        })
        scene['audio']['A2'].append({
            'duration': clip['duration'],
            'src': fg,
        })
    return scene

def get_scene_duration(scene):
    duration = 0
    for key, value in scene.items():
        for name, clips in value.items():
            for clip in clips:
                duration += clip['duration']
            return duration

def render(root, scene, prefix=''):
    fps = 24
    files = []
    for timeline, data in scene.items():
        #print(timeline)
        project = KDEnliveProject(root)

        tracks = []
        for track, clips in data.items():
            #print(track)
            for clip in clips:
                project.append_clip(track, clip)
        path = os.path.join(root, prefix + "%s.kdenlive" % timeline)
        with open(path, 'w') as fd:
            fd.write(project.to_xml())
        files.append(path)
    return files

def get_fragments(clips):
    import itemlist.models
    fragments = []
    for l in itemlist.models.List.objects.filter(status='featured').order_by('name'):
        if l.name.split(' ')[0].isdigit():
            fragment = {
                'name': l.name,
                'tags': [t['value'] for t in l.query['conditions'][1]['conditions']],
                'description': l.description
            }
            fragment['clips'] = []
            for clip in clips:
                if set(clip['tags']) & set(fragment['tags']):
                    fragment['clips'].append(clip)
            fragments.append(fragment)
    fragments.sort(key=lambda f: ox.sort_string(f['name']))
    return fragments


def render_all(options):
    prefix = options['prefix']
    duration = int(options['duration'])
    base = int(options['offset'])

    with open(os.path.join(prefix, "clips.json")) as fd:
        clips = json.load(fd)

    fragments = get_fragments(clips)
    position = target_position = 0
    target = fragment_target = duration / len(fragments)
    base_prefix = os.path.join(prefix, 'render', str(base))
    for fragment in fragments:
        n = int(fragment['name'].split(' ')[0])
        name = fragment['name'].replace(' ', '_')
        if n < 10:
            name = '0' + name
        if not fragment['clips']:
            print("skipping empty fragment", name)
            continue
        fragment_prefix = os.path.join(base_prefix, name)
        os.makedirs(fragment_prefix, exist_ok=True)

        scene = compose(fragment['clips'], target=target, base=base)
        scene_duration = get_scene_duration(scene)
        print("%s %s -> %s (%s)" % (name, target, scene_duration, fragment_target))
        position += scene_duration
        target_position += fragment_target
        if position > target_position:
            target = fragment_target - (position-target_position)
            print("adjusting target from", fragment_target, target)
        elif position < target_position:
            target = target + 0.1 * fragment_target

        timelines = render(prefix, scene, fragment_prefix[len(prefix) + 1:] + '/')

        with open(os.path.join(fragment_prefix, 'scene.json'), 'w') as fd:
            json.dump(scene, fd, indent=2, ensure_ascii=False)

        if not options['no_video']:
            for timeline in timelines:
                ext = '.mp4'
                if '-audio.kdenlive' in timeline:
                    ext = '.wav'
                cmd = [
                    'xvfb-run', '-a',
                    'melt', timeline,
                    '-consumer', 'avformat:%s' % timeline.replace('.kdenlive', ext)
                ]
                subprocess.call(cmd)
                if ext == '.wav':
                    cmd = [
                        'ffmpeg', '-i',
                        timeline.replace('.kdenlive', ext),
                        timeline.replace('.kdenlive', '.mp4')
                    ]
                    subprocess.call(cmd)
                    os.unlink(timeline.replace('.kdenlive', ext))
    print("Duration - Target: %s Actual: %s" % (target_position, position))