import os

import subprocess

import config

env = dict(os.environ)

env['LANG']='C'

def printerr(r):

    print('process returned with error:', r.returncode)

    print('command:', r.args)

    print('output:', r.stdout)

    print('error:', r.stderr)

    return

def ffmpeg(src, dst):

    r = subprocess.run(

        [ config.ffprobe, '-v', 'error',  '-show_entries', 'format=duration:stream=codec_type', '-of', 'default=noprint_wrappers=1', src ],

        capture_output = True, text = True, env = env )

    if r.returncode: return #printerr(r)

    video = False; audio = False; duration = 0

    for l in r.stdout.split():

        f = l.split('=', 1)

        if len(f) != 2: continue

        if l == 'codec_type=video': video = True

        if l == 'codec_type=audio': audio = True

        if l.startswith('duration='):

            try: duration = float(l[9:])

            except ValueError: pass

    if not duration: return

    if video:

        filters = "select='gte(t,%f)',thumbnail,scale=%d:%d:force_original_aspect_ratio=decrease:force_divisible_by=2" % (duration/4, config.thumbw, config.thumbh)

        r = subprocess.run(

            [ config.ffmpeg, '-i', src, '-vf', filters, '-frames:v', '1', '-y', dst ],

            capture_output = True, text = True, env = env )

        #if r.returncode: printerr(r)

        if not r.returncode and os.path.isfile(dst): return dst

    if audio:

        filters = "showwavespic=s=%dx%d:scale=sqrt:colors=%06x" % (config.thumbw, config.thumbh, config.thumbcolor)

        r = subprocess.run(

            [ config.ffmpeg, '-i', src, '-filter_complex', filters, '-frames:v', '1', '-y', dst ],

            capture_output = True, text = True, env = env )

        #if r.returncode: printerr(r)

        if not r.returncode and os.path.isfile(dst): return dst

def magick(src, dst):

    r = subprocess.run(

        [ config.magick, src, '-resize',  '%dx%d>' % (config.thumbw, config.thumbh), dst ],

        capture_output = True, text = True, env = env )

    if r.returncode: return #printerr(r)

    if not r.returncode and os.path.isfile(dst): return dst

def make(src, dst):

    return ffmpeg(src, dst) or magick(src, dst)