#!/usr/bin/env python

# export-video.py
# ---------------
# little python script to encode vide file for the web
#

import sys
import getopt
import re
import os
import subprocess
import logging
logging.basicConfig(format='%(levelname)s:%(message)s', level=logging.DEBUG)


def usage():
    print("export-video -i input -o output [-d --desinterlace]")

params = {
    "desinterlace": False,
    "file_output": "",
    "file_input": "",
    "vbitrate": "600k",
    "abitrate": "96k",
    "h264_vcommand": [
        "-trellis", "0",
        "-me_method", "umh",
        "-subq", "8",
        "-me_range", "16",
        "-bf", "3",
        "-rc_lookahead", "16",
        "-g", "250"
    ],
    "h264_acommand":  ["-strict", "experimental"],
    "webm_vcommand": [
        "-rc_lookahead", "16",
        "-keyint_min", "0"
        "-g", "250",
        "-skip_threshold", "0",
        "-level", "116"
    ],
    "webm_acommand": ["-strict", "experimental"],
    "verbose": True,
    "pattern": "",
    "twopass": False,
    "recursive": False}

VERSION = "0.1dev"


def execute(command, shell=False):
    """
    Execute a system command and return its results.
    Thanxx Strycote from Lutris.net
    """
    try:
        stdout, stderr = subprocess.Popen(command,
                                          shell=shell,
                                          stdout=subprocess.PIPE,
                                          stderr=subprocess.PIPE).communicate()
    except OSError as ex:
        logging.error('Could not run command %s: %s', command, ex)
        return
    return stdout.strip()


def find_executable(exec_name):
    if not exec_name:
        raise ValueError("find_executable: exec_name required")
    return execute(['which', exec_name])


def listFile(directory, pattern, recursive):
    logging.info('searching in directory %s', directory)
    files_list = []
    try:
        dirs = os.listdir(directory)
    except:
        logging.error('error : %s not a directory?', directory)
        return

    for i in dirs:
        if os.path.isdir(directory + "/" + i) and recursive:
            logging.info('directory found : %s', i)
            files_list.extend(listFile(directory + "/" + i, pattern))
        else:
            if re.search(pattern, i) is not None:
                logging.info('file found : %s', i)
                files_list.append(directory + "/" + i)
    return files_list


def get_file_name(path):
    return os.path.splitext(os.path.basename(path))[0]


def process_arg(sysarg):
    try:
        opts, args = getopt.getopt(
            sysarg, "hi:o:dp:a:v:2",
            [
                "help",
                "input=",
                "output=",
                "desinterlace",
                "pattern=",
                "abitrate=",
                "vbitrate=",
                "twopass"
            ]
        )
    except getopt.GetoptError:
        usage()
        sys.exit(2)
    for opt, arg in opts:
        if opt in ("-h", "--help"):
            usage()
            sys.exit()
        if opt in ("-o", "--output"):
            params["file_output"] = arg
        if opt in ("-d", "--desinterlace"):
            logging.info("Desinterlace activated")
            params["h264_vcommand"] += ["-vf", "yadif"]
            params["webm_vcommand"] += ["-vf", "yadif"]
        if opt in ("-i", "--input"):
            params["file_input"] = arg
        if opt in ("-p", "--pattern"):
            params["pattern"] = "^\\w*."+arg+"$"
        if opt in ("-a", "--abitrate"):
            params["abitrate"] = arg
        if opt in ("-v", "--vbitrate"):
            params["vbitrate"] = arg
        if opt in ("-2", "--twopass"):
            params["twopass"] = True
        if opt in ("-r", "--recursive"):
            params["recursive"] = True


def encode_h264(src, dest):
    if (params["twopass"]):
        logging.debug("two pass encoding started ...")
        firstpass = [
            exec_ffmpeg,
            "-y",
            "-i", src,
            "-codec:va", "libx264",
            "-b:v", params["vbitrate"],
            "-pass", "1",
        ] + params["h264_vcommand"] + [
            "-f", "rawvideo",
            "/dev/null"
        ]
        secondpass = [
            exec_ffmpeg,
            "-i", src,
            "-pass", "2",
            "-codec:v", "libx264",
            "-b:v ", params["vbitrate"]
        ] + params["h264_vcommand"] + [
            "-b:a", params["abitrate"]
        ] + params["h264_acommand"] + [
            dest+".mp4"
        ]
        execute(firstpass)
        execute(secondpass)
    else:
        logging.debug("one pass encoding started ...")
        encode = [
            exec_ffmpeg,
            "-i", src,
            "-codec:v", "libx264",
            "-b:v ", params["vbitrate"]
        ] + params["h264_vcommand"] + [
            "-b:a", params["abitrate"]
        ] + params["h264_acommand"] + [
            dest+".mp4",
        ]
        logging.debug(encode)
        execute(encode)


if __name__ == "__main__":
    exec_ffmpeg = find_executable("ffmpeg")
    if not exec_ffmpeg:
        print('ffmpeg not found, exiting')
        sys.exit(2)
    process_arg(sys.argv[1:])
    if not params["file_input"]:
        print("you must specify a file / directory input")
        sys.exit(2)
    if os.path.isdir(params["file_input"]):
        if os.path.isfile(params["file_output"]):
            print("Can't batch export to a single file! Bye Bye")
            sys.exit(2)
        logging.info('%s is a directory', params["file_input"])
        video_files = listFile(
                params["file_input"],
                params["pattern"],
                params["recursive"]
            )
        for f in video_files:
            logging.info('batch encode | file %s to %s', f)
            encode_h264(f, params["file_output"] + get_file_name(f))
    else:
        if os.path.isfile(params["file_input"]):
            if not params["file_output"]:
                params["file_output"] = get_file_name(params["file_input"])
            else:
                if(os.path.isdir(params["file_output"])):
                    params["file_input"] += get_file_name(params["file_input"])
            logging.info('%s is a file', params["file_input"])
            encode_h264(params["file_input"], params["file_output"])
        else:
            logging.info("input file desn't exist, bye bye")
            sys.exit(2)
    sys.exit(0)