"""
Convert Image sequence to Mp4 Format
Uses ffmpeg.exe
Documentation : https://www.ffmpeg.org/ffmpeg.html

Ref to Ruby version here
//[Project]/tools/script/video/
"""

import os
import re
import sys
import time
import getopt
import subprocess

# LD_Keep
ff_profile = "ld"
crf_setting = "25"

TOOLS_BIN = "{}\\Bin".format(os.environ.get('RS_TOOLSROOT'))
FFMPEG_BIN = "{}\\video\\ffmpeg.exe".format(TOOLS_BIN)


def ffmpeg(input_file, output_file, *command_order, **command_parameters):
    """
    Converts a video or set of images into another video format

    This command accepts all the flags that the command line version does as
    keyword arguements. Please refer to the ffmpeg documentation to learn
    what arguments this command accepts.

    When using keyword arguments the positioning of the arguments is not saved
    and will be randomly placed. If you need to

    Keyword values can't be used more than once in python, so if you need to use
    the same flag with different values concecutively, pass the values inside a list

    e.i.

    ffmpeg -i stereo.wav -map 0:0 -map 0:0 -map_channel 0.0.0:0.0 -map_channel 0.0.1:0.1 -y out.ogg

    If you need a specific order and multiple values then you would write it as

    ffmpeg('stereo.wav', 'out.ogg',
           'map', 'map', 'map_channel', 'map_channel',
           map=['0:0,0:0'], map_channel=['0.0.0:0.0','0.0.1:0.1'])

    Arguments:

        in_file: string or list[string, string, etc.]; path(s) to the image sequence(s) or video file(s) to convert.
        out_file: string; path where you want the new mp4 file to be saved out
        *command_order: list[string, string, etc.]; the order you want the flags the ffmpeg command to be in

    Keyword Arguments:

        Any flag that the ffmpeg.exe is accepted as a keyword arguement. If the flag is meant to be used multiple times
        then simply add the multiple values as a list to the keyword arguement.

    Returns:

         None
    """
    command_order = list(command_order)

    #Remove output flags if they are in command_parameters
    command_parameters.pop("o", None)
    command_parameters.pop("y", None)

    #Put the input value(s) into the command_parameters dictionary
    command_parameters["i"] = input_file

    #Convert all command_parameter value to lists if they are not lists already
    for each_flag, each_value in command_parameters.iteritems():

        if not isinstance(each_value, list):
            command_parameters[each_flag] = [each_value]

        if each_flag not in command_order:
            command_order.append(each_flag)

    #Add the i flag into the command order if it isn't there already
    if "i" not in command_order:
        #Insert "i" to the front of the list
        for each in command_parameters["i"]:
            command_order[0:0] = ["i"]

    #Build format string
    command_format = []
    for each in command_order:
        index = 0
        each = each.strip()
        while "{%s[%d]}" % (each, index) in command_format:
            index += 1
        command_format.append("-%s {%s[%d]} " % (each, each, index))
    command_format = "".join(command_format)

    #Build the command
    command = command_format.format(**command_parameters)
    command = r'{} {} -y {}'.format(FFMPEG_BIN, command, os.path.abspath(output_file))

    #Run command
    return subprocess.check_call(command, shell=True)


def convertToMp4(in_file, out_file=None):
    """
    Converts a given image sequence or video into a mp4 format video

    Arguments:

        in_file: string; path to the image sequence or video file to convert.
        out_file: string; path where you want the new mp4 file to be saved out

    Returns:

         None
    """
    flag_order = ['i', 'r', 'vf', 'pix_fmt', 'ar', 'f', 'vcodec', 'strict', 'acodec', 'vpre' , 'crf']

    #If an image sequence is passed, put the rate flag upfront to lower the byte rate
    if re.search('%0[0-9]+d', in_file):
        flag_order[0:0] = "r"

    #Resolve output file
    if not out_file:
        out_file = re.sub('-%0[0-9]+d', '', in_file)
        out_file = setExtension(out_file)

    return ffmpeg(in_file, out_file,
                  r=[30,30], vf="scale=960:520", pix_fmt="yuv420p", ar=44100, f="mp4", vcodec="libx264",
                  strict="experimental", acodec="aac", vpre=ff_profile, crf=crf_setting,
                  *flag_order)


def setExtension(filePath, extension='mp4'):
    """
    changes the extension of the given file to .mp4

    Arguments
        filePath: string ; path of the file that you want to change the extension of

        extension: string ; extension that you want to use, the default extension is mp4

    Return
        string ;  file path with updated extension
    """
    root = os.path.splitext(filePath)[0]
    return '{root}.{extension}'.format(root=root, extension=extension)
   
   
def main(argv):
    """
    Converts files to mp4g
    """
    inputfile = ''
    outputfile = ''

    #Get arguments
    try:
      opts, args = getopt.getopt(argv,"hi:o:",["ifile=","ofile="])
    except getopt.GetoptError:
      print 'sequenceToMp4.py -i <inputfile> -o <outputfile>'
      sys.exit(2)

    for opt, arg in opts:
      if opt == '-h':
         print 'sequenceToMp4.py -i <inputfile> -o <outputfile>'
         sys.exit()
      elif opt in ("-i", "--ifile"):
         inputfile = arg
      elif opt in ("-o", "--ofile"):
         outputfile = arg

    #Check if there is a number after the - in the file name
    numbers_in_input_file = re.search("(?<=-)[0-9]+", inputfile)
    if numbers_in_input_file:
        #Get the number as string
        number_string = numbers_in_input_file.group()
        #Get the string length, which also equals the amount of numbers in the number
        amount_of_numbers = len(number_string)
        #Make the number formatting equal the correct length
        number_formatting ='%0{}d'.format(amount_of_numbers)

        inputfile = inputfile.replace(number_string, number_formatting)
        outputfile = setExtension(inputfile.replace("-{}".format(number_formatting), ''))

    convertToMp4(inputfile, outputfile)

if __name__ == "__main__":
   main(sys.argv[1:])