#!/usr/bin/env python3

# by Bomboclat

# for great justice!

import sys
import json
import argparse
from datetime import timedelta


def convert(seconds):
    sec_to_convert = seconds
    converted_sec = timedelta(seconds = sec_to_convert)
    dot = str(converted_sec).find('.')
    if dot != -1:
        timestamp = str(converted_sec)[:-3].replace('.',',')
    else:
        timestamp = str(converted_sec).replace('.',',')

    return timestamp


def write_file(srt, outfile):
    for d in srt:
        with open(outfile, 'a') as f:
            for value in d.values():
                f.write('%s\n' % (str(value)))

    return 0


def json_to_srt(f):
    '''
    SRT file format:

    sequence number
    two-hash arrow to separate beginning and ending timecodes
    caption
    empty line

    example:
    1
    00:00:00,000 --> 00:00:04,440
    here the subtitle caption string

    2
    -8<--snip!--
    '''
    srt = []
    for d in f:
        sequence_number = f.index(d) + 1
        startstop = convert(float(d['start'])) + "  --> " + convert(float(d['end']))
        #print(startstop)
        new_sub = { 'seq': sequence_number, 'startstop': startstop, 'caption': d['content'], 'newline': '' }
        srt.append(new_sub)

    return srt


def main():
    # parse command line options
    parser = argparse.ArgumentParser()
    parser.add_argument('-i', '--infile', help='input file in json format', type=argparse.FileType('r'))
    parser.add_argument('-o', '--outfile', action='store', dest='outfile', help="Directs the output to a name of your choice")
    args = parser.parse_args()

    # loads a list of dicts
    f = json.load(args.infile)
    outfile = args.outfile
    srt = json_to_srt(f)
    write_file(srt, outfile)

    return 0


if __name__ == '__main__':
    sys.exit(main())