#!/usr/bin/env python
#
# HH:MM:SS.SSS - starts with 00:00:00.0000

import optparse
import string
import math

def generateMkvXml(line, chapterNum):
    matroskaXml = "\t\t<ChapterAtom>\n"
    matroskaXml += "\t\t\t<ChapterTimeStart>" + line.rstrip('\n') + "</ChapterTimeStart>\n"
    matroskaXml += "\t\t\t<ChapterDisplay>\n"
    matroskaXml += "\t\t\t\t<ChapterString>Chapter " + str(chapterNum) + "</ChapterString>\n"
    matroskaXml += "\t\t\t\t<ChapterLanguage>eng</ChapterLanguage>\n"
    matroskaXml += "\t\t\t</ChapterDisplay>\n"
    matroskaXml += "\t\t</ChapterAtom>\n"
    return matroskaXml

def returnTime( ptsMark, offset ):
    ptsFreq = 45000
    ptsMark -= offset
    ptsTime = float(ptsMark) / float(ptsFreq)
    ptsHour = math.modf(ptsTime / 3600)
    ptsMinute = math.modf(float(ptsHour[0]) * 60)
    ptsSecond = ptsMinute[0] * 60

    if ptsSecond >= 10:
        return '%(hour)02d:%(minute)02d:%(second)02.3F' % {'hour': ptsHour[1], 'minute': ptsMinute[1], 'second': ptsSecond}
    else:
        return '%(hour)02d:%(minute)02d:0%(second)02.3F' % {'hour': ptsHour[1], 'minute': ptsMinute[1], 'second': ptsSecond}


def main():
    p = optparse.OptionParser(description=' Deconstructs the MPLS file and converts the PTS information to create properly formatted XML chapter file for Matroska.  This program needs the MPLS file from the BluRay disc associated with the M2TS file(s) that you are processing.',
                              prog='bdchapters',
                              version='BluRay Chapter Converter 0.3',
                              usage='%prog -i [inputfile] -o [outputfile]')
    p.add_option('--input', '-i', action="store", help='the MPLS file from the BluRay disc', dest="inputfile")
    p.add_option('--output', '-o', action="store", help='the output XML file', dest="outputfile")
    (options, arguments) = p.parse_args()

    if options.inputfile == None:
        p.error("no inputfile specified.")
    elif options.outputfile == None:
        options.outputfile = options.inputfile + ".xml"

    print "\n"
    print 'Input file: %s' % options.inputfile
    print 'Output file: %s' % options.outputfile
    print "\n"

    matroskaXmlHeader = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n\n<Chapters>\n\t<EditionEntry>\n"
    matroskaXmlFooter = "\t</EditionEntry>\n</Chapters>"

    input = open(options.inputfile, 'rb')
    output = open(options.outputfile, 'w')

    output.write(matroskaXmlHeader)

    count = 0

    bytelist = []
    ptsinfo = []

    input.seek(-14, 2)
    for x in range(14):
        bytelist.append(input.read(1))

    ptsinfo.append(ord(bytelist[4])*(256**3) + ord(bytelist[5])*(256**2) + ord(bytelist[6])*(256) + ord(bytelist[7]))

    while True:
        input.seek(-28, 1)
        bytelist = []
        for x in range(14):
            bytelist.append(input.read(1))

        if ord(bytelist[13]) != 0:
            break

        ptsinfo.append(ord(bytelist[4])*(256**3) + ord(bytelist[5])*(256**2) + ord(bytelist[6])*(256) + ord(bytelist[7]))
        if ptsinfo[-1] == ptsinfo[-2]:
            ptsinfo.pop([-1])
            break

    ptsOffset = ptsinfo[-1]
    ptsinfo.sort()

    for x in ptsinfo:
        count += 1
        timeStamp = returnTime( x, ptsOffset )
        output.write(generateMkvXml(timeStamp, count))

    output.write(matroskaXmlFooter)

    input.close()
    output.close()


if __name__ == '__main__':
    main()