#!/usr/bin/env python
# From http://www.dwerg.net/projects/python/srttool.py
# Converts AQTitle Scripts into CMML
# More information at http://trac.annodex.net/wiki/CmmlSubtitles

## Copyright (C) 2004- Commonwealth Scientific and Industrial Research
## Organisation (CSIRO) Australia
##
## Redistribution and use in source and binary forms, with or without
## modification, are permitted provided that the following conditions
## are met:
##
## - Redistributions of source code must retain the above copyright
## notice, this list of conditions and the following disclaimer.
##
## - Redistributions in binary form must reproduce the above copyright
## notice, this list of conditions and the following disclaimer in the
## documentation and/or other materials provided with the distribution.
##
## - Neither the name of CSIRO Australia nor the names of its
## contributors may be used to endorse or promote products derived from
## this software without specific prior written permission.
##
## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
## ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
## LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
## PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE ORGANISATION OR
## CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
## EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
## PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
## PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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## SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

import re
import sys
import math
global save_start
global save_msg
global save_msg_flag
global savecmml
global id
frameMarkRe = re.compile('-->> .')
anyValueRe = re.compile('.')

class CorruptAqtError(Exception):
    """
    The AQTitle File is incorrectly formatted
    """
    pass

def time_calculation(seconds, amt_in_sec):
    val = seconds / amt_in_sec
    val_rounded = math.floor(val)
    secs_remainder = (val * amt_in_sec) - (val_rounded * amt_in_sec)
    return (val_rounded, secs_remainder)

def convert_timeperiod(frame, fps):
    try:
        totalsec = frame / fps
        (hours, secs_remainder) = time_calculation(totalsec, 3600)
        (minutes, secs_remainder) = time_calculation(secs_remainder, 60)
        (secs, millisecs) = time_calculation(secs_remainder, 1)
        millisecs = round(millisecs*1000)
        timeperiod = '%(val1)02d:%(val2)02d:%(val3)02d.%(val4)03d' % {'val1':hours, 'val2':minutes, 'val3':secs, 'val4':millisecs}
        return timeperiod
    except IndexError:
        raise CorruptAqtError("Corrupt Frame Format")

def convert_block(lines, fps):
    global savecmml
    global id
    global save_start
    global save_msg
    global save_msg_flag
    last_count = 1
    subtitlemsg = ''
    try:
        # To determine if the next line exists a subtitle
        if anyValueRe.match(lines[1]):
            # When a previous subtitle was saved as a whitespace was made before the ending frame could be found
            if save_msg_flag == 1:
                if frameMarkRe.match(lines[0]):
                    endtemp = lines[0].replace('-->> ', '')
                    endframe = float(endtemp)
                    save_end = convert_timeperiod(endframe, fps)               
                    savecmml += '<clip track="caption" id="c%s" start="%s" end="%s">\n' % (id, save_start, save_end)
                    savecmml += '  <desc>\n'
                    savecmml += save_msg
                    savecmml += '  </desc>\n'
                    savecmml += '</clip>\n'
                    id += 1
                    # To clear last message buffered
                    subtitlemsg = ''
                    save_msg_flag = 0
            # To process frame timings
            if frameMarkRe.match(lines[0]):
                starttemp = lines[0].replace('-->> ', '')
                startframe = float(starttemp)
                start = convert_timeperiod(startframe, fps)
            for array in lines[1:]:
                if not frameMarkRe.match(array):
                    subtitlemsg += '    ' + array + '\n'
                    last_count += 1
                if frameMarkRe.match(array):
                    endtemp = array.replace('-->> ', '')
                    endframe = float(endtemp)
                    end = convert_timeperiod(endframe, fps)
                    last_count += 1
                    # To determine if the next message block continues after the ending frame
                    try:
                        if anyValueRe.match(lines[last_count]):
                            savecmml += '<clip track="caption" id="c%s" start="%s" end="%s">\n' % (id, start, end)
                            savecmml += '  <desc>\n'
                            savecmml += subtitlemsg
                            savecmml += '  </desc>\n'
                            savecmml += '</clip>\n'
                            id += 1
                            # To clear last message buffered
                            subtitlemsg = ''
                            if frameMarkRe.match(array):
                                starttemp = array.replace('-->> ', '')
                                startframe = float(starttemp)
                                start = convert_timeperiod(startframe, fps)
                    except Exception:
                        pass
            # To ensure the ending time was found within the line array
            if start != end:
                savecmml += '<clip track="caption" id="c%s" start="%s" end="%s">\n' % (id, start, end)
                savecmml += '  <desc>\n'
                savecmml += subtitlemsg
                savecmml += '  </desc>\n'
                savecmml += '</clip>\n'
                id += 1
            # When no ending time was found within the existing line array, we need to save the context for the next pass
            else:
                save_start = start
                save_msg = subtitlemsg
                save_msg_flag = 1
    except Exception:
        pass

def convert_clips(file, fps):
    current = []
    for line in file:
        if not line.strip():
            convert_block(current, fps)
            current = []
        else:
            current.append(line.strip())

def convert_aqt(file, fps):
    global savecmml
    global id
    global save_msg_flag
    save_msg_flag = 0
    id = 1
    savecmml = '<cmml>\n'
    savecmml += '<head>\n'
    savecmml += '  <title>' + sys.argv[1] + '</title>\n'
    savecmml += '</head>\n'
    convert_clips (file, fps)
    savecmml += '</cmml>\n'

if __name__ == '__main__':
    global savecmml
    fps = None
    print 'Frames-per-Second of Video Required:\nEnter Frames-per-Second:'
    while not fps:
        try:
            fps = float(raw_input())
        except ValueError:
            print 'Invalid FPS Entered. Try Again.'
    try:
        try:
            filesave = open(sys.argv[2], 'w')
            convert_aqt(file(sys.argv[1]), fps)
            filesave.write(savecmml)
            filesave.close()
        except IndexError:
            convert_aqt(file(sys.argv[1]), fps)
            print savecmml
    except IndexError:
        print "Usage: %s [Input AQTitle File] [Output CMML File]" % sys.argv[0]