#!/usr/bin/env python
###################
# tscut.py
#   file cutter for MythTV
#   cuts transport streams at GOP and reindexes
#   database cutlist to match updated frame counts
###################

from MythTV import Job, Recorded, MythLog, MythError, findfile, MythDB
from subprocess import Popen
from optparse import OptionParser

import sys
import os.path

LOG = MythLog('tscut.py')
DB = MythDB()

def itercopy(input, output, size):
    # copy data in 32KB chunks, or however much is left
    # which ever is smaller
    print 'writing %s bytes' % size
    buff = 2**15 if size > 2**15 else size
    while buff:
        output.write(input.read(buff))
        size -= buff
        buff = 2**15 if size > 2**15 else size

def cut_video(rec):
    seekdata = iter(rec.seek)
    newcutlist = []
    newcutpoint = []

    for left, right in rec.markup.getuncutlist()
        if left == 0:
            seek = 0
            leftbyte = 0
        else:
            while True:
                # search out the closest keyframe inside the cut
                seek = seekdata.next()
                if seek.mark >= left:
                    left = seek.mark
                    leftbyte = seek.offset
                    break

        if right == 9999999:
            rightbyte = rec.filesize
        else:
            while True:
                lastseek = seek
                seek = seekdata.next()
                if seek.mark == right:
                    right = seek.mark
                    rightbyte = seek.offset
                    break
                elif seek.mark > right:
                    right = lastseek.mark
                    rightbyte = lastseek.offset
                    break

        newcutlist.append((left,right))
        newcutpoint.append((leftbyte,rightbyte))

    group = findfile(rec.basename, rec.storagegroup, db=rec._db)
    if group is None:
        raise MythError('Could not find recording')

    recfile = os.path.join(group.dirname, rec.basename)
    tmpfile = os.path.join(group.dirname, 'temp.m2v')

    finfile = recfile.rsplit('.')
    finfile.insert(1,'new')
    finfile = '.'.join(finfile)

    fi = open(recfile)
    proc = Popen(['/usr/local/bin/mythffmpeg', '-i', '-', '-vcodec', 'copy', tmpfile],
                    stdin=-1)#, stdout=null, stderr=null)
    for left,right in newcutpoint:
        cur = fi.tell()
        if left > cur:
            itercopy(fi, proc.stdin, left-cur)
        fi.seek(right)
    proc.stdin.write(fi.read())
    fi.close()
    proc.stdin.close()
    proc.wait()
"""
    null = open('/dev/null','w')
    proc = Popen(['/usr/local/bin/mythffmpeg', '-i', '-', '-target', 'ntsc-dvd', '-vcodec', 'copy', '-acodec', 'copy', tmpfile],
                    stdin=-1)#, stdout=null, stderr=null)

    for left,right in newcutpoint:
        cur = fi.tell()
        if left > cur:
            itercopy(fi, proc.stdin, left-cur)
        fi.seek(right)
    proc.stdin.write(fi.read())
    fi.close()
    proc.stdin.close()
    proc.wait()
"""

def main():
    parser = OptionParser(usage="usage: %prog [options] [jobid]")
    parser.add_option("--chanid", action="store", type="int", dest="chanid",
            help="Use chanid for manual operation")
    parser.add_option("--starttime", action="store", type="int", dest="starttime",
            help="Use starttime for manual operation")
    parser.add_option('-o', '--overwrite', action='store_true', dest='overwrite',
            help="Overwrite the old recording in the database, and update seek and cut tables.")
    parser.add_option('-v', '--verbose', action='store', type='string', dest='verbose',
            help='Verbosity level')

    opts, args = parser.parse_args()

    if opts.verbose:
        if opts.verbose == 'help':
            print MythLog.helptext
            sys.exit(0)
        MythLog._setlevel(opts.verbose)

    if opts.chanid and opts.starttime:
        rec = Recorded((opts.chanid, opts.starttime), db=DB)
    elif len(args) == 1:
        job = Job(args[0], db=DB)
        rec = Recorded((job.chanid, job.starttime), db=DB)
    else:
        parser.print_help()
        sys.exit(2)

    cut_video(rec)
    if opts.overwrite:
        print 'not yet supported'

if __name__ == "__main__":
    main()