import pycmx
import re
import argparse
import sys

import logging


FORMAT = '%(asctime)-15s %(message)s'
logging.basicConfig(format=FORMAT)


log = logging.getLogger(__name__)


def all_video_edits(edl):
    for event in edl.events:
        for edit in event.edits:
            if edit.channels.video:
                yield edit


def get_scene_name(edit, pattern):
    scene_extractor = re.compile(pattern, re.I)
    if edit.clip_name is None:
        return None
    else:
        match_data = re.match(scene_extractor, edit.clip_name)
        if match_data:
            return match_data[1]
        else:
            return edit.clip_name


def output_cmx(outfile, out_list):
    outfile.write("TITLE:  SCENE LIST\r\n")
    outfile.write("FCM: NON-DROP FRAME\r\n")

    for i, o in enumerate(out_list):
        line = '%03i  AX       V     C        ' % (i)
        line += '00:00:00:00 00:00:00:00 %s %s\r\n' % (o['start'], o['end'])
        outfile.write(line)
        outfile.write("* FROM CLIP NAME: %s\r\n" % (o['scene']))


def output_cols(outfile, out_list):
    for o in out_list:
        outfile.write("%-12s\t%-12s\t%s\n" %
                      (o['start'], o['end'], o['scene']))


def scene_list(infile, outfile, out_format, pattern):

    edl = pycmx.parse_cmx3600(infile)

    current_scene_name = None

    grouped_edits = []

    for edit in all_video_edits(edl):
        this_scene_name = get_scene_name(edit, pattern)
        if this_scene_name is not None:
            if current_scene_name != this_scene_name:
                grouped_edits.append([])
                current_scene_name = this_scene_name

            grouped_edits[-1].append(edit)

    out_list = []
    for group in grouped_edits:
        out_list.append({
            'start': group[0].record_in,
            'end': group[-1].record_out,
            'scene': get_scene_name(group[0], pattern)}
        )

    if out_format == 'cmx':
        output_cmx(outfile, out_list)
    if out_format == 'cols':
        output_cols(outfile, out_list)
    else:
        log.warning(f"Format {out_format} unrecognized. Will use cmx.\n")
        output_cmx(outfile, out_list)


def scene_list_cli():
    parser = argparse.ArgumentParser(
        description='Read video events from an input CMX EDL and output '
        'events merged into scenes.')
    parser.add_argument('-o', '--outfile', default=sys.stdout,
                        type=argparse.FileType('w'),
                        help='Output file. Default is stdout.')
    parser.add_argument('-f', '--format', default='cmx', type=str,
                        help='Output format. Options are cols and cmx, cmx '
                        'is the default.')
    parser.add_argument('-p', '--pattern', default='V?([A-Z]*[0-9]+)',
                        help='RE pattern for extracting scene name from clip '
                        'name. The default is "V?([A-Z]*[0-9]+)". ' +
                        'This pattern will be matched case-insensitively.')
    parser.add_argument('input_edl', default=sys.stdin,
                        type=argparse.FileType('r'), nargs='?',
                        help='Input file. Default is stdin.')
    args = parser.parse_args()

    infile = args.input_edl

    scene_list(infile=infile, outfile=args.outfile,
               out_format=args.format, pattern=args.pattern)


if __name__ == '__main__':
    scene_list_cli()