#!/usr/bin/env python3
#
# vidi-timeline - generate GStreamer Editing Services timelines from midi
#
# Copyright (C) 2016  Antonio Ospite <ao2@ao2.it>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import os
import sys
import mido
import vidi

# TODO: turn these into command line options
ADD_REST_BACKGROUND = True
ADD_TITLE = True
TITLE_TEXT = None
TITLE_DURATION = 5
TITLE_CREDITS = "Created with vidi-timeline\nhttps://git.ao2.it/vidi-player.git"
CANVAS_SIZE = (640, 480)


def timeline_from_midi(midi_file, canvas_size, video_font_path):
    timeline = vidi.Timeline(canvas_size)

    if ADD_TITLE:
        title = TITLE_TEXT
        if not title:
            title = os.path.splitext(os.path.basename(midi_file.filename))[0]
            title += "\n\n"
            title += TITLE_CREDITS

        timeline.add_title_clip(title, 0, TITLE_DURATION)

        elapsed_time = start_time = TITLE_DURATION
    else:
        elapsed_time = start_time = 0

    for msg in midi_file:
        elapsed_time += msg.time
        if vidi.is_note_on(msg) and msg.channel == 0:
            start_time = elapsed_time
        elif vidi.is_note_off(msg) and msg.channel == 0:
            note = vidi.MidiNote(msg.note)
            duration = elapsed_time - start_time
            print("Note name: %3s start_time: %f duration: %f" %
                  (note.name, start_time, duration))

            video_sample_path = "%s/sample_%s.webm" % (video_font_path, note.name)

            timeline.add_clip(video_sample_path, start_time, duration)

    if ADD_REST_BACKGROUND:
        rest_sample_path = "%s/sample_rest.png" % video_font_path
        timeline.add_layer_clip(rest_sample_path, 0, elapsed_time)

    return timeline


def usage():
    print("usage: %s <midi_file> <videofont_directory> [<destination_file>]"
          % os.path.basename(sys.argv[0]))


def main():
    if len(sys.argv) > 1 and sys.argv[1] in ["-h", "--help"]:
        usage()
        return 0

    if len(sys.argv) < 3:
        usage()
        return 1

    if not os.path.isdir(sys.argv[2]):
        sys.stderr.write("The second argument must be the path of the videofont directory\n")
        usage()
        return 1

    if len(sys.argv) > 3 and os.path.exists(sys.argv[3]):
        sys.stderr.write("File '%s' exists, exiting!\n" % sys.argv[3])
        return 1

    midi_file = mido.MidiFile(sys.argv[1])

    overlapping_notes = vidi.check_overlapping_notes(midi_file)
    if overlapping_notes:
        sys.stderr.write("Sorry, supporting only midi file with no overlapping notes on channel 0\n")
        return 1

    video_font_path = os.path.realpath(sys.argv[2])

    timeline = timeline_from_midi(midi_file, CANVAS_SIZE, video_font_path)

    if len(sys.argv) > 3:
        timeline.save(sys.argv[3])
    else:
        try:
            timeline.play()
        except KeyboardInterrupt:
            timeline.stop()
            return 1


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