#!/usr/bin/env python3

import settings
import pypianoroll as roll
import matplotlib.pyplot as plt
import numpy as np
import os
from tqdm import tqdm
from math import floor
import sys

def to_samples(midi_file_path, midi_res=settings.midi_resolution):

    # this function export a samples from midi file:
    # and for every track in midi file chopped pianoroll
    # for a samples of given beat_lenth (midi_res)
    # every track is single line

    print('Exporting samples from: {}'.format(midi_file_path))

    all_beats = np.empty((0, settings.midi_resolution, 128))

    for track in roll.Multitrack(midi_file_path).tracks:
        print('Track: {}'.format(track.name))
        if not track.is_drum:
            number_of_beats = floor(track.pianoroll.shape[0] / midi_res)
            track_pianoroll = track.pianoroll[: number_of_beats * midi_res]
            track_beats = track_pianoroll.reshape(number_of_beats, midi_res, 128)
            all_beats = np.concatenate([track_beats, all_beats], axis=0)

            print('Exported {} samples of {}'.format(number_of_beats, settings.midi_program[track.program]))
        else:
            # add code for drums samples
            pass
    return all_beats

def to_midi(samples, output_path=settings.generated_midi_path, program=0, tempo=120, beat_resolution=settings.beat_resolution):
    tracks = [roll.Track(samples, program=program)]
    return_midi = roll.Multitrack(tracks=tracks, tempo=tempo, downbeat=[0, 96, 192, 288], beat_resolution=beat_resolution)
    roll.write(return_midi, settings.generated_midi_path)

# todo: this function is running too slow.
def delete_empty_samples(sample_pack):
    print('Deleting empty samples...')
    temp_sample_pack = sample_pack
    index_manipulator = 1
    for index, sample in enumerate(sample_pack):
        if sample.sum() == 0:
            temp_sample_pack = np.delete(temp_sample_pack, index-index_manipulator, axis=0)
            index_manipulator = index_manipulator + 1
    print('Deleted {} empty samples'.format(index_manipulator-1))
    return temp_sample_pack

def main():

    if sys.argv[1]=='export':
        print('Exporting started...')

        sample_pack = np.empty((0,settings.midi_resolution,128))

        for midi_file in os.listdir(settings.midi_dir):
            midi_file_path = '{}/{}'.format(settings.midi_dir, midi_file)
            midi_samples = to_samples(midi_file_path)
            if midi_samples is None:
                continue
            sample_pack = np.concatenate((midi_samples, sample_pack), axis=0)

        # I commented out this line, because it was too slow
        # sample_pack = delete_empty_samples(sample_pack)

        np.savez_compressed(settings.samples_dir, sample_pack)
        print('Exported {} samples'.format(sample_pack.shape[0]))

        fig, axes = plt.subplots(nrows=10, ncols=10, figsize=(20, 20))
        for idx, ax in enumerate(axes.ravel()):
            n = np.random.randint(0, sample_pack.shape[0])
            sample = sample_pack[n]
            ax.imshow(sample, cmap = plt.get_cmap('gray'))
        plt.savefig(settings.sample_preview_path)

if __name__ == '__main__':
    main()