Fbrowser/MidPlay.py

#Path: MidPlay.py
# Description: A class to play MIDI files and a class to view MIDI files
# probably switching to a different library for midi handling
# pretty_midi is not very good for this purpose or real-time playback of midi files

"""Pretty Midi module type stubs are included but incomplete.
Pretty Midi comes with a statement to cite the following paper
when used in a research project:

Colin Raffel and Daniel P. W. Ellis. Intuitive Analysis, 
Creation and Manipulation of MIDI Data with pretty_midi. 
In Proceedings of the 15th International Conference on Music
Information Retrieval Late Breaking and Demo Papers, 2014.

colinraffel.com/publications/ismir2014intuitive.pdf

"""
import pygame
# Imports
import pretty_midi
import fluidsynth
import sys
import os
from PyQt5.QtWidgets import (QApplication, QLabel, QListWidget, QFileDialog, QMessageBox, QWidget, QPushButton, QHBoxLayout,
    QVBoxLayout,
    QProgressBar,
    QSlider) # structured for readability and to avoid long lines and it annoys my friend XD
from PyQt5.QtCore import QTimer, Qt
import threading
import cProfile # profiler remove for production

pygame.mixer.init()
pygame.init()

class MidPlayGUI(QWidget):
    def __init__(self):
        super().__init__()
        self.player = MidPlay()
        self.current_midi_label = QLabel()
        self.playlist_widget = QListWidget()
        self.setWindowTitle("MidPlay - Midi Player")
        self.init_ui()
        self.timer = QTimer()
        self.timer.timeout.connect(self.handle_song_end)
        self.timer.start(1000)

    def set_volume(self, value):
        volume = value / 100
        pygame.mixer.music.set_volume(volume)

    def update_progress(self):
        if self.player.current_midi:
            current_time = pygame.mixer.music.get_pos() / 1000  # get_pos returns time in milliseconds NOT SECONDS!
            total_time = self.player.current_midi.get_end_time()
            progress = current_time / total_time * 100
            self.progress_bar.setValue(int(progress))

    def handle_song_end(self):
        if self.player.playing and not pygame.mixer.music.get_busy():
            self.player.next_song()
            if self.player.playlist:
                self.player.current_index %= len(self.player.playlist)
                filepath = self.player.playlist[self.player.current_index]
                filename = os.path.basename(filepath)
                self.current_midi_label.setText(f"Current MIDI: {filename}")
        self.update_progress()
        

    def init_ui(self):
        #label = QLabel("MidPlay - Midi player")
        #label.setStyleSheet("font-size: 20px; font-weight: bold;")

        self.progress_bar = QProgressBar()
        self.volume_slider = QSlider(Qt.Horizontal)
        self.volume_slider.setMinimum(0)
        self.volume_slider.setMaximum(100)
        self.volume_slider.setValue(100)
        self.volume_slider.valueChanged.connect(self.set_volume)
        self.current_midi_label.setText("Current MIDI: None")


        self.playlist_widget.itemDoubleClicked.connect(self.play_selected_song)
        pygame.mixer.music.set_endevent(pygame.USEREVENT)

        # Buttons
        play_button = QPushButton("Play")
        play_button.clicked.connect(self.player.play_midi)

        pause_button = QPushButton("Pause")
        pause_button.clicked.connect(self.player.pause)

        stop_button = QPushButton("Stop")
        stop_button.clicked.connect(self.player.stop)

        next_button = QPushButton("Next")
        next_button.clicked.connect(self.player.next_song)

        back_button = QPushButton("Back")
        back_button.clicked.connect(self.previous_song)        

        add_button = QPushButton("Add to Playlist")
        add_button.clicked.connect(self.load_midi_file)

        add_folder_button = QPushButton("Add Folder to Playlist")
        add_folder_button.clicked.connect(self.load_folder)

        clear_button = QPushButton("Clear Playlist")
        clear_button.clicked.connect(self.clear_playlist)
        
        # Window layout
        layout = QVBoxLayout()
        layout.addWidget(self.current_midi_label)
        layout.addWidget(self.playlist_widget)
        layout.addWidget(self.progress_bar)
        layout.addWidget(self.volume_slider)
        layout.addWidget(play_button)
        layout.addWidget(pause_button)
        layout.addWidget(stop_button)
        layout.addWidget(next_button)
        layout.addWidget(back_button)
        layout.addWidget(add_button)
        layout.addWidget(add_folder_button)
        layout.addWidget(clear_button)

        progress_volume_layout = QHBoxLayout() 
        progress_volume_layout.addWidget(self.progress_bar)  
        progress_volume_layout.addWidget(self.volume_slider)
        layout.addLayout(progress_volume_layout) 
        self.setLayout(layout)

    # Event handlers
    def play_selected_song(self, item):
        index = self.playlist_widget.row(item)
        self.current_index = index
        filepath = self.player.playlist[self.current_index]
        self.player.load_midi(filepath)    
        self.player.play_midi() 
        pygame.mixer.music.set_endevent(pygame.USEREVENT)
        filename = os.path.basename(filepath)
        self.current_midi_label.setText(f"Current MIDI: {filename}")

    def load_midi_file(self):
        filepath, _ = QFileDialog.getOpenFileName(self, "Select MIDI File", filter="MIDI files (*.mid *.midi)")
        if filepath:
            filename = os.path.basename(filepath) 
            self.player.load_midi(filepath)
            self.current_midi_label.setText(f"Current MIDI: {filename}")
            self.player.play_midi() 
            self.playlist_widget.addItem(filename)
            self.player.add_to_playlist(filepath)

    def load_folder(self):
        folder = QFileDialog.getExistingDirectory(self, "Select Folder")
        if folder:
            for file in os.listdir(folder):
                if file.endswith((".midi", ".mid")):
                    filepath = os.path.join(folder, file)
                    self.playlist_widget.addItem(file)
                    self.player.add_to_playlist(filepath)  # Only add to playlist, don't load immediately!!!!!!!!!!!!!!!

    #probably should be in the MidPlay class
                    

    def previous_song(self):
        if self.player.playlist:
            filepath = self.player.playlist[self.current_index]
            filename = os.path.basename(filepath)
            self.player.current_index = (self.player.current_index - 1) % len(self.player.playlist)
            self.current_midi_label.setText(f"Current MIDI: {filename}")
            self.player.play_midi()

    def clear_playlist(self):
        self.player.clear_playlist()
        self.playlist_widget.clear()

    def closeEvent(self, event):
        confirmation = QMessageBox.question(self, "Exit Confirmation", "Are you sure you want to exit?", QMessageBox.Yes | QMessageBox.No)
        if confirmation == QMessageBox.Yes:
            pygame.mixer.quit()
            pygame.quit()
            event.accept()  
        else:
            event.ignore()  

class MidPlay:
    """The Heart of Midi Playback"""

    def __init__(self):
        self.playlist = []
        self.current_midi = None
        self.playing = False
        self.current_index = 0

    def load_midi(self, filepath: str) -> None:
        def load():    
            try:
                self.current_midi = pretty_midi.PrettyMIDI(filepath)
                pygame.mixer.music.load(filepath)
            except Exception as e:
                print(f"Error loading MIDI: {e}")
        threading.Thread(target=load).start()

    def add_to_playlist(self, filepath: str) -> None:
        self.playlist.append(filepath)

    def clear_playlist(self) -> None:
        self.playlist = []

    def play_midi(self) -> None:
        def play():
            if self.current_midi:
                self.current_midi.instruments[0].synthesize()
                pygame.mixer.music.play()
                self.playing = True
                pygame.mixer.music.set_endevent(pygame.USEREVENT)
            else:
                print("No MIDI file loaded")
        threading.Thread(target=play).start()

    def pause(self) -> None:
        pygame.mixer.music.pause()
        self.playing = False

    def stop(self) -> None:
        pygame.mixer.music.stop()
        self.playing = False


    def next_song(self) -> None:
        #print("Debug: next_song() called", self.playlist) debug line
        if self.playlist:
            self.current_index = (self.current_index + 1) % len(self.playlist)
            filepath = self.playlist[self.current_index]

            # If a new MIDI was loaded before the last one ended, respect that as the new playlist start
            if self.current_midi and self.playing:
             #   print("Debug: New MIDI loaded before last one ended")  # debug line
                self.load_midi(filepath)
                self.play_midi()
             #   print("Debug: Filepath:", filepath)  # debug line
             #   print("Debug: Current MIDI:", self.current_midi)  # debug line

if __name__ == '__main__':
    app = QApplication([])
    player_gui = MidPlayGUI()
    player_gui.show()
    running = True
    while True:
        for event in pygame.event.get():
            if event.type == pygame.USEREVENT:
                player_gui.player.next_song()
            if event.type == pygame.QUIT:
                running = False
                break
        app.exec_()