import os
import sys
import logging
import qdarktheme
import typing
import traceback
import DBA
from subprocess import run
from pyqtgraph import mkBrush
from mutagen.id3 import ID3
from mutagen.id3._frames import APIC
from configparser import ConfigParser
from pathlib import Path
from appdirs import user_config_dir
from logging import debug, error, warning, basicConfig, INFO, DEBUG
from ui import Ui_MainWindow
from PyQt5.QtWidgets import (
    QFileDialog,
    QLabel,
    QMainWindow,
    QApplication,
    QGraphicsScene,
    QGraphicsPixmapItem,
    QMessageBox,
    QStatusBar,
)
from PyQt5.QtCore import (
    QSize,
    QUrl,
    QTimer,
    Qt,
    pyqtSignal,
    QObject,
    pyqtSlot,
    QThreadPool,
    QRunnable,
)
from PyQt5.QtMultimedia import QMediaPlayer, QMediaContent, QAudioProbe
from PyQt5.QtGui import QClipboard, QCloseEvent, QPixmap, QResizeEvent
from utils import (
    delete_album_art,
    scan_for_music,
    initialize_db,
    add_files_to_database,
    set_album_art,
)
from components import (
    PreferencesWindow,
    AudioVisualizer,
    CreatePlaylistWindow,
    ExportPlaylistWindow,
)
from utils.get_album_art import get_album_art

# good help with signals slots in threads
# https://stackoverflow.com/questions/52993677/how-do-i-setup-signals-and-slots-in-pyqt-with-qthreads-in-both-directions

# GOOD
# https://www.pythonguis.com/tutorials/multithreading-pyqt-applications-qthreadpool/


class WorkerSignals(QObject):
    """
    How to use signals for a QRunnable class;
    Unlike most cases where signals are defined as class attributes directly in the class,
    here we define a class that inherits from QObject
    and define the signals as class attributes in that class.
    Then we can instantiate that class and use it as a signal object.
    """

    # 1)
    # Use a naming convention for signals that makes it clear that they are signals
    # and a corresponding naming convention for the slots that handle them.
    # For example signal_* and handle_*.
    # 2)
    # And try to make the signal content as small as possible. DO NOT pass large objects through signals, like
    # pandas DataFrames or numpy arrays. Instead, pass the minimum amount of information needed
    # (i.e. lists of filepaths)

    signal_started = pyqtSignal()
    signal_result = pyqtSignal(object)
    signal_finished = pyqtSignal()
    signal_progress = pyqtSignal(str)


class Worker(QRunnable):
    """
    This is the thread that is going to do the work so that the
    application doesn't freeze

    Inherits from QRunnable to handle worker thread setup, signals, and tear down
    :param callback: the function callback to run on this worker thread. Supplied
                    arg and kwargs will be passed through to the runner
    :type callback: function
    :param args: Arguments to pass to the callback function
    :param kwargs: Keywords to pass to the callback function
    """

    def __init__(self, fn, *args, **kwargs):
        super(Worker, self).__init__()
        # Store constructor arguments (re-used for processing)
        self.fn = fn
        self.args = args
        self.kwargs = kwargs
        self.signals: WorkerSignals = WorkerSignals()

        # Add a callback to our kwargs
        self.kwargs["progress_callback"] = self.signals.signal_progress

    @pyqtSlot()
    def run(self) -> None:  # type: ignore
        """
        This is where the work is done.
        MUST be called run() in order for QRunnable to work

        Initialize the runner function with passed args & kwargs
        """
        self.signals.signal_started.emit()
        try:
            result = self.fn(*self.args, **self.kwargs)
        except Exception:
            traceback.print_exc()
            exctype, value = sys.exc_info()[:2]
            self.signals.signal_finished.emit((exctype, value, traceback.format_exc()))
            error(f"Worker failed: {exctype} | {value} | {traceback.format_exc()}")
        else:
            if result:
                self.signals.signal_finished.emit()
                self.signals.signal_result.emit(result)
            else:
                self.signals.signal_finished.emit()


class ApplicationWindow(QMainWindow, Ui_MainWindow):
    playlistCreatedSignal = pyqtSignal()
    reloadConfigSignal = pyqtSignal()
    reloadDatabaseSignal = pyqtSignal()

    def __init__(self, clipboard):
        super(ApplicationWindow, self).__init__()
        global stopped
        stopped = False
        # Config
        self.config: ConfigParser = ConfigParser()
        self.cfg_file = (
            Path(user_config_dir(appname="musicpom", appauthor="billypom"))
            / "config.ini"
        )
        # Multithreading stuff...
        self.threadpool = QThreadPool()
        # UI
        self.setupUi(self)
        self.setWindowTitle("musicpom")
        # self.vLayoutAlbumArt.SetFixedSize()
        self.status_bar = QStatusBar()
        self.permanent_status_label = QLabel("Status...")
        self.status_bar.addPermanentWidget(self.permanent_status_label)
        self.setStatusBar(self.status_bar)
        self.selected_song_filepath: str | None = None
        self.current_song_filepath: str | None = None
        self.current_song_metadata: ID3 | dict | None = None
        self.current_song_album_art: bytes | None = None
        self.album_art_scene: QGraphicsScene = QGraphicsScene()
        self.config.read(self.cfg_file)
        self.player: QMediaPlayer = QMediaPlayer()  # Audio player object
        self.probe: QAudioProbe = QAudioProbe()  # Gets audio data
        self.audio_visualizer: AudioVisualizer = AudioVisualizer(self.player)
        self.timer = QTimer(self)  # Audio timing things
        self.clipboard = clipboard
        self.tableView.load_qapp(self)
        self.albumGraphicsView.load_qapp(self)

        # Settings init
        self.current_volume: int = int(self.config["settings"]["volume"])
        self.player.setVolume(self.current_volume)
        self.volumeLabel.setText(str(self.current_volume))
        self.volumeSlider.setValue(self.current_volume)

        # Audio probe for processing audio signal in real time
        self.probe.setSource(self.player)
        self.probe.audioBufferProbed.connect(self.process_probe)
        # Slider Timer (realtime playback feedback horizontal bar)
        self.timer.start(100)
        self.timer.timeout.connect(self.move_slider)

        # Set fixed size for album art
        self.albumGraphicsView.setFixedSize(250, 250)

        # Graphics plot
        # Make sure PlotWidget doesn't exceed album art height
        # Adjust to leave room for playback controls
        self.PlotWidget.setFixedHeight(225)
        # x range
        self.PlotWidget.setXRange(
            0, self.audio_visualizer.get_x_resolution(), padding=0
        )
        # y axis range for decibals (-96db to 0db)
        self.PlotWidget.setYRange(-96, 0, padding=0)
        # Logarithmic x-axis for frequency display
        self.PlotWidget.setLogMode(x=False, y=False)
        self.PlotWidget.setMouseEnabled(x=False, y=False)
        self.PlotWidget.showGrid(x=True, y=True)
        # Performance optimizations
        self.PlotWidget.setAntialiasing(False)
        self.PlotWidget.setDownsampling(auto=True, mode="peak")
        self.PlotWidget.setClipToView(True)

        # Add tick marks for common decibel values (expanded range)
        y_ticks = [
            (-84, "-84dB"),
            (-60, "-60dB"),
            (-36, "-36dB"),
            (-12, "-12dB"),
            (0, "0dB"),
        ]
        self.PlotWidget.getAxis("left").setTicks([y_ticks])

        # Add frequency ticks on x-axis
        freq_ticks = self.audio_visualizer.get_frequency_ticks()
        self.PlotWidget.getAxis("bottom").setTicks([freq_ticks])

        # Connections
        self.playbackSlider.sliderReleased.connect(
            lambda: self.player.setPosition(self.playbackSlider.value())
        )  # sliderReleased works better than sliderMoved
        self.volumeSlider.sliderMoved[int].connect(lambda: self.on_volume_changed())
        self.speedSlider.sliderMoved.connect(
            lambda: self.on_speed_changed(self.speedSlider.value())
        )
        self.playButton.clicked.connect(self.on_play_clicked)  # Click to play/pause
        self.previousButton.clicked.connect(self.on_previous_clicked)
        self.nextButton.clicked.connect(self.on_next_clicked)  # Click to next song

        # FILE MENU
        self.actionOpenFiles.triggered.connect(self.open_files)  # Open files window
        self.actionNewPlaylist.triggered.connect(self.create_playlist)
        self.actionExportPlaylist.triggered.connect(self.export_playlist)

        # EDIT MENU
        self.actionPreferences.triggered.connect(self.open_preferences)
        # VIEW MENU

        # QUICK ACTIONS MENU
        self.actionScanLibraries.triggered.connect(self.scan_libraries)
        self.actionDeleteDatabase.triggered.connect(self.delete_database)
        self.actionSortColumns.triggered.connect(
            self.tableView.sort_table_by_multiple_columns
        )

        # QTableView
        # for drag & drop functionality
        self.tableView.viewport().installEventFilter(self)

        ## CONNECTIONS
        # tableView
        self.tableView.doubleClicked.connect(self.play_audio_file)
        self.tableView.enterKey.connect(self.play_audio_file)
        self.tableView.playPauseSignal.connect(
            self.on_play_clicked
        )  # Spacebar toggle play/pause signal
        self.tableView.handleProgressSignal.connect(self.handle_progress)

        # playlistTreeView
        self.playlistTreeView.playlistChoiceSignal.connect(
            self.tableView.load_music_table
        )
        self.playlistTreeView.allSongsSignal.connect(self.tableView.load_music_table)

        # albumGraphicsView
        self.albumGraphicsView.albumArtDropped.connect(
            self.set_album_art_for_selected_songs
        )
        self.albumGraphicsView.albumArtDeleted.connect(
            self.delete_album_art_for_current_song
        )

    #  _________________
    # |                 |
    # |                 |
    # | Built-in Events |
    # |                 |
    # |_________________|

    def resizeEvent(self, a0: typing.Optional[QResizeEvent]) -> None:
        """Do something when the window resizes"""
        if a0 is not None:
            return super().resizeEvent(a0)

    def closeEvent(self, a0: QCloseEvent | None) -> None:
        """Save settings when closing the application"""
        # MusicTable/tableView column widths
        list_of_column_widths = []
        for i in range(self.tableView.model2.columnCount()):
            list_of_column_widths.append(str(self.tableView.columnWidth(i)))
        column_widths_as_string = ",".join(list_of_column_widths)
        self.config["table"]["column_widths"] = column_widths_as_string
        self.config["settings"]["volume"] = str(self.current_volume)
        self.config["settings"]["window_size"] = (
            str(self.width()) + "," + str(self.height())
        )

        # Save the config
        with open(self.cfg_file, "w") as configfile:
            self.config.write(configfile)
        if a0 is not None:
            super().closeEvent(a0)

    #  ____________________
    # |                    |
    # |                    |
    # | On action handlers |
    # |                    |
    # |____________________|

    def on_volume_changed(self) -> None:
        """Handles volume changes"""
        try:
            self.current_volume = self.volumeSlider.value()
            self.player.setVolume(self.current_volume)
            self.volumeLabel.setText(str(self.current_volume))
        except Exception as e:
            error(f"main.py on_volume_changed() | Changing volume error: {e}")

    def on_speed_changed(self, rate: int) -> None:
        """Handles playback speed changes"""
        self.player.setPlaybackRate(rate / 50)
        self.speedLabel.setText("{:.2f}".format(rate / 50))

    def on_play_clicked(self) -> None:
        """Updates the Play & Pause buttons when clicked"""
        if self.player.state() == QMediaPlayer.State.PlayingState:
            self.player.pause()
            self.playButton.setText("▶️")
        else:
            if self.player.state() == QMediaPlayer.State.PausedState:
                self.player.play()
                self.playButton.setText("⏸️")
            else:
                self.play_audio_file()
                self.playButton.setText("👽")

    def on_previous_clicked(self) -> None:
        """"""
        # TODO: implement this
        debug("main.py on_previous_clicked()")

    def on_next_clicked(self) -> None:
        """"""
        # TODO: implement this
        debug("main.py on_next_clicked()")

    #  ____________________
    # |                    |
    # |                    |
    # |       Verbs        |
    # |                    |
    # |____________________|

    def load_config(self) -> None:
        """does what it says"""
        cfg_file = (
            Path(user_config_dir(appname="musicpom", appauthor="billypom"))
            / "config.ini"
        )
        self.config.read(cfg_file)
        debug("CONFIG LOADED")

    def get_thread_pool(self) -> QThreadPool:
        """Returns the threadpool instance"""
        return self.threadpool

    def set_permanent_status_bar_message(self, message: str) -> None:
        """
        Sets the permanent message label in the status bar
        """
        # what does this do?
        self.permanent_status_label.setText(message)

    def show_status_bar_message(self, message: str, timeout: int | None = None) -> None:
        """
        Show a `message` in the status bar for a length of time - `timeout` in ms
        (bottom left)
        """
        if timeout:
            self.status_bar.showMessage(message, timeout)
        else:
            self.status_bar.showMessage(message)

    def play_audio_file(self) -> None:
        """
        Start playback of `tableView.current_song_filepath` & moves playback slider
        """
        self.tableView.set_current_song_filepath()
        # get metadata
        self.current_song_metadata = self.tableView.get_current_song_metadata()
        # read the file
        url = QUrl.fromLocalFile(self.tableView.get_current_song_filepath())
        # load the audio content
        content = QMediaContent(url)
        # set the player to play the content
        self.player.setMedia(content)
        self.player.play()  # play
        self.move_slider()  # mover
        # self.player.setPlaybackRate(1.5)

        # assign "now playing" labels & album artwork
        if self.current_song_metadata is not None:
            artist = (
                self.current_song_metadata["TPE1"][0]
                if "TPE1" in self.current_song_metadata
                else None
            )
            album = (
                self.current_song_metadata["TALB"][0]
                if "TALB" in self.current_song_metadata
                else None
            )
            title = (
                self.current_song_metadata["TIT2"][0]
                if "TIT2" in self.current_song_metadata
                else None
            )
            self.artistLabel.setText(artist)
            self.albumLabel.setText(album)
            self.titleLabel.setText(title)
            # set album artwork
            album_art_data = self.tableView.get_current_song_album_art()
            self.albumGraphicsView.load_album_art(album_art_data)

    def set_album_art_for_selected_songs(self, album_art_path: str) -> None:
        """Sets the ID3 tag APIC (album art) for all selected song filepaths"""
        selected_songs = self.tableView.get_selected_songs_filepaths()
        for song in selected_songs:
            debug(
                f"main.py set_album_art_for_selected_songs() | updating album art for {song}"
            )
            set_album_art(song, album_art_path)

    def delete_album_art_for_current_song(self) -> None:
        """Handles deleting the ID3 tag APIC (album art) for current song"""
        file = self.tableView.get_current_song_filepath()
        result = delete_album_art(file)
        if result:
            # Load the default album artwork in the qgraphicsview
            album_art_data = get_album_art(None)
            self.albumGraphicsView.load_album_art(album_art_data)

    def process_probe(self, buff) -> None:
        """Audio visualizer buffer processing"""
        buff.startTime()
        self.update_audio_visualization()

    def update_audio_visualization(self) -> None:
        """Handles updating points on the pyqtgraph visual"""
        # Use decibel values instead of raw amplitudes
        y = self.audio_visualizer.get_decibels()
        if len(y) == 0:
            return

        # if self.audio_visualizer._plot_item is None:
        # thanks cursor sonnet whatever
        self.PlotWidget.clear()
        # Use the actual frequency values for x-axis
        self.audio_visualizer._plot_item = self.PlotWidget.plot(
            self.audio_visualizer._x_data,  # We'll keep using indices for drawing
            y,
            pen="b",  # Use pen instead of fill for better performance
            fillLevel=-96
            if self.audio_visualizer.use_decibels
            else 0,  # Fill from -96dB for decibel scale
            fillBrush=mkBrush("b"),
        )
        # else:
        #     self.audio_visualizer._plot_item.setData(self.audio_visualizer._x_data, y)

    def clear_audio_visualization(self) -> None:
        self.PlotWidget.clear()
        self.audio_visualizer._plot_item = None

    def move_slider(self) -> None:
        """Handles moving the playback slider"""
        if stopped:
            return
        else:
            if self.playbackSlider.isSliderDown():
                # Prevents slider from updating when dragging
                return
            # Update the slider
            if self.player.state() == QMediaPlayer.State.PlayingState:
                self.playbackSlider.setMinimum(0)
                self.playbackSlider.setMaximum(self.player.duration())
                slider_position = self.player.position()
                self.playbackSlider.setValue(slider_position)
                current_minutes, current_seconds = divmod(slider_position / 1000, 60)
                duration_minutes, duration_seconds = divmod(
                    self.player.duration() / 1000, 60
                )
                self.startTimeLabel.setText(
                    f"{int(current_minutes):02d}:{int(current_seconds):02d}"
                )
                self.endTimeLabel.setText(
                    f"{int(duration_minutes):02d}:{int(duration_seconds):02d}"
                )

    def add_latest_playlist_to_tree(self) -> None:
        """Refreshes the playlist tree"""
        self.playlistTreeView.add_latest_playlist_to_tree()

    def handle_progress(self, data):
        """
        updates the status bar when progress is emitted
        """
        self.show_status_bar_message(data)

    #  ____________________
    # |                    |
    # |                    |
    # |   menubar verbs    |
    # |                    |
    # |____________________|

    # File

    def open_files(self) -> None:
        """
        Opens the open files window
        - File > Open > List of song(s)
        """
        open_files_window = QFileDialog(
            self, "Open file(s)", ".", "Audio files (*.mp3)"
        )
        # QFileDialog.FileMode enum { AnyFile, ExistingFile, Directory, ExistingFiles }
        open_files_window.setFileMode(QFileDialog.ExistingFiles)
        open_files_window.exec_()
        filenames = open_files_window.selectedFiles()
        # Adds files to the library in a new thread
        worker = Worker(add_files_to_database, filenames)
        worker.signals.signal_finished.connect(self.tableView.load_music_table)
        worker.signals.signal_progress.connect(self.handle_progress)
        self.threadpool.start(worker)

    def create_playlist(self) -> None:
        """Creates a database record for a playlist, given a name"""
        window = CreatePlaylistWindow(self.playlistCreatedSignal)
        window.playlistCreatedSignal.connect(self.add_latest_playlist_to_tree)  # type: ignore
        window.exec_()

    def import_playlist(self) -> None:
        """
        Imports a .m3u file, given a base path attempts to match playlist files to
        database records that currently exist
        """
        # TODO: implement this
        pass

    def export_playlist(self) -> None:
        """
        Export playlist window
        Takes a certain database playlist and turns it into a .m3u file
        """
        export_playlist_window = ExportPlaylistWindow()
        export_playlist_window.exec_()

    # Edit

    def open_preferences(self) -> None:
        """Opens the preferences window"""
        preferences_window = PreferencesWindow(
            self.reloadConfigSignal, self.reloadDatabaseSignal
        )
        preferences_window.reloadConfigSignal.connect(self.load_config)  # type: ignore
        preferences_window.reloadDatabaseSignal.connect(self.tableView.load_music_table)  # type: ignore
        preferences_window.exec_()  # Display the preferences window modally

    # Quick Actions

    def scan_libraries(self) -> None:
        """
        Scans for new files in the configured library folder
        then, refreshes the datagridview
        """
        scan_for_music()
        self.tableView.load_music_table()

    def delete_database(self) -> None:
        """Deletes the entire database"""
        reply = QMessageBox.question(
            self,
            "Confirmation",
            "Delete database?",
            QMessageBox.Yes | QMessageBox.No,
            QMessageBox.Yes,
        )
        if reply == QMessageBox.Yes:
            initialize_db()
            self.tableView.load_music_table()

def update_config_file():
    """
    If the user config file is not up to date, update it with samples from sample config
    """
    cfg_file = (
        Path(user_config_dir(appname="musicpom", appauthor="billypom")) / "config.ini"
    )
    sample_cfg_file = './sample_config.ini'
    cfg_path = str(Path(user_config_dir(appname="musicpom", appauthor="billypom")))

    # If config path doesn't exist, create it
    if not os.path.exists(cfg_path):
        os.makedirs(cfg_path)
    # If the config file doesn't exist, create it from the sample config
    if not os.path.exists(cfg_file):
        debug("copying sample config")
        # Create config file from sample
        run(["cp", "./sample_config.ini", cfg_file])
        return
    # make sure config is up to date
    config = ConfigParser()
    sample_config = ConfigParser()
    config.read(cfg_file)
    sample_config.read(sample_cfg_file)
    orig_sections = config.sections()
    sample_sections = sample_config.sections()
    for section in sample_sections:
        if section not in orig_sections:
            # add new sections to the current config
            config.add_section(section)

        orig_options = dict(config.items(section))
        sample_options = dict(sample_config.items(section))
        for option, value in sample_options.items():
            if option not in orig_options:
                # add new options to the section, for current config
                config.set(section, option, value)

    with open(cfg_file, "w") as configfile:
        config.write(configfile)

if __name__ == "__main__":
    # logging setup
    file_handler = logging.FileHandler(filename="log", encoding="utf-8")
    stdout_handler = logging.StreamHandler(stream=sys.stdout)
    handlers = [file_handler, stdout_handler]
    # basicConfig(filename="log", encoding="utf-8", level=logging.DEBUG)
    basicConfig(
        level=DEBUG,
        format="[%(asctime)s] {%(filename)s:%(lineno)d} %(levelname)s - %(message)s",
        handlers=handlers,
    )
    # Initialization
    update_config_file()

    cfg_file = (
        Path(user_config_dir(appname="musicpom", appauthor="billypom")) / "config.ini"
    )
    cfg_path = str(Path(user_config_dir(appname="musicpom", appauthor="billypom")))
    config = ConfigParser()
    config.read(cfg_file)
    db_filepath: str = config.get("db", "database")

    # If the database location isnt set at the config location, move it
    if not db_filepath.startswith(cfg_path):
        new_path = f"{cfg_path}/{db_filepath}"
        debug(f"setting new db-database path: {new_path}")
        config["db"]["database"] = new_path
        # Save the config
        with open(cfg_file, "w") as configfile:
            config.write(configfile)
        config.read(cfg_file)

    db_filepath: str = config.get("db", "database")
    db_path = db_filepath.split("/")
    db_path.pop()
    db_path = "/".join(db_path)

    # If the db file doesn't exist
    if not os.path.exists(db_filepath):
        # If the db directory doesn't exist
        if not os.path.exists(db_path):
            # Make the directory
            os.makedirs(db_path)
        # Create database on first run
        with DBA.DBAccess() as db:
            with open("utils/init.sql", "r") as file:
                lines = file.read()
                for statement in lines.split(";"):
                    debug(f"executing [{statement}]")
                    db.execute(statement, ())
    # Allow for dynamic imports of my custom classes and utilities?
    project_root = os.path.abspath(os.path.dirname(__file__))
    sys.path.append(project_root)
    # Start the app
    app = QApplication(sys.argv)
    clipboard = app.clipboard()
    # Dark theme >:3
    qdarktheme.setup_theme()
    # qdarktheme.setup_theme("auto")
    # Show the UI
    ui = ApplicationWindow(clipboard)
    # window size
    width, height = tuple(config.get("settings", "window_size").split(","))
    window_size = QSize(int(width), int(height))
    ui.resize(window_size)
    ui.show()
    sys.exit(app.exec_())