import os
from PyQt5.QtCore import QProcess, Qt
from PyQt5.QtWidgets import QApplication, QWidget, QGridLayout, QLabel, QLineEdit, QPushButton, QFileDialog, QMessageBox, QComboBox, QRadioButton

class SAC(QWidget):
    def __init__(self):
        super().__init__()
        self.setWindowTitle('SAC - Simple Audio Converter')
        self.source_file_btn = QPushButton('Browse')
        self.dest_dir_btn = QPushButton('Browse')
        self.convert_btn = QPushButton('Convert')
        self.abort_btn = QPushButton('Abort')
        self.out_codec_dropdown = QComboBox()
        self.bitrate_dropdown = QComboBox()
        self.stereo_radio = QRadioButton('Stereo')
        self.mono_radio = QRadioButton('Mono')
        self.source_file_input = QLineEdit()
        self.dest_dir_input = QLineEdit()

        self.out_codec_dropdown.addItems(['mp3', 'aac', 'wav', 'flac', 'opus'])
        self.out_codec_dropdown.setCurrentText('mp3')
        self.bitrate_dropdown.addItems(['64K', '128K', '256K', '320K'])
        self.bitrate_dropdown.setCurrentText('128K')
        self.stereo_radio.setChecked(True)

        self.source_file_btn.clicked.connect(self.browse_source_file)
        self.dest_dir_btn.clicked.connect(self.browse_dest_dir)
        self.convert_btn.clicked.connect(self.convert_audio)
        self.abort_btn.clicked.connect(self.abort_audio)
        self.out_codec_dropdown.currentTextChanged.connect(self.toggle_bitrate)
        self.source_file_input.setAcceptDrops(True)
        self.dest_dir_input.setAcceptDrops(True)

        layout = QGridLayout()
        layout.addWidget(QLabel('Source File'), 0, 0), layout.addWidget(self.source_file_input, 0, 1), layout.addWidget(self.source_file_btn, 0, 2)
        layout.addWidget(QLabel('Destination Directory'), 1, 0), layout.addWidget(self.dest_dir_input, 1, 1), layout.addWidget(self.dest_dir_btn, 1, 2)
        layout.addWidget(QLabel('Output Codec'), 2, 0), layout.addWidget(self.out_codec_dropdown, 2, 1)
        layout.addWidget(QLabel('Bitrate'), 3, 0), layout.addWidget(self.bitrate_dropdown, 3, 1)
        layout.addWidget(QLabel('Channel'), 4, 0), layout.addWidget(self.stereo_radio, 4, 1), layout.addWidget(self.mono_radio, 4, 2)
        layout.addWidget(self.convert_btn, 5, 0), layout.addWidget(self.abort_btn, 5, 1)

        self.setLayout(layout)
        self.process = None
        self.abort_btn.setDisabled(True)

    def browse_source_file(self):
        filename, _ = QFileDialog.getOpenFileName(self, 'Select Source File', os.getenv('HOME'), 'Audio File (*.*)')
        if filename:
            self.source_file_input.setText(filename)
            self.dest_dir_input.setText(os.path.dirname(filename))

    def browse_dest_dir(self):
        dirpath = QFileDialog.getExistingDirectory(self, 'Select Destination Directory', self.dest_dir_input.text())
        if dirpath:
            self.dest_dir_input.setText(dirpath)

    def convert_audio(self):
        input_path = self.source_file_input.text()
        output_dir = self.dest_dir_input.text()
        out_codec = self.out_codec_dropdown.currentText()
        bitrate = self.bitrate_dropdown.currentText() if not out_codec in ['flac'] else ''
        channel = '2' if self.stereo_radio.isChecked() else '1'

        if not os.path.isfile(input_path) or not os.path.isdir(output_dir): return

        output_filename = os.path.splitext(os.path.basename(input_path))[0] + '.' + out_codec
        output_path = os.path.join(output_dir, output_filename)

        if out_codec == 'opus':
            cmd = f'ffmpeg -i "{input_path}" -ac {channel} -b:a {bitrate.lower()} -c:a libopus -application audio -strict -2 "{output_path}"'
        elif out_codec == 'wav':
            cmd = f'ffmpeg -i "{input_path}" -ac {channel} -c:a pcm_s16le "{output_path}"'
        else:
            cmd = f'ffmpeg -i "{input_path}" -ac {channel} "{output_path}"'

        [btn.setDisabled(True) for btn in [self.convert_btn, self.source_file_btn, self.dest_dir_btn, self.out_codec_dropdown, self.bitrate_dropdown, self.stereo_radio, self.mono_radio]]
        self.abort_btn.setDisabled(False)

        try:
            self.process = QProcess()
            self.process.setProcessChannelMode(QProcess.MergedChannels)
            self.process.start(cmd)
            if not self.process.waitForStarted():
                self.show_error('Error', 'Failed to start process')
            else:
                while self.process.state() == QProcess.Running:
                    QApplication.processEvents()
                if self.process.exitCode() == 0:
                    QMessageBox.information(self, 'Success', f'Audio file converted successfully: {output_path}')
                else:
                    self.show_error('Error', f'Failed to convert audio file: {output_path}')
        except Exception as e:
            self.show_error('Error', str(e))
        finally:
            [btn.setDisabled(False) for btn in [self.convert_btn, self.source_file_btn, self.dest_dir_btn, self.out_codec_dropdown, self.bitrate_dropdown, self.stereo_radio, self.mono_radio]]
            self.abort_btn.setDisabled(True)

    def abort_audio(self):
        self.process.terminate()

    def toggle_bitrate(self):
        is_opus = self.out_codec_dropdown.currentText() == 'opus'
        self.bitrate_dropdown.setDisabled(not is_opus)

    def show_error(self, title, message):
        QMessageBox.critical(self, title, message)

    def dragEnterEvent(self, event):
        if event.mimeData().hasUrls():
            event.acceptProposedAction()

    def dropEvent(self, event):
        if event.mimeData().hasUrls():
            url = event.mimeData().urls()[0]
            path = url.toLocalFile()
            if os.path.isfile(path):
                self.source_file_input.setText(path)
                self.dest_dir_input.setText(os.path.dirname(path))
                event.acceptProposedAction()

if __name__ == '__main__':
    app = QApplication([])
    sac = SAC()
    sac.show()
    app.exec_()