"""
Device Panel — UI for selecting audio input/output devices.
"""

from PyQt6.QtWidgets import (QWidget, QVBoxLayout, QHBoxLayout, 
                             QLabel, QComboBox, QPushButton, QGroupBox,
                             QMessageBox)
from PyQt6.QtCore import pyqtSignal

from core.audio_device import DeviceManager

class DevicePanel(QWidget):
    # Signal emitted when devices are successfully applied
    devices_changed = pyqtSignal()
    
    def __init__(self, device_manager: DeviceManager):
        super().__init__()
        self.device_manager = device_manager
        self._init_ui()
        self.refresh_device_lists()
        
    def _init_ui(self):
        layout = QVBoxLayout()
        layout.setSpacing(20)
        
        # --- Audio Hardware Settings Group ---
        hw_group = QGroupBox("Audio Hardware Setup")
        hw_layout = QVBoxLayout()
        
        # Info text
        info_lbl = QLabel(
            "Select the sound card inputs and outputs connected to your cassette deck.\n"
            "• Connect PC Output to Tape Deck REC IN\n"
            "• Connect Tape Deck PLAY OUT to PC Input"
        )
        info_lbl.setWordWrap(True)
        info_lbl.setStyleSheet("color: #a0a0b0; font-style: italic; margin-bottom: 10px;")
        hw_layout.addWidget(info_lbl)
        
        # Input Device Row
        in_row = QHBoxLayout()
        in_lbl = QLabel("Recording Input (From Tape):")
        in_lbl.setFixedWidth(180)
        self.in_combo = QComboBox()
        self.in_combo.setSizeAdjustPolicy(QComboBox.SizeAdjustPolicy.AdjustToContents)
        in_row.addWidget(in_lbl)
        in_row.addWidget(self.in_combo, 1)
        hw_layout.addLayout(in_row)
        
        # Output Device Row
        out_row = QHBoxLayout()
        out_lbl = QLabel("Playback Output (To Tape):")
        out_lbl.setFixedWidth(180)
        self.out_combo = QComboBox()
        self.out_combo.setSizeAdjustPolicy(QComboBox.SizeAdjustPolicy.AdjustToContents)
        out_row.addWidget(out_lbl)
        out_row.addWidget(self.out_combo, 1)
        hw_layout.addLayout(out_row)
        
        # Sample Rate Row
        sr_row = QHBoxLayout()
        sr_lbl = QLabel("Sample Rate:")
        sr_lbl.setFixedWidth(180)
        self.sr_combo = QComboBox()
        self.sr_combo.addItems(["44100 Hz", "48000 Hz", "96000 Hz"])
        self.sr_combo.setCurrentText("44100 Hz")
        sr_row.addWidget(sr_lbl)
        sr_row.addWidget(self.sr_combo)
        sr_row.addStretch()
        hw_layout.addLayout(sr_row)
        
        hw_group.setLayout(hw_layout)
        layout.addWidget(hw_group)
        
        # --- Actions Row ---
        action_row = QHBoxLayout()
        
        self.refresh_btn = QPushButton("Refresh Devices")
        self.refresh_btn.clicked.connect(self.refresh_device_lists)
        
        self.apply_btn = QPushButton("Apply Settings")
        self.apply_btn.setObjectName("primaryButton")
        self.apply_btn.clicked.connect(self.apply_settings)
        
        action_row.addWidget(self.refresh_btn)
        action_row.addStretch()
        action_row.addWidget(self.apply_btn)
        
        layout.addLayout(action_row)
        layout.addStretch()
        
        self.setLayout(layout)

    def refresh_device_lists(self):
        """Update the dropdowns with available devices."""
        self.device_manager.refresh_devices()
        
        self.in_combo.clear()
        for dev in self.device_manager.get_input_devices():
            self.in_combo.addItem(str(dev), dev.index)
            
        self.out_combo.clear()
        for dev in self.device_manager.get_output_devices():
            self.out_combo.addItem(str(dev), dev.index)
            
        # Try to select current if set
        if self.device_manager.input_device_id is not None:
            idx = self.in_combo.findData(self.device_manager.input_device_id)
            if idx >= 0:
                self.in_combo.setCurrentIndex(idx)
                
        if self.device_manager.output_device_id is not None:
            idx = self.out_combo.findData(self.device_manager.output_device_id)
            if idx >= 0:
                self.out_combo.setCurrentIndex(idx)

    def apply_settings(self):
        """Apply selected devices to the DeviceManager."""
        in_idx = self.in_combo.currentData()
        out_idx = self.out_combo.currentData()
        
        sr_str = self.sr_combo.currentText().split()[0]
        sr = int(sr_str)
        
        try:
            if in_idx is not None:
                self.device_manager.input_device_id = in_idx
            if out_idx is not None:
                self.device_manager.output_device_id = out_idx
                
            self.device_manager.sample_rate = sr
            
            self.devices_changed.emit()
            
            # Change button appearance briefly to show success
            original_text = self.apply_btn.text()
            self.apply_btn.setText("Applied ✓")
            self.apply_btn.setStyleSheet("background-color: #4CAF50; color: white;")
            
            # Reset after 2 seconds
            import PyQt6.QtCore as QtCore
            QtCore.QTimer.singleShot(2000, lambda: self._reset_apply_btn(original_text))
            
        except Exception as e:
            QMessageBox.critical(self, "Device Error", f"Failed to apply audio settings:\n{str(e)}")
            
    def _reset_apply_btn(self, text):
        self.apply_btn.setText(text)
        self.apply_btn.setStyleSheet("") # Revert to stylesheet default