Ensemble/lib/widgets/player/player_controls.dart

import 'package:flutter/material.dart';
import '../animated_icon_button.dart';
import '../../theme/design_tokens.dart';

/// Playback control buttons (shuffle, previous, play/pause, next, repeat)
class PlayerControls extends StatelessWidget {
  final bool isPlaying;
  final bool? shuffle;
  final String? repeatMode;
  final Color textColor;
  final Color primaryColor;
  final Color backgroundColor;
  final double skipButtonSize;
  final double playButtonSize;
  final double playButtonContainerSize;
  final double progress; // Animation progress 0-1
  final double expandedElementsOpacity;
  final bool isLoadingQueue;
  final VoidCallback onPrevious;
  final VoidCallback onPlayPause;
  final VoidCallback onNext;
  final VoidCallback? onStop;
  final VoidCallback? onToggleShuffle;
  final VoidCallback? onCycleRepeat;

  const PlayerControls({
    super.key,
    required this.isPlaying,
    this.shuffle,
    this.repeatMode,
    required this.textColor,
    required this.primaryColor,
    required this.backgroundColor,
    required this.skipButtonSize,
    required this.playButtonSize,
    required this.playButtonContainerSize,
    required this.progress,
    required this.expandedElementsOpacity,
    required this.isLoadingQueue,
    required this.onPrevious,
    required this.onPlayPause,
    required this.onNext,
    this.onStop,
    this.onToggleShuffle,
    this.onCycleRepeat,
  });

  @override
  Widget build(BuildContext context) {
    final t = progress;
    final isExpanded = t > 0.5;

    return Row(
      mainAxisSize: MainAxisSize.min,
      mainAxisAlignment: isExpanded ? MainAxisAlignment.center : MainAxisAlignment.end,
      children: [
        // Shuffle (expanded only)
        // GPU PERF: Use color alpha instead of Opacity to avoid saveLayer
        if (isExpanded && expandedElementsOpacity > 0.1)
          _buildSecondaryButton(
            icon: Icons.shuffle_rounded,
            // Fix: compute final opacity once to avoid multiplicative opacity bug
            color: shuffle == true
                ? primaryColor.withOpacity(expandedElementsOpacity)
                : textColor.withOpacity(0.5 * expandedElementsOpacity),
            onPressed: isLoadingQueue ? null : onToggleShuffle,
          ),
        if (isExpanded) SizedBox(width: _lerpDouble(0, 20, t)),

        // Previous
        Semantics(
          button: true,
          label: 'Previous track',
          child: _buildControlButton(
            icon: Icons.skip_previous_rounded,
            color: textColor,
            size: skipButtonSize,
            onPressed: onPrevious,
            useAnimation: isExpanded,
          ),
        ),
        SizedBox(width: _lerpDouble(0, 20, t)),

        // Play/Pause
        _buildPlayButton(),
        SizedBox(width: _lerpDouble(0, 20, t)),

        // Next
        Semantics(
          button: true,
          label: 'Next track',
          child: _buildControlButton(
            icon: Icons.skip_next_rounded,
            color: textColor,
            size: skipButtonSize,
            onPressed: onNext,
            useAnimation: isExpanded,
          ),
        ),

        // Repeat (expanded only)
        // GPU PERF: Use color alpha instead of Opacity to avoid saveLayer
        if (isExpanded) SizedBox(width: _lerpDouble(0, 20, t)),
        if (isExpanded && expandedElementsOpacity > 0.1)
          _buildSecondaryButton(
            icon: repeatMode == 'one' ? Icons.repeat_one_rounded : Icons.repeat_rounded,
            // Fix: compute final opacity once to avoid multiplicative opacity bug
            color: (repeatMode != null && repeatMode != 'off')
                ? primaryColor.withOpacity(expandedElementsOpacity)
                : textColor.withOpacity(0.5 * expandedElementsOpacity),
            onPressed: isLoadingQueue ? null : onCycleRepeat,
          ),
      ],
    );
  }

  Widget _buildControlButton({
    required IconData icon,
    required Color color,
    required double size,
    required VoidCallback onPressed,
    required bool useAnimation,
  }) {
    if (useAnimation) {
      return AnimatedIconButton(
        icon: icon,
        color: color,
        iconSize: size,
        onPressed: onPressed,
      );
    }
    return IconButton(
      icon: Icon(icon),
      color: color,
      iconSize: size,
      onPressed: onPressed,
      padding: Spacing.paddingAll4,
      constraints: const BoxConstraints(),
    );
  }

  Widget _buildSecondaryButton({
    required IconData icon,
    required Color color,
    VoidCallback? onPressed,
  }) {
    return SizedBox(
      width: 44,
      height: 44,
      child: IconButton(
        icon: Icon(icon),
        color: color,
        iconSize: 22,
        onPressed: onPressed,
        padding: EdgeInsets.zero,
      ),
    );
  }

  Widget _buildPlayButton() {
    final bgColor = Color.lerp(Colors.transparent, primaryColor, progress);
    final iconColor = Color.lerp(textColor, backgroundColor, progress);

    return Semantics(
      button: true,
      label: isPlaying ? 'Pause' : 'Play',
      hint: 'Long press to stop',
      child: GestureDetector(
        onLongPress: onStop,
        child: Container(
          width: playButtonContainerSize,
          height: playButtonContainerSize,
          decoration: BoxDecoration(
            color: bgColor,
            shape: BoxShape.circle,
          ),
          child: IconButton(
            icon: Icon(isPlaying ? Icons.pause_rounded : Icons.play_arrow_rounded),
            color: iconColor,
            iconSize: playButtonSize,
            onPressed: onPlayPause,
            padding: EdgeInsets.zero,
          ),
        ),
      ),
    );
  }

  double _lerpDouble(double a, double b, double t) {
    return a + (b - a) * t;
  }
}