import 'dart:async';
import 'dart:math';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:sensors_plus/sensors_plus.dart';
import 'package:wakelock_plus/wakelock_plus.dart';
import '../models/channel.dart';
import '../services/auth_service.dart';
import '../services/ptt_service.dart';
import '../config/app_config.dart';

class ChannelScreen extends StatefulWidget {
  final Channel channel;

  const ChannelScreen({super.key, required this.channel});

  @override
  State<ChannelScreen> createState() => _ChannelScreenState();
}

class _ChannelScreenState extends State<ChannelScreen>
    with SingleTickerProviderStateMixin {
  late final PttService _ptt;

  PttState _state = PttState.idle;
  String? _speaker;

  // Pulse animation for speaking/receiving states
  late final AnimationController _pulseCtrl;
  late final Animation<double> _pulseAnim;

  // ── Wrist-flip detection (gyroscope) ────────────────────────────────
  static const double _gyroThreshold = 9.0; // rad/s
  static const Duration _flipWindow = Duration(milliseconds: 900);
  static const Duration _flipCooldown = Duration(milliseconds: 380);

  bool _wristEnabled = false;
  bool _wristAvailable = false;
  DateTime? _firstFlipTime;
  DateTime? _lastFlipTime;
  StreamSubscription<GyroscopeEvent>? _gyroSub;

  @override
  void initState() {
    super.initState();
    _ptt = PttService();

    _pulseCtrl = AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: 700),
    );
    _pulseAnim = Tween<double>(
      begin: 1.0,
      end: 1.12,
    ).animate(CurvedAnimation(parent: _pulseCtrl, curve: Curves.easeInOut));

    _ptt.stateStream.listen((s) {
      if (!mounted) return;
      setState(() => _state = s);
      if (s == PttState.speaking || s == PttState.receiving) {
        _pulseCtrl.repeat(reverse: true);
      } else {
        _pulseCtrl.stop();
        _pulseCtrl.reset();
      }
    });

    _ptt.speakerStream.listen((name) {
      if (!mounted) return;
      setState(() => _speaker = name);
    });

    _ptt.errorStream.listen((err) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text(
            err,
            style: const TextStyle(fontSize: 11),
            textAlign: TextAlign.center,
          ),
          duration: const Duration(seconds: 2),
          backgroundColor: const Color(0xFF333333),
          behavior: SnackBarBehavior.floating,
          margin: const EdgeInsets.symmetric(horizontal: 16, vertical: 40),
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(20),
          ),
        ),
      );
    });

    WakelockPlus.enable();
    _connect();
    _checkGyroscope();
  }

  Future<void> _checkGyroscope() async {
    try {
      final sub = gyroscopeEventStream().listen((_) {});
      await sub.cancel();
      if (mounted) setState(() => _wristAvailable = true);
    } catch (_) {}
  }

  void _toggleWrist() {
    setState(() => _wristEnabled = !_wristEnabled);

    if (_wristEnabled) {
      _gyroSub = gyroscopeEventStream().listen(_onGyroscope);
    } else {
      _gyroSub?.cancel();
      _gyroSub = null;
      _firstFlipTime = null;
      _lastFlipTime = null;
    }
  }

  void _onGyroscope(GyroscopeEvent event) {
    final magnitude = sqrt(
      event.x * event.x + event.y * event.y + event.z * event.z,
    );

    if (magnitude < _gyroThreshold) return;

    final now = DateTime.now();

    if (_lastFlipTime != null &&
        now.difference(_lastFlipTime!) < _flipCooldown) {
      return;
    }
    _lastFlipTime = now;

    if (_firstFlipTime == null ||
        now.difference(_firstFlipTime!) > _flipWindow) {
      _firstFlipTime = now;
    } else {
      _firstFlipTime = null;
      _onPttTap();
    }
  }

  Future<void> _connect() async {
    final token = await AuthService().getToken();
    if (!mounted) return;
    if (token == null) {
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: const Text(
            'لطفاً دوباره وارد شوید',
            style: TextStyle(fontSize: 11),
            textAlign: TextAlign.center,
          ),
          duration: const Duration(seconds: 3),
          backgroundColor: const Color(0xFF333333),
          behavior: SnackBarBehavior.floating,
          margin: const EdgeInsets.symmetric(horizontal: 16, vertical: 40),
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(20),
          ),
        ),
      );
      return;
    }
    await _ptt.connectToGroup(
      widget.channel.id,
      token,
      AppConfig.livekitUrl,
    );
  }

  @override
  void dispose() {
    WakelockPlus.disable();
    _gyroSub?.cancel();
    _ptt.dispose();
    _pulseCtrl.dispose();
    super.dispose();
  }

  Future<void> _onPttTap() async {
    if (_state == PttState.connected) {
      HapticFeedback.heavyImpact();
      await _ptt.startSpeaking();
    } else if (_state == PttState.speaking) {
      HapticFeedback.mediumImpact();
      await _ptt.stopSpeaking();
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.black,
      body: SafeArea(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            // Channel name
            Padding(
              padding: const EdgeInsets.symmetric(horizontal: 16),
              child: Text(
                widget.channel.name,
                textAlign: TextAlign.center,
                maxLines: 1,
                overflow: TextOverflow.ellipsis,
                style: const TextStyle(
                  color: Colors.white,
                  fontSize: 13,
                  fontWeight: FontWeight.bold,
                  letterSpacing: 0.5,
                ),
              ),
            ),
            const SizedBox(height: 10),

            // PTT Button
            Center(
              child: AnimatedBuilder(
                animation: _pulseAnim,
                builder: (_, child) =>
                    Transform.scale(scale: _pulseAnim.value, child: child),
                child: GestureDetector(
                  onTap: _onPttTap,
                  child: _PttButton(state: _state, speaker: _speaker),
                ),
              ),
            ),
            const SizedBox(height: 10),

            // Bottom bar: back + wrist-flip toggle
            Row(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                // Back button
                IconButton(
                  onPressed: () => Navigator.pop(context),
                  padding: EdgeInsets.zero,
                  constraints: const BoxConstraints(
                    minWidth: 36,
                    minHeight: 36,
                  ),
                  icon: const Icon(
                    Icons.arrow_back_ios_new,
                    color: Colors.white70,
                    size: 18,
                  ),
                ),

                // Wrist-flip toggle (فقط اگه ژیروسکوپ دارد)
                if (_wristAvailable) ...[
                  const SizedBox(width: 16),
                  AnimatedContainer(
                    duration: const Duration(milliseconds: 200),
                    width: 36,
                    height: 36,
                    decoration: BoxDecoration(
                      color: _wristEnabled
                          ? const Color(0xFF00C853).withValues(alpha: 0.2)
                          : Colors.transparent,
                      shape: BoxShape.circle,
                    ),
                    child: IconButton(
                      onPressed: _toggleWrist,
                      padding: EdgeInsets.zero,
                      constraints: const BoxConstraints(
                        minWidth: 36,
                        minHeight: 36,
                      ),
                      icon: Icon(
                        Icons.rotate_right,
                        color: _wristEnabled
                            ? const Color(0xFF00C853)
                            : Colors.white38,
                        size: 18,
                      ),
                    ),
                  ),
                ],
              ],
            ),
          ],
        ),
      ),
    );
  }
}

// ────────────────────────────────────────────
class _PttButton extends StatelessWidget {
  final PttState state;
  final String? speaker;

  const _PttButton({required this.state, this.speaker});

  @override
  Widget build(BuildContext context) {
    final (color, icon, label) = switch (state) {
      PttState.speaking => (const Color(0xFFFF1744), Icons.mic, 'TALKING'),
      PttState.receiving => (
        const Color(0xFF2979FF),
        Icons.volume_up,
        speaker ?? '...',
      ),
      PttState.connected => (
        const Color(0xFF00C853),
        Icons.settings_input_antenna,
        'PUSH',
      ),
      PttState.idle => (const Color(0xFF424242), Icons.wifi_off, '...'),
    };

    final bool enabled =
        state == PttState.connected || state == PttState.speaking;

    return AnimatedContainer(
      duration: const Duration(milliseconds: 250),
      width: 110,
      height: 110,
      decoration: BoxDecoration(
        color: color,
        shape: BoxShape.circle,
        boxShadow: [
          BoxShadow(
            color: color.withValues(alpha: enabled ? 0.45 : 0.15),
            blurRadius: state == PttState.speaking ? 20 : 8,
            spreadRadius: state == PttState.speaking ? 4 : 2,
          ),
        ],
      ),
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Icon(icon, color: Colors.white, size: 32),
          const SizedBox(height: 3),
          Text(
            label,
            textAlign: TextAlign.center,
            maxLines: 1,
            overflow: TextOverflow.ellipsis,
            style: const TextStyle(
              color: Colors.white,
              fontWeight: FontWeight.bold,
              fontSize: 10,
              letterSpacing: 0.5,
            ),
          ),
        ],
      ),
    );
  }
}