import 'dart:async';
import 'dart:math' as math;

import 'package:flutter/material.dart';

import '../../core/theme/app_colors.dart';
import '../../core/theme/app_decorations.dart';
import '../../core/theme/app_text_styles.dart';

class WalkGuideLoadingScreen extends StatefulWidget {
  final String subtitle;

  const WalkGuideLoadingScreen({
    super.key,
    required this.subtitle,
  });

  @override
  State<WalkGuideLoadingScreen> createState() => _WalkGuideLoadingScreenState();
}

class _WalkGuideLoadingScreenState extends State<WalkGuideLoadingScreen>
    with SingleTickerProviderStateMixin {
  late final AnimationController _controller;
  late final Animation<double> _logoScale;
  bool _showName = false;
  Timer? _nameTimer;

  @override
  void initState() {
    super.initState();
    _controller = AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: 1200),
    )..repeat();
    _logoScale = TweenSequence<double>([
      TweenSequenceItem(
        tween: Tween(begin: 1.0, end: 1.08).chain(
          CurveTween(curve: Curves.easeInOut),
        ),
        weight: 50,
      ),
      TweenSequenceItem(
        tween: Tween(begin: 1.08, end: 1.0).chain(
          CurveTween(curve: Curves.easeInOut),
        ),
        weight: 50,
      ),
    ]).animate(_controller);
    _nameTimer = Timer(const Duration(milliseconds: 300), () {
      if (mounted) setState(() => _showName = true);
    });
  }

  @override
  void dispose() {
    _nameTimer?.cancel();
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: AppColors.softBlueBg,
      body: DecoratedBox(
        decoration: const BoxDecoration(
          gradient: LinearGradient(
            begin: Alignment.topCenter,
            end: Alignment.bottomCenter,
            colors: [AppColors.softBlueBg, Colors.white],
          ),
        ),
        child: SafeArea(
          child: Center(
            child: ConstrainedBox(
              constraints: const BoxConstraints(maxWidth: 340),
              child: Padding(
                padding: const EdgeInsets.symmetric(horizontal: 28),
                child: Column(
                  mainAxisSize: MainAxisSize.min,
                  children: [
                    AnimatedBuilder(
                      animation: _logoScale,
                      child: Container(
                        width: 92,
                        height: 92,
                        decoration: BoxDecoration(
                          gradient: AppDecorations.blueGradient,
                          borderRadius: BorderRadius.circular(28),
                          boxShadow: const [
                            BoxShadow(
                              color: Color(0x334A90D9),
                              blurRadius: 28,
                              offset: Offset(0, 14),
                            ),
                          ],
                        ),
                        child: const Icon(
                          Icons.navigation_rounded,
                          color: Colors.white,
                          size: 54,
                        ),
                      ),
                      builder: (context, child) => Transform.scale(
                        scale: _logoScale.value,
                        child: child,
                      ),
                    ),
                    const SizedBox(height: 24),
                    AnimatedOpacity(
                      opacity: _showName ? 1 : 0,
                      duration: const Duration(milliseconds: 420),
                      curve: Curves.easeOutCubic,
                      child: Column(
                        children: [
                          Text(
                            'WalkGuide',
                            textAlign: TextAlign.center,
                            style: AppTextStyles.heading.copyWith(
                              fontSize: 32,
                              fontWeight: FontWeight.w800,
                            ),
                          ),
                          const SizedBox(height: 8),
                          Text(
                            widget.subtitle,
                            textAlign: TextAlign.center,
                            style: AppTextStyles.body.copyWith(
                              color: AppColors.textMuted,
                              fontWeight: FontWeight.w500,
                            ),
                          ),
                        ],
                      ),
                    ),
                    const SizedBox(height: 34),
                    _DotWave(controller: _controller),
                  ],
                ),
              ),
            ),
          ),
        ),
      ),
    );
  }
}

class _DotWave extends StatelessWidget {
  final AnimationController controller;

  const _DotWave({required this.controller});

  @override
  Widget build(BuildContext context) {
    return AnimatedBuilder(
      animation: controller,
      builder: (context, child) {
        return Row(
          mainAxisSize: MainAxisSize.min,
          children: List.generate(
            3,
            (index) {
              final phase = (controller.value + index * 0.18) % 1.0;
              final y = math.sin(phase * math.pi * 2) * -5;
              final opacity = 0.45 + (math.sin(phase * math.pi * 2) + 1) * 0.25;
              return Transform.translate(
                offset: Offset(0, y),
                child: Container(
                  width: 9,
                  height: 9,
                  margin: const EdgeInsets.symmetric(horizontal: 5),
                  decoration: BoxDecoration(
                    color: AppColors.primaryBlue.withValues(alpha: opacity),
                    shape: BoxShape.circle,
                  ),
                ),
              );
            },
          ),
        );
      },
    );
  }
}