import 'package:flutter/material.dart';
import '../theme.dart';
import '../route_transitions.dart';
import 'mobile_login_screen.dart';

class WelcomeScreen extends StatefulWidget {
  const WelcomeScreen({super.key});

  @override
  State<WelcomeScreen> createState() => _WelcomeScreenState();
}

class _WelcomeScreenState extends State<WelcomeScreen> with SingleTickerProviderStateMixin {
  late AnimationController _controller;
  late Animation<double> _fadeAnimation;
  late Animation<double> _logoScaleAnimation;
  late Animation<double> _logoRotateAnimation;
  double _btnScale = 1.0;

  @override
  void initState() {
    super.initState();
    _controller = AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: 900),
    );

    _fadeAnimation = CurvedAnimation(
      parent: _controller,
      curve: Curves.easeIn,
    );

    _logoScaleAnimation = Tween<double>(begin: 0.0, end: 1.0).animate(
      CurvedAnimation(
        parent: _controller,
        curve: const Interval(0.2, 0.8, curve: Curves.elasticOut),
      ),
    );

    _logoRotateAnimation = Tween<double>(begin: -0.1, end: 0.0).animate(
      CurvedAnimation(
        parent: _controller,
        curve: const Interval(0.2, 0.8, curve: Curves.easeOutBack),
      ),
    );

    _controller.forward();
  }

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

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final isMobile = context.isMobile;

    return Scaffold(
      body: FadeTransition(
        opacity: _fadeAnimation,
        child: SafeArea(
          child: Column(
            children: [
              // Top Progress bar indicator - 1st segment active
              Padding(
                padding: const EdgeInsets.symmetric(horizontal: 16.0, vertical: 16.0),
                child: Row(
                  children: List.generate(5, (index) {
                    return Expanded(
                      child: AnimatedContainer(
                        duration: const Duration(milliseconds: 350),
                        height: 4,
                        margin: const EdgeInsets.symmetric(horizontal: 2.0),
                        decoration: BoxDecoration(
                          color: index == 0 ? theme.colorScheme.primary : theme.colorScheme.surfaceContainerHighest,
                          borderRadius: BorderRadius.circular(2),
                        ),
                      ),
                    );
                  }),
                ),
              ),

              // Scrollable / Responsive Content
              Expanded(
                child: LayoutBuilder(
                  builder: (context, constraints) {
                    final maxWidth = constraints.maxWidth;
                    if (maxWidth >= 768) {
                      // Desktop / Tablet Double-Column Layout
                      return SingleChildScrollView(
                        physics: const BouncingScrollPhysics(),
                        child: Center(
                          child: ConstrainedBox(
                            constraints: const BoxConstraints(maxWidth: 1000),
                            child: Padding(
                              padding: const EdgeInsets.symmetric(horizontal: 16.0, vertical: 16.0),
                              child: Row(
                                crossAxisAlignment: CrossAxisAlignment.center,
                                children: [
                                  // Left column: content + button
                                  Expanded(
                                    flex: 5,
                                    child: Column(
                                      crossAxisAlignment: CrossAxisAlignment.start,
                                      children: [
                                        _buildLogo(theme),
                                        const SizedBox(height: 16),
                                        Text(
                                          'Manage your business billing in 3 clicks!',
                                          style: theme.textTheme.headlineLarge?.copyWith(
                                            fontWeight: FontWeight.bold,
                                          ),
                                        ),
                                        const SizedBox(height: 16),
                                        Text(
                                          'The fastest, most reliable tool for Indian MSMEs to run their shop.',
                                          style: theme.textTheme.bodyMedium?.copyWith(
                                            color: theme.colorScheme.onSurfaceVariant,
                                          ),
                                        ),
                                        const SizedBox(height: 16),
                                        _buildSeal(theme),
                                        const SizedBox(height: 16),
                                        _buildCTAColumn(context, theme),
                                      ],
                                    ),
                                  ),
                                  const SizedBox(width: 32),
                                  // Right column: mock card
                                  Expanded(
                                    flex: 4,
                                    child: Center(
                                      child: _buildMockDashboard(theme),
                                    ),
                                  ),
                                ],
                              ),
                            ),
                          ),
                        ),
                      );
                    } else {
                      // Mobile Single Column Layout
                      return SingleChildScrollView(
                        physics: const BouncingScrollPhysics(),
                        child: Padding(
                          padding: const EdgeInsets.symmetric(horizontal: 16.0),
                          child: Column(
                            crossAxisAlignment: CrossAxisAlignment.start,
                            children: [
                              const SizedBox(height: 16),
                              _buildLogo(theme),
                              const SizedBox(height: 16),
                              Text(
                                'Manage your business billing in 3 clicks!',
                                textAlign: TextAlign.left,
                                style: theme.textTheme.headlineLarge?.copyWith(
                                  fontWeight: FontWeight.bold,
                                ),
                              ),
                              const SizedBox(height: 16),
                              Text(
                                'The fastest, most reliable tool for Indian MSMEs to run their shop.',
                                textAlign: TextAlign.left,
                                style: theme.textTheme.bodyMedium?.copyWith(
                                  color: theme.colorScheme.onSurfaceVariant,
                                ),
                              ),
                              const SizedBox(height: 16),
                              _buildSeal(theme),
                              const SizedBox(height: 24),
                              Center(child: _buildMockDashboard(theme)),
                              const SizedBox(height: 24),
                            ],
                          ),
                        ),
                      );
                    }
                  },
                ),
              ),

              // Pinned Bottom Button on Mobile
              if (isMobile)
                Padding(
                  padding: const EdgeInsets.symmetric(horizontal: 16.0, vertical: 16.0),
                  child: _buildCTAColumn(context, theme),
                ),
            ],
          ),
        ),
      ),
    );
  }

  Widget _buildLogo(ThemeData theme) {
    return ScaleTransition(
      scale: _logoScaleAnimation,
      child: RotationTransition(
        turns: _logoRotateAnimation,
        child: Container(
          width: 80,
          height: 80,
          decoration: BoxDecoration(
            color: theme.colorScheme.primary,
            borderRadius: BorderRadius.circular(20),
            boxShadow: [
              BoxShadow(
                color: theme.colorScheme.primary.withOpacity(0.15),
                blurRadius: 24,
                offset: const Offset(0, 8),
              )
            ],
          ),
          alignment: Alignment.center,
          child: Stack(
            clipBehavior: Clip.none,
            children: [
              Text(
                'Pozo',
                style: theme.textTheme.headlineMedium?.copyWith(
                  color: Colors.white,
                  fontWeight: FontWeight.w800,
                  letterSpacing: -1.0,
                ),
              ),
              Positioned(
                top: -16,
                right: -16,
                child: Container(
                  padding: const EdgeInsets.all(4),
                  decoration: BoxDecoration(
                    color: Colors.amber[700],
                    shape: BoxShape.circle,
                    border: Border.all(color: Colors.white, width: 2),
                  ),
                  child: const Text(
                    'IN',
                    style: TextStyle(
                      color: Colors.white,
                      fontSize: 8,
                      fontWeight: FontWeight.bold,
                    ),
                  ),
                ),
              )
            ],
          ),
        ),
      ),
    );
  }

  Widget _buildSeal(ThemeData theme) {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 8),
      decoration: BoxDecoration(
        color: theme.colorScheme.surfaceContainerLow,
        borderRadius: BorderRadius.circular(20),
        border: Border.all(color: theme.colorScheme.outlineVariant),
      ),
      child: Row(
        mainAxisSize: MainAxisSize.min,
        children: [
          Icon(
            Icons.verified,
            size: 16,
            color: theme.colorScheme.tertiary,
          ),
          const SizedBox(width: 6),
          Text(
            'Trusted by 10,000+ merchants',
            style: theme.textTheme.bodySmall?.copyWith(
              fontWeight: FontWeight.w600,
              color: theme.colorScheme.onSurfaceVariant,
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildMockDashboard(ThemeData theme) {
    return Container(
      width: 280,
      height: 230,
      decoration: BoxDecoration(
        color: Colors.white,
        borderRadius: BorderRadius.circular(24),
        border: Border.all(color: theme.colorScheme.outlineVariant),
        boxShadow: [
          BoxShadow(
            color: Colors.black.withOpacity(0.04),
            blurRadius: 20,
            offset: const Offset(0, 8),
          )
        ],
      ),
      child: Stack(
        clipBehavior: Clip.none,
        children: [
          Column(
            children: [
              Container(
                height: 44,
                padding: const EdgeInsets.symmetric(horizontal: 16),
                decoration: BoxDecoration(
                  color: Colors.grey[50],
                  borderRadius: const BorderRadius.vertical(top: Radius.circular(24)),
                  border: Border(bottom: BorderSide(color: Colors.grey[200]!)),
                ),
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
                  children: [
                    Row(
                      children: [
                        Container(
                          width: 8,
                          height: 8,
                          decoration: BoxDecoration(
                            color: theme.colorScheme.primary,
                            shape: BoxShape.circle,
                          ),
                        ),
                        const SizedBox(width: 8),
                        Container(
                          width: 70,
                          height: 8,
                          decoration: BoxDecoration(
                            color: Colors.grey[300],
                            borderRadius: BorderRadius.circular(4),
                          ),
                        ),
                      ],
                    ),
                    Container(
                      width: 14,
                      height: 14,
                      decoration: BoxDecoration(
                        color: Colors.grey[300],
                        shape: BoxShape.circle,
                      ),
                    )
                  ],
                ),
              ),
              Expanded(
                child: Padding(
                  padding: const EdgeInsets.all(16.0),
                  child: Column(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: [
                      _buildMockRow(Icons.description, Colors.red[50]!, Colors.red),
                      const SizedBox(height: 14),
                      _buildMockRow(Icons.poll, Colors.green[50]!, Colors.green),
                    ],
                  ),
                ),
              )
            ],
          ),
          Positioned(
            top: 60,
            right: -12,
            child: Container(
              padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 8),
              decoration: BoxDecoration(
                color: Colors.white,
                borderRadius: BorderRadius.circular(14),
                border: Border.all(color: Colors.grey[200]!),
                boxShadow: [
                  BoxShadow(
                    color: Colors.black.withOpacity(0.06),
                    blurRadius: 10,
                    offset: const Offset(0, 4),
                  )
                ],
              ),
              child: Row(
                children: [
                  Container(
                    padding: const EdgeInsets.all(2),
                    decoration: const BoxDecoration(
                      color: Colors.green,
                      shape: BoxShape.circle,
                    ),
                    child: const Icon(
                      Icons.check,
                      color: Colors.white,
                      size: 10,
                    ),
                  ),
                  const SizedBox(width: 6),
                  const Text(
                    'Saved',
                    style: TextStyle(
                      fontWeight: FontWeight.bold,
                      fontSize: 11,
                      color: Colors.black,
                    ),
                  )
                ],
              ),
            ),
          ),
          Positioned(
            bottom: 30,
            left: -16,
            child: Container(
              padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 8),
              decoration: BoxDecoration(
                color: theme.colorScheme.primary,
                borderRadius: BorderRadius.circular(16),
                boxShadow: [
                  BoxShadow(
                    color: theme.colorScheme.primary.withOpacity(0.2),
                    blurRadius: 12,
                    offset: const Offset(0, 6),
                  )
                ],
              ),
              child: const Text(
                '₹ 4,500',
                style: TextStyle(
                  color: Colors.white,
                  fontWeight: FontWeight.bold,
                  fontSize: 12,
                ),
              ),
            ),
          )
        ],
      ),
    );
  }

  Widget _buildCTAColumn(BuildContext context, ThemeData theme) {
    return Column(
      mainAxisSize: MainAxisSize.min,
      crossAxisAlignment: context.isMobile ? CrossAxisAlignment.center : CrossAxisAlignment.start,
      children: [
        MouseRegion(
          onEnter: (_) => setState(() => _btnScale = 1.03),
          onExit: (_) => setState(() => _btnScale = 1.0),
          child: GestureDetector(
            onTapDown: (_) => setState(() => _btnScale = 0.95),
            onTapUp: (_) => setState(() => _btnScale = 1.03),
            onTapCancel: () => setState(() => _btnScale = 1.0),
            child: AnimatedScale(
              scale: _btnScale,
              duration: const Duration(milliseconds: 150),
              curve: Curves.easeOut,
              child: ElevatedButton(
                onPressed: () {
                  Navigator.push(
                    context,
                    FadeSlidePageRoute(child: const MobileLoginScreen()),
                  );
                },
                style: ElevatedButton.styleFrom(
                  minimumSize: const Size(260, 54),
                ),
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.center,
                  mainAxisSize: MainAxisSize.min,
                  children: const [
                    Text('Get Started'),
                    SizedBox(width: 8),
                    Icon(Icons.arrow_forward, size: 18),
                  ],
                ),
              ),
            ),
          ),
        ),
        const SizedBox(height: 16),
        Row(
          mainAxisAlignment: context.isMobile ? MainAxisAlignment.center : MainAxisAlignment.start,
          children: [
            Container(
              width: 10,
              height: 10,
              decoration: BoxDecoration(
                color: theme.colorScheme.primary,
                shape: BoxShape.circle,
              ),
            ),
            const SizedBox(width: 6),
            Container(
              width: 8,
              height: 8,
              decoration: BoxDecoration(
                color: Colors.grey[300],
                shape: BoxShape.circle,
              ),
            ),
            const SizedBox(width: 6),
            Container(
              width: 8,
              height: 8,
              decoration: BoxDecoration(
                color: Colors.grey[300],
                shape: BoxShape.circle,
              ),
            ),
          ],
        )
      ],
    );
  }

  Widget _buildMockRow(IconData icon, Color bg, Color color) {
    return Container(
      height: 48,
      padding: const EdgeInsets.all(8),
      decoration: BoxDecoration(
        color: bg.withOpacity(0.4),
        borderRadius: BorderRadius.circular(12),
        border: Border.all(color: Colors.grey[100]!),
      ),
      child: Row(
        children: [
          Container(
            padding: const EdgeInsets.all(6),
            decoration: BoxDecoration(
              color: Colors.white,
              borderRadius: BorderRadius.circular(8),
            ),
            child: Icon(icon, color: color, size: 16),
          ),
          const SizedBox(width: 12),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                Container(
                  width: 100,
                  height: 6,
                  decoration: BoxDecoration(
                    color: Colors.grey[400],
                    borderRadius: BorderRadius.circular(3),
                  ),
                ),
                const SizedBox(height: 6),
                Container(
                  width: 50,
                  height: 4,
                  decoration: BoxDecoration(
                    color: Colors.grey[300],
                    borderRadius: BorderRadius.circular(2),
                  ),
                ),
              ],
            ),
          ),
          Icon(Icons.more_vert, color: Colors.grey[400], size: 16)
        ],
      ),
    );
  }
}