import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter_lucide/flutter_lucide.dart';

import '../../core/adjust/adjust_events.dart';
import '../../core/api/services/payment_api.dart';
import '../../core/auth/auth_service.dart';
import '../../core/theme/app_colors.dart';
import '../../core/user/user_state.dart';
import '../../core/theme/app_spacing.dart';
import '../../core/theme/app_typography.dart';
import '../../shared/widgets/top_nav_bar.dart';

import 'models/activity_item.dart';

/// Recharge screen - matches Pencil tPjdN
/// Tier cards (DC6NS, YRaOG, QlNz6) 对接 getGooglePayActivities / getApplePayActivities
class RechargeScreen extends StatefulWidget {
  const RechargeScreen({super.key});

  @override
  State<RechargeScreen> createState() => _RechargeScreenState();
}

class _RechargeScreenState extends State<RechargeScreen> {
  List<ActivityItem> _activities = [];
  bool _loadingTiers = true;
  String? _tierError;

  @override
  void initState() {
    super.initState();
    _fetchActivities();
  }

  Future<void> _fetchActivities() async {
    setState(() {
      _loadingTiers = true;
      _tierError = null;
    });
    try {
      await AuthService.loginComplete;
      final country = UserState.navigate.value ?? '';
          
      final res = defaultTargetPlatform == TargetPlatform.iOS
          ? await PaymentApi.getApplePayActivities(
              vambrace: country.isEmpty ? null : country,
            )
          : await PaymentApi.getGooglePayActivities(
              vambrace: country.isEmpty ? null : country,
            );
      if (!mounted) return;
      if (res.isSuccess && res.data != null) {
        final data = res.data as Map<String, dynamic>?;
        final summon = data?['summon'] as List<dynamic>? ?? [];
        final list = summon
            .whereType<Map<String, dynamic>>()
            .map((e) => ActivityItem.fromJson(e))
            .where((e) => e.code.isNotEmpty)
            .toList();
        setState(() {
          _activities = list;
          _loadingTiers = false;
        });
      } else {
        setState(() {
          _activities = [];
          _loadingTiers = false;
          _tierError = res.msg.isNotEmpty ? res.msg : 'Failed to load';
        });
      }
    } catch (e) {
      if (mounted) {
        setState(() {
          _activities = [];
          _loadingTiers = false;
          _tierError = e.toString();
        });
      }
    }
  }

  void _onBuy(ActivityItem item) {
    final price = AdjustEvents.parsePrice(item.actualAmount);
    if (price != null) {
      final tierToken = AdjustEvents.tierTokenFromPrice(price);
      if (tierToken != null) {
        AdjustEvents.trackTier(tierToken);
      }
    }
    final titleLower = item.title.toLowerCase();
    if (titleLower.contains('monthly vip')) {
      AdjustEvents.trackMonthlyVip();
    } else if (titleLower.contains('weekly vip')) {
      AdjustEvents.trackWeeklyVip();
    }
    // TODO: 创建支付订单；成功时调用 AdjustEvents.trackPurchaseSuccess()，失败时调用 AdjustEvents.trackPaymentFailed()
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: AppColors.background,
      appBar: PreferredSize(
        preferredSize: const Size.fromHeight(56),
        child: TopNavBar(
          title: 'Recharge',
          credits: UserCreditsData.of(context)?.creditsDisplay ?? '--',
          showBackButton: true,
          onBack: () => Navigator.of(context).pop(),
          onCreditsTap: null,
        ),
      ),
      body: SingleChildScrollView(
        padding: const EdgeInsets.only(bottom: AppSpacing.screenPaddingLarge),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            _CreditsSection(
              currentCredits:
                  UserCreditsData.of(context)?.creditsDisplay ?? '--',
            ),
            Padding(
              padding: const EdgeInsets.symmetric(
                horizontal: AppSpacing.screenPaddingLarge,
                vertical: AppSpacing.xxl,
              ),
              child: Text(
                'Select Tier',
                style: AppTypography.bodyMedium.copyWith(
                  color: AppColors.textPrimary,
                ),
              ),
            ),
            if (_loadingTiers)
              const Padding(
                padding: EdgeInsets.all(AppSpacing.xxl),
                child: Center(
                  child: SizedBox(
                    width: 24,
                    height: 24,
                    child: CircularProgressIndicator(strokeWidth: 2),
                  ),
                ),
              )
            else if (_tierError != null)
              Padding(
                padding: const EdgeInsets.symmetric(
                    horizontal: AppSpacing.screenPadding),
                child: Column(
                  children: [
                    Text(
                      _tierError!,
                      style: AppTypography.bodyRegular.copyWith(
                        color: AppColors.textSecondary,
                      ),
                    ),
                    const SizedBox(height: AppSpacing.md),
                    TextButton(
                      onPressed: _fetchActivities,
                      child: const Text('Retry'),
                    ),
                  ],
                ),
              )
            else if (_activities.isEmpty)
              Padding(
                padding: const EdgeInsets.symmetric(
                    horizontal: AppSpacing.screenPadding),
                child: Text(
                  'No packages available',
                  style: AppTypography.bodyRegular.copyWith(
                    color: AppColors.textSecondary,
                  ),
                ),
              )
            else
              ...List.generate(_activities.length, (i) {
                final item = _activities[i];
                final isRecommended = i == 1;
                final isPopular = i == 2;
                return Padding(
                  padding: EdgeInsets.only(
                    bottom: i < _activities.length - 1
                        ? AppSpacing.xl
                        : 0,
                  ),
                  child: _TierCardFromActivity(
                    item: item,
                    badge: isRecommended
                        ? _TierBadge.recommended
                        : isPopular
                            ? _TierBadge.popular
                            : _TierBadge.none,
                    onBuy: () => _onBuy(item),
                  ),
                );
              }),
          ],
        ),
      ),
    );
  }
}

enum _TierBadge { none, recommended, popular }

class _TierCardFromActivity extends StatelessWidget {
  const _TierCardFromActivity({
    required this.item,
    required this.badge,
    required this.onBuy,
  });

  final ActivityItem item;
  final _TierBadge badge;
  final VoidCallback onBuy;

  @override
  Widget build(BuildContext context) {
    final content = Container(
      margin: const EdgeInsets.symmetric(horizontal: AppSpacing.screenPadding),
      padding: const EdgeInsets.symmetric(
        horizontal: AppSpacing.xxl,
        vertical: AppSpacing.xl,
      ),
      decoration: BoxDecoration(
        color: AppColors.surface,
        borderRadius: BorderRadius.circular(16),
        border: Border.all(color: AppColors.border),
        boxShadow: [
          BoxShadow(
            color: AppColors.shadowLight,
            blurRadius: 6,
            offset: const Offset(0, 2),
          ),
        ],
      ),
      child: Row(
        mainAxisAlignment: MainAxisAlignment.spaceBetween,
        children: [
          Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Text(
                item.creditsDisplay,
                style: AppTypography.bodyLarge.copyWith(
                  color: AppColors.textPrimary,
                ),
              ),
              SizedBox(height: badge == _TierBadge.none ? AppSpacing.xs : AppSpacing.sm),
              Text(
                item.priceDisplay,
                style: AppTypography.bodyRegular.copyWith(
                  color: AppColors.textSecondary,
                ),
              ),
            ],
          ),
          _BuyButton(onTap: onBuy),
        ],
      ),
    );

    if (badge == _TierBadge.none) {
      return content;
    }

    return Stack(
      clipBehavior: Clip.none,
      children: [
        content,
        Positioned(
          top: 0,
          right: AppSpacing.screenPadding,
          child: Container(
            padding: const EdgeInsets.symmetric(
              horizontal: AppSpacing.md,
              vertical: AppSpacing.xs,
            ),
            decoration: BoxDecoration(
              color: badge == _TierBadge.recommended
                  ? AppColors.primaryLight
                  : AppColors.accentOrangeLight,
              borderRadius: const BorderRadius.only(
                topRight: Radius.circular(16),
                bottomLeft: Radius.circular(16),
              ),
            ),
            child: Text(
              badge == _TierBadge.recommended
                  ? 'Recommended'
                  : 'Most Popular',
              style: AppTypography.label.copyWith(
                color: badge == _TierBadge.recommended
                    ? AppColors.primary
                    : AppColors.accentOrange,
                fontWeight: FontWeight.w600,
              ),
            ),
          ),
        ),
      ],
    );
  }
}

class _CreditsSection extends StatelessWidget {
  const _CreditsSection({required this.currentCredits});

  final String currentCredits;

  @override
  Widget build(BuildContext context) {
    return Container(
      margin: const EdgeInsets.all(AppSpacing.screenPadding),
      padding: const EdgeInsets.symmetric(
        horizontal: AppSpacing.xxl,
        vertical: AppSpacing.xl,
      ),
      decoration: BoxDecoration(
        color: AppColors.primary,
        borderRadius: BorderRadius.circular(16),
        border: Border.all(
          color: AppColors.primary.withValues(alpha: 0.5),
        ),
        boxShadow: [
          BoxShadow(
            color: AppColors.primaryShadow.withValues(alpha: 0.25),
            blurRadius: 8,
            offset: const Offset(0, 2),
          ),
        ],
      ),
      child: Row(
        children: [
          Icon(LucideIcons.sparkles, size: 28, color: AppColors.surface),
          const SizedBox(width: AppSpacing.md),
          Text(
            currentCredits,
            style: AppTypography.bodyLarge.copyWith(
              fontSize: 32,
              fontWeight: FontWeight.w700,
              color: AppColors.surface,
            ),
          ),
          const Spacer(),
          Text(
            'Current Credits',
            style: AppTypography.caption.copyWith(
              color: AppColors.surface.withValues(alpha: 0.8),
            ),
          ),
        ],
      ),
    );
  }
}

class _BuyButton extends StatelessWidget {
  const _BuyButton({required this.onTap});

  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onTap: onTap,
      child: Container(
        padding: const EdgeInsets.symmetric(
          horizontal: AppSpacing.xl,
          vertical: AppSpacing.md,
        ),
        decoration: BoxDecoration(
          color: AppColors.primary,
          borderRadius: BorderRadius.circular(12),
        ),
        child: Text(
          'Buy',
          style: AppTypography.bodyRegular.copyWith(
            color: AppColors.surface,
            fontWeight: FontWeight.w600,
          ),
        ),
      ),
    );
  }
}