import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';

import '../../core/network/api_exception.dart';
import '../../core/theme/app_theme.dart';
import '../../models/membership_models.dart';
import '../../providers/auth_provider.dart';
import '../../providers/member_provider.dart';
import '../feed/widgets/feed_overlays.dart';

/// 会员中心：当前状态卡 + 套餐列表 + 权益说明 + 开通历史
/// 游客可浏览套餐，点开通时引导登录。
class MembershipScreen extends ConsumerWidget {
  const MembershipScreen({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final state = ref.watch(memberProvider);
    final isLoggedIn = ref.watch(authProvider).isLoggedIn;

    return Scaffold(
      appBar: AppBar(title: const Text('会员中心')),
      body: state.isLoading && state.plans.isEmpty
          ? const Center(child: CircularProgressIndicator())
          : state.loadFailed && state.plans.isEmpty
              ? _LoadFailed(onRetry: () => ref.read(memberProvider.notifier).load())
              : RefreshIndicator(
                  onRefresh: () => ref.read(memberProvider.notifier).load(),
                  child: ListView(
                    padding: const EdgeInsets.all(16),
                    children: [
                      if (isLoggedIn && state.me != null)
                        _StatusCard(me: state.me!),
                      if (isLoggedIn && state.me != null)
                        const SizedBox(height: 16),

                      // 套餐列表
                      ...state.plans.map((plan) => Padding(
                            padding: const EdgeInsets.only(bottom: 12),
                            child: _PlanCard(
                              plan: plan,
                              isLifetimeOwned:
                                  state.me?.isLifetime == true,
                              redeeming: state.redeeming,
                              onRedeem: () =>
                                  _onRedeem(context, ref, plan),
                            ),
                          )),

                      // 权益说明
                      if (state.benefits.isNotEmpty) ...[
                        const SizedBox(height: 8),
                        const Text('会员权益',
                            style: TextStyle(
                                fontSize: 15, fontWeight: FontWeight.w700)),
                        const SizedBox(height: 8),
                        ...state.benefits.map((b) => Padding(
                              padding: const EdgeInsets.symmetric(vertical: 3),
                              child: Row(
                                children: [
                                  const Icon(Icons.check_circle,
                                      size: 14, color: AppColors.gold),
                                  const SizedBox(width: 6),
                                  Expanded(
                                    child: Text(b,
                                        style: const TextStyle(
                                            color: AppColors.textSecondary,
                                            fontSize: 13)),
                                  ),
                                ],
                              ),
                            )),
                      ],

                      // 开通历史
                      if (isLoggedIn &&
                          state.me != null &&
                          state.me!.history.isNotEmpty) ...[
                        const SizedBox(height: 20),
                        const Text('开通记录',
                            style: TextStyle(
                                fontSize: 15, fontWeight: FontWeight.w700)),
                        const SizedBox(height: 4),
                        ...state.me!.history.map(_HistoryTile.new),
                      ],
                    ],
                  ),
                ),
    );
  }

  Future<void> _onRedeem(
      BuildContext context, WidgetRef ref, MembershipPlan plan) async {
    // 游客 → 引导登录
    if (!ref.read(authProvider).isLoggedIn) {
      showTopToast(context, '请先登录后再开通会员');
      context.push('/login');
      return;
    }
    final points = ref.read(authProvider).user?.points ?? 0;
    final ok = await showDialog<bool>(
      context: context,
      builder: (ctx) => AlertDialog(
        backgroundColor: AppColors.surface,
        title: Text('开通${plan.name}', style: const TextStyle(fontSize: 16)),
        content: Text(
          '需消耗 ${plan.points} 积分，当前积分 $points。\n'
          '${plan.days == 0 ? '有效期：终身' : '有效期：${plan.days} 天'}',
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(ctx, false),
            child: const Text('取消'),
          ),
          TextButton(
            onPressed: () => Navigator.pop(ctx, true),
            child:
                const Text('确认开通', style: TextStyle(color: AppColors.gold)),
          ),
        ],
      ),
    );
    if (ok != true || !context.mounted) return;

    try {
      final result =
          await ref.read(memberProvider.notifier).redeem(plan.planCode);
      if (context.mounted) {
        showTopToast(context,
            '开通成功：${result.planName}，剩余积分 ${result.remainingPoints}');
      }
    } on ApiException catch (e) {
      if (!context.mounted) return;
      if (e.code == 2004) {
        showTopToast(context, '终身卡已开通，无需重复购买');
      } else if (e.isPointsInsufficient) {
        showTopToast(context, '积分不足，已为你打开充值页');
        context.push('/recharge');
      } else {
        showTopToast(context, e.message);
      }
    } catch (_) {
      if (context.mounted) showTopToast(context, '开通失败，请稍后重试');
    }
  }
}

/// 当前会员状态卡
class _StatusCard extends StatelessWidget {
  const _StatusCard({required this.me});

  final MyMemberState me;

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(
        gradient: AppColors.goldGradient,
        borderRadius: BorderRadius.circular(12),
      ),
      child: Row(
        children: [
          const Icon(Icons.workspace_premium, size: 36, color: Colors.black87),
          const SizedBox(width: 12),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  me.isMember
                      ? (me.isLifetime ? '终身会员' : (me.planName ?? '会员'))
                      : '暂未开通会员',
                  style: const TextStyle(
                    color: Colors.black87,
                    fontSize: 16,
                    fontWeight: FontWeight.w700,
                  ),
                ),
                const SizedBox(height: 4),
                Text(
                  me.isMember
                      ? (me.isLifetime
                          ? '永久有效'
                          : '剩余 ${me.remainingDays} 天 · ${me.expireAt ?? ''} 到期')
                      : '开通会员尊享多项特权',
                  style:
                      const TextStyle(color: Colors.black54, fontSize: 12),
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }
}

/// 套餐卡片
class _PlanCard extends StatelessWidget {
  const _PlanCard({
    required this.plan,
    required this.isLifetimeOwned,
    required this.redeeming,
    required this.onRedeem,
  });

  final MembershipPlan plan;

  /// 已持有终身卡：所有套餐不可再开通（终身卡重复开通 2004）
  final bool isLifetimeOwned;
  final bool redeeming;
  final VoidCallback onRedeem;

  @override
  Widget build(BuildContext context) {
    final disabled = !plan.enabled || isLifetimeOwned || redeeming;
    return Container(
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(
        color: AppColors.surface,
        borderRadius: BorderRadius.circular(12),
        border: plan.days == 0
            ? Border.all(color: AppColors.goldDeep, width: 1.2)
            : null,
      ),
      child: Row(
        children: [
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Row(
                  children: [
                    Text(plan.name,
                        style: const TextStyle(
                            fontSize: 16, fontWeight: FontWeight.w700)),
                    if (plan.days == 0) ...[
                      const SizedBox(width: 6),
                      Container(
                        padding: const EdgeInsets.symmetric(
                            horizontal: 5, vertical: 1),
                        decoration: BoxDecoration(
                          gradient: AppColors.goldGradient,
                          borderRadius: BorderRadius.circular(4),
                        ),
                        child: const Text('推荐',
                            style: TextStyle(
                                color: Colors.black,
                                fontSize: 10,
                                fontWeight: FontWeight.w700)),
                      ),
                    ],
                  ],
                ),
                const SizedBox(height: 4),
                Text(
                  plan.days == 0 ? '终身有效' : '${plan.days} 天',
                  style: const TextStyle(
                      color: AppColors.textSecondary, fontSize: 12),
                ),
                if (plan.desc.isNotEmpty) ...[
                  const SizedBox(height: 2),
                  Text(plan.desc,
                      style: const TextStyle(
                          color: AppColors.textWeak, fontSize: 12)),
                ],
              ],
            ),
          ),
          const SizedBox(width: 12),
          Column(
            crossAxisAlignment: CrossAxisAlignment.end,
            children: [
              Text('${plan.points} 积分',
                  style: const TextStyle(
                      color: AppColors.gold,
                      fontSize: 15,
                      fontWeight: FontWeight.w700)),
              const SizedBox(height: 8),
              SizedBox(
                height: 34,
                child: ElevatedButton(
                  onPressed: disabled ? null : onRedeem,
                  style: ElevatedButton.styleFrom(
                    minimumSize: const Size(84, 34),
                    padding: const EdgeInsets.symmetric(horizontal: 14),
                    textStyle: const TextStyle(fontSize: 13),
                  ),
                  child: Text(isLifetimeOwned ? '已开通' : '开通'),
                ),
              ),
            ],
          ),
        ],
      ),
    );
  }
}

/// 开通历史条目
class _HistoryTile extends StatelessWidget {
  const _HistoryTile(this.item);

  final MemberHistoryItem item;

  @override
  Widget build(BuildContext context) {
    return ListTile(
      contentPadding: EdgeInsets.zero,
      dense: true,
      title: Text(item.planName, style: const TextStyle(fontSize: 14)),
      subtitle: Text(
        '${item.startAt} ~ ${item.endAt.isEmpty ? '终身' : item.endAt} · ${item.sourceLabel}',
        style: const TextStyle(color: AppColors.textWeak, fontSize: 12),
      ),
      trailing: Text('${item.pointsCost} 积分',
          style: const TextStyle(color: AppColors.gold, fontSize: 13)),
    );
  }
}

class _LoadFailed extends StatelessWidget {
  const _LoadFailed({required this.onRetry});

  final VoidCallback onRetry;

  @override
  Widget build(BuildContext context) {
    return Center(
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          const Text('加载失败', style: TextStyle(color: AppColors.textSecondary)),
          const SizedBox(height: 12),
          TextButton(onPressed: onRetry, child: const Text('点击重试')),
        ],
      ),
    );
  }
}