// screens/license/license_screen.dart — 授权管理独立一级屏（原型 license.html /
// m-license.html），三 tab：授权信息 / 在线购买续费 / 订单管理。
// 桌面 `/license`、移动 `/me/license` 复用同一 Widget，内部按 context.isMobile
// 切换两种形态（桌面：头部+DsSeg+卡片区；移动：通栏 DsSeg+滚动内容）。
//
// tab 可见性：
// - 「在线购买续费」iOS App Store 合规态（hideExternalPurchaseUi）整 tab 隐藏；
// - 「订单管理」GET /license/purchases 仅管理员可用（后端判权），非管理员隐藏该 tab。
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:lucide_icons_flutter/lucide_icons.dart';

import '../../core/auth/auth_state.dart';
import '../../core/config/store_compliance.dart';
import '../../core/responsive/responsive.dart';
import '../../core/theme/app_dims.g.dart';
import '../../core/theme/context_tokens.dart';
import '../../core/utils/money.dart';
import '../../core/utils/web_launch.dart';
import '../../providers/license_purchase_provider.dart';
import '../../widgets/ds/ds_atoms.dart';
import 'license_orders_tab.dart';
import '../settings/license_panel.dart';
import '../settings/purchase_card.dart';
import '../settings/settings_card.dart';

enum _LicSection { info, buy, orders }

class LicenseScreen extends ConsumerStatefulWidget {
  const LicenseScreen({super.key});

  @override
  ConsumerState<LicenseScreen> createState() => _LicenseScreenState();
}

class _LicenseScreenState extends ConsumerState<LicenseScreen> {
  _LicSection _section = _LicSection.info;

  void _goInfo() => setState(() => _section = _LicSection.info);
  void _goBuy() => setState(() => _section = _LicSection.buy);

  @override
  Widget build(BuildContext context) {
    final t = context.tokens;
    final role = ref.watch(authStateProvider.select((s) => s.user?.role));
    final isAdmin = role == 'admin' || role == 'superadmin';
    final showBuy = !hideExternalPurchaseUi;
    final showOrders = isAdmin;

    // 当前 tab 若因权限/合规态变得不可见，回退到「授权信息」。
    if ((_section == _LicSection.buy && !showBuy) ||
        (_section == _LicSection.orders && !showOrders)) {
      _section = _LicSection.info;
    }

    final sections = [
      _LicSection.info,
      if (showBuy) _LicSection.buy,
      if (showOrders) _LicSection.orders,
    ];

    final mobile = context.isMobile;
    final segLabels = {
      _LicSection.info: '授权信息',
      _LicSection.buy: mobile ? '购买 / 续费' : '在线购买 / 续费',
      _LicSection.orders: '订单管理',
    };

    Widget seg = DsSeg(
      items: [for (final s in sections) segLabels[s]!],
      index: sections.indexOf(_section).clamp(0, sections.length - 1),
      onChanged: (i) => setState(() => _section = sections[i]),
    );

    Widget body = switch (_section) {
      _LicSection.info => _infoBody(mobile),
      _LicSection.buy => _buyBody(mobile, isAdmin),
      _LicSection.orders => LicenseOrdersTab(
          onGoInfo: _goInfo,
          onGoBuy: showBuy ? _goBuy : null,
        ),
    };

    if (mobile) {
      return Container(
        color: t.bg,
        child: Column(
          children: [
            Padding(
              padding: const EdgeInsets.fromLTRB(14, 12, 14, 0),
              child: Align(alignment: Alignment.centerLeft, child: seg),
            ),
            const SizedBox(height: 12),
            Expanded(child: body),
          ],
        ),
      );
    }

    return Container(
      color: t.bg,
      padding: const EdgeInsets.fromLTRB(26, 22, 26, 22),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          _buildHeader(context, ref, t),
          const SizedBox(height: 18),
          Align(alignment: Alignment.centerLeft, child: seg),
          const SizedBox(height: 18),
          Expanded(child: body),
        ],
      ),
    );
  }

  Widget _buildHeader(BuildContext context, WidgetRef ref, dynamic t) {
    final sub = switch (_section) {
      _LicSection.info => '授权状态 · 兑换券 · 降级规则',
      _LicSection.buy => '选择套餐支付宝支付 · 到账自动续期',
      _LicSection.orders => () {
          final result = ref.watch(purchaseListProvider).valueOrNull;
          if (result == null) return '订单流水';
          return '共 ${result.total} 笔 · '
              '累计 ¥${yuanFromMinor(result.summary.paidTotalMinor)}';
        }(),
    };
    return Row(
      crossAxisAlignment: CrossAxisAlignment.end,
      children: [
        Text('授权管理',
            style: TextStyle(
                fontSize: AppDims.fsH1,
                fontWeight: FontWeight.w700,
                color: t.heading)),
        const SizedBox(width: AppDims.sp3),
        Padding(
          padding: const EdgeInsets.only(bottom: 2),
          child: Text(sub, style: TextStyle(fontSize: AppDims.fsSm, color: t.muted)),
        ),
        const Spacer(),
        if (_section == _LicSection.orders)
          DsButton('刷新',
              icon: LucideIcons.refreshCw,
              onPressed: () =>
                  ref.read(purchaseListProvider.notifier).reload()),
      ],
    );
  }

  Widget _infoBody(bool mobile) {
    final child = mobile
        ? const LicensePanel()
        : ConstrainedBox(
            constraints: const BoxConstraints(maxWidth: 720),
            child: const LicensePanel(),
          );
    return SingleChildScrollView(
      padding: mobile ? const EdgeInsets.fromLTRB(14, 0, 14, 14) : EdgeInsets.zero,
      child: child,
    );
  }

  Widget _buyBody(bool mobile, bool isAdmin) {
    final card = SettingsCard(
      title: '在线购买 / 续费',
      desc: isAdmin ? '选择套餐支付宝支付，到账后授权自动续期' : '在线购买仅门店管理员可操作',
      child: isAdmin
          ? const PurchaseCard()
          : Builder(builder: (ctx) {
              final t = ctx.tokens;
              return Row(children: [
                Text('在线购买请联系门店管理员 · ',
                    style: TextStyle(fontSize: AppDims.fsSm, color: t.muted)),
                InkWell(
                  onTap: () => launchAuthedWebPath(ref, '/#pricing'),
                  child: Text('查看套餐价格 →',
                      style: TextStyle(
                          fontSize: AppDims.fsSm,
                          fontWeight: FontWeight.w600,
                          color: t.primary)),
                ),
              ]);
            }),
    );
    final child = mobile
        ? card
        : ConstrainedBox(constraints: const BoxConstraints(maxWidth: 560), child: card);
    return SingleChildScrollView(
      padding: mobile ? const EdgeInsets.fromLTRB(14, 0, 14, 14) : EdgeInsets.zero,
      child: child,
    );
  }
}