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

import '../../core/responsive/responsive.dart';
import '../../core/theme/context_tokens.dart';
import '../../core/theme/app_dims.g.dart';
import '../../repositories/auth_repository.dart';

/// 应用内自助注册新门店（公开页）。提交后创建门店 + 管理员账号，
/// 返回门店编号引导去登录。对应后端 POST /api/v1/register。
class RegisterScreen extends ConsumerStatefulWidget {
  const RegisterScreen({super.key});

  @override
  ConsumerState<RegisterScreen> createState() => _RegisterScreenState();
}

class _RegisterScreenState extends ConsumerState<RegisterScreen> {
  final _formKey = GlobalKey<FormState>();
  final _shopName = TextEditingController();
  final _phone = TextEditingController();
  final _address = TextEditingController();
  final _manager = TextEditingController();
  final _username = TextEditingController();
  final _password = TextEditingController();
  final _confirm = TextEditingController();
  bool _agree = false;
  bool _obscure = true;
  bool _submitting = false;

  @override
  void dispose() {
    for (final c in [
      _shopName, _phone, _address, _manager, _username, _password, _confirm
    ]) {
      c.dispose();
    }
    super.dispose();
  }

  Future<void> _submit() async {
    if (!(_formKey.currentState?.validate() ?? false)) return;
    if (!_agree) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('请先阅读并同意服务条款与隐私政策')),
      );
      return;
    }
    setState(() => _submitting = true);
    try {
      final r = await AuthRepository.register(
        shopName: _shopName.text.trim(),
        phone: _phone.text.trim(),
        address: _address.text.trim(),
        managerName: _manager.text.trim(),
        username: _username.text.trim(),
        password: _password.text,
      );
      if (!mounted) return;
      await showDialog<void>(
        context: context,
        barrierDismissible: false,
        builder: (ctx) => AlertDialog(
          title: const Text('注册成功'),
          content: Column(
            mainAxisSize: MainAxisSize.min,
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Text('门店「${r.shopName}」已创建。'),
              const SizedBox(height: 12),
              Text('门店编号（登录时需用）：',
                  style: TextStyle(color: context.tokens.muted, fontSize: 13)),
              const SizedBox(height: 4),
              SelectableText(r.shopCode,
                  style: const TextStyle(
                      fontFamily: 'monospace',
                      fontSize: 18,
                      fontWeight: FontWeight.w700)),
            ],
          ),
          actions: [
            ElevatedButton(
              onPressed: () {
                Navigator.of(ctx).pop();
                context.go('/login');
              },
              child: const Text('去登录'),
            ),
          ],
        ),
      );
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
              content: Text(e.toString().replaceFirst('AuthException: ', '')),
              backgroundColor: context.tokens.danger),
        );
      }
    } finally {
      if (mounted) setState(() => _submitting = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    final t = context.tokens;
    final wide = !context.isMobile;
    return Scaffold(
      backgroundColor: t.page,
      body: Center(
        child: ConstrainedBox(
          constraints: const BoxConstraints(maxWidth: 920, maxHeight: 720),
          child: Card(
            clipBehavior: Clip.antiAlias,
            shape: RoundedRectangleBorder(
                borderRadius: BorderRadius.circular(AppDims.rXl)),
            child: Row(
              children: [
                if (wide) SizedBox(width: 320, child: _brandPanel(t)),
                Expanded(child: _formPanel(t)),
              ],
            ),
          ),
        ),
      ),
    );
  }

  Widget _brandPanel(t) {
    Widget step(int n, String title, String sub) => Padding(
          padding: const EdgeInsets.only(bottom: 18),
          child: Row(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Container(
                width: 24,
                height: 24,
                alignment: Alignment.center,
                decoration: BoxDecoration(
                    color: t.onPrimary.withValues(alpha: 0.18),
                    shape: BoxShape.circle),
                child: Text('$n',
                    style: TextStyle(
                        color: t.onPrimary,
                        fontSize: 12,
                        fontWeight: FontWeight.w700)),
              ),
              const SizedBox(width: 10),
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text(title,
                        style: TextStyle(
                            color: t.onPrimary,
                            fontSize: AppDims.fsBody,
                            fontWeight: FontWeight.w600)),
                    Text(sub,
                        style: TextStyle(
                            color: t.onPrimary.withValues(alpha: 0.72),
                            fontSize: AppDims.fsSm)),
                  ],
                ),
              ),
            ],
          ),
        );
    return Container(
      color: t.primary,
      padding: const EdgeInsets.all(28),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Icon(Icons.local_bar, color: t.onPrimary, size: 32),
          const SizedBox(height: 16),
          Text('开通门店',
              style: TextStyle(
                  color: t.onPrimary,
                  fontSize: AppDims.fsH1,
                  fontWeight: FontWeight.w700)),
          const SizedBox(height: 8),
          Text('几分钟创建你的酒水进销存门店，立即开始入库出库',
              style: TextStyle(
                  color: t.onPrimary.withValues(alpha: 0.78),
                  fontSize: AppDims.fsSm,
                  height: 1.6)),
          const SizedBox(height: 28),
          step(1, '填写门店信息', '店名、编号与联系人'),
          step(2, '创建管理员账号', '用于登录与管理成员'),
          step(3, '开始使用', '入库录单即自动建档'),
        ],
      ),
    );
  }

  Widget _formPanel(t) {
    return SingleChildScrollView(
      padding: const EdgeInsets.all(28),
      child: Form(
        key: _formKey,
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Row(
              children: [
                Text('注册新门店',
                    style: TextStyle(
                        fontSize: AppDims.fsH2, fontWeight: FontWeight.w700)),
                const Spacer(),
                TextButton(
                  onPressed: () => context.go('/login'),
                  child: const Text('已有门店？直接登录 →'),
                ),
              ],
            ),
            const SizedBox(height: 16),
            _field(_shopName, '门店名称 *', '例如 鼎昌酒行', required: true),
            _row2(
              _field(_phone, '联系电话 *', '11 位手机号',
                  required: true, keyboard: TextInputType.phone),
              _field(_address, '门店地址 *', '省 / 市 / 区 详细地址', required: true),
            ),
            _field(_manager, '管理员姓名 *', '例如 王经理', required: true),
            _row2(
              _field(_username, '登录账号 *', '字母 / 数字', required: true),
              const SizedBox.shrink(),
            ),
            _row2(
              _field(_password, '登录密码 *', '至少 6 位',
                  required: true, obscure: _obscure, minLen: 6),
              _field(_confirm, '确认密码 *', '再次输入',
                  required: true,
                  obscure: _obscure,
                  validator: (v) =>
                      v != _password.text ? '两次密码不一致' : null),
            ),
            CheckboxListTile(
              value: _agree,
              onChanged: (v) => setState(() => _agree = v ?? false),
              controlAffinity: ListTileControlAffinity.leading,
              contentPadding: EdgeInsets.zero,
              dense: true,
              title: Text('我已阅读并同意 服务条款 与 隐私政策',
                  style: TextStyle(fontSize: AppDims.fsSm, color: t.muted)),
            ),
            const SizedBox(height: 12),
            SizedBox(
              width: double.infinity,
              child: ElevatedButton(
                onPressed: _submitting ? null : _submit,
                style: ElevatedButton.styleFrom(
                    padding: const EdgeInsets.symmetric(vertical: 14)),
                child: _submitting
                    ? const SizedBox(
                        width: 18,
                        height: 18,
                        child: CircularProgressIndicator(
                            strokeWidth: 2, color: Colors.white))
                    : const Text('创建门店并进入'),
              ),
            ),
          ],
        ),
      ),
    );
  }

  Widget _row2(Widget a, Widget b) => Row(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Expanded(child: a),
          const SizedBox(width: 12),
          Expanded(child: b),
        ],
      );

  Widget _field(
    TextEditingController ctrl,
    String label,
    String hint, {
    bool required = false,
    bool obscure = false,
    int? minLen,
    TextInputType? keyboard,
    String? Function(String?)? validator,
  }) {
    return Padding(
      padding: const EdgeInsets.only(bottom: 14),
      child: TextFormField(
        controller: ctrl,
        obscureText: obscure,
        keyboardType: keyboard,
        decoration: InputDecoration(
          labelText: label,
          hintText: hint,
          isDense: true,
          border: const OutlineInputBorder(),
        ),
        validator: validator ??
            (v) {
              if (required && (v == null || v.trim().isEmpty)) return '必填';
              if (minLen != null && (v?.length ?? 0) < minLen) {
                return '至少 $minLen 位';
              }
              return null;
            },
      ),
    );
  }
}