import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:sunny_mochi/core/utils/validator.dart';
import 'package:sunny_mochi/core/widgets/app_button.dart';
import 'package:sunny_mochi/core/widgets/app_text_field.dart';
import 'package:sunny_mochi/core/widgets/app_toast.dart';
import 'package:sunny_mochi/core/widgets/count_down_button.dart';
import 'package:sunny_mochi/features/auth/presentation/notifiers/auth_notifier.dart';

/// 通用登录页骨架 — 手机号 + 双模式（短信验证码 / 密码）。
///
/// TODO: 替换为项目品牌 UI（logo / 背景 / 色彩）。
class LoginPage extends ConsumerStatefulWidget {
  const LoginPage({super.key});

  @override
  ConsumerState<LoginPage> createState() => _LoginPageState();
}

class _LoginPageState extends ConsumerState<LoginPage>
    with SingleTickerProviderStateMixin {
  late final TabController _tabCtrl;
  final _phoneCtrl = TextEditingController();
  final _codeCtrl = TextEditingController();
  final _passwordCtrl = TextEditingController();
  bool _obscurePassword = true;

  @override
  void initState() {
    super.initState();
    _tabCtrl = TabController(length: 2, vsync: this);
  }

  @override
  void dispose() {
    _tabCtrl.dispose();
    _phoneCtrl.dispose();
    _codeCtrl.dispose();
    _passwordCtrl.dispose();
    super.dispose();
  }

  bool get _isSms => _tabCtrl.index == 0;

  Future<void> _onSendCode() async {
    final phone = _phoneCtrl.text.trim();
    if (!Validator.isValidPhone(phone)) {
      if (mounted) {
        AppToast.show(context, '请输入有效的手机号码', type: ToastType.warning);
      }
      return;
    }
    try {
      final echoCode = await ref
          .read(authProvider.notifier)
          .sendSmsCode(phone);
      if (echoCode != null && mounted) {
        _codeCtrl.text = echoCode; // dev/test 环境自动填入
      }
    } on Object catch (e) {
      if (mounted) {
        AppToast.show(context, e.toString(), type: ToastType.error);
      }
    }
  }

  Future<void> _onLogin() async {
    final phone = _phoneCtrl.text.trim();
    if (!Validator.isValidPhone(phone)) {
      AppToast.show(context, '请输入有效的手机号码', type: ToastType.warning);
      return;
    }
    if (_isSms) {
      final code = _codeCtrl.text.trim();
      if (code.isEmpty) {
        AppToast.show(context, '请输入验证码', type: ToastType.warning);
        return;
      }
      await ref.read(authProvider.notifier).loginWithPhone(phone, code);
    } else {
      final pwd = _passwordCtrl.text;
      if (pwd.isEmpty) {
        AppToast.show(context, '请输入密码', type: ToastType.warning);
        return;
      }
      await ref
          .read(authProvider.notifier)
          .loginWithPassword(phone, pwd);
    }
  }

  @override
  Widget build(BuildContext context) {
    final authState = ref.watch(authProvider);
    final isLoading = authState is AuthLoading;

    ref.listen(authProvider, (_, next) {
      if (next is AuthError && mounted) {
        AppToast.show(context, next.message, type: ToastType.error);
      }
    });

    return Scaffold(
      body: SafeArea(
        child: SingleChildScrollView(
          padding: const EdgeInsets.symmetric(horizontal: 24, vertical: 40),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              const SizedBox(height: 48),
              // TODO: 替换为项目 Logo
              const FlutterLogo(size: 64),
              const SizedBox(height: 32),
              Text(
                '欢迎登录',
                style: Theme.of(context).textTheme.headlineSmall?.copyWith(
                      fontWeight: FontWeight.bold,
                    ),
              ),
              const SizedBox(height: 32),
              // 手机号
              AppTextField(
                controller: _phoneCtrl,
                label: '手机号',
                hint: '请输入手机号',
                keyboardType: TextInputType.phone,
                maxLength: 11,
                prefixIcon: const Icon(Icons.phone_outlined),
              ),
              const SizedBox(height: 16),
              // 模式切换 Tab
              TabBar(
                controller: _tabCtrl,
                onTap: (_) => setState(() {}),
                tabs: const [
                  Tab(text: '短信验证码'),
                  Tab(text: '密码登录'),
                ],
              ),
              const SizedBox(height: 16),
              // 验证码 / 密码输入
              if (_isSms)
                Row(
                  children: [
                    Expanded(
                      child: AppTextField(
                        controller: _codeCtrl,
                        label: '验证码',
                        hint: '请输入验证码',
                        keyboardType: TextInputType.number,
                        maxLength: 6,
                      ),
                    ),
                    const SizedBox(width: 12),
                    CountDownButton(onSend: _onSendCode),
                  ],
                )
              else
                AppTextField(
                  controller: _passwordCtrl,
                  label: '密码',
                  hint: '请输入密码',
                  obscureText: _obscurePassword,
                  suffix: IconButton(
                    icon: Icon(
                      _obscurePassword
                          ? Icons.visibility_outlined
                          : Icons.visibility_off_outlined,
                    ),
                    onPressed: () =>
                        setState(() => _obscurePassword = !_obscurePassword),
                  ),
                ),
              const SizedBox(height: 32),
              AppButton(
                label: '登录',
                onPressed: _onLogin,
                loading: isLoading,
              ),
            ],
          ),
        ),
      ),
    );
  }
}