import 'package:flutter/material.dart';

import '../../core/module/app_module.dart';
import '../../widgets/cute_icon.dart';
import '../assistant/assistant_page.dart';

/// 首页仪表盘：AI 输入入口 + 模块卡片网格。
///
/// 这个页面是「模块目录」，不是某个模块的主页 —— 卡片全部从 [appModules]
/// 生成，所以将来加模块时**这个文件不需要改**。
///
/// 副作用是：打开 App 第一眼看不到账单了，要点一下「记账」卡片才进账单首页。
/// 这是刻意的 —— 记账不再是主角。
class DashboardPage extends StatelessWidget {
  const DashboardPage({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Container(
        width: double.infinity,
        height: double.infinity,
        decoration: const BoxDecoration(
          gradient: LinearGradient(
            begin: Alignment.topLeft,
            end: Alignment.bottomRight,
            colors: [Color(0xFFFFE5CC), Color(0xFFFFD4A8), Color(0xFFFFC08A)],
          ),
        ),
        child: SafeArea(
          child: ListView(
            physics: const AlwaysScrollableScrollPhysics(),
            padding: const EdgeInsets.fromLTRB(16, 16, 16, 0),
            children: [
              _header(),
              const SizedBox(height: 16),
              _aiEntry(context),
              const SizedBox(height: 22),
              const Text(
                '功能模块',
                style: TextStyle(
                  fontSize: 14,
                  fontWeight: FontWeight.w600,
                  color: Color(0xFF5D4037),
                ),
              ),
              const SizedBox(height: 10),
              _moduleGrid(context),
              const SizedBox(height: 90), // 底部导航避让
            ],
          ),
        ),
      ),
    );
  }

  // ---- 标题 + 问候 ----
  Widget _header() {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        const Text(
          '强宝小助手',
          style: TextStyle(
            fontSize: 22,
            fontWeight: FontWeight.bold,
            color: Color(0xFF5D4037),
            letterSpacing: 1,
          ),
        ),
        const SizedBox(height: 4),
        Text(
          _greeting(),
          style: const TextStyle(fontSize: 13, color: Color(0xFF8D6E63)),
        ),
      ],
    );
  }

  String _greeting() {
    final hour = DateTime.now().hour;
    if (hour < 6) return '夜深了，注意休息';
    if (hour < 12) return '早上好，今天想做点什么？';
    if (hour < 18) return '下午好，今天想做点什么？';
    return '晚上好，今天想做点什么？';
  }

  // ---- AI 入口（阶段 B 接上，现在点进去是占位页）----
  Widget _aiEntry(BuildContext context) {
    return GestureDetector(
      onTap: () => Navigator.of(context).push(
        MaterialPageRoute(builder: (_) => const AssistantPage()),
      ),
      child: Container(
        padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 15),
        decoration: BoxDecoration(
          color: Colors.white,
          borderRadius: BorderRadius.circular(16),
          border: Border.all(color: const Color(0xFFC8956E), width: 1.2),
          boxShadow: [
            BoxShadow(
              color: const Color(0xFF5D4037).withValues(alpha: 0.08),
              blurRadius: 10,
              offset: const Offset(0, 3),
            ),
          ],
        ),
        child: Row(
          children: [
            const CuteIcon('assistant', size: 19),
            const SizedBox(width: 10),
            const Expanded(
              child: Text(
                '问点什么，或者说一句…',
                style: TextStyle(fontSize: 14, color: Color(0xFFBCAAA4)),
              ),
            ),
            const Icon(Icons.chevron_right, size: 20, color: Color(0xFFBCAAA4)),
          ],
        ),
      ),
    );
  }

  // ---- 模块卡片网格 ----
  //
  // 两列。不用 GridView + childAspectRatio：卡片高度由内容（摘要可有可无）
  // 决定，估错比例就会在开发时刷一屏溢出警告 —— GridView 卡片的经典坑。
  // 这里让每张卡片自己撑高，居上对齐。
  Widget _moduleGrid(BuildContext context) {
    const gap = 12.0;
    final rows = <Widget>[];

    for (var i = 0; i < appModules.length; i += 2) {
      final end = i + 2 <= appModules.length ? i + 2 : appModules.length;
      final pair = appModules.sublist(i, end);

      if (rows.isNotEmpty) rows.add(const SizedBox(height: gap));
      rows.add(
        Row(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            for (var j = 0; j < pair.length; j++) ...[
              if (j > 0) const SizedBox(width: gap),
              Expanded(child: _moduleCard(context, pair[j])),
            ],
            // 模块数是奇数时补一个空位，否则最后一张卡片会被拉成通栏
            if (pair.length == 1) ...[
              const SizedBox(width: gap),
              const Expanded(child: SizedBox()),
            ],
          ],
        ),
      );
    }

    return Column(children: rows);
  }

  Widget _moduleCard(BuildContext context, AppModule module) {
    return GestureDetector(
      onTap: () => Navigator.of(context).push(MaterialPageRoute(builder: module.open)),
      child: Container(
        padding: const EdgeInsets.all(14),
        decoration: BoxDecoration(
          color: Colors.white,
          borderRadius: BorderRadius.circular(16),
          boxShadow: [
            BoxShadow(
              color: const Color(0xFF5D4037).withValues(alpha: 0.08),
              blurRadius: 10,
              offset: const Offset(0, 3),
            ),
          ],
        ),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            CuteIcon(module.icon, size: 26),
            const SizedBox(height: 8),
            Text(
              module.name,
              style: const TextStyle(
                fontSize: 16,
                fontWeight: FontWeight.w600,
                color: Color(0xFF5D4037),
              ),
            ),
            const SizedBox(height: 3),
            Text(
              module.blurb,
              maxLines: 1,
              overflow: TextOverflow.ellipsis,
              style: const TextStyle(fontSize: 11.5, color: Color(0xFF8D6E63)),
            ),
            if (module.summary != null) ...[
              const SizedBox(height: 10),
              module.summary!(context),
            ],
          ],
        ),
      ),
    );
  }
}