import 'package:flutter/material.dart';

import '../../app/app_controller.dart';
import '../../app/app_theme.dart';
import '../../data/json_schedule_import.dart';
import '../../domain/course.dart';

class ImportPreview extends StatefulWidget {
  const ImportPreview({
    super.key,
    required this.draft,
    required this.controller,
  });
  final ImportDraft draft;
  final AppController controller;
  @override
  State<ImportPreview> createState() => _ImportPreviewState();
}

class _ImportPreviewState extends State<ImportPreview> {
  bool _clearConfirmed = false, _busy = false;
  @override
  Widget build(BuildContext context) {
    final draft = widget.draft, empty = draft.courses.isEmpty;
    final allowed =
        !_busy && (!empty || (draft.explicitlyEmpty && _clearConfirmed));
    return SafeArea(
      child: SingleChildScrollView(
        padding: const EdgeInsets.fromLTRB(24, 8, 24, 28),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          mainAxisSize: MainAxisSize.min,
          children: [
            const Text(
              '确认你的课表',
              style: TextStyle(fontSize: 24, fontWeight: FontWeight.w700),
            ),
            const SizedBox(height: 8),
            Text(
              '${draft.courses.length} 条课程安排 · ${draft.source == CourseSource.demo ? '示例体验' : '导入预览'}',
              style: const TextStyle(color: river),
            ),
            if (draft.semesterLabel != null) Text('学期：${draft.semesterLabel}'),
            const SizedBox(height: 18),
            if (empty)
              Text(draft.explicitlyEmpty ? '此操作会清空当前课表。' : '没有识别到课程，当前课表保持不变。'),
            if (empty && draft.explicitlyEmpty)
              CheckboxListTile(
                value: _clearConfirmed,
                onChanged: (v) => setState(() => _clearConfirmed = v ?? false),
                title: const Text('确认清空当前课表'),
                contentPadding: EdgeInsets.zero,
              ),
            for (final c in draft.courses)
              Padding(
                padding: const EdgeInsets.only(bottom: 10),
                child: SurfaceCard(
                  padding: const EdgeInsets.all(14),
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Text(
                        c.name,
                        style: const TextStyle(fontWeight: FontWeight.w700),
                      ),
                      const SizedBox(height: 5),
                      Text(
                        '${c.teacher} · ${c.room}',
                        style: const TextStyle(fontSize: 12),
                      ),
                      const SizedBox(height: 4),
                      Text(
                        '周${const ['一', '二', '三', '四', '五', '六', '日'][c.weekday - 1]} · 第 ${c.startPeriod}–${c.endPeriod} 节',
                        style: TextStyle(
                          fontSize: 12,
                          color: ink.withValues(alpha: 0.5),
                        ),
                      ),
                    ],
                  ),
                ),
              ),
            if (widget.controller.snapshot.settings.semester == null &&
                draft.source != CourseSource.demo)
              const Padding(
                padding: EdgeInsets.only(bottom: 16),
                child: Text(
                  '导入后请在设置中选择真实学期开始日，课表与提醒才会显示。',
                  style: TextStyle(fontSize: 12, height: 1.6),
                ),
              ),
            SizedBox(
              width: double.infinity,
              child: FilledButton(
                onPressed: allowed
                    ? () async {
                        setState(() => _busy = true);
                        await widget.controller.applyImport(
                          draft,
                          confirmedEmpty: _clearConfirmed,
                        );
                        if (!context.mounted) return;
                        if (widget.controller.lastError == null) {
                          Navigator.pop(context, true);
                        } else {
                          setState(() => _busy = false);
                          ScaffoldMessenger.of(context).showSnackBar(
                            SnackBar(
                              content: Text(widget.controller.lastError!),
                            ),
                          );
                        }
                      }
                    : null,
                child: Text(
                  _busy
                      ? '正在保存…'
                      : draft.source == CourseSource.demo
                      ? '开始体验'
                      : '确认导入',
                ),
              ),
            ),
            const SizedBox(height: 8),
            Center(
              child: TextButton(
                onPressed: _busy ? null : () => Navigator.pop(context, false),
                child: const Text('取消'),
              ),
            ),
          ],
        ),
      ),
    );
  }
}