// 关卡清单：从 assets/levels.json 加载内置关卡，并提供与 web 版
// levels/index.js 一致的 TYPE_LABEL / TYPE_CLASS / makeCustomLevel / findLevel。
import 'dart:convert';
import 'package:flutter/services.dart' show rootBundle;
import 'package:iwbtc/src/core/save.dart';

const Map<String, String> TYPE_LABEL = {
  'jump': '跳刺',
  'endur': '耐久',
  'boss': 'BOSS',
  'troll': '坑向',
  'custom': '自制',
};

const Map<String, String> TYPE_CLASS = {
  'jump': 't-jump',
  'endur': 't-endur',
  'boss': 't-boss',
  'troll': 't-troll',
  'custom': 't-custom',
};

List<Map<String, dynamic>> _builtin = <Map<String, dynamic>>[];
bool _loaded = false;

/// 加载内置关卡（assets/levels.json）。重复调用安全。
Future<void> loadLevels() async {
  if (_loaded) return;
  final s = await rootBundle.loadString('assets/levels.json');
  final m = (jsonDecode(s) as Map).cast<String, dynamic>();
  final list = ((m['levels'] as List?) ?? <dynamic>[])
      .cast<Map<String, dynamic>>()
      .toList();
  for (int i = 0; i < list.length; i++) {
    list[i] = <String, dynamic>{...list[i], 'index': i, 'builtin': true};
  }
  _builtin = list;
  _loaded = true;
}

/// 内置关卡清单（已标注 index / builtin）。
List<Map<String, dynamic>> get LEVELS => _builtin;

/// 合成一张自制关卡数据对象（与 web makeCustomLevel 一致）。
Map<String, dynamic> makeCustomLevel(Map<String, dynamic> data) {
  return <String, dynamic>{
    ...data,
    'id': 'u' + (DateTime.now().millisecondsSinceEpoch % 100000).toString() + (_uid++).toString(),
    'type': 'custom',
    'builtin': false,
    'index': -1,
  };
}

int _uid = 0;

/// 按 id 查找关卡（内置优先，其次自制）。
Map<String, dynamic>? findLevel(String id) {
  for (final l in _builtin) {
    if (l['id'] == id) return l;
  }
  for (final l in Save.customs()) {
    if (l['id'] == id) return l as Map<String, dynamic>;
  }
  return null;
}