import 'json_util.dart';

/// 笔记列表项（不含正文）
///
/// 后端列表接口刻意不返回 content —— 一页 20 条正文可能有几 MB，
/// 而这个后端在公网服务器上，列表页只需要摘要。
class NoteListItem {
  final int id;
  final int? folderId;
  final String title;
  final String summary;
  final List<String> tags;
  final bool pinned;
  final String updateTime;

  const NoteListItem({
    required this.id,
    required this.folderId,
    required this.title,
    required this.summary,
    required this.tags,
    required this.pinned,
    required this.updateTime,
  });

  factory NoteListItem.fromJson(Map<String, dynamic> json) {
    return NoteListItem(
      id: asInt(json['id']),
      folderId: asNullableInt(json['folderId']),
      title: asNonEmpty(json['title'], '无标题笔记'),
      summary: asString(json['summary']),
      tags: asStringList(json['tagList']),
      pinned: asInt(json['isPinned']) == 1,
      updateTime: formatDateTime(json['updateTime']),
    );
  }
}

/// 笔记详情（含正文）
class NoteDetail {
  final int id;
  final int? folderId;
  final String title;
  final String content;
  final List<String> tags;
  final bool pinned;
  final String createTime;
  final String updateTime;

  const NoteDetail({
    required this.id,
    required this.folderId,
    required this.title,
    required this.content,
    required this.tags,
    required this.pinned,
    required this.createTime,
    required this.updateTime,
  });

  factory NoteDetail.fromJson(Map<String, dynamic> json) {
    return NoteDetail(
      id: asInt(json['id']),
      folderId: asNullableInt(json['folderId']),
      title: asNonEmpty(json['title'], '无标题笔记'),
      content: asString(json['content']),
      tags: asStringList(json['tagList']),
      pinned: asInt(json['isPinned']) == 1,
      createTime: formatDateTime(json['createTime']),
      updateTime: formatDateTime(json['updateTime']),
    );
  }
}

/// 分页结果
class NotePage {
  final List<NoteListItem> items;
  final int total;
  final bool hasMore;

  const NotePage({required this.items, required this.total, required this.hasMore});

  static const empty = NotePage(items: [], total: 0, hasMore: false);

  factory NotePage.fromJson(Map<String, dynamic> json) {
    return NotePage(
      items: asMapList(json['list']).map(NoteListItem.fromJson).toList(),
      total: asInt(json['total']),
      hasMore: json['hasMore'] == true,
    );
  }
}

/// 目录树节点
class FolderNode {
  final int id;
  final String name;
  final int? parentId;

  /// 该目录下的笔记数（**含所有子目录**），和后端列表接口的口径一致
  final int noteCount;
  final List<FolderNode> children;

  const FolderNode({
    required this.id,
    required this.name,
    required this.parentId,
    required this.noteCount,
    required this.children,
  });

  factory FolderNode.fromJson(Map<String, dynamic> json) {
    return FolderNode(
      id: asInt(json['id']),
      name: asNonEmpty(json['name'], '未命名'),
      parentId: asNullableInt(json['parentId']),
      noteCount: asInt(json['noteCount']),
      children: asMapList(json['children']).map(FolderNode.fromJson).toList(),
    );
  }
}

/// 目录树接口的完整返回
class FolderTree {
  final List<FolderNode> folders;
  final int uncategorizedCount;
  final int totalCount;

  const FolderTree({
    required this.folders,
    required this.uncategorizedCount,
    required this.totalCount,
  });

  static const empty = FolderTree(folders: [], uncategorizedCount: 0, totalCount: 0);

  factory FolderTree.fromJson(Map<String, dynamic> json) {
    return FolderTree(
      folders: asMapList(json['folders']).map(FolderNode.fromJson).toList(),
      uncategorizedCount: asInt(json['uncategorizedCount']),
      totalCount: asInt(json['totalCount']),
    );
  }

  /// 按 id 找节点，用于拼当前目录的面包屑路径
  List<FolderNode>? findPath(int id) {
    List<FolderNode>? walk(List<FolderNode> nodes, List<FolderNode> trail) {
      for (final node in nodes) {
        final next = [...trail, node];
        if (node.id == id) return next;
        final found = walk(node.children, next);
        if (found != null) return found;
      }
      return null;
    }

    return walk(folders, []);
  }
}

/// 当前浏览的位置
///
/// 用三个 scope 对应目录树上的三种节点，而不是用 `folderId == null`
/// 来表达「全部」—— 那样就没法区分「全部」和「未分类」了。
enum NoteScope { all, uncategorized, folder }

class NoteLocation {
  final NoteScope scope;
  final int? folderId;
  final String folderName;

  const NoteLocation({
    required this.scope,
    this.folderId,
    this.folderName = '全部',
  });

  static const all = NoteLocation(scope: NoteScope.all, folderName: '全部');
  static const uncategorized =
      NoteLocation(scope: NoteScope.uncategorized, folderName: '未分类');

  /// 传给后端 list 接口的 scope 参数
  String get apiScope {
    switch (scope) {
      case NoteScope.all:
        return 'all';
      case NoteScope.uncategorized:
        return 'uncategorized';
      case NoteScope.folder:
        return 'folder';
    }
  }
}

/// 后端给的是 `yyyy-MM-dd HH:mm:ss`，这里裁成 `yyyy-MM-dd HH:mm`
/// 列表里显示到秒没有意义，还会把卡片撑宽。
String formatDateTime(Object? value) {
  final text = asString(value);
  return text.length >= 16 ? text.substring(0, 16) : text;
}