import { needsImageDecrypt, parseImageExtra, toBusinessImagePath } from '@/utils/im/message';

/** 消息中心私信列表的一行数据（纯 SDK 会话映射） */
export type PrivateSessionItem = {
  id: string;
  /** 业务 uid；列表由 SDK 驱动时为 0，进会话前用 /im/user-id 反查 */
  userId: number;
  /** 对端 IM userId（= conv.receiverId） */
  friendImUserId: number;
  userName: string;
  userAvatar: string;
  preContent: string;
  createdAt: string | number;
  noReadNum: number;
};

/** SDK conversation.subscribeList 推送的会话结构 */
export type SdkConversation = {
  type?: string;
  receiverId?: number | string;
  unreadCount?: number;
  extra?: string;
  lastMessageTime?: number;
  updatedAt?: number;
  createdAt?: number;
  content?: string;
  chatMessageType?: string | number;
  user?: {
    id?: number;
    nickName?: string;
    nickname?: string;
    name?: string;
    avatar?: string;
    portrait?: string;
    imgUrl?: string;
  };
  remark?: string;
};

// —— 展示文案 ——

/** blob/data 本地地址、http(s) 公网图无需再走 imgDecypt */
export function isPublicImageUrl(url?: string): boolean {
  return !needsImageDecrypt(url);
}

export function formatSessionPreview(content?: string): string {
  const text = (content || '').trim();
  if (!text) return '暂无消息';
  if (/^\[图片\]|^图片$|image/i.test(text)) return '[图片]';
  return text;
}

export function formatSessionListTime(date: string | number): string {
  if (date == null || date === '') return '';
  const d = typeof date === 'number' ? new Date(date) : new Date(date);
  if (Number.isNaN(d.getTime()) || d.getFullYear() === 1) return '';
  return `${d.getFullYear()}-${d.getMonth() + 1}-${d.getDate()}`;
}

export function buildMessagePreview(msg: {
  content?: string;
  chatMessageType?: string | number;
  extra?: unknown;
}): string {
  const type = msg.chatMessageType;
  if (type === 'IMAGE' || type === 2 || parseImageExtra(msg.extra)) return '[图片]';
  return (msg.content || '').trim() || '暂无消息';
}

// —— SDK 会话 → 列表行 ——

function toTimestamp(value: string | number | undefined): number {
  if (value == null || value === '') return 0;
  const ts = typeof value === 'number' ? value : new Date(value).getTime();
  return Number.isFinite(ts) ? ts : 0;
}

function isDirectConversation(conv: SdkConversation): boolean {
  if (conv.type && conv.type !== 'direct') return false;
  const imId = Number(conv.receiverId);
  return Number.isFinite(imId) && imId > 0;
}

/** IM 快照偶发幽灵会话（user 资料整体缺失），无法渲染也无法跳转，不展示 */
function hasUserProfile(conv: SdkConversation): boolean {
  const user = conv.user;
  return !!(user?.nickName || user?.nickname || user?.name || user?.avatar || user?.portrait || user?.imgUrl);
}

function toSessionItem(conv: SdkConversation): PrivateSessionItem {
  const imId = Number(conv.receiverId);
  const user = conv.user;

  return {
    id: String(imId),
    userId: 0,
    friendImUserId: imId,
    userName: user?.nickName || user?.nickname || user?.name || conv.remark || '',
    userAvatar: toBusinessImagePath(user?.avatar || user?.portrait || user?.imgUrl || ''),
    preContent: parseImageExtra(conv.extra)
      ? '[图片]'
      : buildMessagePreview({
          content: conv.content,
          chatMessageType: conv.chatMessageType,
          extra: conv.extra,
        }),
    createdAt: conv.lastMessageTime ?? conv.updatedAt ?? conv.createdAt ?? '',
    noReadNum: Number(conv.unreadCount ?? 0),
  };
}

/** SDK 会话快照 → 私信列表（仅单聊；按最后消息时间倒序） */
export function mapSdkConversations(conversations: SdkConversation[]): PrivateSessionItem[] {
  const seen = new Set<number>();
  const list: PrivateSessionItem[] = [];

  for (const conv of conversations) {
    if (!isDirectConversation(conv) || !hasUserProfile(conv)) continue;
    const imId = Number(conv.receiverId);
    if (seen.has(imId)) continue;
    seen.add(imId);
    list.push(toSessionItem(conv));
  }

  return list.sort((a, b) => toTimestamp(b.createdAt) - toTimestamp(a.createdAt));
}