export const NOTICE_STATUS_VALUES = ["draft", "published", "retracted"] as const;
export type NoticeStatus = (typeof NOTICE_STATUS_VALUES)[number];

export const NOTICE_STATUS_LABELS: Record<NoticeStatus, string> = {
  draft: "草稿",
  published: "已发布",
  retracted: "已撤回",
};

export type Notice = {
  id: string;
  organizationId: string;
  title: string;
  content: string;
  audience: string;
  status: NoticeStatus;
  publishedAt?: string;
  createdByAccountId?: string;
  createdByName?: string;
  updatedByAccountId?: string;
  updatedByName?: string;
  readCount: number;
  hasRead: boolean;
  createdAt: string;
  updatedAt: string;
};

export type NoticeCenterData = {
  metrics: {
    published: number;
    drafts: number;
    unread: number;
    retracted: number;
  };
  notices: Notice[];
};

export type NoticeInput = {
  title: string;
  content: string;
  audience: string;
  status: NoticeStatus;
};

type ValidationSuccess<T> = {
  success: true;
  data: T;
};

type ValidationFailure = {
  success: false;
  reason: string;
};

export type ValidationResult<T> = ValidationSuccess<T> | ValidationFailure;

function isRecord(value: unknown): value is Record<string, unknown> {
  return typeof value === "object" && value !== null && !Array.isArray(value);
}

function readString(source: Record<string, unknown>, key: string): string {
  const value = source[key];
  return typeof value === "string" ? value.trim() : "";
}

function readEnum<T extends string>(value: unknown, values: readonly T[]): T | null {
  return typeof value === "string" ? values.find((item) => item === value) ?? null : null;
}

export function validateNoticeInput(value: unknown): ValidationResult<NoticeInput> {
  if (!isRecord(value)) {
    return { success: false, reason: "请求数据格式无效" };
  }

  const title = readString(value, "title");
  const content = readString(value, "content");
  if (!title || !content) {
    return { success: false, reason: "公告标题和内容不能为空" };
  }

  const status = readEnum(value.status, NOTICE_STATUS_VALUES);
  if (!status) {
    return { success: false, reason: "公告状态无效" };
  }

  return {
    success: true,
    data: {
      title,
      content,
      audience: readString(value, "audience") || "全体员工",
      status,
    },
  };
}