/**
 * 功能：配送合同 PDF 附件的上传、失败清理与鉴权预览客户端。
 * 版本：v1.0.0
 */
import { getToken } from '@/utils/auth';

const platformApiBaseURL =
  import.meta.env.VITE_API_BASE_URL ||
  'http://localhost:12426/heqi/platform/v1';

export type ContractAttachmentMetadata = {
  has_file: boolean;
  available: boolean;
  requires_reupload: boolean;
  display_name: string;
  version: string;
};

export type ContractAttachmentUploadReply = {
  receipt: string;
  cleanup_token: string;
  display_name: string;
  size: number;
};

type ApiEnvelope<T> = { code?: number; message?: string; details?: T };

/** 返回当前登录凭证请求头。 */
function authorizationHeaders(): Record<string, string> {
  const token = getToken();
  return token ? { Authorization: token } : {};
}

/** 上传经过前端预检的单个 PDF，服务端仍会验证真实内容。 */
async function upload(file: File): Promise<ContractAttachmentUploadReply> {
  const form = new FormData();
  form.append('file', file);
  const response = await fetch(
    `${platformApiBaseURL}/gasorder_contract/attachment/upload`,
    { method: 'POST', headers: authorizationHeaders(), body: form },
  );
  const payload = (await response.json()) as ApiEnvelope<ContractAttachmentUploadReply>;
  if (!response.ok || payload.code !== 0 || !payload.details) {
    throw new Error(payload.message || '合同附件上传失败');
  }
  return payload.details;
}

/** 使用受签名保护的清理凭证删除尚未绑定的临时文件。 */
async function cleanup(cleanupToken: string): Promise<void> {
  const response = await fetch(
    `${platformApiBaseURL}/gasorder_contract/attachment/cleanup`,
    {
      method: 'POST',
      headers: { 'Content-Type': 'application/json', ...authorizationHeaders() },
      body: JSON.stringify({ cleanup_token: cleanupToken }),
    },
  );
  if (!response.ok) throw new Error('临时合同附件清理失败');
  const payload = (await response.json()) as ApiEnvelope<{ deleted: boolean }>;
  if (payload.code !== 0) throw new Error(payload.message || '临时合同附件清理失败');
}

/** 获取鉴权 PDF Blob；内部存储 URI 始终不会暴露给浏览器。 */
async function load(identity: string): Promise<Blob> {
  const response = await fetch(
    `${platformApiBaseURL}/gasorder_contract/${encodeURIComponent(identity)}/attachment`,
    { headers: authorizationHeaders() },
  );
  if (!response.ok) throw new Error('合同附件不可用，请重新上传');
  return response.blob();
}

export const contractAttachmentApi = { upload, cleanup, load };