browser_api.ts

import { apiPort, DatasetApiClient } from "./deps.ts";
import { apiPathParse } from "./utils.ts";
import { renderJSON } from "./render.ts";

/**
 * handleBrowserAPI implements the browser accessible API represented in COLD.
 * It is a read API only and responses are always in JSON.
 */
export async function handleBrowserAPI(
  req: Request,
  options: { debug: boolean; htdocs: string; baseUrl: string; apiUrl: string },
): Promise<Response> {
  if (req.method !== "GET") {
    return renderJSON({
      "ok": false,
      "msg": `${req.method} method not supported`,
    }, 501);
  }
  let basePath: string = "";
  try {
    basePath = new URL(options.baseUrl).pathname.replace(/\/$/, "");
  } catch {
    basePath = "";
  }
  const apiReq: { [key: string]: string } = apiPathParse(req.url, basePath);
  if (apiReq.c_name === undefined) {
    return renderJSON({
      "ok": false,
      "msg": `${apiReq.c_name} collection not found`,
    }, 404);
  }
  if (apiReq.query_name === undefined) {
    return renderJSON({
      "ok": false,
      "msg": `${apiReq.query_name} query not found`,
    }, 404);
  }
  let ds = new DatasetApiClient(apiPort, apiReq.c_name);
  // NOTE: We have more than FIXME: Need to pass in the parameter value(s)
  let qObj: { [key: string]: string } = {};
  let body: string = "";
  let pList: string[] = [];
  if (apiReq.query_name === "lookup_clgid") {
    body = JSON.stringify({ name: apiReq.q, alternative: apiReq.q });
    pList = ["name", "alternative"];
  } else {
    for (let k of Object.keys(apiReq)) {
      if (k !== "query_name" && k !== "c_name") {
        if (apiReq.hasOwnProperty(k)) {
          // handle special case for alternative name search ..., pre-paramaterized requests
          const v = apiReq[k];
          qObj[k] = v;
          pList.push(k);
        }
      }
    }
    body = JSON.stringify(qObj);
  }
  let resp = await ds.query(apiReq.query_name, pList, body);
  if (resp.ok) {
    try {
      let data = await resp.json();
      return renderJSON(data, 200);
    } catch (err) {
      return renderJSON({
        "ok": false,
        "msg": `query ${apiReq.query_name} failed to read response: ${err}`,
        "api": apiReq,
      }, 500);
    }
  }
  // Consume the error body to avoid corrupting the keep-alive connection
  await resp.body?.cancel();
  return renderJSON({
    "ok": false,
    "msg": `query ${apiReq.query_name} failed with status ${resp.status}`,
    "api": apiReq,
  }, resp.status === 404 ? 404 : 500);
}