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import basePath from "lib/base-path";
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import LRU from "lru-cache";
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import { join } from "path";
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const VERSION = "v2";
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export default async function apiPost(
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  path: string,
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  data?: object,
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  cache_s: number = 0 // if given, cache results for this many seconds to avoid overfetching
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): Promise<any> {
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  let cache, key;
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  if (cache_s) {
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    cache = getCache(cache_s);
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    key = JSON.stringify({ path, data });
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    if (cache.has(key)) {
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      return cache.get(key);
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    }
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  }
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  const response = await fetch(join(basePath, "api", VERSION, path), {
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    method: "POST",
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    headers: { "Content-Type": "application/json" },
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    body: JSON.stringify(data),
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  });
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  let result;
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  try {
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    result = await response.json();
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    if (result.error) {
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      // if error is set in response, then just throw exception (this greatly simplifies client code).
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      throw Error(result.error);
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    }
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  } catch (err) {
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    if (response.statusText == "Not Found") {
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      throw Error(`The API endpoint ${path} does not exist`);
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    }
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    throw err;
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  }
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  if (cache_s) {
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    cache.set(key, result);
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  }
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  return result;
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}
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const caches: { [seconds: number]: LRU<string, object> } = {};
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function getCache(seconds: number) {
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  if (!caches[seconds]) {
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    caches[seconds] = new LRU<string, object>({
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      ttl: 1000 * seconds,
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      max: 200,
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    });
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  }
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  return caches[seconds];
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}
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