api.re

module type ApiClient = {let getFile: unit => string;};

module FakeApiClient: ApiClient = {
  let getFile = () => "cat.jpg";
};

let unwrapUnsafely = data =>
  switch (data) {
  | Some(v) => v
  | None => raise(Invalid_argument("unwrapUnsafely called on None"))
  };

module HttpApiClient: ApiClient = {
  let getFile = () =>
    Js.Promise.(
      Fetch.fetch("https://aws.random.cat/meow")
      |> then_(Fetch.Response.json)
      |> then_(json => Js.Json.decodeObject(json) |> resolve)
      |> then_(opt => unwrapUnsafely(opt) |> resolve)
      |> then_(~file => file |> resolve)
    );
};