1 files changed, 151 insertions, 0 deletions
diff --git a/fetch.ts b/fetch.ts
new file mode 100644
index 000000000..dac019048
--- /dev/null
+++ b/fetch.ts
@@ -0,0 +1,151 @@
+import { assert, log, createResolvable, Resolvable } from "./util";
+import * as util from "./util";
+import * as dispatch from "./dispatch";
+import { main as pb } from "./msg.pb";
+import { TextDecoder } from "text-encoding";
+
+export function initFetch() {
+  dispatch.sub("fetch", (payload: Uint8Array) => {
+    const msg = pb.Msg.decode(payload);
+    assert(msg.command === pb.Msg.Command.FETCH_RES);
+    const id = msg.fetchResId;
+    const f = fetchRequests.get(id);
+    assert(f != null, `Couldn't find FetchRequest id ${id}`);
+
+    f.onMsg(msg);
+  });
+}
+
+const fetchRequests = new Map<number, FetchRequest>();
+
+class FetchResponse implements Response {
+  readonly url: string;
+  body: null;
+  bodyUsed = false; // TODO
+  status: number;
+  statusText = "FIXME"; // TODO
+  readonly type = "basic"; // TODO
+  redirected = false; // TODO
+  headers: null; // TODO
+  //private bodyChunks: Uint8Array[] = [];
+  private first = true;
+
+  constructor(readonly req: FetchRequest) {
+    this.url = req.url;
+  }
+
+  bodyWaiter: Resolvable<ArrayBuffer>;
+  arrayBuffer(): Promise<ArrayBuffer> {
+    this.bodyWaiter = createResolvable();
+    return this.bodyWaiter;
+  }
+
+  blob(): Promise<Blob> {
+    throw Error("not implemented");
+  }
+
+  formData(): Promise<FormData> {
+    throw Error("not implemented");
+  }
+
+  async json(): Promise<object> {
+    const text = await this.text();
+    return JSON.parse(text);
+  }
+
+  async text(): Promise<string> {
+    const ab = await this.arrayBuffer();
+    const enc = new TextDecoder("utf-8");
+    // Maybe new Uint8Array(ab)
+    return enc.decode(ab);
+  }
+
+  get ok(): boolean {
+    return 200 <= this.status && this.status < 300;
+  }
+
+  clone(): Response {
+    throw Error("not implemented");
+  }
+
+  onHeader: (res: Response) => void;
+  onError: (error: Error) => void;
+
+  onMsg(msg: pb.Msg) {
+    if (msg.error !== null && msg.error !== "") {
+      //throw new Error(msg.error)
+      this.onError(new Error(msg.error));
+      return;
+    }
+
+    if (this.first) {
+      this.first = false;
+      this.status = msg.fetchResStatus;
+      this.onHeader(this);
+    } else {
+      // Body message. Assuming it all comes in one message now.
+      const ab = util.typedArrayToArrayBuffer(msg.fetchResBody);
+      this.bodyWaiter.resolve(ab);
+    }
+  }
+}
+
+let nextFetchId = 0;
+//TODO implements Request
+class FetchRequest {
+  private readonly id: number;
+  response: FetchResponse;
+  constructor(readonly url: string) {
+    this.id = nextFetchId++;
+    fetchRequests.set(this.id, this);
+    this.response = new FetchResponse(this);
+  }
+
+  onMsg(msg: pb.Msg) {
+    this.response.onMsg(msg);
+  }
+
+  destroy() {
+    fetchRequests.delete(this.id);
+  }
+
+  start() {
+    log("dispatch FETCH_REQ", this.id, this.url);
+    const res = dispatch.sendMsg("fetch", {
+      command: pb.Msg.Command.FETCH_REQ,
+      fetchReqId: this.id,
+      fetchReqUrl: this.url
+    });
+    assert(res == null);
+  }
+}
+
+export function fetch(
+  input?: Request | string,
+  init?: RequestInit
+): Promise<Response> {
+  const fetchReq = new FetchRequest(input as string);
+  const response = fetchReq.response;
+  return new Promise((resolve, reject) => {
+    // tslint:disable-next-line:no-any
+    response.onHeader = (response: any) => {
+      log("onHeader");
+      resolve(response);
+    };
+    response.onError = (error: Error) => {
+      log("onError", error);
+      reject(error);
+    };
+    fetchReq.start();
+  });
+}
+
+/*
+fetch('http://example.com/movies.json')
+  .then(function(response) {
+    return response.json();
+  })
+  .then(function(myJson) {
+    console.log(myJson);
+  });
+  */