import { KeyValueStorage } from "./basic.ts";
import { Application, oakCors, readAll } from "../deps.server.ts";
import { HEADER_REPLYIER, HEADER_REQUESTER } from "./remote.ts";

type Server = {
  close: () => Promise<void>;
};

/**
 * Start a server compliant with RestRemoteStorage
 */
export function startRestServer(
  port: number,
  storage: KeyValueStorage,
): Server {
  const app = new Application();
  const controller = new AbortController();

  app.use(oakCors());
  app.use(async (context) => {
    if (context.request.headers.get(HEADER_REQUESTER)) {
      context.response.headers.set(HEADER_REPLYIER, "ok");

      const method = context.request.method;
      const path = context.request.url.pathname;

      if (method == "GET") {
        const result = await storage.get(path);
        if (result === null) {
          context.response.status = 404;
        } else {
          context.response.body = result;
        }
      } else if (method == "PUT") {
        const body = context.request.body({ type: "reader" });
        const data = await readAll(body.value);
        const value = new TextDecoder().decode(data);
        await storage.set(path, value);
      } else if (method == "DELETE") {
        await storage.set(path, null);
      } else {
        context.response.status = 405;
      }
    } else {
      context.response.status = 400;
    }
  });

  const listen = app.listen({ port, signal: controller.signal });
  return {
    close: async () => {
      controller.abort();
      await listen;
    },
  };
}