import { assertEquals, assertThrows } from "../testing/asserts.ts";
import { delay } from "../async/delay.ts";
import { signal, onSignal } from "./mod.ts";

Deno.test({
  name: "signal() throws when called with empty signals",
  ignore: Deno.build.os === "windows",
  fn() {
    assertThrows(
      () => {
        // eslint-disable-next-line @typescript-eslint/no-explicit-any
        (signal as any)();
      },
      Error,
      "No signals are given. You need to specify at least one signal to create a signal stream.",
    );
  },
});

Deno.test({
  name: "signal() iterates for multiple signals",
  ignore: Deno.build.os === "windows",
  fn: async (): Promise<void> => {
    // This prevents the program from exiting.
    const t = setInterval(() => {}, 1000);

    let c = 0;
    const sig = signal(
      Deno.Signal.SIGUSR1,
      Deno.Signal.SIGUSR2,
      Deno.Signal.SIGINT,
    );

    setTimeout(async () => {
      await delay(20);
      Deno.kill(Deno.pid, Deno.Signal.SIGINT);
      await delay(20);
      Deno.kill(Deno.pid, Deno.Signal.SIGUSR2);
      await delay(20);
      Deno.kill(Deno.pid, Deno.Signal.SIGUSR1);
      await delay(20);
      Deno.kill(Deno.pid, Deno.Signal.SIGUSR2);
      await delay(20);
      Deno.kill(Deno.pid, Deno.Signal.SIGUSR1);
      await delay(20);
      Deno.kill(Deno.pid, Deno.Signal.SIGINT);
      await delay(20);
      sig.dispose();
    });

    for await (const _ of sig) {
      c += 1;
    }

    assertEquals(c, 6);

    clearTimeout(t);
  },
});

Deno.test({
  name: "onSignal() registers and disposes of event handler",
  ignore: Deno.build.os === "windows",
  async fn() {
    // This prevents the program from exiting.
    const t = setInterval(() => {}, 1000);

    let calledCount = 0;
    const handle = onSignal(Deno.Signal.SIGINT, () => {
      calledCount++;
    });

    await delay(20);
    Deno.kill(Deno.pid, Deno.Signal.SIGINT);
    await delay(20);
    Deno.kill(Deno.pid, Deno.Signal.SIGINT);
    await delay(20);
    Deno.kill(Deno.pid, Deno.Signal.SIGUSR2);
    await delay(20);
    handle.dispose(); // stop monitoring SIGINT
    await delay(20);
    Deno.kill(Deno.pid, Deno.Signal.SIGUSR1);
    await delay(20);
    Deno.kill(Deno.pid, Deno.Signal.SIGINT);
    await delay(20);
    assertEquals(calledCount, 2);

    clearTimeout(t);
  },
});