import { afterEach, beforeEach, expect, it, vi } from "vitest";

let processor: AudioWorkletProcessor;
const port = { onmessage: undefined as ((event: MessageEvent) => void) | undefined, postMessage: vi.fn() };
beforeEach(async () => {
  vi.resetModules();
  port.postMessage.mockClear();
  vi.stubGlobal("sampleRate", 48000);
  vi.stubGlobal(
    "AudioWorkletProcessor",
    class {
      port = port;
    },
  );
  vi.stubGlobal("registerProcessor", (_name: string, Processor: new () => AudioWorkletProcessor) => {
    processor = new Processor();
  });
  await import("./audio-playback.worklet");
});
afterEach(() => {
  vi.unstubAllGlobals();
});
function send(data: unknown) {
  port.onmessage?.(new MessageEvent("message", { data }));
}
function render(blocks: number) {
  let audible = false;
  for (let index = 0; index < blocks; index++) {
    const output = new Float32Array(128);
    processor.process([], [[output]]);
    audible ||= output.some((value) => value !== 0);
  }
  return audible;
}
it("flushes a final chunk shorter than the prebuffer and signals after playback finishes", () => {
  send({ kind: "audio", samples: new Float32Array(160).fill(0.5), sequence: 1 });
  expect(render(1)).toBe(false);
  expect(port.postMessage).not.toHaveBeenCalled();
  send({ kind: "finish", sequence: 1 });
  expect(render(1)).toBe(true);
  expect(port.postMessage).not.toHaveBeenCalled();
  render(12);
  expect(port.postMessage).toHaveBeenCalledExactlyOnceWith({ kind: "drained", sequence: 1 });
});
it("discards cleared samples and identifies the latest playback generation", () => {
  send({ kind: "audio", samples: new Float32Array(16000).fill(0.5), sequence: 1 });
  expect(render(1)).toBe(true);
  send({ kind: "clear", sequence: 2 });
  render(2);
  expect(port.postMessage).toHaveBeenLastCalledWith({ kind: "drained", sequence: 2 });
  expect(render(10)).toBe(false);
  send({ kind: "audio", samples: new Float32Array(160).fill(0.25), sequence: 3 });
  send({ kind: "finish", sequence: 3 });
  expect(render(12)).toBe(true);
  expect(port.postMessage).toHaveBeenLastCalledWith({ kind: "drained", sequence: 3 });
});