import { createHash } from "node:crypto";
import { beforeEach, describe, expect, it, vi } from "vitest";

const readFileMock = vi.hoisted(() => vi.fn());

vi.mock("node:fs/promises", () => ({ readFile: readFileMock }));
vi.mock("@ekklesia/shell/display-assets", () => ({
  displayHostAssetUrls: Object.freeze({
    html: "file:///surface/browser/display/index.html",
    script: "file:///surface/browser/display/app.js",
    serviceWorker: "file:///surface/browser/display/sw.js",
  }),
}));

import {
  createDisplayHostAssets,
  DisplayHostAssetError,
  loadDisplayHostAssets,
} from "../src/display-host-assets.js";

describe("display host asset loading", () => {
  beforeEach(() => readFileMock.mockReset());

  it("reads only the three declared file URLs in order and freezes one consistent snapshot", async () => {
    const html = '<!doctype html><div id="ekklesia-display"></div>';
    const script = "export const displayHost = true;\n";
    const serviceWorker = "export const displayWorker = true;\n";
    readFileMock
      .mockResolvedValueOnce(html)
      .mockResolvedValueOnce(script)
      .mockResolvedValueOnce(serviceWorker);

    const assets = await loadDisplayHostAssets();

    expect(readFileMock.mock.calls).toEqual([
      [new URL("file:///surface/browser/display/index.html"), "utf8"],
      [new URL("file:///surface/browser/display/app.js"), "utf8"],
      [new URL("file:///surface/browser/display/sw.js"), "utf8"],
    ]);
    expect(assets).toEqual({
      html,
      script,
      scriptEtag: `"${createHash("sha256").update(script).digest("base64url")}"`,
      serviceWorker,
      serviceWorkerEtag: `"${createHash("sha256").update(serviceWorker).digest("base64url")}"`,
    });
    expect(Object.isFrozen(assets)).toBe(true);
  });

  it("fails deterministically without attempting a neighboring file or exposing the read error", async () => {
    readFileMock.mockRejectedValueOnce(
      new Error("ENOENT /home/operator/private/surface-build secret-token"),
    );

    const failure = await loadDisplayHostAssets().catch((error: unknown) => error);

    expect(readFileMock).toHaveBeenCalledTimes(1);
    expect(failure).toBeInstanceOf(DisplayHostAssetError);
    expect(failure).toMatchObject({
      code: "DISPLAY_HOST_ASSET_UNAVAILABLE",
      message: "The display host browser assets are unavailable.",
      name: "DisplayHostAssetError",
    });
    expect((failure as Error).stack).toBe(
      "DisplayHostAssetError: The display host browser assets are unavailable.",
    );
    const publicText = `${String(failure)}\n${JSON.stringify(failure)}\n${(failure as Error).stack}`;
    for (const secret of ["/home/", "operator", "ENOENT", "secret-token"]) {
      expect(publicText).not.toContain(secret);
    }
  });

  it("rejects an empty page, script, or service worker as an unavailable host build", () => {
    for (const [html, script, serviceWorker] of [
      ["", "export {};", "export {};"],
      ["<html></html>", "   \n", "export {};"],
      ["<html></html>", "export {};", "  \n"],
    ] as const) {
      expect(() => createDisplayHostAssets(html, script, serviceWorker)).toThrow(
        DisplayHostAssetError,
      );
    }
  });
});