import { expect, test, type Page, type Route } from "@playwright/test";

function deferred() {
  let resolve!: () => void;
  const promise = new Promise<void>((done) => { resolve = done; });
  return { promise, resolve };
}

function response(campaignId = "campaign-a", revision = 1, versionId = `${campaignId}-version`, hasMore = false) {
  const version = { id: versionId, campaign_id: campaignId, version_number: 1, edit_revision: revision, raw_json: {} };
  return {
    campaign: { id: campaignId, current_version_id: versionId },
    versions: [version], current_version: version, summary: null,
    deleted: [], watermark: `watermark-${campaignId}-${revision}`, has_more: hasMore, full: true
  };
}

async function fixture(page: Page) {
  const requests: URL[] = [];
  const state = {
    handler: async (route: Route) => {
      const url = new URL(route.request().url());
      const campaignId = url.pathname.split("/")[4];
      await route.fulfill({ json: response(campaignId, 1, url.searchParams.get("version_id") ?? undefined) });
    }
  };
  await page.route((url) => url.pathname.startsWith("/api/"), async (route) => {
    const url = new URL(route.request().url());
    if (url.pathname.endsWith("/workspace/delta")) {
      requests.push(url);
      await state.handler(route);
    } else await route.fulfill({ json: {} });
  });
  await page.goto("/?campaign-workspace");
  await expect(page.getByTestId("workspace-version")).toHaveText("campaign-a-version");
  await expect(page.getByTestId("workspace-loading")).toHaveText("false");
  requests.length = 0;
  return { state, requests };
}

test("failed refresh retains saved workspace and retries without a stale watermark", async ({ page }) => {
  const { state, requests } = await fixture(page);
  state.handler = async (route) => { await route.fulfill({ status: 503, json: { detail: "Refresh unavailable" } }); };
  await page.getByRole("button", { name: "Force reload workspace", exact: true }).click();
  await expect(page.getByTestId("workspace-error")).toContainText("Refresh unavailable");
  await expect(page.getByTestId("workspace-loading")).toHaveText("false");
  await expect(page.getByTestId("workspace-version")).toHaveText("campaign-a-version");
  state.handler = async (route) => { await route.fulfill({ json: response("campaign-a", 2) }); };
  await page.getByRole("button", { name: "Reload workspace", exact: true }).click();
  await expect(page.getByTestId("workspace-revision")).toHaveText("2");
  expect(requests[requests.length - 1].searchParams.has("since")).toBe(false);
  await expect(page.getByTestId("workspace-error")).toBeEmpty();
});

for (const staleFails of [false, true]) {
  test(`newer reload wins over an older ${staleFails ? "failed" : "successful"} response`, async ({ page }) => {
    const { state } = await fixture(page);
    const pending = deferred(); const finished = deferred();
    let requestCount = 0;
    state.handler = async (route) => {
      requestCount += 1;
      if (requestCount === 1) {
        await pending.promise;
        await route.fulfill(staleFails ? { status: 503, json: { detail: "Obsolete error" } } : { json: response("campaign-a", 2) });
        finished.resolve();
      } else await route.fulfill({ json: response("campaign-a", 3) });
    };
    await page.getByRole("button", { name: "Reload workspace", exact: true }).click();
    await expect.poll(() => requestCount).toBe(1);
    await page.getByRole("button", { name: "Reload workspace", exact: true }).click();
    await expect(page.getByTestId("workspace-revision")).toHaveText("3");
    pending.resolve(); await finished.promise;
    await page.evaluate(() => new Promise((done) => requestAnimationFrame(() => requestAnimationFrame(done))));
    await expect(page.getByTestId("workspace-revision")).toHaveText("3");
    await expect(page.getByTestId("workspace-loading")).toHaveText("false");
    await expect(page.getByTestId("workspace-error")).toBeEmpty();
  });
}

for (const change of ["campaign", "identity", "version"] as const) {
  test(`changing ${change} discards old responses and cancels obsolete pagination`, async ({ page }) => {
    const { state, requests } = await fixture(page);
    const pending = deferred(); const finished = deferred();
    let requestCount = 0;
    state.handler = async (route) => {
      requestCount += 1;
      if (requestCount === 1) {
        await pending.promise;
        await route.fulfill({ json: response("campaign-a", 99, "obsolete-version", true) });
        finished.resolve();
      } else await route.fulfill({ json: response(change === "campaign" ? "campaign-b" : "campaign-a", 2, "fresh-version") });
    };
    await page.getByRole("button", { name: "Reload workspace", exact: true }).click();
    await expect.poll(() => requestCount).toBe(1);
    await page.getByRole("button", { name: { campaign: "Switch campaign", identity: "Switch identity", version: "Select version" }[change] }).click();
    await expect(page.getByTestId("workspace-version")).toHaveText("fresh-version");
    pending.resolve(); await finished.promise;
    await page.evaluate(() => new Promise((done) => requestAnimationFrame(() => requestAnimationFrame(done))));
    await expect(page.getByTestId("workspace-version")).toHaveText("fresh-version");
    expect(requests).toHaveLength(2);
    expect(requests[1].searchParams.has("since")).toBe(false);
  });
}

test("failed initial load for a different campaign never reveals the old campaign", async ({ page }) => {
  const { state } = await fixture(page);
  state.handler = async (route) => { await route.fulfill({ status: 403, json: { detail: "Campaign unavailable" } }); };
  await page.getByRole("button", { name: "Switch campaign" }).click();
  await expect(page.getByTestId("workspace-error")).toContainText("Campaign unavailable");
  await expect(page.getByTestId("workspace-campaign")).toHaveText("none");
  await expect(page.getByTestId("workspace-version")).toHaveText("none");
});

test("a failed later page never publishes a partially refreshed workspace", async ({ page }) => {
  const { state } = await fixture(page);
  let requestCount = 0;
  state.handler = async (route) => {
    requestCount += 1;
    await route.fulfill(requestCount === 1
      ? { json: response("campaign-a", 4, "partial-version", true) }
      : { status: 503, json: { detail: "Second page unavailable" } });
  };
  await page.getByRole("button", { name: "Reload workspace", exact: true }).click();
  await expect(page.getByTestId("workspace-error")).toContainText("Second page unavailable");
  await expect(page.getByTestId("workspace-version")).toHaveText("campaign-a-version");
  await expect(page.getByTestId("workspace-revision")).toHaveText("1");
});