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

import { installMockBridge } from "../helpers/bridge";

async function getTimelineMetrics(page: import("@playwright/test").Page) {
  return page.getByTestId("message-timeline").evaluate((element) => {
    const timeline = element as HTMLDivElement;

    return {
      clientHeight: timeline.clientHeight,
      scrollHeight: timeline.scrollHeight,
      scrollTop: timeline.scrollTop,
      distanceFromBottom:
        timeline.scrollHeight - timeline.clientHeight - timeline.scrollTop,
    };
  });
}

async function ensureTimelineScrollable(
  page: import("@playwright/test").Page,
  prefix: string,
) {
  const input = page.getByTestId("message-input");
  const sendButton = page.getByTestId("send-message");

  for (let index = 0; index < 24; index += 1) {
    const metrics = await getTimelineMetrics(page);
    if (metrics.scrollHeight > metrics.clientHeight + 160) {
      return;
    }

    const message = `${prefix} seed ${index}`;

    await input.fill(message);
    await sendButton.click();
    await expect(page.getByTestId("message-timeline")).toContainText(message);
  }

  const metrics = await getTimelineMetrics(page);
  expect(metrics.scrollHeight).toBeGreaterThan(metrics.clientHeight + 160);
}

test.beforeEach(async ({ page }) => {
  await installMockBridge(page);
});

test("loads the app shell with mocked channels", async ({ page }) => {
  await page.goto("/");

  await expect(page.getByTestId("app-sidebar")).toBeVisible();
  await expect(page.getByTestId("stream-list")).toContainText("general");
  await expect(page.getByTestId("forum-list")).toContainText("watercooler");
  await expect(page.getByTestId("dm-list")).toContainText("alice-tyler");
});

test("creates a new mocked stream", async ({ page }) => {
  const channelName = `release-notes-${Date.now()}`;

  await page.goto("/");
  await page.getByRole("button", { name: "Create a stream" }).click();
  await page.getByTestId("create-stream-name").fill(channelName);
  await page
    .getByTestId("create-stream-description")
    .fill("Release coordination");
  await page.getByRole("button", { name: "Create" }).click();

  await expect(page.getByTestId("stream-list")).toContainText(channelName);
  await expect(page.getByTestId("chat-title")).toHaveText(channelName);
});

test("opens a mocked channel from the home feed", async ({ page }) => {
  const mentionsSection = page.locator("section").filter({
    has: page.getByRole("heading", { name: "@Mentions" }),
  });

  await page.goto("/");

  await expect(page.getByTestId("chat-title")).toHaveText("Home");
  await expect(
    page.getByRole("heading", { name: "Focus queue" }),
  ).toBeVisible();
  await expect(
    page.getByText("Please review the release checklist."),
  ).toBeVisible();

  await mentionsSection.getByRole("button", { name: "Open" }).click();

  await expect(page.getByTestId("chat-title")).toHaveText("general");
  await expect(page.getByTestId("message-timeline")).toContainText(
    "Welcome to #general",
  );
});

test("replaces the channel pane when switching channels", async ({ page }) => {
  await page.goto("/");

  await page.getByTestId("channel-general").click();
  await expect(page.getByTestId("chat-title")).toHaveText("general");
  await expect(page.getByTestId("message-timeline")).toContainText(
    "Welcome to #general",
  );

  await page.getByTestId("channel-random").click();
  await expect(page.getByTestId("chat-title")).toHaveText("random");
  await expect(page.getByTestId("message-empty")).toBeVisible();
  await expect(page.getByTestId("message-timeline")).not.toContainText(
    "Welcome to #general",
  );
  await expect(page.getByTestId("message-timeline")).toHaveCount(1);
  await expect(page.getByTestId("message-timeline-day-divider")).toHaveCount(1);

  await page.getByTestId("channel-engineering").click();
  await expect(page.getByTestId("chat-title")).toHaveText("engineering");
  await expect(page.getByTestId("message-empty")).toBeVisible();
  await expect(page.getByTestId("message-timeline")).toHaveCount(1);
  await expect(page.getByTestId("message-timeline-day-divider")).toHaveCount(1);
});

test("sends a mocked channel message", async ({ page }) => {
  const message = `Smoke message ${Date.now()}`;

  await page.goto("/");
  await page.getByTestId("channel-general").click();
  await expect(page.getByTestId("chat-title")).toHaveText("general");
  await page.getByTestId("message-input").fill(message);
  await page.getByTestId("send-message").click();

  await expect(page.getByTestId("message-timeline")).toContainText(message);
});

test("supports multiline drafts with Ctrl+Enter and sends with Enter", async ({
  page,
}) => {
  const firstLine = `Shortcut smoke line one ${Date.now()}`;
  const restOfLines = [
    "Shortcut smoke line two",
    "Shortcut smoke line three",
    "Shortcut smoke line four",
    "Shortcut smoke line five",
  ];
  const input = page.getByTestId("message-input");

  await page.goto("/");
  await page.getByTestId("channel-general").click();
  await expect(page.getByTestId("chat-title")).toHaveText("general");
  await expect(page.getByTestId("send-message")).toContainText("Send");
  const initialInputHeight = await input.evaluate(
    (element) => (element as HTMLTextAreaElement).clientHeight,
  );
  expect(initialInputHeight).toBeLessThan(40);
  await input.fill(firstLine);
  for (const line of restOfLines) {
    await input.press("Control+Enter");
    await input.type(line);
  }
  await expect(input).toHaveValue([firstLine, ...restOfLines].join("\n"));
  const expandedInputHeight = await input.evaluate(
    (element) => (element as HTMLTextAreaElement).clientHeight,
  );
  expect(expandedInputHeight).toBeLessThanOrEqual(100);
  await expect(page.getByTestId("message-timeline")).not.toContainText(
    firstLine,
  );
  await input.press("Enter");

  await expect(page.getByTestId("message-timeline")).toContainText(firstLine);
  await expect(page.getByTestId("message-timeline")).toContainText(
    restOfLines[restOfLines.length - 1],
  );
});

test("does not shift the timeline when the composer grows", async ({
  page,
}) => {
  const input = page.getByTestId("message-input");
  const prefix = `Composer growth ${Date.now()}`;

  await page.goto("/");
  await page.getByTestId("channel-general").click();
  await expect(page.getByTestId("chat-title")).toHaveText("general");

  await ensureTimelineScrollable(page, prefix);
  await page.waitForTimeout(400);
  await page.getByTestId("message-timeline").evaluate((element) => {
    const timeline = element as HTMLDivElement;
    timeline.scrollTop = 0;
    timeline.dispatchEvent(new Event("scroll"));
  });
  await expect
    .poll(async () => (await getTimelineMetrics(page)).distanceFromBottom)
    .toBeGreaterThan(160);
  const before = await getTimelineMetrics(page);

  await input.fill("Composer growth line one");
  await input.press("Control+Enter");
  await input.type("Composer growth line two");
  await input.press("Control+Enter");
  await input.type("Composer growth line three");
  await input.press("Control+Enter");
  await input.type("Composer growth line four");

  await page.waitForTimeout(1200);

  const after = await getTimelineMetrics(page);
  expect(after.clientHeight).toBeLessThan(before.clientHeight);
  expect(Math.abs(after.scrollTop - before.scrollTop)).toBeLessThanOrEqual(2);
  expect(after.distanceFromBottom).toBeGreaterThan(160);
});