// Boosted navigation: outside the editor, page links swap the next page into
// the open document instead of loading a new one. A marker on window survives
// a boosted navigation and disappears with a full page load.
import { test, expect } from "@playwright/test";
import { mkdirSync, readFileSync, writeFileSync } from "node:fs";
import { dirname, join } from "node:path";
import { fileURLToPath } from "node:url";

const wiki = join(dirname(fileURLToPath(import.meta.url)), "..", ".tmp", "wiki");

test.beforeEach(({ page }) => {
  page.on("pageerror", (err) => {
    // Chrome aborts the cross-document view transition (style.css) when the
    // next document can't take part, e.g. a plain-text file, and reports it
    // as an unhandled rejection that no page script can catch.
    if (err.message.includes("ViewTransition opt-in disabled")) return;
    throw err;
  });
});

function randomWord(n) {
  return Array.from({ length: n }, () => String.fromCharCode(97 + Math.floor(Math.random() * 26))).join("");
}

function sandbox(pages) {
  const root = "t" + randomWord(7);
  for (const [rel, body] of Object.entries(pages)) {
    const dir = join(wiki, root, rel);
    mkdirSync(dir, { recursive: true });
    if (body !== null) writeFileSync(join(dir, "index.md"), body);
  }
  return root;
}

const sidebar = (page) => page.locator("aside.tree-sidebar");
const link = (scope, name) => scope.getByRole("link", { name, exact: true });
const mark = (page) => page.evaluate(() => (window.__marker = 1));
const marked = (page) => page.evaluate(() => window.__marker === 1);
const long = (title) => `# ${title}\n\n` + Array.from({ length: 40 }, (_, i) => `## Part ${i}\n\ntext\n`).join("\n");

test("sidebar navigation swaps the page in without a reload", async ({ page }) => {
  const root = sandbox({
    "": "# Parent\n",
    Child: "# Child\n\n## First\n\none\n\n## Second\n\n- [ ] boosted task\n",
  });
  await page.goto(`/${root}/`);
  await mark(page);
  await link(sidebar(page), "Child").click();
  await expect(page).toHaveURL(new RegExp(`/${root}/Child/$`));
  await expect(page.locator("main h1")).toContainText("Child");
  await expect(page).toHaveTitle("Child");
  expect(await marked(page)).toBe(true);
  await expect(sidebar(page).locator(".tree-row.is-active")).toHaveText("Child");
  // Page scripts ran for the new content: TOC and section edit links.
  await expect(page.locator("nav.toc")).toContainText("Second");
  await expect(page.locator("main h2", { hasText: "First" }).getByRole("link", { name: "[edit]" })).toBeVisible();
  // htmx attributes in the new content work: the task toggles.
  await page.locator("main input.task-checkbox").check();
  await expect.poll(() => readFileSync(join(wiki, root, "Child", "index.md"), "utf8")).toContain("- [x] boosted task");
});

test("Back and Forward restore pages and scroll without a reload", async ({ page }) => {
  const root = sandbox({ "": long("Parent"), Child: long("Child") });
  await page.goto(`/${root}/`);
  await mark(page);
  const center = page.locator(".center");
  await center.evaluate((el) => (el.scrollTop = 600));
  await link(sidebar(page), "Child").click();
  await expect(page.locator("main h1")).toContainText("Child");
  // A new page starts at the top.
  expect(await center.evaluate((el) => el.scrollTop)).toBe(0);
  await page.goBack();
  await expect(page).toHaveURL(new RegExp(`/${root}/$`));
  await expect(page.locator("main h1")).toContainText("Parent");
  await expect(page).toHaveTitle("Parent");
  await expect.poll(() => center.evaluate((el) => el.scrollTop)).toBeGreaterThan(500);
  await page.goForward();
  await expect(page.locator("main h1")).toContainText("Child");
  expect(await marked(page)).toBe(true);
});

test("Back to the first, fully loaded page works", async ({ page }) => {
  const root = sandbox({ "": "# Parent\n", Child: "# Child\n" });
  await page.goto(`/${root}/Child/`);
  await mark(page);
  await link(sidebar(page), root).click();
  await expect(page.locator("main h1")).toContainText("Parent");
  await page.goBack();
  await expect(page).toHaveURL(new RegExp(`/${root}/Child/$`));
  await expect(page.locator("main h1")).toContainText("Child");
  expect(await marked(page)).toBe(true);
});

test("files and the editor load as full pages", async ({ page }) => {
  const root = sandbox({ "": "# Parent\n" });
  writeFileSync(join(wiki, root, "note.txt"), "plain file");
  await page.goto(`/${root}/`);
  await mark(page);
  await page.locator("main").getByRole("link", { name: "note.txt" }).click();
  await expect(page).toHaveURL(new RegExp(`/${root}/note.txt$`));
  await expect(page.locator("body")).toContainText("plain file");
  expect(await marked(page)).toBe(false);

  await page.goto(`/${root}/`);
  await mark(page);
  await page.locator("header").getByTitle("Edit page (E)").click();
  await expect(page).toHaveURL(/\?edit/);
  await expect(page.locator(".cm-content")).toBeVisible();
  expect(await marked(page)).toBe(false);
});

test("header actions follow the page", async ({ page }) => {
  const root = sandbox({ "": "# Parent\n" });
  await page.goto("/");
  await mark(page);
  const move = page.locator("header").getByTitle("Move page (M)");
  await expect(move).toHaveCount(0);
  await link(sidebar(page), root).click();
  await expect(page.locator("main h1")).toContainText("Parent");
  await expect(move).toBeVisible();
  await page.goBack();
  await expect(page.locator("main h1")).toContainText("Home");
  await expect(move).toHaveCount(0);
  expect(await marked(page)).toBe(true);
});

test("search results and the search box follow boosted navigation", async ({ page }) => {
  const root = sandbox({ "": "# Parent\n", Child: "# Child\n" });
  expect((await page.request.post("/_reindex")).status()).toBe(204);
  await page.goto(`/${root}/`);
  await mark(page);
  const input = page.locator("header .search-input");
  await input.fill(root);
  await input.press("Enter");
  await expect(page).toHaveURL(new RegExp(`/\?q=${root}$`));
  await expect(page).toHaveTitle(`Search: ${root}`);
  await expect(page.locator("main .search-card").first()).toBeVisible();
  await link(sidebar(page), root).click();
  await expect(page.locator("main h1")).toContainText("Parent");
  await expect(input).toHaveValue("");
  expect(await marked(page)).toBe(true);
});

test("a mutation swaps in its result without a reload", async ({ page }) => {
  const root = sandbox({ "": "# Parent\n", Gone: "# Gone\n" });
  await page.goto(`/${root}/Gone/`);
  await mark(page);
  await page.locator("header").getByTitle("Delete page").click();
  await page.locator(".modal").getByRole("button", { name: "DELETE" }).click();
  await expect(page).toHaveURL(new RegExp(`/${root}/$`));
  await expect(page.locator("main h1")).toContainText("Parent");
  await expect(page.locator(".modal")).toHaveCount(0);
  await expect(link(sidebar(page), "Gone")).toHaveCount(0);
  expect(await marked(page)).toBe(true);
});