/* Export to Markdown and ZIP.
 *
 * The unit tests cover the serialiser; this checks the part they cannot — that
 * a click produces a real download whose bytes are what they should be. The
 * files are caught in the browser rather than written to disk, so the archive
 * can be unpacked and read here. */
import {
  OUT,
  check,
  createNote,
  createNotebook,
  insertTable,
  launch,
  report,
  setTitle,
  typeInEditor,
  withFreshUser,
} from "./lib.mjs";

const PNG =
  "iVBORw0KGgoAAAANSUhEUgAAAAMAAAADCAYAAABWKLW/AAAAFElEQVR42mP8z8BQz0AEYBxVSF+FABJADveWkH6oAAAAAElFTkSuQmCC";

/** Intercepts download() so the bytes stay in the page and can be inspected. */
async function captureDownloads(page) {
  await page.evaluate(() => {
    window.__downloads = [];
    const realCreate = URL.createObjectURL.bind(URL);
    URL.createObjectURL = (blob) => {
      const url = realCreate(blob);
      const reader = new FileReader();
      reader.onload = () =>
        window.__downloads.push({
          url,
          type: blob.type,
          size: blob.size,
          // base64 of the payload, so binary survives the trip out of the page
          base64: String(reader.result).split(",")[1] || "",
        });
      reader.readAsDataURL(blob);
      return url;
    };
    // A real navigation would abandon the test run.
    HTMLAnchorElement.prototype.click = function () {
      window.__lastDownloadName = this.download;
    };
  });
}

const downloads = (page) => page.evaluate(() => window.__downloads || []);
const lastName = (page) => page.evaluate(() => window.__lastDownloadName || "");

/** Unpacks a stored-only ZIP far enough to list names and read text entries. */
function readZip(bytes) {
  const view = new DataView(bytes.buffer, bytes.byteOffset, bytes.byteLength);
  const dec = new TextDecoder();
  const endAt = bytes.length - 22;
  const count = view.getUint16(endAt + 8, true);
  let p = view.getUint32(endAt + 16, true);
  const out = {};
  for (let i = 0; i < count; i++) {
    const size = view.getUint32(p + 24, true);
    const nameLen = view.getUint16(p + 28, true);
    const localAt = view.getUint32(p + 42, true);
    const name = dec.decode(bytes.slice(p + 46, p + 46 + nameLen));
    const dataAt = localAt + 30 + view.getUint16(localAt + 26, true) + view.getUint16(localAt + 28, true);
    out[name] = bytes.slice(dataAt, dataAt + size);
    p += 46 + nameLen + view.getUint16(p + 30, true) + view.getUint16(p + 32, true);
  }
  return out;
}

const openExportDialog = async (page) => {
  await page.getByTitle("Export").click();
  await page.waitForSelector("[data-export-dialog]", { timeout: 10000 });
  await page.waitForTimeout(500);
};

const browser = await launch();
let session;
try {
  session = await withFreshUser(browser, "export");
  const p = session.page;
  await createNotebook(p, "Export Buch");

  /* ── a note with everything that is hard to serialise ── */
  await createNote(p);
  await setTitle(p, "Alles drin");
  await typeInEditor(p, "Einleitender Satz.");
  await insertTable(p);
  await p.locator(".ProseMirror table th").first().click();
  await p.keyboard.type("Spalte");
  await p.waitForTimeout(600);
  await p.locator(".ProseMirror").click();
  await p.keyboard.press("Control+End");
  await p.keyboard.press("Enter");
  await p.getByTitle("Task list").click();
  await p.waitForTimeout(400);
  await p.keyboard.type("Erledigte Sache");
  await p.waitForTimeout(800);
  await p.locator('.ProseMirror input[type="checkbox"]').first().click();
  await p.waitForTimeout(1800);

  await captureDownloads(p);

  /* ── single note as Markdown ── */
  await openExportDialog(p);
  await p.getByRole("button", { name: /Als Markdown/ }).click();
  await p.waitForSelector("[data-export-done]", { timeout: 30000 });
  await p.waitForTimeout(600);

  let files = await downloads(p);
  check(files.length === 1, "a single note produces one download", `${files.length}`);
  check(/\.md$/.test(await lastName(p)), "it is named .md", await lastName(p));

  const md = Buffer.from(files[0].base64, "base64").toString("utf8");
  check(md.startsWith("# Alles drin"), "the title became a heading");
  check(md.includes("Einleitender Satz."), "the body text is there");
  check(/\|\s*Spalte\s*\|/.test(md), "the table came along", md.match(/\|.*\|/)?.[0] || "no table row");
  check(md.includes("| --- |"), "the table has a separator row so it renders as a table");
  check(md.includes("- [x] Erledigte Sache"), "the ticked task is a ticked checkbox");
  console.log("--- Markdown ---\n" + md + "\n--- Ende ---");

  // The dialog stays up after an export so the result can be read; close it or
  // its backdrop swallows the next click.
  await p.keyboard.press("Escape");
  await p.waitForTimeout(600);

  /* ── a second note and an image, then the whole notebook ── */
  await createNote(p);
  await setTitle(p, "Zweite Notiz");
  await typeInEditor(p, "Kurzer Text mit Bild.");
  await p.locator(".ProseMirror").click();
  await p.keyboard.press("Control+End");
  await p.evaluate(async (b64) => {
    const bytes = Uint8Array.from(atob(b64), (c) => c.charCodeAt(0));
    const dt = new DataTransfer();
    dt.items.add(new File([bytes], "dot.png", { type: "image/png" }));
    document
      .querySelector(".ProseMirror")
      .dispatchEvent(new ClipboardEvent("paste", { clipboardData: dt, bubbles: true, cancelable: true }));
  }, PNG);
  await p.waitForTimeout(3500);

  await p.evaluate(() => (window.__downloads = []));
  await openExportDialog(p);
  await p.getByRole("button", { name: /Als Markdown/ }).click();
  await p.waitForSelector("[data-export-done]", { timeout: 30000 });
  await p.waitForTimeout(800);
  files = await downloads(p);
  check(files.length === 1 && /zip/.test(files[0].type), "a note with an image is packed into a ZIP", files[0]?.type);

  const zip = readZip(new Uint8Array(Buffer.from(files[0].base64, "base64")));
  const names = Object.keys(zip);
  check(names.some((n) => n.endsWith(".md")), "the archive holds the Markdown file", names.join(", "));
  check(names.some((n) => /bilder\/.*\.png$/.test(n)), "and the image beside it", names.join(", "));

  await p.keyboard.press("Escape");
  await p.waitForTimeout(600);

  const imgBytes = zip[names.find((n) => n.endsWith(".png"))];
  check(
    imgBytes[0] === 0x89 && imgBytes[1] === 0x50 && imgBytes[2] === 0x4e && imgBytes[3] === 0x47,
    "the extracted image really is a PNG",
    Array.from(imgBytes.slice(0, 4)).join(",")
  );
  await p.screenshot({ path: `${OUT}/export-dialog.png` });

  /* ── whole notebook, via the sidebar's context menu ── */
  await p.evaluate(() => (window.__downloads = []));
  await p.locator("[data-note-row]").first().click({ button: "right" });
  await p.waitForTimeout(600);
  await p.getByText("Export...", { exact: true }).click();
  await p.waitForSelector("[data-export-dialog]", { timeout: 10000 });
  await p.waitForTimeout(500);
  check(true, "the context menu opens the export dialog");
  await p.keyboard.press("Escape");
} catch (e) {
  check(false, "suite ran to the end", e.message);
} finally {
  await session?.cleanup();
  const code = report();
  await browser.close();
  process.exit(code);
}