/* 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,
  captureDownloads,
  check,
  clearDownloads,
  createNote,
  createNotebook,
  downloads,
  insertTable,
  lastDownloadName,
  launch,
  report,
  setTitle,
  typeInEditor,
  withFreshUser,
} from "./lib.mjs";

const PNG =
  "iVBORw0KGgoAAAANSUhEUgAAAAMAAAADCAYAAABWKLW/AAAAFElEQVR42mP8z8BQz0AEYBxVSF+FABJADveWkH6oAAAAAElFTkSuQmCC";


/** 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", { exact: true }).click();
  await page.waitForSelector("[data-export-dialog]", { timeout: 10000 });
  await page.waitForTimeout(800);
};

/** Draws a couple of strokes so the note has something to export as a picture. */
async function drawSomething(page) {
  await page.locator("button").filter({ hasText: "Draw" }).first().click();
  await page.waitForTimeout(1200);
  const box = await page.locator("canvas").first().boundingBox();
  for (const [x1, y1, x2, y2] of [
    [0.2, 0.25, 0.7, 0.4],
    [0.3, 0.6, 0.7, 0.55],
  ]) {
    await page.mouse.move(box.x + box.width * x1, box.y + box.height * y1);
    await page.mouse.down();
    await page.mouse.move(box.x + box.width * x2, box.y + box.height * y2, { steps: 12 });
    await page.mouse.up();
    await page.waitForTimeout(250);
  }
  await page.waitForTimeout(2500);
  await page.locator("button").filter({ hasText: "Write" }).first().click();
  await page.waitForTimeout(800);
}

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);

  /* A quote holding more than one kind of block. Written on consecutive lines,
     Markdown reads the closing sentence as more of the last bullet — so the
     blocks inside a quote have to be divided by a quoted blank line. */
  await p.locator(".ProseMirror").click();
  await p.keyboard.press("Control+End");
  await p.keyboard.press("Enter");
  await p.keyboard.press("Enter"); // out of the task list again
  await p.keyboard.type("> ### Quartalszahlen");
  await p.keyboard.press("Enter");
  await p.keyboard.type("- Umsatz");
  await p.keyboard.press("Enter");
  await p.keyboard.type("Gewinn");
  await p.keyboard.press("Enter");
  await p.keyboard.press("Enter");
  await p.keyboard.type("Alles nach Plan.");
  await p.waitForTimeout(1800);

  await captureDownloads(p);

  /* ── single note as Markdown ── */
  await openExportDialog(p);
  await p.locator("[data-export-dialog]").getByRole("button", { name: /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 lastDownloadName(p)), "it is named .md", await lastDownloadName(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");
  check(
    md.includes("> ### Quartalszahlen\n>\n> - Umsatz"),
    "the blocks inside a quote are divided by a quoted blank line",
    md.split("\n").filter((l) => l.startsWith(">")).join(" ⏎ ")
  );
  check(
    md.includes("> - Gewinn\n>\n> Alles nach Plan."),
    "so the sentence after a quoted list stays a sentence"
  );
  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 clearDownloads(p);
  await openExportDialog(p);
  await p.locator("[data-export-dialog]").getByRole("button", { name: /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) => /images\/.*\.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` });

  /* ── the wizard on a note that has a drawing ── */
  await createNote(p);
  await setTitle(p, "Mit Zeichnung");
  await typeInEditor(p, "Text und Bild.");
  await drawSomething(p);

  await clearDownloads(p);
  await openExportDialog(p);
  check(
    (await p.getByText("What should come along?").count()) > 0,
    "a note with a drawing is asked what should come along"
  );
  check(
    (await p.getByRole("button", { name: /Only the drawing/ }).count()) > 0,
    "the drawing-only option is offered"
  );
  await p.screenshot({ path: `${OUT}/export-wizard.png` });

  // drawing only → PNG
  await p.getByRole("button", { name: /Only the drawing/ }).click();
  await p.waitForTimeout(500);
  check((await p.getByRole("button", { name: /PNG image/ }).count()) > 0, "PNG is offered for the drawing");
  check(
    (await p.locator("[data-export-dialog]").getByRole("button", { name: /Markdown/ }).count()) === 0,
    "Markdown is not offered for a drawing, since it cannot hold one"
  );
  await p.getByRole("button", { name: /PNG image/ }).click();
  await p.waitForSelector("[data-export-done]", { timeout: 30000 });
  await p.waitForTimeout(800);

  files = await downloads(p);
  check(files.length === 1 && files[0].type === "image/png", "the PNG was produced", files[0]?.type);
  const png = Buffer.from(files[0].base64, "base64");
  check(
    png[0] === 0x89 && png[1] === 0x50 && png[2] === 0x4e && png[3] === 0x47,
    "and it really is a PNG",
    Array.from(png.slice(0, 4)).join(",")
  );
  check(/\.png$/.test(await lastDownloadName(p)), "named .png", await lastDownloadName(p));
  check(png.length > 1000, "the image has actual content, not an empty canvas", `${png.length} bytes`);

  // back, then text only → Markdown must carry no drawing
  await p.getByRole("button", { name: /Back/ }).click();
  await p.waitForTimeout(500);
  await p.getByRole("button", { name: /Only the note text/ }).click();
  await p.waitForTimeout(500);
  await clearDownloads(p);
  await p.locator("[data-export-dialog]").getByRole("button", { name: /Markdown/ }).click();
  await p.waitForSelector("[data-export-done]", { timeout: 30000 });
  await p.waitForTimeout(800);
  files = await downloads(p);
  const textMd = Buffer.from(files[0].base64, "base64").toString("utf8");
  check(textMd.includes("Text und Bild."), "the text-only export has the text");
  await p.keyboard.press("Escape");
  await p.waitForTimeout(600);

  /* ── whole notebook, via the sidebar's context menu ── */
  await clearDownloads(p);
  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);
}