import { expect, test } from "bun:test";
import { readFileSync } from "node:fs";
import { Window } from "happy-dom";

const code = new Bun.Transpiler({ loader: "ts" }).transformSync(readFileSync(new URL("../src/canvas.ts", import.meta.url), "utf8"))
  .replace(/^import .*;\s*$/gm, "").replace("export function mountBlockCanvas", "function mountBlockCanvas");

test("canvas annotates exact node locations and cleans editor decorations without changing content", () => {
  const window = new Window();
  const root = window.document.body;
  root.innerHTML = '<table data-block-id="root"><tbody><tr><td data-block-id="column" draggable="true"><table></table></td></tr></tbody></table>';
  const original = root.innerHTML;
  const tree = { id: "root", type: "layout.email-document", slots: { content: [{ id: "column", type: "layout.column", slots: { content: [] } }] } };
  const before = JSON.stringify(tree);
  let destroyed = 0;
  const mount = new Function("mountBlockEditor", code + ";return mountBlockCanvas;")(() => ({ destroy: () => destroyed++, refresh() {} }));
  const mounted = mount(root, tree, {});
  const column = root.querySelector('[data-block-id="column"]')!;
  expect(column.getAttribute("data-block-parent")).toBe("root");
  expect(column.getAttribute("data-block-slot")).toBe("content");
  expect(column.getAttribute("draggable")).toBe("false");
  expect(root.querySelectorAll("[data-block-handle]")).toHaveLength(1);
  expect(root.querySelector("[data-block-slot-target]")?.getAttribute("data-block-parent")).toBe("column");
  expect(JSON.stringify(tree)).toBe(before);
  mounted.destroy(); mounted.destroy();
  expect(destroyed).toBe(1);
  expect(root.innerHTML).toBe(original);
});

test("failed canvas mounting rolls back annotations", () => {
  const root = new Window().document.body;
  root.innerHTML = '<div data-block-id="root"><div data-block-id="child">Content</div></div>';
  const before = root.innerHTML;
  const mount = new Function("mountBlockEditor", code + ";return mountBlockCanvas;")(() => { throw new Error("backend unavailable"); });
  expect(() => mount(root, { id: "root", type: "root", slots: { content: [{ id: "child", type: "text", slots: {} }] } }, {})).toThrow("backend unavailable");
  expect(root.innerHTML).toBe(before);
});