import assert from "node:assert/strict";
import test from "node:test";

import {
  appendPathPenAnchor,
  closePathPenDraft,
  constrainPathPenPoint,
  createPathPenNode,
  pathPenDraftToPathData,
  setLastPathPenAnchorHandles,
  startPathPenDraft
} from "../src/ui/pages/CanvasWorkspace/canvas/pathPen.ts";

const settings = { color: "#123456", width: 3 };

function point(x, y) {
  return { screen: { x, y }, world: { x, y } };
}

test("creates one Pen anchor for each user click", () => {
  let draft = startPathPenDraft(settings, 1, point(10, 20));
  draft = appendPathPenAnchor(draft, point(110, 20));
  draft = appendPathPenAnchor(draft, point(110, 80));

  assert.equal(draft.anchors.length, 3);
  assert.deepEqual(pathPenDraftToPathData(draft), [1, 10, 20, 2, 110, 20, 2, 110, 80]);
});

test("turns click-drag anchors into Photoshop-style mirrored Bezier handles", () => {
  let draft = startPathPenDraft(settings, 1, point(10, 20));
  draft = setLastPathPenAnchorHandles(draft, point(40, 20));
  draft = appendPathPenAnchor(draft, point(110, 80));
  draft = setLastPathPenAnchorHandles(draft, point(130, 100));

  assert.deepEqual(draft.anchors[0].handleIn?.world, { x: -20, y: 20 });
  assert.deepEqual(draft.anchors[0].handleOut?.world, { x: 40, y: 20 });
  assert.deepEqual(draft.anchors[1].handleIn?.world, { x: 90, y: 60 });
  assert.deepEqual(pathPenDraftToPathData(draft), [1, 10, 20, 5, 40, 20, 90, 60, 110, 80]);
});

test("constrains Pen anchors and handles to 45-degree increments with Shift", () => {
  const constrained = constrainPathPenPoint({ x: 10, y: 10 }, { x: 42, y: 24 });

  assert.equal(Math.round(constrained.x), 35);
  assert.equal(Math.round(constrained.y), 35);
});

test("closes a Pen path back to its first user anchor", () => {
  let draft = startPathPenDraft(settings, 1, point(0, 0));
  draft = appendPathPenAnchor(draft, point(100, 0));
  draft = appendPathPenAnchor(draft, point(100, 100));
  draft = closePathPenDraft(draft);

  assert.deepEqual(pathPenDraftToPathData(draft), [1, 0, 0, 2, 100, 0, 2, 100, 100, 11]);
});

test("persists a completed Pen path as an editable shape node", () => {
  let draft = startPathPenDraft(settings, 1, point(10, 20));
  draft = appendPathPenAnchor(draft, point(110, 20));
  const node = createPathPenNode(draft, "Pen");
  const options = JSON.parse(node.content);

  assert.equal(node.type, "frame");
  assert.equal(node.layerRole, "shape");
  assert.equal(node.strokeColor, settings.color);
  assert.equal(options.kind, "path");
  assert.deepEqual(options.pathData, [1, 0.04955, 0.5, 2, 0.95045, 0.5]);
});