import { describe, it, expect } from "vitest";
import { signatoryLayout } from "@/lib/po-export-layout";

const BLOCK = 503; // px width of the A-D signatory block

describe("signatoryLayout", () => {
  it("centres the signature in the block", () => {
    const { sigLeft } = signatoryLayout({ blockPx: BLOCK, sig: { width: 153, height: 44 }, stamp: null });
    expect(sigLeft).not.toBeNull();
    expect(sigLeft! + 153 / 2).toBeCloseTo(BLOCK / 2, 0); // centre ≈ block centre
  });

  it("places the stamp to the RIGHT of the signature with no overlap", () => {
    const sig = { width: 153, height: 44 };
    const stamp = { width: 67, height: 66 };
    const { sigLeft, stampLeft } = signatoryLayout({ blockPx: BLOCK, sig, stamp, gap: 10 });
    expect(stampLeft! ).toBeGreaterThanOrEqual(sigLeft! + sig.width); // starts at/after signature ends
    expect(stampLeft! + stamp.width).toBeLessThanOrEqual(BLOCK);     // stays inside the block
  });

  it("never overlaps even with the widest signature + stamp", () => {
    const sig = { width: 165, height: 44 };   // scaleToBox caps
    const stamp = { width: 80, height: 66 };   // scaleToBox caps
    const { sigLeft, stampLeft } = signatoryLayout({ blockPx: BLOCK, sig, stamp });
    expect(stampLeft!).toBeGreaterThanOrEqual(sigLeft! + sig.width);
    expect(stampLeft! + stamp.width).toBeLessThanOrEqual(BLOCK);
  });

  it("right-aligns the stamp when there is no signature", () => {
    const { sigLeft, stampLeft } = signatoryLayout({ blockPx: BLOCK, sig: null, stamp: { width: 67, height: 66 } });
    expect(sigLeft).toBeNull();
    expect(stampLeft! + 67).toBeLessThanOrEqual(BLOCK);
    expect(stampLeft!).toBeGreaterThan(BLOCK / 2); // on the right side
  });

  it("returns nulls when there are no images", () => {
    expect(signatoryLayout({ blockPx: BLOCK, sig: null, stamp: null })).toEqual({ sigLeft: null, stampLeft: null });
  });
});