import { describe, expect, it } from 'vitest';

import {
  ensureResourceBookContentVisible,
  keepResourceBookViewportAtReadableScale,
  panResourceBookViewport,
} from '../src/view/project-development/resourceBookViewport';

describe('resource book viewport', () => {
  it('keeps an initially fitted child canvas readable instead of shrinking it below 1:1', () => {
    expect(
      keepResourceBookViewportAtReadableScale({
        viewport: { x: 120, y: 80, scale: 0.42 },
        bounds: { x: 0, y: 0, width: 1_600, height: 1_000 },
        canvasSize: { width: 900, height: 640 },
        padding: 16,
      }),
    ).toEqual({
      x: -350,
      y: -180,
      scale: 1,
    });
  });

  it('allows panning beyond the content bounds in both directions', () => {
    expect(
      panResourceBookViewport(
        { x: 0, y: 0, scale: 1 },
        { x: -4_000, y: 3_000 },
      ),
    ).toEqual({ x: -4_000, y: 3_000, scale: 1 });
  });

  it('keeps a viewport that already shows a card', () => {
    const viewport = { x: -40, y: -20, scale: 1 };
    expect(
      ensureResourceBookContentVisible({
        viewport,
        cards: [{ x: 100, y: 100, width: 180, height: 128 }],
        canvasSize: { width: 900, height: 640 },
        padding: 16,
      }),
    ).toEqual(viewport);
  });

  it('centers the nearest card when the viewport would show nothing', () => {
    expect(
      ensureResourceBookContentVisible({
        viewport: { x: 0, y: 0, scale: 1 },
        cards: [
          { x: 4_000, y: 4_000, width: 180, height: 128 },
          { x: 2_000, y: 2_000, width: 180, height: 128 },
        ],
        canvasSize: { width: 900, height: 640 },
        padding: 16,
      }),
    ).toEqual({ x: -1_640, y: -1_744, scale: 1 });
  });

  it('leaves an empty category viewport untouched', () => {
    const viewport = { x: 12, y: 34, scale: 1.5 };
    expect(
      ensureResourceBookContentVisible({
        viewport,
        cards: [],
        canvasSize: { width: 900, height: 640 },
      }),
    ).toEqual(viewport);
  });
});