const { test } = require('node:test');
const assert = require('node:assert');
const { packMaxRects } = require('../src/pack');

test('pack: 3 32x32 tiles fit in 64x64', () => {
    const rects = [
        { name: 'a', w: 32, h: 32 },
        { name: 'b', w: 32, h: 32 },
        { name: 'c', w: 32, h: 32 },
    ];
    const result = packMaxRects(rects, 4096);
    assert.strictEqual(result.error, undefined);
    assert.strictEqual(result.placed.length, 3);
    assert.strictEqual(result.boundsW, 128);
    assert.strictEqual(result.boundsH, 64);
    // Positions must not overlap
    for (let i = 0; i < 3; i++) {
        for (let j = i + 1; j < 3; j++) {
            const a = result.placed[i];
            const b = result.placed[j];
            const overlap = a.x < b.x + b.w && b.x < a.x + a.w
                         && a.y < b.y + b.h && b.y < a.y + a.h;
            assert.ok(!overlap, `tiles ${i} and ${j} overlap`);
        }
    }
});

test('pack: oversize triggers error', () => {
    const rects = [];
    // 200 tiles of 64x64 cannot fit in 1024x1024 (needs 16x16 = 256 slots, has only ~256)
    for (let i = 0; i < 300; i++) {
        rects.push({ name: `t${i}`, w: 64, h: 64 });
    }
    const result = packMaxRects(rects, 1024);
    assert.strictEqual(result.error, 'oversize');
    assert.ok(result.message.includes('does not fit'));
});

test('pack: deterministic across runs', () => {
    const rects = [
        { name: 'a', w: 32, h: 32 },
        { name: 'b', w: 32, h: 32 },
        { name: 'c', w: 64, h: 32 },
    ];
    const r1 = packMaxRects(rects, 4096);
    const r2 = packMaxRects(rects, 4096);
    assert.deepStrictEqual(r1.placed, r2.placed);
});