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

import { computeDiff } from '../src/lib/marketplace/diff.ts';

const fromInfo = { semver: '1.0.0', versionId: 'v1' };
const toInfo = { semver: '1.1.0', versionId: 'v2' };

function fullCard(ord: number, hash: string, front = `Q${ord}`, back = `A${ord}`) {
	return { contentHash: hash, type: 'basic', fields: { front, back }, ord };
}

describe('computeDiff', () => {
	it('classifies all-unchanged when nothing moved', () => {
		const diff = computeDiff({
			from: [
				{ contentHash: 'h1', ord: 0 },
				{ contentHash: 'h2', ord: 1 },
			],
			to: [fullCard(0, 'h1'), fullCard(1, 'h2')],
			fromInfo,
			toInfo,
		});
		expect(diff.unchanged).toHaveLength(2);
		expect(diff.added).toHaveLength(0);
		expect(diff.changed).toHaveLength(0);
		expect(diff.removed).toHaveLength(0);
	});

	it('detects added when a brand-new card appears', () => {
		const diff = computeDiff({
			from: [{ contentHash: 'h1', ord: 0 }],
			to: [fullCard(0, 'h1'), fullCard(1, 'h2')],
			fromInfo,
			toInfo,
		});
		expect(diff.added).toHaveLength(1);
		expect(diff.added[0].contentHash).toBe('h2');
		expect(diff.unchanged).toHaveLength(1);
	});

	it('detects removed when a card vanishes (and ord is unique)', () => {
		const diff = computeDiff({
			from: [
				{ contentHash: 'h1', ord: 0 },
				{ contentHash: 'h2', ord: 1 },
			],
			to: [fullCard(0, 'h1')],
			fromInfo,
			toInfo,
		});
		expect(diff.removed).toHaveLength(1);
		expect(diff.removed[0].contentHash).toBe('h2');
	});

	it('detects changed when same ord has different hash', () => {
		const diff = computeDiff({
			from: [{ contentHash: 'h1', ord: 0 }],
			to: [fullCard(0, 'h1-tweaked', 'Q0', 'A0-edited')],
			fromInfo,
			toInfo,
		});
		expect(diff.changed).toHaveLength(1);
		expect(diff.changed[0].previous.contentHash).toBe('h1');
		expect(diff.changed[0].next.contentHash).toBe('h1-tweaked');
		expect(diff.added).toHaveLength(0);
		expect(diff.removed).toHaveLength(0);
	});

	it('mixed: 1 unchanged, 1 changed, 1 added, 1 removed', () => {
		const diff = computeDiff({
			from: [
				{ contentHash: 'h-stay', ord: 0 },
				{ contentHash: 'h-old', ord: 1 },
				{ contentHash: 'h-bye', ord: 2 },
			],
			to: [
				fullCard(0, 'h-stay'),
				fullCard(1, 'h-new', 'replaced', 'card'),
				fullCard(3, 'h-fresh', 'new', 'card'),
			],
			fromInfo,
			toInfo,
		});
		expect(diff.unchanged.map((c) => c.contentHash)).toEqual(['h-stay']);
		expect(diff.changed).toHaveLength(1);
		expect(diff.changed[0].previous.contentHash).toBe('h-old');
		expect(diff.changed[0].next.contentHash).toBe('h-new');
		expect(diff.added).toHaveLength(1);
		expect(diff.added[0].contentHash).toBe('h-fresh');
		expect(diff.removed).toHaveLength(1);
		expect(diff.removed[0].contentHash).toBe('h-bye');
	});

	it('returns the version-info verbatim', () => {
		const diff = computeDiff({
			from: [],
			to: [],
			fromInfo,
			toInfo,
		});
		expect(diff.from).toEqual(fromInfo);
		expect(diff.to).toEqual(toInfo);
	});
});