import { ItemSelection } from '$lib/Selection';
import { expect, test } from 'vitest';

interface TestItem {
	id: number;
	selectable: boolean;
}

const items: TestItem[] = [
	{ id: 1, selectable: true },
	{ id: 2, selectable: true },
	{ id: 3, selectable: false },
	{ id: 4, selectable: true }
];

const all = items.map((i) => i.id);
const selectable = items.filter((i) => i.selectable).map((i) => i.id);

const setup = () => {
	const selection = new ItemSelection<TestItem>();
	selection.view = items;
	return selection;
};

test('selects a single item', () => {
	let selection = setup();

	selection = selection.update(0, false);

	expect(selection.ids).toStrictEqual([items[0].id]);
});

test('selects a single item (with empty shift select)', () => {
	let selection = setup();

	selection = selection.update(0, true);

	expect(selection.ids).toStrictEqual([items[0].id]);
});

test('selects multiple items (forwards)', () => {
	let selection = setup();

	selection = selection.update(0, false);
	selection = selection.update(2, true);

	expect(selection.ids.toSorted((a, b) => a - b)).toStrictEqual(all.slice(0, 3));
});

test('selects multiple items (backwards)', () => {
	let selection = setup();

	selection = selection.update(2, false);
	selection = selection.update(0, true);

	expect(selection.ids.toSorted((a, b) => a - b)).toStrictEqual(all.slice(0, 3));
});

test('selects multiple items (only selectables)', () => {
	let selection = setup();
	selection.selectable = (i) => i.selectable;

	selection = selection.update(0, false);
	selection = selection.update(3, true);

	expect(selection.ids).toStrictEqual(selectable);
});

test('selects all', () => {
	const selection = setup().all();

	expect(selection.ids).toStrictEqual(all);
});

test('selects all selectables', () => {
	let selection = setup();
	selection.selectable = (i) => i.selectable;

	selection = selection.all();

	expect(selection.ids).toStrictEqual(selectable);
});

test('deselects all', () => {
	let selection = setup().all();

	selection = selection.none();

	expect(selection.ids).empty;
});

test('deselects a single item', () => {
	let selection = setup().all();

	selection = selection.update(0, false);

	expect(selection.ids).toStrictEqual(all.slice(1));
});

test('deselects multiple items', () => {
	let selection = setup();

	selection = selection.update(0, false);
	selection = selection.update(2, true);
	selection = selection.update(2, true);

	expect(selection.ids).empty;
});

test('retains selection', () => {
	let selection = setup();

	selection = selection.all();

	selection.view = items.slice(0, 2);
	expect(selection.ids).toStrictEqual(all.slice(0, 2));

	selection.view = items;
	expect(selection.ids).toStrictEqual(all);
});

test('is inactive by default', () => {
	const selection = setup();
	expect(selection.active).toBe(false);
});

test('is inactive after clearing', () => {
	let selection = setup();

	selection.active = true;

	selection = selection.clear();
	expect(selection.active).false;
});

test('can be toggled', () => {
	let selection = setup();

	selection = selection.toggle();
	expect(selection.active).toBe(true);

	selection = selection.all();
	selection = selection.toggle();
	expect(selection.active).toBe(false);
	expect(selection.ids).empty;
});

test('can be cleared', () => {
	let selection = setup();

	selection = selection.all();

	selection = selection.clear();
	expect(selection.ids).empty;
});

test('reports selected items', () => {
	let selection = setup();

	selection = selection.update(0, false);
	selection = selection.update(2, false);

	expect(selection.contains(all[0])).toBeTruthy();
	expect(selection.contains(all[1])).toBeFalsy();
	expect(selection.contains(all[2])).toBeTruthy();
	expect(selection.contains(all[3])).toBeFalsy();
});

test('reports size', () => {
	const selection = setup().all();

	expect(selection.size).toBe(all.length);
});

test('reports size of visible items', () => {
	const selection = setup().all();

	selection.view = items.slice(0, 2);
	expect(selection.size).toBe(2);

	selection.view = items;
	expect(selection.size).toBe(all.length);
});