import { LiveArray } from '../src/livearray.js';
import { pouchDocArrayHash } from '../src/utils.js';

describe('A LiveArray', () => {
	let fakePouch;
	const selector = {};
	const opts = {};

	beforeEach(() => {
		fakePouch = {
			find: () => {},
			changes: () => fakePouch,
			on: () => fakePouch
		};
	});

	it('returns a computed (subscribable).', () => {
		const la = LiveArray(fakePouch, selector, opts);

		expect(typeof la).toEqual('function');
		expect(typeof la.subscribe).toEqual('function');

		expect(JSON.stringify(la())).toEqual('[]');
	});

	it('has a "ready" subscribable that is fired once and subscribers cleared when the main subscribable has data for the first time.', () => {
		let sub = null;

		const db = {
			changes: options => {
				return db;
			},
			on: (eventName, callback) => {
				if (eventName == 'change') {
					sub = callback;
				}
				expect(['change', 'error'].indexOf(eventName) !== -1).toBeTruthy();
				return db;
			},
			cancel: () => (sub = null),
			find: async selector => {
				return Promise.resolve({ docs: [{ _id: 234 }] });
			}
		};

		const la = LiveArray(db, selector, opts);

		return new Promise((resolve, reject) => {
			const unsub = la.ready.subscribe(() => {
				unsub();
				resolve();
			});
		});
	});

	it('fires when data changes.', () => {
		let state = 0;
		const changes = {
			234: { id: 234, deleted: false, doc: { _id: 234 } },
			34: { id: 34, deleted: true, doc: { _id: 34 } },
			4564565: { id: 4564565, deleted: false, doc: { _id: 4564565 } }
		};
		const changeKeys = Object.keys(changes);
		let sub = null;

		const db = {
			changes: options => {
				expect(state).toEqual(1);
				expect(options.live).toEqual(true);
				expect(options.since).toEqual('now');
				expect(options.selector).toBe(selector);
				return db;
			},
			on: (eventName, callback) => {
				if (eventName == 'change') {
					sub = callback;
				}
				expect(['change', 'error'].indexOf(eventName) !== -1).toBeTruthy();
				return db;
			},
			cancel: () => (sub = null),
			find: async selector => {
				const doc = changes[parseInt(changeKeys[state - 1])];
				state += 1;
				if (doc === undefined || doc.deleted) {
					return Promise.resolve({ docs: [] });
				}
				return Promise.resolve({ docs: [doc.doc] });
			}
		};

		const la = LiveArray(db, selector, opts);
		state = 1;

		let innerState = 0;

		return new Promise((resolve, reject) => {
			const unsub = la.ready.subscribe(() => {
				la.subscribe(data => {
					if (data.length) {
						expect(data[0]._id).toEqual(parseInt(changeKeys[innerState]));
					}
					innerState += 1;

					resolve();
				});

				changeKeys.forEach(id => {
					const doc = changes[parseInt(id)];
					sub(doc);
				});

				unsub();
			});
		});
	});
});