import { describe, expect, it } from 'vitest';
import type { Photo } from './types';
import { computeViewerSource, editPendingOf } from './viewer-source';

const BASE = {
	originalUrl: '/orig.jpg',
	previewUrl: '/preview.jpg',
	editUrl: '/edit.jpg',
	editPreviewUrl: '/edit-preview.jpg'
};

describe('computeViewerSource', () => {
	it('shows the server render when it matches the saved edits', () => {
		const src = computeViewerSource({
			zoomed: false,
			dirty: false,
			editPending: false,
			localParamsEmpty: false,
			...BASE
		});
		expect(src.useBase).toBe(false);
		expect(src.serverSrc).toBe('/edit-preview.jpg');
		expect(src.baseSrc).toBe('/preview.jpg');
	});

	it('uses the full-size variants in zoom', () => {
		const src = computeViewerSource({
			zoomed: true,
			dirty: false,
			editPending: false,
			localParamsEmpty: false,
			...BASE
		});
		expect(src.serverSrc).toBe('/edit.jpg');
		expect(src.baseSrc).toBe('/orig.jpg');
	});

	it('keeps the client preview while local edits are unsaved', () => {
		const src = computeViewerSource({
			zoomed: true,
			dirty: true,
			editPending: false,
			localParamsEmpty: false,
			...BASE
		});
		expect(src.useBase).toBe(true);
		expect(src.drawCanvas).toBe(true);
		expect(src.baseSrc).toBe('/orig.jpg');
	});

	it('shows the base version immediately when the edits are reset to defaults', () => {
		const src = computeViewerSource({
			zoomed: true,
			dirty: true,
			editPending: false,
			localParamsEmpty: true,
			...BASE
		});
		expect(src.useBase).toBe(true);
		expect(src.drawCanvas).toBe(false);
		expect(src.baseSrc).toBe('/orig.jpg');
	});

	it('ignores a stale server render while the saved edits are still rendering', () => {
		const src = computeViewerSource({
			zoomed: false,
			dirty: false,
			editPending: true,
			localParamsEmpty: false,
			...BASE
		});
		expect(src.useBase).toBe(true);
		expect(src.drawCanvas).toBe(true);
	});

	it('keeps the client preview when a second edit is pending over an old render', () => {
		const src = computeViewerSource({
			zoomed: true,
			dirty: false,
			editPending: true,
			localParamsEmpty: false,
			...BASE
		});
		expect(src.useBase).toBe(true);
		expect(src.drawCanvas).toBe(true);
		expect(src.baseSrc).toBe('/orig.jpg');
	});

	it('falls back to the base version when there is no edit render', () => {
		const src = computeViewerSource({
			zoomed: false,
			dirty: false,
			editPending: false,
			localParamsEmpty: true,
			originalUrl: '/orig.jpg',
			previewUrl: '/preview.jpg'
		});
		expect(src.useBase).toBe(true);
		expect(src.drawCanvas).toBe(false);
		expect(src.serverSrc).toBe('/preview.jpg');
	});

	it('prefers the full-size base when zoomed without a preview', () => {
		const src = computeViewerSource({
			zoomed: true,
			dirty: false,
			editPending: false,
			localParamsEmpty: true,
			originalUrl: '/orig.jpg'
		});
		expect(src.baseSrc).toBe('/orig.jpg');
		expect(src.serverSrc).toBe('/orig.jpg');
	});

	it('treats the old backend without edit_pending as a finished render', () => {
		expect(editPendingOf(undefined)).toBe(false);
		expect(editPendingOf({ id: 'p' } as Photo)).toBe(false);
		expect(editPendingOf({ id: 'p', edit_pending: true } as Photo)).toBe(true);
	});
});