'use strict';

const { test } = require('node:test');
const assert = require('node:assert/strict');
const fs = require('node:fs');
const path = require('node:path');
const { JSDOM } = require('jsdom');

const SOURCE = fs.readFileSync(path.join(__dirname, '../../static/read-more.js'), 'utf8');

// jsdom has no layout: heights come from data-h on each .text element.
const measure = (el) => Number(el.dataset.h || 0);

function entry(id, height, notRead = false) {
	return `<div class="flux${notRead ? ' not_read' : ''}" id="flux_${id}">
		<article class="flux_content"><div class="content">
			<div class="text" data-h="${height}"><p>Article ${id}</p><img src="x.png"></div>
		</div></article>
	</div>`;
}

function setup(entries) {
	const dom = new JSDOM(`<!DOCTYPE html><body><main id="stream">${entries.join('')}</main></body>`,
		{ runScripts: 'outside-only' });
	dom.window.eval(SOURCE);
	return { window: dom.window, document: dom.window.document, ReadMore: dom.window.ReadMore };
}

const OPTS = { collapsedHeight: 250, label: 'Lire plus', measure };

function setContext(window, view) {
	window.context = {
		current_view: view,
		extensions: { read_more: { collapsed_height: 250, label: 'Lire plus' } },
	};
}

test('shouldCollapse thresholds', () => {
	const { ReadMore } = setup([]);
	assert.equal(ReadMore.THRESHOLD_RATIO, 1.5);
	assert.equal(ReadMore.shouldCollapse(374, 250), false);
	assert.equal(ReadMore.shouldCollapse(375, 250), true);
	assert.equal(ReadMore.shouldCollapse(1000, 250), true);
});

test('collapses tall entry', () => {
	const { document, ReadMore } = setup([entry(1, 1000)]);
	ReadMore.processEntries(document, OPTS);
	const flux = document.getElementById('flux_1');
	const text = flux.querySelector('.text');
	assert.ok(text.classList.contains('read-more-collapsed'));
	assert.equal(text.style.getPropertyValue('--read-more-height'), '250px');
	const buttons = flux.querySelectorAll('.read-more-btn');
	assert.equal(buttons.length, 1);
	assert.equal(buttons[0].textContent, 'Lire plus');
	assert.equal(buttons[0].type, 'button');
	assert.equal(text.nextElementSibling, buttons[0]);
	assert.equal(flux.dataset.readMore, 'collapsed');
});

test('skips short entry', () => {
	const { document, ReadMore } = setup([entry(1, 300)]);
	ReadMore.processEntries(document, OPTS);
	const flux = document.getElementById('flux_1');
	assert.ok(!flux.querySelector('.text').classList.contains('read-more-collapsed'));
	assert.equal(flux.querySelectorAll('.read-more-btn').length, 0);
	assert.equal(flux.dataset.readMore, 'short');
});

test('is idempotent', () => {
	const { document, ReadMore } = setup([entry(1, 1000), entry(2, 1000)]);
	ReadMore.processEntries(document, OPTS);
	ReadMore.processEntries(document, OPTS);
	for (const flux of document.querySelectorAll('.flux')) {
		assert.equal(flux.querySelectorAll('.read-more-btn').length, 1);
	}
});

test('click expands', () => {
	const { window, document, ReadMore } = setup([entry(1, 1000)]);
	ReadMore.processEntries(document, OPTS);
	const flux = document.getElementById('flux_1');
	let parentClicks = 0;
	flux.addEventListener('click', () => { parentClicks++; });
	const event = new window.MouseEvent('click', { bubbles: true, cancelable: true });
	flux.querySelector('.read-more-btn').dispatchEvent(event);
	assert.ok(!flux.querySelector('.text').classList.contains('read-more-collapsed'));
	assert.equal(flux.querySelectorAll('.read-more-btn').length, 0);
	assert.equal(flux.dataset.readMore, 'expanded');
	assert.equal(event.defaultPrevented, true);
	assert.equal(parentClicks, 0);
});

test('does not re-collapse expanded entry', () => {
	const { document, ReadMore } = setup([entry(1, 1000)]);
	ReadMore.processEntries(document, OPTS);
	document.querySelector('.read-more-btn').click();
	ReadMore.processEntries(document, OPTS);
	const flux = document.getElementById('flux_1');
	assert.ok(!flux.querySelector('.text').classList.contains('read-more-collapsed'));
	assert.equal(flux.querySelectorAll('.read-more-btn').length, 0);
	assert.equal(flux.dataset.readMore, 'expanded');
});

test('does not touch read state', () => {
	const { document, ReadMore } = setup([entry(1, 1000, true)]);
	ReadMore.processEntries(document, OPTS);
	const flux = document.getElementById('flux_1');
	assert.ok(flux.classList.contains('not_read'));
	flux.querySelector('.read-more-btn').click();
	assert.ok(flux.classList.contains('not_read'));
});

test('reevaluates short entry after image load', () => {
	const { window, document, ReadMore } = setup([entry(1, 300)]);
	setContext(window, 'reader');
	ReadMore.init(window, measure);
	const flux = document.getElementById('flux_1');
	assert.equal(flux.dataset.readMore, 'short');
	const text = flux.querySelector('.text');
	text.dataset.h = '1000';
	text.querySelector('img').dispatchEvent(new window.Event('load'));
	assert.ok(text.classList.contains('read-more-collapsed'));
	assert.equal(flux.dataset.readMore, 'collapsed');
	assert.equal(flux.querySelectorAll('.read-more-btn').length, 1);
});

test('init ignores non-reader view', () => {
	const { window, document, ReadMore } = setup([entry(1, 1000)]);
	setContext(window, 'normal');
	ReadMore.init(window, measure);
	assert.equal(document.querySelectorAll('.read-more-btn').length, 0);
	assert.equal(document.getElementById('flux_1').dataset.readMore, undefined);
});

test('init handles load-more', () => {
	const { window, document, ReadMore } = setup([entry(1, 1000)]);
	setContext(window, 'reader');
	ReadMore.init(window, measure);
	assert.equal(document.querySelectorAll('.read-more-btn').length, 1);
	document.getElementById('stream').insertAdjacentHTML('beforeend', entry(2, 1000));
	document.body.dispatchEvent(new window.Event('freshrss:load-more', { bubbles: true }));
	assert.equal(document.querySelectorAll('.read-more-btn').length, 2);
	assert.equal(document.getElementById('flux_2').dataset.readMore, 'collapsed');
});

test('init works before body is parsed', () => {
	const { window, document, ReadMore } = setup([]);
	document.documentElement.removeChild(document.body);
	setContext(window, 'reader');
	assert.doesNotThrow(() => ReadMore.init(window, measure));
	const body = document.createElement('body');
	body.innerHTML = entry(1, 1000);
	document.documentElement.appendChild(body);
	body.dispatchEvent(new window.Event('freshrss:load-more', { bubbles: true }));
	assert.equal(document.getElementById('flux_1').dataset.readMore, 'collapsed');
});

test('late image load does not collapse entry already above viewport top', () => {
	const { window, document, ReadMore } = setup([entry(1, 300)]);
	setContext(window, 'reader');
	ReadMore.init(window, measure);
	const flux = document.getElementById('flux_1');
	flux.getBoundingClientRect = () => ({ top: -100, bottom: 200 });
	const text = flux.querySelector('.text');
	text.dataset.h = '1000';
	text.querySelector('img').dispatchEvent(new window.Event('load'));
	assert.ok(!text.classList.contains('read-more-collapsed'));
	assert.equal(flux.querySelectorAll('.read-more-btn').length, 0);
});

test('load-more does not collapse short entry already above viewport top', () => {
	const { window, document, ReadMore } = setup([entry(1, 300)]);
	setContext(window, 'reader');
	ReadMore.init(window, measure);
	const flux = document.getElementById('flux_1');
	flux.getBoundingClientRect = () => ({ top: -100, bottom: 200 });
	flux.querySelector('.text').dataset.h = '1000';
	document.body.dispatchEvent(new window.Event('freshrss:load-more', { bubbles: true }));
	assert.equal(flux.dataset.readMore, 'short');
	assert.equal(flux.querySelectorAll('.read-more-btn').length, 0);
});