const FEATURE_DEFAULTS = {
	image_generation: false,
	code_interpreter: false,
	web_search: false,
	memory: true,
};

const FEATURE_METADATA = {
	image_generation: {
		label: 'Image Generation',
		description: 'Request image outputs from supported models. When enabled the assistant may produce images alongside text responses.',
	},
	code_interpreter: {
		label: 'Code Interpreter',
		description: 'Grant access to the sandboxed runtime for running Python snippets and data transformations during the task.',
	},
	web_search: {
		label: 'Web Search',
		description: 'Allow the assistant to perform outbound web searches to enrich the response with current information.',
	},
	memory: {
		label: 'Memory',
		description: 'Persist relevant conversation context for future automations so runs can recall prior outcomes.',
	},
};

const FEATURE_SECTION_TAG = 'Feature';

function renderFeatureList(featureState) {
	const container = document.querySelector('#features-select');
	const hiddenInput = document.querySelector('#features-select-input');
	if (!container || !hiddenInput) return;

	const baseState = normalizeFeatureState(featureState),
		featureKeys = Object.keys(baseState);

	container.innerHTML = '';
	container.setAttribute('data-has-features', String(featureKeys.length > 0));

	const selection = { ...baseState },
		syncHidden = () => {
			hiddenInput.value = JSON.stringify(selection);
			hiddenInput.dispatchEvent(new Event('input', { bubbles: true }));
			hiddenInput.dispatchEvent(new Event('change', { bubbles: true }));
		};

	featureKeys.forEach((id) => {
		const meta = getFeatureMeta(id);
		const pill = document.createElement('div');
		pill.className = 'feature-pill';
		pill.dataset.featureId = id;
		pill.setAttribute('role', 'option');
		pill.setAttribute('tabindex', '-1');

		const toggleBtn = document.createElement('button');
		toggleBtn.type = 'button';
		toggleBtn.className = 'feature-pill-toggle';
		toggleBtn.textContent = meta.label;
		toggleBtn.setAttribute('aria-pressed', String(Boolean(selection[id])));
		toggleBtn.addEventListener('click', () => {
			selection[id] = !selection[id];
			const isSelected = Boolean(selection[id]);
			pill.classList.toggle('feature-pill--selected', isSelected);
			pill.setAttribute('aria-selected', String(isSelected));
			toggleBtn.setAttribute('aria-pressed', String(isSelected));
			syncHidden();
		});

		const infoBtn = document.createElement('button');
		infoBtn.type = 'button';
		infoBtn.className = 'feature-pill-info';
		infoBtn.setAttribute('aria-label', `Show info for ${meta.label}`);
		infoBtn.innerHTML = '<span aria-hidden="true">i</span>';
		infoBtn.addEventListener('click', (event) => {
			event.stopPropagation();
			generateFeatureCard({ id, ...meta, selected: Boolean(selection[id]) }, { trigger: infoBtn });
		});

		const isSelected = Boolean(selection[id]);
		pill.classList.toggle('feature-pill--selected', isSelected);
		pill.setAttribute('aria-selected', String(isSelected));

		pill.appendChild(toggleBtn);
		pill.appendChild(infoBtn);
		container.appendChild(pill);
	});

	syncHidden();
}

function normalizeFeatureState(featureState) {
	const normalized = { ...FEATURE_DEFAULTS };
	if (featureState && typeof featureState === 'object' && !Array.isArray(featureState)) {
		for (const [key, value] of Object.entries(featureState)) {
			if (Object.prototype.hasOwnProperty.call(FEATURE_DEFAULTS, key) || Object.prototype.hasOwnProperty.call(FEATURE_METADATA, key)) {
				normalized[key] = Boolean(value);
			}
		}
	}
	return normalized;
}

function getFeatureMeta(id) {
	if (Object.prototype.hasOwnProperty.call(FEATURE_METADATA, id)) {
		return FEATURE_METADATA[id];
	}
	const label = id.replace(/_/g, ' ').replace(/\b\w/g, (c) => c.toUpperCase());
	return {
		label,
		description: 'Toggle this capability for the scheduled run.',
	};
}

function generateFeatureCard(feature, options = {}) {
	const mount = options.mountSelector ? document.querySelector(options.mountSelector) : document.body;
	if (!mount) throw new Error('mount element not found');

	const overlay = document.createElement('div');
	overlay.className = 'fc-overlay';
	overlay.setAttribute('data-testid', 'feature-card-overlay');

	const dialog = document.createElement('div');
	dialog.className = 'fc-dialog';
	dialog.setAttribute('role', 'dialog');
	dialog.setAttribute('aria-modal', 'true');

	const titleId = `fc-title-${Math.random().toString(36).slice(2)}`;
	const descId = `fc-desc-${Math.random().toString(36).slice(2)}`;
	dialog.setAttribute('aria-labelledby', titleId);
	dialog.setAttribute('aria-describedby', descId);

	const header = document.createElement('header');
	header.className = 'fc-header';

	const titleWrap = document.createElement('div');
	titleWrap.className = 'fc-titlewrap';

	const h1 = document.createElement('h1');
	h1.id = titleId;
	h1.className = 'fc-title';
	h1.textContent = feature.label;

	const tag = document.createElement('span');
	tag.className = 'fc-tag';
	tag.textContent = FEATURE_SECTION_TAG;
	tag.setAttribute('data-testid', 'feature-tag');

	titleWrap.appendChild(h1);
	titleWrap.appendChild(tag);

	const closeBtn = document.createElement('button');
	closeBtn.className = 'fc-close';
	closeBtn.type = 'button';
	closeBtn.setAttribute('aria-label', 'close');
	closeBtn.textContent = '×';

	header.appendChild(titleWrap);
	header.appendChild(closeBtn);

	const body = document.createElement('div');
	body.className = 'fc-body';

	const desc = document.createElement('p');
	desc.id = descId;
	desc.className = 'fc-desc';
	desc.textContent = feature.description;

	const details = document.createElement('dl');
	details.className = 'fc-details';

	const pairs = [
		['Identifier', feature.id],
		['Current state', feature.selected ? 'Enabled' : 'Disabled'],
	];

	pairs.forEach(([label, value]) => {
		const dt = document.createElement('dt');
		dt.textContent = label;
		const dd = document.createElement('dd');
		dd.textContent = value;
		details.appendChild(dt);
		details.appendChild(dd);
	});

	body.appendChild(desc);
	body.appendChild(details);

	dialog.appendChild(header);
	dialog.appendChild(body);
	overlay.appendChild(dialog);
	mount.appendChild(overlay);

	const opener = options.trigger instanceof HTMLElement ? options.trigger : document.activeElement;

	const focusableSelectors = [
		'a[href]',
		'button:not([disabled])',
		'input:not([disabled])',
		'select:not([disabled])',
		'textarea:not([disabled])',
		'[tabindex]:not([tabindex="-1"])'
	].join(',');

	const getFocusable = () => /** @type {HTMLElement[]} */(Array.from(dialog.querySelectorAll(focusableSelectors)));

	const focusFirst = () => {
		const items = getFocusable();
		(items[0] || closeBtn).focus();
	};

	const onKeydown = (event) => {
		if (event.key === 'Tab') {
			const items = getFocusable();
			if (items.length === 0) {
				event.preventDefault();
				closeBtn.focus();
				return;
			}
			const first = items[0];
			const last = items[items.length - 1];
			const active = /** @type {HTMLElement} */(document.activeElement);
			if (!event.shiftKey && active === last) {
				event.preventDefault();
				first.focus();
			} else if (event.shiftKey && active === first) {
				event.preventDefault();
				last.focus();
			}
		}
		if (event.key === 'Escape') {
			event.preventDefault();
			close();
		}
	};

	const onOverlayClick = (event) => {
		if (event.target === overlay) close();
	};

	overlay.addEventListener('click', onOverlayClick);
	document.addEventListener('keydown', onKeydown);
	closeBtn.addEventListener('click', () => close());

	const prevOverflow = document.documentElement.style.overflow;
	document.documentElement.style.overflow = 'hidden';

	setTimeout(focusFirst, 0);

	function close() {
		overlay.removeEventListener('click', onOverlayClick);
		document.removeEventListener('keydown', onKeydown);
		document.documentElement.style.overflow = prevOverflow;
		overlay.remove();
		if (opener && typeof opener.focus === 'function') opener.focus();
	}

	return { close, root: overlay };
}