/**
 * Settings → Viator Structure editor. Regions and cities are plain DOM
 * blocks; cities can only be added from the Viator destination search, and
 * indexed field names are assigned on submit.
 */
(function () {
	'use strict';

	var cfg = window.vcStructure || {};
	var i18n = cfg.i18n || {};
	var form = document.getElementById('vc-structure-form');
	var list = document.getElementById('vc-regions');
	if (!form || !list) {
		return;
	}

	function slugify(s) {
		return String(s).toLowerCase().replace(/[^a-z0-9]+/g, '-').replace(/^-+|-+$/g, '');
	}

	function fromTemplate(id) {
		var tpl = document.getElementById(id);
		return tpl.content.firstElementChild.cloneNode(true);
	}

	function usedIds() {
		var ids = {};
		list.querySelectorAll('.vc-city [data-f="id"]').forEach(function (input) {
			ids[input.value] = true;
		});
		return ids;
	}

	function move(el, dir) {
		if (dir < 0 && el.previousElementSibling) {
			el.parentNode.insertBefore(el, el.previousElementSibling);
		} else if (dir > 0 && el.nextElementSibling) {
			el.parentNode.insertBefore(el.nextElementSibling, el);
		}
	}

	function addCity(region, item) {
		var row = fromTemplate('vc-tpl-city');
		row.querySelector('[data-f="id"]').value = item.id;
		row.querySelector('[data-f="name"]').value = item.name;
		row.querySelector('[data-f="slug"]').value = item.slug || slugify(item.name);
		row.querySelector('.vc-city__name').textContent = item.name;
		row.querySelector('.vc-city__id').textContent = item.id;
		region.querySelector('.vc-cities tbody').appendChild(row);
	}

	function search(region) {
		var q = region.querySelector('.vc-city-search input[type="search"]');
		var out = region.querySelector('.vc-results');
		out.textContent = i18n.searching || '…';

		var data = new FormData();
		data.append('action', 'vc_search_destinations');
		data.append('_ajax_nonce', cfg.nonce);
		data.append('q', q.value);

		fetch(cfg.ajaxUrl, { method: 'POST', credentials: 'same-origin', body: data })
			.then(function (r) { return r.json(); })
			.then(function (res) {
				if (!res || !res.success) {
					out.textContent = (res && res.data && res.data.message) || i18n.failed;
					return;
				}
				if (!res.data.results.length) {
					out.textContent = i18n.noMatches;
					return;
				}
				var used = usedIds();
				out.innerHTML = '';
				res.data.results.forEach(function (item) {
					var row = document.createElement('div');
					var btn = document.createElement('button');
					btn.type = 'button';
					btn.className = 'button button-small';
					if (used[item.id]) {
						btn.disabled = true;
						btn.textContent = i18n.used;
					} else {
						btn.textContent = i18n.add;
						btn.addEventListener('click', function () {
							addCity(region, item);
							out.innerHTML = '';
							q.value = '';
						});
					}
					var label = document.createElement('span');
					label.textContent = item.name + ' (ID ' + item.id + ')';
					row.appendChild(btn);
					row.appendChild(label);
					out.appendChild(row);
				});
			})
			.catch(function () { out.textContent = i18n.failed; });
	}

	list.addEventListener('click', function (e) {
		var btn = e.target.closest('[data-act]');
		if (!btn) {
			return;
		}
		var region = btn.closest('.vc-region');
		var city = btn.closest('.vc-city');
		var target = city || region;
		switch (btn.getAttribute('data-act')) {
			case 'up': move(target, -1); break;
			case 'down': move(target, 1); break;
			case 'remove-city': city.remove(); break;
			case 'remove-region':
				if (window.confirm(i18n.confirm)) {
					region.remove();
				}
				break;
			case 'search': search(region); break;
		}
	});

	list.addEventListener('keydown', function (e) {
		if (e.key === 'Enter' && e.target.matches('.vc-city-search input[type="search"]')) {
			e.preventDefault();
			search(e.target.closest('.vc-region'));
		}
	});

	// Suggest a region slug from its name until the slug is edited by hand.
	list.addEventListener('input', function (e) {
		var input = e.target;
		if (input.matches('.vc-region__head [data-f="slug"]')) {
			input.dataset.touched = '1';
		}
		if (input.matches('.vc-region__head [data-f="name"]')) {
			var slug = input.closest('.vc-region__head').querySelector('[data-f="slug"]');
			if (!slug.dataset.touched && (slug.value === '' || slug.dataset.auto === '1')) {
				slug.value = slugify(input.value);
				slug.dataset.auto = '1';
			}
		}
	});

	document.getElementById('vc-add-region').addEventListener('click', function () {
		var region = fromTemplate('vc-tpl-region');
		list.appendChild(region);
		region.querySelector('[data-f="name"]').focus();
	});

	function hidden(name) {
		var input = document.createElement('input');
		input.type = 'hidden';
		input.name = name;
		input.value = '1';
		form.appendChild(input);
	}

	form.addEventListener('submit', function (e) {
		var regions = list.querySelectorAll('.vc-region');
		if (!regions.length) {
			if (!window.confirm(i18n.confirmEmpty)) {
				e.preventDefault();
				return;
			}
			hidden('vc_confirm_empty');
		}
		// Proves the editor ran: the server refuses a save without it, so a
		// failed script can never submit an empty structure by accident.
		hidden('vc_structure_present');
		regions.forEach(function (region, i) {
			region.querySelectorAll('.vc-region__head [data-f]').forEach(function (input) {
				input.name = 'vc_structure[' + i + '][' + input.dataset.f + ']';
			});
			region.querySelectorAll('.vc-city').forEach(function (city, j) {
				city.querySelectorAll('[data-f]').forEach(function (input) {
					input.name = 'vc_structure[' + i + '][cities][' + j + '][' + input.dataset.f + ']';
				});
			});
		});
	});
})();