"use strict";
		(function() {
			function getTotalTopOffset(element) {
				var result = 0;
				while (element) {
					result += element.offsetTop;
					element = element.offsetParent;
				}
				return result;
			}

			var $select = $(".keyword-tags").select2({
				language: "en",
				maximumSelectionSize: 20,
				minimumInputLength: 3,
				width: '100%',
				ajax: {
					quietMillis: 1000,
					dataType: "json",
					url: "/edudocs/subject-version.json?lang=en",
					cache: true,
					transport: function (params, success, failure) {
						var request = new XMLHttpRequest();
						request.open("GET", params.url + "&term=" + params.data.term);
						request.onload = function (event) {
							var target = event.target;
							if (target.status == 200)
								success(target.response);
							else
								failure();
						};

						request.onerror = failure;

						request.send();
						return request;
					},
					processResults: function (response, params) {
						var result = { results: [] };
						try {
							var jsonData = JSON.parse(response);
							var keywords = jsonData.subjectVersions;
							var keywordsLen = keywords.length;
							console.log("Nalezeno " + keywordsLen + " předmětů");

							for (var i = 0; i < keywordsLen; i++) {
								var term = jsonData.term.toLowerCase();
								//console.log("TERM=" + term);
								var isCsTitle = false;
								var isEnTitle = false;
								var isCode = false;
								if (keywords[i].titleCs.toLowerCase().indexOf(term) != -1) {
									isCsTitle  = true;
								}
								if (keywords[i].titleEn.toLowerCase().indexOf(term) != -1) {
									isEnTitle  = true;
								}
								if (keywords[i].versionCode.toLowerCase().indexOf(term) != -1) {
									isCode  = true;
								}
								//console.log("isCsTitle=" + isCsTitle + ", isEnTitle=" + isEnTitle + ", isCode=" + isCode);
								if(isEnTitle && !isCsTitle) {
									result.results.push({id: keywords[i].subjectVersionId, text: keywords[i].titleEn + " (" + keywords[i].versionCode + ")", code: keywords[i].versionCode });
								} else {
									result.results.push({id: keywords[i].subjectVersionId, text: keywords[i].titleCs + " (" + keywords[i].versionCode + ")", code: keywords[i].versionCode});
								}

							}
						} catch (e) {
							console.error(e.message);
						}
						return result;
					}
				}
			});

			window.$select = $select;

			$(".keyword-tags").on("select2:select", function(e) {
				var data = e.params.data;
				window.location.href='/e-vyuka/en/subject/' + data.code;
			});

			if ("".length > 0)
				$select.val([]).trigger("change");


			// ------- filter state handling -------

			var filterSize = {};
			filterSize.BASIC = 0;
			filterSize.FULL = 1;

			var currentFilterSize = filterSize.BASIC;

			function loadFilterState() {
				var filterState = {};

				try {
					filterState = JSON.parse(sessionStorage.getItem("vsb-pbs-filter-state"));
				} catch (e) {
					console.error(e.message);
				}

				if (filterState !== null) {
					// load academic year selectbox values
					var academicYearSelect = document.querySelector('#pbsfilter .academicYearSelect');
					if ((academicYearSelect !== null) && (filterState.academicYear !== undefined)) {
						setTimeout(function () {
							var value = filterState.academicYear;
							var displayedOption = academicYearSelect.parentElement.querySelector(".select-selected");

							var academicYearOptions = academicYearSelect.getElementsByTagName("option");
							academicYearOptions = Array.prototype.slice.call(academicYearOptions, 0);	   // Array.from for Internet Explorer
							academicYearOptions.forEach(function (option) {
								if (option.value === value) {
									option.setAttribute("selected", "true");
									displayedOption.innerHTML = option.innerHTML;
								} else {
									option.removeAttribute("selected");
								}
							});
						}, 1000);
					}

					// load form checkboxes
					var checkboxes = document.querySelectorAll("#pbsfilter input[name=faculty], #pbsfilter input[name=studyType], #pbsfilter input[name=studyForm], #pbsfilter input[name=language], #pbsfilter input[name=tutorialCentre]");
					checkboxes = Array.prototype.slice.call(checkboxes, 0);  // Array.from for Internet Explorer
					if (filterState.checkboxes !== undefined) {
						filterState.checkboxes.forEach(function (checkboxState) {
							checkboxes.forEach(function (checkbox) {
								if ((checkbox.name === checkboxState.name) && (checkbox.value === checkboxState.value))
									checkbox.checked = checkboxState.checked;
							});
						});
					}

					// load keywords field
					var keywordsInput = document.querySelector("#pbsfilter .keyword-tags");
					if ((keywordsInput !== null) && (filterState.keywords !== undefined) && (filterState.keywords !== null)) {
						filterState.keywords.forEach(function (keyword) {
							$select.append($("<option></option>").val(keyword).text(keyword));
						});

						$select.val(filterState.keywords).trigger("change");
					}


					// load filter size
					if (filterState.size !== undefined) {
						currentFilterSize = filterState.size;

						var el = document.querySelector("#pbsfilter .toggle-type-button");

						if (el !== null) {
							if (currentFilterSize === filterSize.BASIC) {
								showBasicFilter(el, "noeffects");
							} else {
								showFullFilter(el, "noeffects");
							}
						}
					}
				}
			}


			function saveFilterState() {
				var filterState = {};

				// save academic year selectbox values
				var academicYearSelect = document.querySelector('#pbsfilter .academicYearSelect');
				if (academicYearSelect !== null)
					filterState.academicYear = academicYearSelect.value;

				// save form checkboxes
				var checkboxes = document.querySelectorAll("#pbsfilter input[name=faculty], #pbsfilter input[name=studyType], #pbsfilter input[name=studyForm], #pbsfilter input[name=language], #pbsfilter input[name=tutorialCentre]");
				checkboxes = Array.prototype.slice.call(checkboxes, 0);	  // Array.from for Internet Explorer
				filterState.checkboxes = [];
				checkboxes.forEach(function (checkbox) {
					filterState.checkboxes.push({name: checkbox.name, value: checkbox.value, checked: checkbox.checked});
				});

				// save keywords field
				var keywordsInput = document.querySelector("#pbsfilter .keyword-tags");
				if (keywordsInput !== null) {
					filterState.keywords = $(keywordsInput).val();
				}

				// save filter size
				filterState.size = currentFilterSize;

				sessionStorage.setItem("vsb-pbs-filter-state", JSON.stringify(filterState));
			}


			function toggleFilterSize(el, event) {
				if (currentFilterSize === filterSize.BASIC)
					showFullFilter(el);
				else
					showBasicFilter(el);

				event.preventDefault();
			}

			window["pbsfilter"] = {};
			window["pbsfilter"].toggleFilterSize = toggleFilterSize;

			function scrollToTop() {
				var formContainer = document.getElementById("pbsfilter");
				var topOffset = getTotalTopOffset(formContainer);

				var topbarHeight = document.querySelector(".topbar").offsetHeight;
				var navbarHeight = document.querySelector(".navbar-wrapper").offsetHeight;
				window.scrollTo(0, topOffset - topbarHeight - navbarHeight - 50);
			}


			function showFullFilter(el, effects) {
				currentFilterSize = filterSize.FULL;
				el.innerHTML = "<i class='far fa-chevron-up'></i>&nbsp;&nbsp;" + el.getAttribute("data-full-state-label");

				var sections = document.querySelectorAll("#pbsfilter .filter-section");
				sections = Array.prototype.slice.call(sections, 0);	   // Array.from for Internet Explorer

				var container = document.querySelector("#pbsfilter .filter-container");

				sections.forEach(function (section) {
					section.style.display = "block";
				});

				if (effects !== "noeffects")
					setTimeout(scrollToTop, 100);
			}


			function showBasicFilter(el, effects) {
				currentFilterSize = filterSize.BASIC;
				el.innerHTML = "<i class='far fa-chevron-down'></i>&nbsp;&nbsp;" + el.getAttribute("data-basic-state-label");

				var sections = document.querySelectorAll("#pbsfilter .filter-section:not(.basic)");
				sections = Array.prototype.slice.call(sections, 0);	   // Array.from for Internet Explorer

				var container = document.querySelector("#pbsfilter .filter-container");

				sections.forEach(function (section) {
					section.style.display = "none";
				});

				if (effects !== "noeffects")
					setTimeout(scrollToTop, 100);
			}


			function clearFilter() {
				// clear academic year selectpox
				var academicYearSelect = document.querySelector('#pbsfilter .academicYearSelect');
				if (academicYearSelect !== null) {
					var academicYearOptions = academicYearSelect.getElementsByTagName("option");
					academicYearOptions = Array.prototype.slice.call(academicYearOptions, 0);	   // Array.from for Internet Explorer
					academicYearOptions.forEach(function (option) {
						option.removeAttribute("selected");
					});
					academicYearOptions[3].setAttribute("selected", "true");

					var displayedOption = academicYearSelect.parentElement.querySelector(".select-selected");
					displayedOption.innerHTML = academicYearOptions[3].innerHTML;
				}

				// clear form checkboxes
				var checkboxes = document.querySelectorAll("#pbsfilter input[name=faculty], #pbsfilter input[name=studyType], #pbsfilter input[name=studyForm], #pbsfilter input[name=language], #pbsfilter input[name=tutorialCentre]");
				var checkboxes = Array.prototype.slice.call(checkboxes, 0);	   // Array.from for Internet Explorer
				checkboxes.forEach(function (checkbox) {
					checkbox.checked = false;
				});

				// clear keywords field
				$('#pbsfilter .keyword-tags').val(null).trigger('change');
			}

			window["pbsfilter"].clearFilter = clearFilter;


			window.addEventListener("load", function () {
				if (window.location.href.indexOf("backLink=true") !== -1)
					loadFilterState();
			});

			window.addEventListener("unload", function () {
				saveFilterState();

				history.pushState({test: 1}, window.title, window.location.href);
			});
		})();