export default function alpineSelect2(Alpine) {
    Alpine.directive(
        "select2",
        function (el, { expression }, { evaluate, cleanup }) {
            let config = evaluate(expression) || {};

            if (
                (window.jQuery || window.jquery || window.$) &&
                typeof window.$.fn.select2 !== "undefined"
            ) {
                let modalContainer = el.closest(".modal");
                let select2Default = {
                    placeholder: config.placeholder || "Select an option",
                    dropdownParent: config.dropdownParent || modalContainer || el.parentElement,
                    allowClear: config.allowClear ?? true,
                    ajax: config.url
                        ? {
                              url: config.url,
                              dataType: "json",
                              delay: 250,
                              xhrFields: {
                                  withCredentials: true,
                              },
                              data: function (params) {
                                  return {
                                      search: params.terms,
                                  };
                              },
                              processResults: function (data) {
                                  return {
                                      results: data.data || data,
                                  };
                              },
                          }
                        : undefined,
                };

                const container = document.createElement("div");
                el.parentElement.insertBefore(container, el);

                // Keep wire:ignore on container so Livewire DOM diffing does not destroy Select2 UI
                container.setAttribute("wire:ignore", "");
                container.appendChild(el);

                config = Object.assign(select2Default, config);
                let $el = $(el).select2(config);

                const $select2Container = $el.next(".select2-container");

                const modelName =
                    el.getAttribute("wire:model") ||
                    el.getAttribute("wire:model.live") ||
                    el.getAttribute("wire:model.blur") ||
                    "select2";

                let isUpdating = false;

                $el.on("change", (e) => {
                    if (isUpdating) return;
                    isUpdating = true;
                    el.dispatchEvent(new Event("change", { bubbles: true }));
                    isUpdating = false;
                });

                // Fix for allowClear: prevent dropdown from opening when clicking the 'x'
                $el.on("select2:unselecting", function (e) {
                    $(this).data("unselecting", true);
                }).on("select2:opening", function (e) {
                    if ($(this).data("unselecting")) {
                        $(this).removeData("unselecting");
                        e.preventDefault();
                    }
                });

                const event = (e) => {
                    $el.val(null).trigger("change", { bubbles: true });
                };

                window.addEventListener(`${modelName}-clear`, event);

                // Sync error state (is-invalid) from native select to Select2 container
                const syncErrorState = () => {
                    if (el.classList.contains("is-invalid")) {
                        container.classList.add("is-invalid");
                        $select2Container
                            .find(".select2-selection")
                            .addClass("is-invalid border-danger");
                    } else {
                        container.classList.remove("is-invalid");
                        $select2Container
                            .find(".select2-selection")
                            .removeClass("is-invalid border-danger");
                    }
                };

                // Run initial check on load
                syncErrorState();

                // Observe attribute changes on the native <select> element
                const observer = new MutationObserver((mutations) => {
                    if (isUpdating) return;

                    mutations.forEach((mutation) => {
                        // Update Select2 UI if value attribute changes
                        if (mutation.attributeName === "value") {
                            isUpdating = true;
                            $el.trigger("change.select2");
                            isUpdating = false;
                        }

                        // Sync error styling if class attribute changes (e.g. is-invalid added/removed)
                        if (mutation.attributeName === "class") {
                            syncErrorState();
                        }
                    });
                });

                observer.observe(el, {
                    attributes: true,
                    attributeFilter: ["value", "class"],
                });

                // Listen to Livewire DOM updates to force error styling inside wire:ignore wrapper
                if (window.Livewire) {
                    Livewire.hook("morph.updated", ({ el: updatedEl }) => {
                        if (updatedEl === el || updatedEl.contains(el)) {
                            syncErrorState();
                        }
                    });
                }

                cleanup(() => {
                    $el.select2("destroy");
                    window.removeEventListener(`${modelName}-clear`, event);
                    observer.disconnect();
                });
            }
        },
    );
}