import { useResponsive } from "./use-responsive.svelte.js";
import { useForm } from "./use-form.svelte.js";

export function useMasterDetail(options = {}) {
  const { onSelect = null, formConfig = null, } = options;

  let selectedItem = $state(null);
  let mode = $state("view");
  let isLoadingDetail = $state(false);

  const formState = useForm(formConfig);

  const { isMobile } = useResponsive();

  const isFormMode = $derived(mode === "create" || mode === "edit");

  const showMaster = $derived(!isMobile || (mode === "view" && !selectedItem));

  const showDetail = $derived(!isMobile || selectedItem || isFormMode);

  const layout = $derived({
    masterWidth: isMobile ? "w-full" : isFormMode ? "w-[3%]" : "w-[35%]",
    detailWidth: isMobile ? "w-full" : isFormMode ? "w-[97%]" : "w-[65%]",
  });

  async function select(item) {
    mode = "view";
    
    if (onSelect) {
      isLoadingDetail = true;
      try {
        const detailData = await onSelect(item);
        selectedItem = detailData;
      } catch (error) {
        console.error("Failed to fetch detail:", error);
        selectedItem = null;
      } finally {
        isLoadingDetail = false;
      }
    } else {
      selectedItem = item;
    }
  }

function enterCreate(initialData = null) {
  mode = "create";
  selectedItem = null;

  formState.reset();

  if (initialData) {
    formState.setForm({
      ...formState.form,
      ...initialData
    });
  }

}

  function enterEdit(mapToForm = null) {
    if (!selectedItem) return;
    mode = "edit";

    const data = mapToForm
    ? mapToForm(selectedItem)
    : selectedItem;

    formState.reset();
    Object.assign(formState.form, data);

    Object.keys(formState.errors).forEach(key => {
        formState.errors[key] = null;
    });
  }

  function exitForm() {
      // const confirmed = confirm('You have unsaved changes. Are you sure you want to exit?');
      // if (!confirmed) return;

    mode = "view";
    selectedItem = null;
  }

  function backToList() {
    selectedItem = null;
    mode = "view";
  }

  function saveForm() {
    // Commit changes (mark as saved)
    formSnapshot = { ...form };
  }

  return {
    // State
    get selectedItem() {
      return selectedItem;
    },
    get mode() {
      return mode;
    },
    get isFormMode() {
      return isFormMode;
    },
    get isMobile() {
      return isMobile;
    },
    get showMaster() {
      return showMaster;
    },
    get showDetail() {
      return showDetail;
    },
    get layout() {
      return layout;
    },
    // get form() {
    //   return form;
    // },
    // get isDirty() {
    //   return isDirty;
    // },
    get isLoadingDetail() {
      return isLoadingDetail;
    },
    get formState() {
      return formState;
    },

    // Actions
    select,
    enterCreate,
    enterEdit,
    exitForm,
    backToList,
    saveForm,
  };
}