import React, { useState } from "react";
import { useRouter } from "next/router";
import useSWR from "swr";
import { Combobox, Dialog, Transition } from "@headlessui/react";

// store
import { observer } from "mobx-react-lite";
import { useMobxStore } from "lib/mobx/store-provider";

// icons
import { LayerStackIcon } from "@plane/ui";
import { Search } from "lucide-react";
// types
import { IIssueLabel } from "types";

type Props = {
  isOpen: boolean;
  handleClose: () => void;
  parent: IIssueLabel | undefined;
};

export const LabelsListModal: React.FC<Props> = observer((props) => {
  const { isOpen, handleClose, parent } = props;

  // router
  const router = useRouter();
  const { workspaceSlug, projectId } = router.query;

  // store
  const {
    projectLabel: { projectLabels, fetchProjectLabels, updateLabel },
  } = useMobxStore();

  // states
  const [query, setQuery] = useState("");

  // api call to fetch project details
  useSWR(
    workspaceSlug && projectId ? "PROJECT_LABELS" : null,
    workspaceSlug && projectId ? () => fetchProjectLabels(workspaceSlug.toString(), projectId.toString()) : null
  );

  // derived values
  const filteredLabels: IIssueLabel[] =
    query === ""
      ? projectLabels ?? []
      : projectLabels?.filter((l) => l.name.toLowerCase().includes(query.toLowerCase())) ?? [];

  const handleModalClose = () => {
    handleClose();
    setQuery("");
  };

  const addChildLabel = async (label: IIssueLabel) => {
    if (!workspaceSlug || !projectId) return;

    await updateLabel(workspaceSlug.toString(), projectId.toString(), label.id, {
      parent: parent?.id!,
    });
  };

  return (
    <Transition.Root show={isOpen} as={React.Fragment} afterLeave={() => setQuery("")} appear>
      <Dialog as="div" className="relative z-20" onClose={handleModalClose}>
        <Transition.Child
          as={React.Fragment}
          enter="ease-out duration-300"
          enterFrom="opacity-0"
          enterTo="opacity-100"
          leave="ease-in duration-200"
          leaveFrom="opacity-100"
          leaveTo="opacity-0"
        >
          <div className="fixed inset-0 bg-custom-backdrop transition-opacity" />
        </Transition.Child>

        <div className="fixed inset-0 z-20 overflow-y-auto p-4 sm:p-6 md:p-20">
          <Transition.Child
            as={React.Fragment}
            enter="ease-out duration-300"
            enterFrom="opacity-0 scale-95"
            enterTo="opacity-100 scale-100"
            leave="ease-in duration-200"
            leaveFrom="opacity-100 scale-100"
            leaveTo="opacity-0 scale-95"
          >
            <Dialog.Panel className="relative mx-auto max-w-2xl transform rounded-lg bg-custom-background-100 shadow-custom-shadow-md transition-all">
              <Combobox>
                <div className="relative m-1">
                  <Search
                    className="pointer-events-none absolute left-4 top-3.5 h-5 w-5 text-custom-text-100 text-opacity-40"
                    aria-hidden="true"
                  />
                  <Combobox.Input
                    className="h-12 w-full border-0 bg-transparent pl-11 pr-4 text-custom-text-100 outline-none focus:ring-0 sm:text-sm"
                    placeholder="Search..."
                    onChange={(e) => setQuery(e.target.value)}
                  />
                </div>

                <Combobox.Options static className="max-h-80 scroll-py-2 overflow-y-auto">
                  {filteredLabels.length > 0 && (
                    <li className="p-2">
                      {query === "" && (
                        <h2 className="mb-2 mt-4 px-3 text-xs font-semibold text-custom-text-100">Labels</h2>
                      )}
                      <ul className="text-sm text-gray-700">
                        {filteredLabels.map((label) => {
                          const children = projectLabels?.filter((l) => l.parent === label.id);

                          if (
                            (label.parent === "" || label.parent === null) && // issue does not have any other parent
                            label.id !== parent?.id && // issue is not itself
                            children?.length === 0 // issue doesn't have any other children
                          )
                            return (
                              <Combobox.Option
                                key={label.id}
                                value={{
                                  name: label.name,
                                }}
                                className={({ active }) =>
                                  `flex w-full cursor-pointer select-none items-center gap-2 rounded-md px-3 py-2 text-custom-text-200 ${
                                    active ? "bg-custom-background-80 text-custom-text-100" : ""
                                  }`
                                }
                                onClick={() => {
                                  addChildLabel(label);
                                }}
                              >
                                <span
                                  className="block h-1.5 w-1.5 flex-shrink-0 rounded-full"
                                  style={{
                                    backgroundColor: label.color !== "" ? label.color : "#000000",
                                  }}
                                />
                                {label.name}
                              </Combobox.Option>
                            );
                        })}
                      </ul>
                    </li>
                  )}
                </Combobox.Options>

                {query !== "" && filteredLabels.length === 0 && (
                  <div className="px-6 py-14 text-center sm:px-14">
                    <LayerStackIcon
                      className="mx-auto h-6 w-6 text-custom-text-100 text-opacity-40"
                      aria-hidden="true"
                    />
                    <p className="mt-4 text-sm text-custom-text-100">
                      We couldn{"'"}t find any label with that term. Please try again.
                    </p>
                  </div>
                )}
              </Combobox>
            </Dialog.Panel>
          </Transition.Child>
        </div>
      </Dialog>
    </Transition.Root>
  );
});
