import React, { useState, useRef } from "react";

import { useRouter } from "next/router";

import useSWR from "swr";

// hooks
import useUserAuth from "hooks/use-user-auth";
// services
import { IssueLabelService } from "services/issue";
// layouts
import { ProjectSettingLayout } from "layouts/setting-layout/project-setting-layout";
// components
import {
  CreateUpdateLabelInline,
  DeleteLabelModal,
  LabelsListModal,
  SingleLabel,
  SingleLabelGroup,
} from "components/labels";
import { ProjectSettingHeader } from "components/headers";
// ui
import { Button, Loader } from "@plane/ui";
import { EmptyState } from "components/common";
// images
import emptyLabel from "public/empty-state/label.svg";
// types
import { IIssueLabels } from "types";
import type { NextPage } from "next";
// fetch-keys
import { PROJECT_ISSUE_LABELS } from "constants/fetch-keys";

// services
const issueLabelService = new IssueLabelService();

const LabelsSettings: NextPage = () => {
  // create/edit label form
  const [labelForm, setLabelForm] = useState(false);

  // edit label
  const [isUpdating, setIsUpdating] = useState(false);
  const [labelToUpdate, setLabelToUpdate] = useState<IIssueLabels | null>(null);

  // labels list modal
  const [labelsListModal, setLabelsListModal] = useState(false);
  const [parentLabel, setParentLabel] = useState<IIssueLabels | undefined>(undefined);

  // delete label
  const [selectDeleteLabel, setSelectDeleteLabel] = useState<IIssueLabels | null>(null);

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

  const { user } = useUserAuth();

  const scrollToRef = useRef<HTMLDivElement>(null);

  const { data: issueLabels } = useSWR(
    workspaceSlug && projectId ? PROJECT_ISSUE_LABELS(projectId as string) : null,
    workspaceSlug && projectId
      ? () => issueLabelService.getProjectIssueLabels(workspaceSlug as string, projectId as string)
      : null
  );

  const newLabel = () => {
    setIsUpdating(false);
    setLabelForm(true);
  };

  const addLabelToGroup = (parentLabel: IIssueLabels) => {
    setLabelsListModal(true);
    setParentLabel(parentLabel);
  };

  const editLabel = (label: IIssueLabels) => {
    setLabelForm(true);
    setIsUpdating(true);
    setLabelToUpdate(label);
  };

  return (
    <>
      <LabelsListModal
        isOpen={labelsListModal}
        handleClose={() => setLabelsListModal(false)}
        parent={parentLabel}
        user={user}
      />
      <DeleteLabelModal
        isOpen={!!selectDeleteLabel}
        data={selectDeleteLabel ?? null}
        onClose={() => setSelectDeleteLabel(null)}
        user={user}
      />
      <ProjectSettingLayout header={<ProjectSettingHeader title="Labels Settings" />}>
        <section className="pr-9 py-8 gap-10 w-full overflow-y-auto">
          <div className="flex items-center justify-between py-3.5 border-b border-custom-border-200">
            <h3 className="text-xl font-medium">Labels</h3>

            <Button variant="primary" onClick={newLabel} size="sm">
              Add label
            </Button>
          </div>
          <div className="space-y-3 py-6 h-full w-full">
            {labelForm && (
              <CreateUpdateLabelInline
                labelForm={labelForm}
                setLabelForm={setLabelForm}
                isUpdating={isUpdating}
                labelToUpdate={labelToUpdate}
                onClose={() => {
                  setLabelForm(false);
                  setIsUpdating(false);
                  setLabelToUpdate(null);
                }}
                ref={scrollToRef}
              />
            )}
            <>
              {issueLabels ? (
                issueLabels.length > 0 ? (
                  issueLabels.map((label) => {
                    const children = issueLabels?.filter((l) => l.parent === label.id);

                    if (children && children.length === 0) {
                      if (!label.parent)
                        return (
                          <SingleLabel
                            key={label.id}
                            label={label}
                            addLabelToGroup={() => addLabelToGroup(label)}
                            editLabel={(label) => {
                              editLabel(label);
                              scrollToRef.current?.scrollIntoView({
                                behavior: "smooth",
                              });
                            }}
                            handleLabelDelete={() => setSelectDeleteLabel(label)}
                          />
                        );
                    } else
                      return (
                        <SingleLabelGroup
                          key={label.id}
                          label={label}
                          labelChildren={children}
                          addLabelToGroup={addLabelToGroup}
                          editLabel={(label) => {
                            editLabel(label);
                            scrollToRef.current?.scrollIntoView({
                              behavior: "smooth",
                            });
                          }}
                          handleLabelDelete={() => setSelectDeleteLabel(label)}
                          user={user}
                        />
                      );
                  })
                ) : (
                  <EmptyState
                    title="No labels yet"
                    description="Create labels to help organize and filter issues in you project"
                    image={emptyLabel}
                    primaryButton={{
                      text: "Add label",
                      onClick: () => newLabel(),
                    }}
                  />
                )
              ) : (
                <Loader className="space-y-5">
                  <Loader.Item height="40px" />
                  <Loader.Item height="40px" />
                  <Loader.Item height="40px" />
                  <Loader.Item height="40px" />
                </Loader>
              )}
            </>
          </div>
        </section>
      </ProjectSettingLayout>
    </>
  );
};

export default LabelsSettings;