import React, { FC, useState, useRef, useEffect, Fragment } from "react";
import { observer } from "mobx-react-lite";
import { useRouter } from "next/router";
import { Controller, useForm } from "react-hook-form";
import { LayoutPanelTop, Sparkle, X } from "lucide-react";
import { EditorRefApi } from "@plane/rich-text-editor";
import type { TIssue, ISearchIssueResponse } from "@plane/types";
// hooks
import { Button, CustomMenu, Input, Loader, ToggleSwitch, TOAST_TYPE, setToast } from "@plane/ui";
import { GptAssistantPopover } from "@/components/core";
import {
  CycleDropdown,
  DateDropdown,
  EstimateDropdown,
  ModuleDropdown,
  PriorityDropdown,
  ProjectDropdown,
  MemberDropdown,
  StateDropdown,
} from "@/components/dropdowns";
import { RichTextEditor } from "@/components/editor/rich-text-editor/rich-text-editor";
import { ParentIssuesListModal } from "@/components/issues";
import { IssueLabelSelect } from "@/components/issues/select";
import { CreateLabelModal } from "@/components/labels";
import { renderFormattedPayloadDate, getDate } from "@/helpers/date-time.helper";
import { getChangedIssuefields, getDescriptionPlaceholder } from "@/helpers/issue.helper";
import { shouldRenderProject } from "@/helpers/project.helper";
import { useApplication, useEstimate, useIssueDetail, useProject, useWorkspace } from "@/hooks/store";
import { useProjectIssueProperties } from "@/hooks/use-project-issue-properties";
// services
import { AIService } from "@/services/ai.service";
// components
// ui
// helpers
// types

const defaultValues: Partial<TIssue> = {
  project_id: "",
  name: "",
  description_html: "",
  estimate_point: null,
  state_id: "",
  parent_id: null,
  priority: "none",
  assignee_ids: [],
  label_ids: [],
  cycle_id: null,
  module_ids: null,
  start_date: null,
  target_date: null,
};

export interface IssueFormProps {
  data?: Partial<TIssue>;
  issueTitleRef: React.MutableRefObject<HTMLInputElement | null>;
  isCreateMoreToggleEnabled: boolean;
  onCreateMoreToggleChange: (value: boolean) => void;
  onChange?: (formData: Partial<TIssue> | null) => void;
  onClose: () => void;
  onSubmit: (values: Partial<TIssue>, is_draft_issue?: boolean) => Promise<void>;
  projectId: string;
  isDraft: boolean;
}

// services
const aiService = new AIService();

const TAB_INDICES = [
  "name",
  "description_html",
  "feeling_lucky",
  "ai_assistant",
  "state_id",
  "priority",
  "assignee_ids",
  "label_ids",
  "start_date",
  "target_date",
  "cycle_id",
  "module_ids",
  "estimate_point",
  "parent_id",
  "create_more",
  "discard_button",
  "draft_button",
  "submit_button",
  "project_id",
  "remove_parent",
];

const getTabIndex = (key: string) => TAB_INDICES.findIndex((tabIndex) => tabIndex === key) + 1;

export const IssueFormRoot: FC<IssueFormProps> = observer((props) => {
  const {
    data,
    issueTitleRef,
    onChange,
    onClose,
    onSubmit,
    projectId: defaultProjectId,
    isCreateMoreToggleEnabled,
    onCreateMoreToggleChange,
    isDraft,
  } = props;
  // states
  const [labelModal, setLabelModal] = useState(false);
  const [parentIssueListModalOpen, setParentIssueListModalOpen] = useState(false);
  const [selectedParentIssue, setSelectedParentIssue] = useState<ISearchIssueResponse | null>(null);
  const [gptAssistantModal, setGptAssistantModal] = useState(false);
  const [iAmFeelingLucky, setIAmFeelingLucky] = useState(false);

  // refs
  const editorRef = useRef<EditorRefApi>(null);
  // router
  const router = useRouter();
  const { workspaceSlug } = router.query;
  const workspaceStore = useWorkspace();
  const workspaceId = workspaceStore.getWorkspaceBySlug(workspaceSlug as string)?.id as string;

  // store hooks
  const {
    config: { envConfig },
    router: { projectId: routeProjectId },
  } = useApplication();
  const { getProjectById } = useProject();
  const { areEstimatesEnabledForProject } = useEstimate();

  const {
    issue: { getIssueById },
  } = useIssueDetail();
  const { fetchCycles } = useProjectIssueProperties();
  // form info
  const {
    formState: { errors, isDirty, isSubmitting, dirtyFields },
    handleSubmit,
    reset,
    watch,
    control,
    getValues,
    setValue,
  } = useForm<TIssue>({
    defaultValues: { ...defaultValues, project_id: defaultProjectId, ...data },
    reValidateMode: "onChange",
  });

  const projectId = watch("project_id");

  //reset few fields on projectId change
  useEffect(() => {
    if (isDirty) {
      const formData = getValues();

      reset({
        ...defaultValues,
        project_id: projectId,
        name: formData.name,
        description_html: formData.description_html,
        priority: formData.priority,
        start_date: formData.start_date,
        target_date: formData.target_date,
        parent_id: formData.parent_id,
      });
    }
    if (projectId && routeProjectId !== projectId) fetchCycles(workspaceSlug, projectId);
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [projectId]);

  useEffect(() => {
    if (data?.description_html) setValue("description_html", data?.description_html);
  }, [data?.description_html]);

  const issueName = watch("name");

  const handleFormSubmit = async (formData: Partial<TIssue>, is_draft_issue = false) => {
    const submitData = !data?.id
      ? formData
      : {
          ...getChangedIssuefields(formData, dirtyFields as { [key: string]: boolean | undefined }),
          project_id: getValues("project_id"),
          id: data.id,
          description_html: formData.description_html ?? "<p></p>",
        };

    // this condition helps to move the issues from draft to project issues
    if (formData.hasOwnProperty("is_draft")) submitData.is_draft = formData.is_draft;

    await onSubmit(submitData, is_draft_issue);

    setGptAssistantModal(false);

    reset({
      ...defaultValues,
      ...(isCreateMoreToggleEnabled ? { ...data } : {}),
      project_id: getValues("project_id"),
      description_html: data?.description_html ?? "<p></p>",
    });
    editorRef?.current?.clearEditor();
  };

  const handleAiAssistance = async (response: string) => {
    if (!workspaceSlug || !projectId) return;

    editorRef.current?.setEditorValueAtCursorPosition(response);
  };

  const handleAutoGenerateDescription = async () => {
    if (!workspaceSlug || !projectId) return;

    setIAmFeelingLucky(true);

    aiService
      .createGptTask(workspaceSlug.toString(), projectId, {
        prompt: issueName,
        task: "Generate a proper description for this issue.",
      })
      .then((res) => {
        if (res.response === "")
          setToast({
            type: TOAST_TYPE.ERROR,
            title: "Error!",
            message:
              "Issue title isn't informative enough to generate the description. Please try with a different title.",
          });
        else handleAiAssistance(res.response_html);
      })
      .catch((err) => {
        const error = err?.data?.error;

        if (err.status === 429)
          setToast({
            type: TOAST_TYPE.ERROR,
            title: "Error!",
            message: error || "You have reached the maximum number of requests of 50 requests per month per user.",
          });
        else
          setToast({
            type: TOAST_TYPE.ERROR,
            title: "Error!",
            message: error || "Some error occurred. Please try again.",
          });
      })
      .finally(() => setIAmFeelingLucky(false));
  };

  const handleFormChange = () => {
    if (!onChange) return;

    if (isDirty && (watch("name") || watch("description_html"))) onChange(watch());
    else onChange(null);
  };

  const startDate = watch("start_date");
  const targetDate = watch("target_date");

  const minDate = getDate(startDate);
  minDate?.setDate(minDate.getDate());

  const maxDate = getDate(targetDate);
  maxDate?.setDate(maxDate.getDate());

  const projectDetails = getProjectById(projectId);

  // executing this useEffect when the parent_id coming from the component prop
  useEffect(() => {
    const parentId = watch("parent_id") || undefined;
    if (!parentId) return;
    if (parentId === selectedParentIssue?.id || selectedParentIssue) return;

    const issue = getIssueById(parentId);
    if (!issue) return;

    const projectDetails = getProjectById(issue.project_id);
    if (!projectDetails) return;

    setSelectedParentIssue({
      id: issue.id,
      name: issue.name,
      project_id: issue.project_id,
      project__identifier: projectDetails.identifier,
      project__name: projectDetails.name,
      sequence_id: issue.sequence_id,
    } as ISearchIssueResponse);
  }, [watch, getIssueById, getProjectById, selectedParentIssue]);

  return (
    <>
      {projectId && (
        <CreateLabelModal
          isOpen={labelModal}
          handleClose={() => setLabelModal(false)}
          projectId={projectId}
          onSuccess={(response) => {
            setValue("label_ids", [...watch("label_ids"), response.id]);
            handleFormChange();
          }}
        />
      )}
      <form onSubmit={handleSubmit((data) => handleFormSubmit(data))}>
        <div className="space-y-5">
          <div className="flex items-center gap-x-2">
            {/* Don't show project selection if editing an issue */}
            {!data?.id && (
              <Controller
                control={control}
                name="project_id"
                rules={{
                  required: true,
                }}
                render={({ field: { value, onChange } }) => (
                  <div className="h-7">
                    <ProjectDropdown
                      value={value}
                      onChange={(projectId) => {
                        onChange(projectId);
                        handleFormChange();
                      }}
                      buttonVariant="border-with-text"
                      renderCondition={(project) => shouldRenderProject(project)}
                      tabIndex={getTabIndex("project_id")}
                    />
                  </div>
                )}
              />
            )}
            <h3 className="text-xl font-semibold leading-6 text-custom-text-100">
              {data?.id ? "Update" : "Create"} issue
            </h3>
          </div>
          {watch("parent_id") && selectedParentIssue && (
            <Controller
              control={control}
              name="parent_id"
              render={({ field: { onChange } }) => (
                <div className="flex w-min items-center gap-2 whitespace-nowrap rounded bg-custom-background-80 p-2 text-xs">
                  <div className="flex items-center gap-2">
                    <span
                      className="block h-1.5 w-1.5 rounded-full"
                      style={{
                        backgroundColor: selectedParentIssue.state__color,
                      }}
                    />
                    <span className="flex-shrink-0 text-custom-text-200">
                      {selectedParentIssue.project__identifier}-{selectedParentIssue.sequence_id}
                    </span>
                    <span className="truncate font-medium">{selectedParentIssue.name.substring(0, 50)}</span>
                    <button
                      type="button"
                      className="grid place-items-center"
                      onClick={() => {
                        onChange(null);
                        handleFormChange();
                        setSelectedParentIssue(null);
                      }}
                      tabIndex={getTabIndex("remove_parent")}
                    >
                      <X className="h-3 w-3 cursor-pointer" />
                    </button>
                  </div>
                </div>
              )}
            />
          )}
          <div className="space-y-3">
            <div className="mt-2 space-y-3">
              <Controller
                control={control}
                name="name"
                rules={{
                  required: "Title is required",
                  maxLength: {
                    value: 255,
                    message: "Title should be less than 255 characters",
                  },
                }}
                render={({ field: { value, onChange, ref } }) => (
                  <Input
                    id="name"
                    name="name"
                    type="text"
                    value={value}
                    onChange={(e) => {
                      onChange(e.target.value);
                      handleFormChange();
                    }}
                    ref={issueTitleRef || ref}
                    hasError={Boolean(errors.name)}
                    placeholder="Issue Title"
                    className="w-full resize-none text-xl"
                    tabIndex={getTabIndex("name")}
                    autoFocus
                  />
                )}
              />
              <span className="text-xs text-red-500">{errors?.name?.message}</span>

              <div className="relative">
                {data?.description_html === undefined ? (
                  <Loader className="min-h-[7rem] space-y-2 overflow-hidden rounded-md border border-custom-border-200 p-2 py-2">
                    <Loader.Item width="100%" height="26px" />
                    <div className="flex items-center gap-2">
                      <Loader.Item width="26px" height="26px" />
                      <Loader.Item width="400px" height="26px" />
                    </div>
                    <div className="flex items-center gap-2">
                      <Loader.Item width="26px" height="26px" />
                      <Loader.Item width="400px" height="26px" />
                    </div>
                    <Loader.Item width="80%" height="26px" />
                    <div className="flex items-center gap-2">
                      <Loader.Item width="50%" height="26px" />
                    </div>
                    <div className="border-0.5 absolute bottom-3.5 right-3.5 z-10 flex items-center gap-2">
                      <Loader.Item width="100px" height="26px" />
                      <Loader.Item width="50px" height="26px" />
                    </div>
                  </Loader>
                ) : (
                  <Fragment>
                    <div className="border-0.5 absolute bottom-3.5 right-3.5 z-10 flex items-center gap-2">
                      {issueName && issueName.trim() !== "" && envConfig?.has_openai_configured && (
                        <button
                          type="button"
                          className={`flex items-center gap-1 rounded bg-custom-background-80 px-1.5 py-1 text-xs ${
                            iAmFeelingLucky ? "cursor-wait" : ""
                          }`}
                          onClick={handleAutoGenerateDescription}
                          disabled={iAmFeelingLucky}
                          tabIndex={getTabIndex("feeling_lucky")}
                        >
                          {iAmFeelingLucky ? (
                            "Generating response"
                          ) : (
                            <>
                              <Sparkle className="h-3.5 w-3.5" />I{"'"}m feeling lucky
                            </>
                          )}
                        </button>
                      )}
                      {envConfig?.has_openai_configured && (
                        <GptAssistantPopover
                          isOpen={gptAssistantModal}
                          projectId={projectId}
                          handleClose={() => {
                            setGptAssistantModal((prevData) => !prevData);
                            // this is done so that the title do not reset after gpt popover closed
                            reset(getValues());
                          }}
                          onResponse={(response) => {
                            handleAiAssistance(response);
                          }}
                          placement="top-end"
                          button={
                            <button
                              type="button"
                              className="flex items-center gap-1 rounded px-1.5 py-1 text-xs hover:bg-custom-background-90"
                              onClick={() => setGptAssistantModal((prevData) => !prevData)}
                              tabIndex={getTabIndex("ai_assistant")}
                            >
                              <Sparkle className="h-4 w-4" />
                              AI
                            </button>
                          }
                        />
                      )}
                    </div>
                    <Controller
                      name="description_html"
                      control={control}
                      render={({ field: { value, onChange } }) => (
                        <RichTextEditor
                          initialValue={value}
                          value={data.description_html}
                          workspaceSlug={workspaceSlug?.toString() as string}
                          workspaceId={workspaceId}
                          projectId={projectId}
                          onChange={(_description: object, description_html: string) => {
                            onChange(description_html);
                            handleFormChange();
                          }}
                          ref={editorRef}
                          tabIndex={getTabIndex("description_html")}
                          placeholder={getDescriptionPlaceholder}
                          containerClassName="border-[0.5px] border-custom-border-200 py-3"
                        />
                      )}
                    />
                  </Fragment>
                )}
              </div>
              <div className="flex flex-wrap items-center gap-2">
                <Controller
                  control={control}
                  name="state_id"
                  render={({ field: { value, onChange } }) => (
                    <div className="h-7">
                      <StateDropdown
                        value={value}
                        onChange={(stateId) => {
                          onChange(stateId);
                          handleFormChange();
                        }}
                        projectId={projectId}
                        buttonVariant="border-with-text"
                        tabIndex={getTabIndex("state_id")}
                      />
                    </div>
                  )}
                />
                <Controller
                  control={control}
                  name="priority"
                  render={({ field: { value, onChange } }) => (
                    <div className="h-7">
                      <PriorityDropdown
                        value={value}
                        onChange={(priority) => {
                          onChange(priority);
                          handleFormChange();
                        }}
                        buttonVariant="border-with-text"
                        tabIndex={getTabIndex("priority")}
                      />
                    </div>
                  )}
                />
                <Controller
                  control={control}
                  name="assignee_ids"
                  render={({ field: { value, onChange } }) => (
                    <div className="h-7">
                      <MemberDropdown
                        projectId={projectId}
                        value={value}
                        onChange={(assigneeIds) => {
                          onChange(assigneeIds);
                          handleFormChange();
                        }}
                        buttonVariant={value?.length > 0 ? "transparent-without-text" : "border-with-text"}
                        buttonClassName={value?.length > 0 ? "hover:bg-transparent" : ""}
                        placeholder="Assignees"
                        multiple
                        tabIndex={getTabIndex("assignee_ids")}
                      />
                    </div>
                  )}
                />
                <Controller
                  control={control}
                  name="label_ids"
                  render={({ field: { value, onChange } }) => (
                    <div className="h-7">
                      <IssueLabelSelect
                        setIsOpen={setLabelModal}
                        value={value}
                        onChange={(labelIds) => {
                          onChange(labelIds);
                          handleFormChange();
                        }}
                        projectId={projectId}
                        tabIndex={getTabIndex("label_ids")}
                      />
                    </div>
                  )}
                />
                <Controller
                  control={control}
                  name="start_date"
                  render={({ field: { value, onChange } }) => (
                    <div className="h-7">
                      <DateDropdown
                        value={value}
                        onChange={(date) => onChange(date ? renderFormattedPayloadDate(date) : null)}
                        buttonVariant="border-with-text"
                        maxDate={maxDate ?? undefined}
                        placeholder="Start date"
                        tabIndex={getTabIndex("start_date")}
                      />
                    </div>
                  )}
                />
                <Controller
                  control={control}
                  name="target_date"
                  render={({ field: { value, onChange } }) => (
                    <div className="h-7">
                      <DateDropdown
                        value={value}
                        onChange={(date) => onChange(date ? renderFormattedPayloadDate(date) : null)}
                        buttonVariant="border-with-text"
                        minDate={minDate ?? undefined}
                        placeholder="Due date"
                        tabIndex={getTabIndex("target_date")}
                      />
                    </div>
                  )}
                />
                {projectDetails?.cycle_view && (
                  <Controller
                    control={control}
                    name="cycle_id"
                    render={({ field: { value, onChange } }) => (
                      <div className="h-7">
                        <CycleDropdown
                          projectId={projectId}
                          onChange={(cycleId) => {
                            onChange(cycleId);
                            handleFormChange();
                          }}
                          placeholder="Cycle"
                          value={value}
                          buttonVariant="border-with-text"
                          tabIndex={getTabIndex("cycle_id")}
                        />
                      </div>
                    )}
                  />
                )}
                {projectDetails?.module_view && workspaceSlug && (
                  <Controller
                    control={control}
                    name="module_ids"
                    render={({ field: { value, onChange } }) => (
                      <div className="h-7">
                        <ModuleDropdown
                          projectId={projectId}
                          value={value ?? []}
                          onChange={(moduleIds) => {
                            onChange(moduleIds);
                            handleFormChange();
                          }}
                          placeholder="Modules"
                          buttonVariant="border-with-text"
                          tabIndex={getTabIndex("module_ids")}
                          multiple
                          showCount
                        />
                      </div>
                    )}
                  />
                )}
                {areEstimatesEnabledForProject(projectId) && (
                  <Controller
                    control={control}
                    name="estimate_point"
                    render={({ field: { value, onChange } }) => (
                      <div className="h-7">
                        <EstimateDropdown
                          value={value}
                          onChange={(estimatePoint) => {
                            onChange(estimatePoint);
                            handleFormChange();
                          }}
                          projectId={projectId}
                          buttonVariant="border-with-text"
                          tabIndex={getTabIndex("estimate_point")}
                          placeholder="Estimate"
                        />
                      </div>
                    )}
                  />
                )}
                {watch("parent_id") ? (
                  <CustomMenu
                    customButton={
                      <button
                        type="button"
                        className="flex cursor-pointer items-center justify-between gap-1 rounded border-[0.5px] border-custom-border-300 px-2 py-1.5 text-xs hover:bg-custom-background-80"
                      >
                        <LayoutPanelTop className="h-3 w-3 flex-shrink-0" />
                        <span className="whitespace-nowrap">
                          {selectedParentIssue &&
                            `${selectedParentIssue.project__identifier}-${selectedParentIssue.sequence_id}`}
                        </span>
                      </button>
                    }
                    placement="bottom-start"
                    tabIndex={getTabIndex("parent_id")}
                  >
                    <>
                      <CustomMenu.MenuItem className="!p-1" onClick={() => setParentIssueListModalOpen(true)}>
                        Change parent issue
                      </CustomMenu.MenuItem>
                      <Controller
                        control={control}
                        name="parent_id"
                        render={({ field: { onChange } }) => (
                          <CustomMenu.MenuItem
                            className="!p-1"
                            onClick={() => {
                              onChange(null);
                              handleFormChange();
                            }}
                          >
                            Remove parent issue
                          </CustomMenu.MenuItem>
                        )}
                      />
                    </>
                  </CustomMenu>
                ) : (
                  <button
                    type="button"
                    className="flex cursor-pointer items-center justify-between gap-1 rounded border-[0.5px] border-custom-border-300 px-2 py-1.5 text-xs hover:bg-custom-background-80"
                    onClick={() => setParentIssueListModalOpen(true)}
                  >
                    <LayoutPanelTop className="h-3 w-3 flex-shrink-0" />
                    <span className="whitespace-nowrap">Add parent</span>
                  </button>
                )}
                <Controller
                  control={control}
                  name="parent_id"
                  render={({ field: { onChange } }) => (
                    <ParentIssuesListModal
                      isOpen={parentIssueListModalOpen}
                      handleClose={() => setParentIssueListModalOpen(false)}
                      onChange={(issue) => {
                        onChange(issue.id);
                        handleFormChange();
                        setSelectedParentIssue(issue);
                      }}
                      projectId={projectId}
                      issueId={isDraft ? undefined : data?.id}
                    />
                  )}
                />
              </div>
            </div>
          </div>
        </div>
        <div className="-mx-5 mt-5 flex items-center justify-between gap-2 border-t border-custom-border-100 px-5 pt-5">
          <div>
            {!data?.id && (
              <div
                className="inline-flex cursor-default items-center gap-1.5"
                onClick={() => onCreateMoreToggleChange(!isCreateMoreToggleEnabled)}
                onKeyDown={(e) => {
                  if (e.key === "Enter") onCreateMoreToggleChange(!isCreateMoreToggleEnabled);
                }}
                tabIndex={getTabIndex("create_more")}
              >
                <div className="flex cursor-pointer items-center justify-center">
                  <ToggleSwitch value={isCreateMoreToggleEnabled} onChange={() => {}} size="sm" />
                </div>
                <span className="text-xs">Create more</span>
              </div>
            )}
          </div>

          <div className="flex items-center gap-2">
            <Button variant="neutral-primary" size="sm" onClick={onClose} tabIndex={getTabIndex("discard_button")}>
              Discard
            </Button>

            {isDraft && (
              <Fragment>
                {data?.id ? (
                  <Button
                    variant="neutral-primary"
                    size="sm"
                    loading={isSubmitting}
                    onClick={handleSubmit((data) => handleFormSubmit({ ...data, is_draft: false }))}
                    tabIndex={getTabIndex("draft_button")}
                  >
                    {isSubmitting ? "Moving" : "Move from draft"}
                  </Button>
                ) : (
                  <Button
                    variant="neutral-primary"
                    size="sm"
                    loading={isSubmitting}
                    onClick={handleSubmit((data) => handleFormSubmit(data, true))}
                    tabIndex={getTabIndex("draft_button")}
                  >
                    {isSubmitting ? "Saving" : "Save as draft"}
                  </Button>
                )}
              </Fragment>
            )}

            <Button
              variant="primary"
              type="submit"
              size="sm"
              loading={isSubmitting}
              tabIndex={isDraft ? getTabIndex("submit_button") : getTabIndex("draft_button")}
            >
              {data?.id ? (isSubmitting ? "Updating" : "Update issue") : isSubmitting ? "Creating" : "Create issue"}
            </Button>
          </div>
        </div>
      </form>
    </>
  );
});