import React, { useEffect, useRef, useState } from "react";
import { Combobox } from "@headlessui/react";
import { usePopper } from "react-popper";
import { Placement } from "@popperjs/core";
import { DateRange, DayPicker, Matcher } from "react-day-picker";
import { ArrowRight, CalendarDays } from "lucide-react";
// hooks
import useOutsideClickDetector from "hooks/use-outside-click-detector";
import { useDropdownKeyDown } from "hooks/use-dropdown-key-down";
// components
import { DropdownButton } from "./buttons";
// ui
import { Button } from "@plane/ui";
// helpers
import { cn } from "helpers/common.helper";
import { renderFormattedDate } from "helpers/date-time.helper";
// types
import { TButtonVariants } from "./types";

type Props = {
  applyButtonText?: string;
  bothRequired?: boolean;
  buttonClassName?: string;
  buttonContainerClassName?: string;
  buttonFromDateClassName?: string;
  buttonToDateClassName?: string;
  buttonVariant: TButtonVariants;
  cancelButtonText?: string;
  className?: string;
  disabled?: boolean;
  hideIcon?: {
    from?: boolean;
    to?: boolean;
  };
  icon?: React.ReactNode;
  minDate?: Date;
  maxDate?: Date;
  onSelect: (range: DateRange | undefined) => void;
  placeholder?: {
    from?: string;
    to?: string;
  };
  placement?: Placement;
  required?: boolean;
  showTooltip?: boolean;
  tabIndex?: number;
  value: {
    from: Date | undefined;
    to: Date | undefined;
  };
};

export const DateRangeDropdown: React.FC<Props> = (props) => {
  const {
    applyButtonText = "Apply changes",
    bothRequired = true,
    buttonClassName,
    buttonContainerClassName,
    buttonFromDateClassName,
    buttonToDateClassName,
    buttonVariant,
    cancelButtonText = "Cancel",
    className,
    disabled = false,
    hideIcon = {
      from: true,
      to: true,
    },
    icon = <CalendarDays className="h-3 w-3 flex-shrink-0" />,
    minDate,
    maxDate,
    onSelect,
    placeholder = {
      from: "Add date",
      to: "Add date",
    },
    placement,
    required = false,
    showTooltip = false,
    tabIndex,
    value,
  } = props;
  // states
  const [isOpen, setIsOpen] = useState(false);
  const [dateRange, setDateRange] = useState<DateRange>(value);
  // refs
  const dropdownRef = useRef<HTMLDivElement | null>(null);
  // popper-js refs
  const [referenceElement, setReferenceElement] = useState<HTMLButtonElement | null>(null);
  const [popperElement, setPopperElement] = useState<HTMLDivElement | null>(null);
  // popper-js init
  const { styles, attributes } = usePopper(referenceElement, popperElement, {
    placement: placement ?? "bottom-start",
    modifiers: [
      {
        name: "preventOverflow",
        options: {
          padding: 12,
        },
      },
    ],
  });

  const onOpen = () => {
    if (referenceElement) referenceElement.focus();
  };

  const handleClose = () => {
    if (!isOpen) return;
    setIsOpen(false);
    setDateRange({
      from: value.from,
      to: value.to,
    });
    if (referenceElement) referenceElement.blur();
  };

  const toggleDropdown = () => {
    if (!isOpen) onOpen();
    setIsOpen((prevIsOpen) => !prevIsOpen);
  };

  const handleKeyDown = useDropdownKeyDown(toggleDropdown, handleClose);

  const handleOnClick = (e: React.MouseEvent<HTMLButtonElement, MouseEvent>) => {
    e.stopPropagation();
    e.preventDefault();
    toggleDropdown();
  };

  useOutsideClickDetector(dropdownRef, handleClose);

  const disabledDays: Matcher[] = [];
  if (minDate) disabledDays.push({ before: minDate });
  if (maxDate) disabledDays.push({ after: maxDate });

  useEffect(() => {
    setDateRange(value);
  }, [value]);

  return (
    <Combobox
      as="div"
      ref={dropdownRef}
      tabIndex={tabIndex}
      className={cn("h-full", className)}
      onKeyDown={(e) => {
        if (e.key === "Enter") {
          if (!isOpen) handleKeyDown(e);
        } else handleKeyDown(e);
      }}
    >
      <Combobox.Button as={React.Fragment}>
        <button
          ref={setReferenceElement}
          type="button"
          className={cn(
            "clickable block h-full max-w-full outline-none",
            {
              "cursor-not-allowed text-custom-text-200": disabled,
              "cursor-pointer": !disabled,
            },
            buttonContainerClassName
          )}
          onClick={handleOnClick}
        >
          <DropdownButton
            className={buttonClassName}
            isActive={isOpen}
            tooltipHeading="Date range"
            tooltipContent={
              <>
                {dateRange.from ? renderFormattedDate(dateRange.from) : "N/A"}
                {" - "}
                {dateRange.to ? renderFormattedDate(dateRange.to) : "N/A"}
              </>
            }
            showTooltip={showTooltip}
            variant={buttonVariant}
          >
            <span
              className={cn(
                "h-full flex items-center justify-center gap-1 rounded-sm flex-grow",
                buttonFromDateClassName
              )}
            >
              {!hideIcon.from && icon}
              {dateRange.from ? renderFormattedDate(dateRange.from) : placeholder.from}
            </span>
            <ArrowRight className="h-3 w-3 flex-shrink-0" />
            <span
              className={cn(
                "h-full flex items-center justify-center gap-1 rounded-sm flex-grow",
                buttonToDateClassName
              )}
            >
              {!hideIcon.to && icon}
              {dateRange.to ? renderFormattedDate(dateRange.to) : placeholder.to}
            </span>
          </DropdownButton>
        </button>
      </Combobox.Button>
      {isOpen && (
        <Combobox.Options className="fixed z-10" static>
          <div
            className="my-1 bg-custom-background-100 shadow-custom-shadow-rg rounded-md overflow-hidden p-3"
            ref={setPopperElement}
            style={styles.popper}
            {...attributes.popper}
          >
            <DayPicker
              selected={dateRange}
              onSelect={(val) => {
                // if both the dates are not required, immediately call onSelect
                if (!bothRequired) onSelect(val);
                setDateRange({
                  from: val?.from ?? undefined,
                  to: val?.to ?? undefined,
                });
              }}
              mode="range"
              disabled={disabledDays}
              showOutsideDays
              initialFocus
              footer={
                bothRequired && (
                  <div className="grid grid-cols-2 items-center gap-3.5 pt-6 relative">
                    <div className="absolute left-0 top-1 h-[0.5px] w-full border-t-[0.5px] border-custom-border-300" />
                    <Button
                      variant="neutral-primary"
                      onClick={() => {
                        setDateRange({
                          from: undefined,
                          to: undefined,
                        });
                        handleClose();
                      }}
                    >
                      {cancelButtonText}
                    </Button>
                    <Button
                      onClick={() => {
                        onSelect(dateRange);
                        handleClose();
                      }}
                      // if required, both the dates should be selected
                      // if not required, either both or none of the dates should be selected
                      disabled={required ? !(dateRange.from && dateRange.to) : !!dateRange.from !== !!dateRange.to}
                    >
                      {applyButtonText}
                    </Button>
                  </div>
                )
              }
            />
          </div>
        </Combobox.Options>
      )}
    </Combobox>
  );
};