import { Fragment, ReactNode, useRef, useState } from "react";
import { Combobox } from "@headlessui/react";
import { usePopper } from "react-popper";
import { Check, ChevronDown, Search } from "lucide-react";
// hooks
import { useDropdownKeyDown } from "hooks/use-dropdown-key-down";
import useOutsideClickDetector from "hooks/use-outside-click-detector";
// icons
import { PriorityIcon } from "@plane/ui";
// helpers
import { cn } from "helpers/common.helper";
// types
import { TIssuePriorities } from "@plane/types";
import { TDropdownProps } from "./types";
// constants
import { ISSUE_PRIORITIES } from "constants/issue";
import { useTheme } from "next-themes";

type Props = TDropdownProps & {
  button?: ReactNode;
  dropdownArrow?: boolean;
  highlightUrgent?: boolean;
  onChange: (val: TIssuePriorities) => void;
  value: TIssuePriorities;
};

type ButtonProps = {
  className?: string;
  dropdownArrow: boolean;
  hideText?: boolean;
  highlightUrgent: boolean;
  priority: TIssuePriorities;
};

const BorderButton = (props: ButtonProps) => {
  const { className, dropdownArrow, hideText = false, highlightUrgent, priority } = props;

  const priorityDetails = ISSUE_PRIORITIES.find((p) => p.key === priority);

  const priorityClasses = {
    urgent: "bg-red-500/20 text-red-950 border-red-500",
    high: "bg-orange-500/20 text-orange-950 border-orange-500",
    medium: "bg-yellow-500/20 text-yellow-950 border-yellow-500",
    low: "bg-custom-primary-100/20 text-custom-primary-950 border-custom-primary-100",
    none: "bg-custom-background-80 border-custom-border-300",
  };

  return (
    <div
      className={cn(
        "h-full flex items-center gap-1.5 border-[0.5px] rounded text-xs px-2 py-0.5",
        priorityClasses[priority],
        {
          // compact the icons if text is hidden
          "px-0.5": hideText,
          // highlight the whole button if text is hidden and priority is urgent
          "bg-red-500 border-red-500": priority === "urgent" && hideText && highlightUrgent,
        },
        className
      )}
    >
      <div
        className={cn({
          // highlight just the icon if text is visible and priority is urgent
          "bg-red-500 p-1 rounded": priority === "urgent" && !hideText && highlightUrgent,
        })}
      >
        <PriorityIcon
          priority={priority}
          size={12}
          className={cn("flex-shrink-0", {
            // increase the icon size if text is hidden
            "h-3.5 w-3.5": hideText,
            // centre align the icons if text is hidden
            "translate-x-[0.0625rem]": hideText && priority === "high",
            "translate-x-0.5": hideText && priority === "medium",
            "translate-x-1": hideText && priority === "low",
            // highlight the icon if priority is urgent
            "text-white": priority === "urgent" && highlightUrgent,
          })}
        />
      </div>
      {!hideText && <span className="flex-grow truncate">{priorityDetails?.title}</span>}
      {dropdownArrow && <ChevronDown className="h-2.5 w-2.5 flex-shrink-0" aria-hidden="true" />}
    </div>
  );
};

const BackgroundButton = (props: ButtonProps) => {
  const { className, dropdownArrow, hideText = false, highlightUrgent, priority } = props;

  const priorityDetails = ISSUE_PRIORITIES.find((p) => p.key === priority);

  const priorityClasses = {
    urgent: "bg-red-500/20 text-red-950",
    high: "bg-orange-500/20 text-orange-950",
    medium: "bg-yellow-500/20 text-yellow-950",
    low: "bg-blue-500/20 text-blue-950",
    none: "bg-custom-background-80",
  };

  return (
    <div
      className={cn(
        "h-full flex items-center gap-1.5 rounded text-xs px-2 py-0.5",
        priorityClasses[priority],
        {
          // compact the icons if text is hidden
          "px-0.5": hideText,
          // highlight the whole button if text is hidden and priority is urgent
          "bg-red-500 border-red-500": priority === "urgent" && hideText && highlightUrgent,
        },
        className
      )}
    >
      <div
        className={cn({
          // highlight just the icon if text is visible and priority is urgent
          "bg-red-500 p-1 rounded": priority === "urgent" && !hideText && highlightUrgent,
        })}
      >
        <PriorityIcon
          priority={priority}
          size={12}
          className={cn("flex-shrink-0", {
            // increase the icon size if text is hidden
            "h-3.5 w-3.5": hideText,
            // centre align the icons if text is hidden
            "translate-x-[0.0625rem]": hideText && priority === "high",
            "translate-x-0.5": hideText && priority === "medium",
            "translate-x-1": hideText && priority === "low",
            // highlight the icon if priority is urgent
            "text-white": priority === "urgent" && highlightUrgent,
          })}
        />
      </div>
      {!hideText && <span className="flex-grow truncate">{priorityDetails?.title}</span>}
      {dropdownArrow && <ChevronDown className="h-2.5 w-2.5 flex-shrink-0" aria-hidden="true" />}
    </div>
  );
};

const TransparentButton = (props: ButtonProps) => {
  const { className, dropdownArrow, hideText = false, highlightUrgent, priority } = props;

  const priorityDetails = ISSUE_PRIORITIES.find((p) => p.key === priority);

  const priorityClasses = {
    urgent: "text-red-950",
    high: "text-orange-950",
    medium: "text-yellow-950",
    low: "text-blue-950",
    none: "",
  };

  return (
    <div
      className={cn(
        "h-full flex items-center gap-1.5 rounded text-xs px-2 py-0.5 hover:bg-custom-background-80",
        priorityClasses[priority],
        {
          // compact the icons if text is hidden
          "px-0.5": hideText,
          // highlight the whole button if text is hidden and priority is urgent
          "bg-red-500 border-red-500": priority === "urgent" && hideText && highlightUrgent,
        },
        className
      )}
    >
      <div
        className={cn({
          // highlight just the icon if text is visible and priority is urgent
          "bg-red-500 p-1 rounded": priority === "urgent" && !hideText && highlightUrgent,
        })}
      >
        <PriorityIcon
          priority={priority}
          size={12}
          className={cn("flex-shrink-0", {
            // increase the icon size if text is hidden
            "h-3.5 w-3.5": hideText,
            // centre align the icons if text is hidden
            "translate-x-[0.0625rem]": hideText && priority === "high",
            "translate-x-0.5": hideText && priority === "medium",
            "translate-x-1": hideText && priority === "low",
            // highlight the icon if priority is urgent
            "text-white": priority === "urgent" && highlightUrgent,
          })}
        />
      </div>
      {!hideText && <span className="flex-grow truncate">{priorityDetails?.title}</span>}
      {dropdownArrow && <ChevronDown className="h-2.5 w-2.5 flex-shrink-0" aria-hidden="true" />}
    </div>
  );
};

export const PriorityDropdown: React.FC<Props> = (props) => {
  const {
    button,
    buttonClassName,
    buttonContainerClassName,
    buttonVariant,
    className = "",
    disabled = false,
    dropdownArrow = false,
    highlightUrgent = true,
    onChange,
    placement,
    value,
    tabIndex,
  } = props;
  // states
  const [query, setQuery] = useState("");
  const [isOpen, setIsOpen] = useState(false);
  // 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,
        },
      },
    ],
  });
  // next-themes
  // TODO: remove this after new theming implementation
  const { resolvedTheme } = useTheme();

  const options = ISSUE_PRIORITIES.map((priority) => ({
    value: priority.key,
    query: priority.key,
    content: (
      <div className="flex items-center gap-2">
        <PriorityIcon priority={priority.key} size={14} withContainer />
        <span className="flex-grow truncate">{priority.title}</span>
      </div>
    ),
  }));

  const filteredOptions =
    query === "" ? options : options.filter((o) => o.query.toLowerCase().includes(query.toLowerCase()));

  const openDropdown = () => {
    setIsOpen(true);
    if (referenceElement) referenceElement.focus();
  };
  const closeDropdown = () => setIsOpen(false);
  const handleKeyDown = useDropdownKeyDown(openDropdown, closeDropdown, isOpen);
  useOutsideClickDetector(dropdownRef, closeDropdown);

  return (
    <Combobox
      as="div"
      ref={dropdownRef}
      tabIndex={tabIndex}
      className={cn("h-full flex-shrink-0", {
        className,
      })}
      value={value}
      onChange={onChange}
      disabled={disabled}
      onKeyDown={handleKeyDown}
    >
      <Combobox.Button as={Fragment}>
        {button ? (
          <button
            ref={setReferenceElement}
            type="button"
            className={cn("block h-full w-full outline-none", buttonContainerClassName)}
            onClick={openDropdown}
          >
            {button}
          </button>
        ) : (
          <button
            ref={setReferenceElement}
            type="button"
            className={cn(
              "block h-full max-w-full outline-none",
              {
                "cursor-not-allowed text-custom-text-200": disabled,
                "cursor-pointer": !disabled,
              },
              buttonContainerClassName
            )}
            onClick={openDropdown}
          >
            {buttonVariant === "border-with-text" ? (
              <BorderButton
                priority={value}
                className={cn(buttonClassName, {
                  "text-white": resolvedTheme === "dark",
                })}
                highlightUrgent={highlightUrgent}
                dropdownArrow={dropdownArrow && !disabled}
              />
            ) : buttonVariant === "border-without-text" ? (
              <BorderButton
                priority={value}
                className={cn(buttonClassName, {
                  "text-white": resolvedTheme === "dark",
                })}
                highlightUrgent={highlightUrgent}
                dropdownArrow={dropdownArrow && !disabled}
                hideText
              />
            ) : buttonVariant === "background-with-text" ? (
              <BackgroundButton
                priority={value}
                className={cn(buttonClassName, {
                  "text-white": resolvedTheme === "dark",
                })}
                highlightUrgent={highlightUrgent}
                dropdownArrow={dropdownArrow && !disabled}
              />
            ) : buttonVariant === "background-without-text" ? (
              <BackgroundButton
                priority={value}
                className={cn(buttonClassName, {
                  "text-white": resolvedTheme === "dark",
                })}
                highlightUrgent={highlightUrgent}
                dropdownArrow={dropdownArrow && !disabled}
                hideText
              />
            ) : buttonVariant === "transparent-with-text" ? (
              <TransparentButton
                priority={value}
                className={cn(buttonClassName, {
                  "text-white": resolvedTheme === "dark",
                })}
                highlightUrgent={highlightUrgent}
                dropdownArrow={dropdownArrow && !disabled}
              />
            ) : buttonVariant === "transparent-without-text" ? (
              <TransparentButton
                priority={value}
                className={cn(buttonClassName, {
                  "text-white": resolvedTheme === "dark",
                })}
                highlightUrgent={highlightUrgent}
                dropdownArrow={dropdownArrow && !disabled}
                hideText
              />
            ) : null}
          </button>
        )}
      </Combobox.Button>
      {isOpen && (
        <Combobox.Options className="fixed z-10" static>
          <div
            className="my-1 w-48 rounded border-[0.5px] border-custom-border-300 bg-custom-background-100 px-2 py-2.5 text-xs shadow-custom-shadow-rg focus:outline-none"
            ref={setPopperElement}
            style={styles.popper}
            {...attributes.popper}
          >
            <div className="flex items-center gap-1.5 rounded border border-custom-border-100 bg-custom-background-90 px-2">
              <Search className="h-3.5 w-3.5 text-custom-text-400" strokeWidth={1.5} />
              <Combobox.Input
                className="w-full bg-transparent py-1 text-xs text-custom-text-200 placeholder:text-custom-text-400 focus:outline-none"
                value={query}
                onChange={(e) => setQuery(e.target.value)}
                placeholder="Search"
                displayValue={(assigned: any) => assigned?.name}
              />
            </div>
            <div className="mt-2 max-h-48 space-y-1 overflow-y-scroll">
              {filteredOptions.length > 0 ? (
                filteredOptions.map((option) => (
                  <Combobox.Option
                    key={option.value}
                    value={option.value}
                    className={({ active, selected }) =>
                      `w-full truncate flex items-center justify-between gap-2 rounded px-1 py-1.5 cursor-pointer select-none ${
                        active ? "bg-custom-background-80" : ""
                      } ${selected ? "text-custom-text-100" : "text-custom-text-200"}`
                    }
                    onClick={closeDropdown}
                  >
                    {({ selected }) => (
                      <>
                        <span className="flex-grow truncate">{option.content}</span>
                        {selected && <Check className="h-3.5 w-3.5 flex-shrink-0" />}
                      </>
                    )}
                  </Combobox.Option>
                ))
              ) : (
                <p className="text-custom-text-400 italic py-1 px-1.5">No matching results</p>
              )}
            </div>
          </div>
        </Combobox.Options>
      )}
    </Combobox>
  );
};