import data from "@emoji-mart/data";
import Picker from "@emoji-mart/react";
import { SmileyIcon } from "outline-icons";
import * as React from "react";
import { useTranslation } from "react-i18next";
import { usePopoverState, PopoverDisclosure } from "reakit/Popover";
import styled, { useTheme } from "styled-components";
import { depths, s } from "@shared/styles";
import { toRGB } from "@shared/utils/color";
import Button from "~/components/Button";
import Popover from "~/components/Popover";
import useStores from "~/hooks/useStores";
import useUserLocale from "~/hooks/useUserLocale";
import { Emoji, EmojiButton } from "./components";

/* Locales supported by emoji-mart */
const supportedLocales = [
  "en",
  "ar",
  "be",
  "cs",
  "de",
  "es",
  "fa",
  "fi",
  "fr",
  "hi",
  "it",
  "ja",
  "ko",
  "nl",
  "pl",
  "pt",
  "ru",
  "sa",
  "tr",
  "uk",
  "vi",
  "zh",
];

/**
 * React hook to derive emoji picker's theme from UI theme
 *
 * @returns {string} Theme to use for emoji picker
 */
function usePickerTheme(): string {
  const { ui } = useStores();
  const { theme } = ui;

  if (theme === "system") {
    return "auto";
  }

  return theme;
}

type Props = {
  /** The selected emoji, if any */
  value?: string | null;
  /** Callback when an emoji is selected */
  onChange: (emoji: string | null) => void | Promise<void>;
  /** Callback when the picker is opened */
  onOpen?: () => void;
  /** Callback when the picker is closed */
  onClose?: () => void;
  /** Callback when the picker is clicked outside of */
  onClickOutside: () => void;
  /** Whether to auto focus the search input on open */
  autoFocus?: boolean;
  /** Class name to apply to the trigger button */
  className?: string;
};

function EmojiPicker({
  value,
  onOpen,
  onClose,
  onChange,
  onClickOutside,
  autoFocus,
  className,
}: Props) {
  const { t } = useTranslation();
  const pickerTheme = usePickerTheme();
  const theme = useTheme();
  const locale = useUserLocale(true) ?? "en";

  const popover = usePopoverState({
    placement: "bottom-start",
    modal: true,
    unstable_offset: [0, 0],
  });

  const [emojisPerLine, setEmojisPerLine] = React.useState(9);

  const pickerRef = React.useRef<HTMLDivElement>(null);

  React.useEffect(() => {
    if (popover.visible) {
      onOpen?.();
    } else {
      onClose?.();
    }
  }, [popover.visible, onOpen, onClose]);

  React.useEffect(() => {
    if (popover.visible && pickerRef.current) {
      // 28 is picker's observed width when perLine is set to 0
      // and 36 is the default emojiButtonSize
      // Ref: https://github.com/missive/emoji-mart#options--props
      setEmojisPerLine(Math.floor((pickerRef.current.clientWidth - 28) / 36));
    }
  }, [popover.visible]);

  const handleEmojiChange = React.useCallback(
    async (emoji) => {
      popover.hide();
      await onChange(emoji ? emoji.native : null);
    },
    [popover, onChange]
  );

  const handleClick = React.useCallback(
    (ev: React.MouseEvent) => {
      ev.stopPropagation();
      if (popover.visible) {
        popover.hide();
      } else {
        popover.show();
      }
    },
    [popover]
  );

  const handleClickOutside = React.useCallback(() => {
    // It was observed that onClickOutside got triggered
    // even when the picker wasn't open or opened at all.
    // Hence, this guard here...
    if (popover.visible) {
      onClickOutside();
    }
  }, [popover.visible, onClickOutside]);

  // Auto focus search input when picker is opened
  React.useLayoutEffect(() => {
    if (autoFocus && popover.visible) {
      requestAnimationFrame(() => {
        const searchInput = pickerRef.current
          ?.querySelector("em-emoji-picker")
          ?.shadowRoot?.querySelector(
            "input[type=search]"
          ) as HTMLInputElement | null;
        searchInput?.focus();
      });
    }
  }, [autoFocus, popover.visible]);

  return (
    <>
      <PopoverDisclosure {...popover}>
        {(props) => (
          <EmojiButton
            {...props}
            className={className}
            onClick={handleClick}
            icon={
              value ? (
                <Emoji size={32} align="center" justify="center">
                  {value}
                </Emoji>
              ) : (
                <StyledSmileyIcon size={32} color={theme.textTertiary} />
              )
            }
            neutral
            borderOnHover
          />
        )}
      </PopoverDisclosure>
      <PickerPopover
        {...popover}
        tabIndex={0}
        // This prevents picker from closing when any of its
        // children are focused, e.g, clicking on search bar or
        // a click on skin tone button
        onClick={(e) => e.stopPropagation()}
        width={352}
        aria-label={t("Emoji Picker")}
      >
        {popover.visible && (
          <>
            {value && (
              <RemoveButton neutral onClick={() => handleEmojiChange(null)}>
                {t("Remove")}
              </RemoveButton>
            )}
            <PickerStyles ref={pickerRef}>
              <Picker
                locale={supportedLocales.includes(locale) ? locale : "en"}
                data={data}
                onEmojiSelect={handleEmojiChange}
                theme={pickerTheme}
                previewPosition="none"
                perLine={emojisPerLine}
                onClickOutside={handleClickOutside}
              />
            </PickerStyles>
          </>
        )}
      </PickerPopover>
    </>
  );
}

const StyledSmileyIcon = styled(SmileyIcon)`
  flex-shrink: 0;

  @media print {
    display: none;
  }
`;

const RemoveButton = styled(Button)`
  margin-left: -12px;
  margin-bottom: 8px;
  border-radius: 6px;
  height: 24px;
  font-size: 13px;

  > :first-child {
    min-height: unset;
    line-height: unset;
  }
`;

const PickerPopover = styled(Popover)`
  z-index: ${depths.popover};
  > :first-child {
    padding-top: 8px;
    padding-bottom: 0;
    max-height: 488px;
    overflow: unset;
  }
`;

const PickerStyles = styled.div`
  margin-left: -24px;
  margin-right: -24px;
  em-emoji-picker {
    --shadow: none;
    --font-family: ${s("fontFamily")};
    --rgb-background: ${(props) => toRGB(props.theme.menuBackground)};
    --rgb-accent: ${(props) => toRGB(props.theme.accent)};
    --border-radius: 6px;
    margin-left: auto;
    margin-right: auto;
    min-height: 443px;
  }
`;

export default EmojiPicker;