import { useTranslation } from "react-i18next";
import { useEffect, useState, useRef, useCallback, useContext } from "react";
import classNames from "classnames";

import { resolveIcon } from "./services/item";

import { SettingsContext } from "utils/contexts/settings";

export default function QuickLaunch({servicesAndBookmarks, searchString, setSearchString, isOpen, close, searchDescriptions}) {
  const { t } = useTranslation();
  const { settings } = useContext(SettingsContext);

  const searchField = useRef();

  const [results, setResults] = useState([]);
  const [currentItemIndex, setCurrentItemIndex] = useState(null);

  function openCurrentItem(newWindow) {
    const result = results[currentItemIndex];
    window.open(result.href, newWindow ? "_blank" : result.target ?? settings.target ?? "_blank");
  }

  const closeAndReset = useCallback(() => {
    close(false);
    setTimeout(() => {
      setSearchString("");
      setCurrentItemIndex(null);
    }, 200); // delay a little for animations
  }, [close, setSearchString, setCurrentItemIndex]);

  function handleSearchChange(event) {
    setSearchString(event.target.value.toLowerCase())
  }

  function handleSearchKeyDown(event) {
    if (event.key === "Escape") {
      closeAndReset();
    } else if (event.key === "Enter" && results.length) {
      closeAndReset();
      openCurrentItem(event.metaKey);
    } else if (event.key === "ArrowDown" && results[currentItemIndex + 1]) {
      setCurrentItemIndex(currentItemIndex + 1);
      event.preventDefault();
    } else if (event.key === "ArrowUp" && currentItemIndex > 0) {
      setCurrentItemIndex(currentItemIndex - 1);
      event.preventDefault();
    }
  }

  function handleItemHover(event) {
    setCurrentItemIndex(parseInt(event.target?.dataset?.index, 10));
  }

  function handleItemClick(event) {
    closeAndReset();
    openCurrentItem(event.metaKey);
  }

  useEffect(() => {
    if (searchString.length === 0) setResults([]);
    else {
      let newResults = servicesAndBookmarks.filter(r => {
        const nameMatch = r.name.toLowerCase().includes(searchString);
        let descriptionMatch;
        if (searchDescriptions) {
          descriptionMatch = r.description?.toLowerCase().includes(searchString)
          r.priority = nameMatch ? 2 * (+nameMatch) : +descriptionMatch; // eslint-disable-line no-param-reassign
        }
        return nameMatch || descriptionMatch;
      });

      if (searchDescriptions) {
        newResults = newResults.sort((a, b) => b.priority - a.priority);
      }

      setResults(newResults);

      if (newResults.length) {
        setCurrentItemIndex(0);
      }
    }
  }, [searchString, servicesAndBookmarks, searchDescriptions]);


  const [hidden, setHidden] = useState(true);
  useEffect(() => {
    function handleBackdropClick(event) {
      if (event.target?.tagName === "DIV") closeAndReset();
    }
    
    if (isOpen) {
      searchField.current.focus();
      document.body.addEventListener('click', handleBackdropClick);
      setHidden(false);
    } else {
      document.body.removeEventListener('click', handleBackdropClick);
      setTimeout(() => {
        setHidden(true);
      }, 300); // disable on close
    }

  }, [isOpen, closeAndReset]);

  function highlightText(text) {
    const parts = text.split(new RegExp(`(${searchString})`, 'gi'));
    return <span>{parts.map(part => part.toLowerCase() === searchString.toLowerCase() ? <span className="bg-theme-300/10">{part}</span> : part)}</span>;
  }

  return (
    <div className={classNames(
      "relative z-10 ease-in-out duration-300 transition-opacity",
      hidden && !isOpen && "hidden",
      !hidden && isOpen && "opacity-100",
      !isOpen && "opacity-0",
    )} role="dialog" aria-modal="true">
      <div className="fixed inset-0 bg-gray-500 bg-opacity-50" />
      <div className="fixed inset-0 z-10 overflow-y-auto">
        <div className="flex min-h-full min-w-full items-start justify-center text-center">
          <dialog className="mt-[10%] min-w-[80%] max-w-[90%] md:min-w-[40%] rounded-md p-0 block font-medium text-theme-700 dark:text-theme-200 dark:hover:text-theme-300 shadow-md shadow-theme-900/10 dark:shadow-theme-900/20 bg-theme-50 dark:bg-theme-800">
            <input placeholder="Search" className={classNames(
              results.length > 0 && "rounded-t-md",
              results.length === 0 && "rounded-md",
              "w-full p-4 m-0 border-0 border-b border-slate-700 focus:border-slate-700 focus:outline-0 focus:ring-0 text-sm md:text-xl text-theme-700 dark:text-theme-200 bg-theme-60 dark:bg-theme-800"
              )} type="text" autoCorrect="false" ref={searchField} value={searchString} onChange={handleSearchChange} onKeyDown={handleSearchKeyDown} />
            {results.length > 0 && <ul className="max-h-[60vh] overflow-y-auto m-2">
              {results.map((r, i) => (
                <li key={r.name}>
                  <button type="button" data-index={i} onMouseEnter={handleItemHover} className={classNames(
                    "flex flex-row w-full items-center justify-between rounded-md text-sm md:text-xl py-2 px-4 cursor-pointer text-theme-700 dark:text-theme-200",
                    i === currentItemIndex && "bg-theme-300/50 dark:bg-theme-700/50",
                    )} onClick={handleItemClick}>
                    <div className="flex flex-row items-center mr-4 pointer-events-none">
                      <div className="w-5 text-xs mr-4">
                        {r.icon && resolveIcon(r.icon)}
                        {r.abbr && r.abbr}
                      </div>
                      <div className="flex flex-col md:flex-row text-left items-baseline mr-4 pointer-events-none">
                        <span className="mr-4">{r.name}</span>
                        {r.description && 
                          <span className="text-xs text-theme-600 text-light">
                            {searchDescriptions && r.priority < 2 ? highlightText(r.description) : r.description}
                          </span>
                        }
                      </div>
                    </div>
                    <div className="text-xs text-theme-600 font-bold pointer-events-none">{r.abbr ? t("homepagesearch.bookmark") : t("homepagesearch.service")}</div>
                  </button>
                </li>
              ))}
            </ul>}
          </dialog>
        </div>
      </div>
    </div>
  );
}