import { useEffect, useState } from 'react';
import { Link, useNavigate, useSearchParams, useLocation, useMatch } from 'react-router-dom';
import type { Feed, Category } from '../types';
import './FeedList.css';
import './FeedListVariants.css';
import { apiFetch } from '../utils';

export default function FeedList({
  theme,
  setTheme,
  setSidebarVisible,
  isMobile,
}: {
  theme: string;
  setTheme: (t: string) => void;
  setSidebarVisible: (visible: boolean) => void;
  isMobile: boolean;
}) {
  const [feeds, setFeeds] = useState<Feed[]>([]);
  const [tags, setTags] = useState<Category[]>([]);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState('');
  const [feedsExpanded, setFeedsExpanded] = useState(false);
  const [tagsExpanded, setTagsExpanded] = useState(true);
  const [searchQuery, setSearchQuery] = useState('');
  const navigate = useNavigate();
  const [searchParams] = useSearchParams();
  const location = useLocation();
  const feedMatch = useMatch('/feed/:feedId');
  const tagMatch = useMatch('/tag/:tagName');
  const isRoot = useMatch('/');
  const isStreamPage = !!(isRoot || feedMatch || tagMatch);

  const feedId = feedMatch?.params.feedId;
  const tagName = tagMatch?.params.tagName;

  const sidebarVariant = searchParams.get('sidebar') || localStorage.getItem('neko-sidebar-variant') || 'glass';

  useEffect(() => {
    const variant = searchParams.get('sidebar');
    if (variant) {
      localStorage.setItem('neko-sidebar-variant', variant);
    }
  }, [searchParams]);

  const currentFilter = searchParams.get('filter') || (isStreamPage ? 'unread' : '');

  const getFilterLink = (filter: string) => {
    const baseStreamPath = isStreamPage ? location.pathname : '/';
    const params = new URLSearchParams(searchParams);
    params.set('filter', filter);
    return `${baseStreamPath}?${params.toString()}`;
  };

  const getNavPath = (path: string) => {
    const params = new URLSearchParams(searchParams);
    if (!params.has('filter') && currentFilter) {
      params.set('filter', currentFilter);
    }
    const qs = params.toString();
    return `${path}${qs ? '?' + qs : ''}`;
  };

  const handleSearch = (e: React.FormEvent) => {
    e.preventDefault();
    if (searchQuery.trim()) {
      const params = new URLSearchParams(searchParams);
      params.set('q', searchQuery.trim());
      if (currentFilter) params.set('filter', currentFilter);
      navigate(`/?${params.toString()}`);
    }
  };

  const toggleFeeds = () => {
    setFeedsExpanded(!feedsExpanded);
  };

  const toggleTags = () => {
    setTagsExpanded(!tagsExpanded);
  };

  const handleLinkClick = () => {
    if (isMobile) {
      setSidebarVisible(false);
    }
  };

  useEffect(() => {
    Promise.all([
      apiFetch('/api/feed/').then((res) => {
        if (!res.ok) throw new Error('Failed to fetch feeds');
        return res.json() as Promise<Feed[]>;
      }),
      apiFetch('/api/tag').then((res) => {
        if (!res.ok) throw new Error('Failed to fetch tags');
        return res.json() as Promise<Category[]>;
      }),
    ])
      .then(([feedsData, tagsData]) => {
        setFeeds(feedsData);
        setTags(tagsData);
        setLoading(false);
      })
      .catch((err) => {
        setError(err.message);
        setLoading(false);
      });
  }, []);

  if (loading) return <div className="feed-list-loading">Loading feeds...</div>;
  if (error) return <div className="feed-list-error">Error: {error}</div>;

  const handleLogout = () => {
    apiFetch('/api/logout', { method: 'POST' }).then(() => (window.location.href = '/v2/login'));
  };

  return (
    <div className={`feed-list variant-${sidebarVariant}`}>
      <h1 className="logo" onClick={() => setSidebarVisible(false)}>
        🐱
      </h1>

      <div className="search-section">
        <form onSubmit={handleSearch} className="search-form">
          <input
            type="search"
            placeholder="search..."
            value={searchQuery}
            onChange={(e) => setSearchQuery(e.target.value)}
            className="search-input"
          />
        </form>
      </div>

      <div className="filter-section">
        <ul className="filter-list">
          <li className="unread_filter">
            <Link
              to={getFilterLink('unread')}
              className={currentFilter === 'unread' ? 'active' : ''}
              onClick={handleLinkClick}
            >
              unread
            </Link>
          </li>
          <li className="all_filter">
            <Link
              to={getFilterLink('all')}
              className={currentFilter === 'all' ? 'active' : ''}
              onClick={handleLinkClick}
            >
              all
            </Link>
          </li>
          <li className="starred_filter">
            <Link
              to={getFilterLink('starred')}
              className={currentFilter === 'starred' ? 'active' : ''}
              onClick={handleLinkClick}
            >
              starred
            </Link>
          </li>
        </ul>
      </div>

      <div className="tag-section">
        <h4 onClick={toggleTags} className="section-header">
          <span className={`caret ${tagsExpanded ? 'expanded' : ''}`}>▶</span> Tags
        </h4>
        {tagsExpanded && (
          <ul className="tag-list-items">
            {tags.map((tag) => (
              <li key={tag.title} className="tag-item">
                <Link
                  to={getNavPath(`/tag/${encodeURIComponent(tag.title)}`)}
                  className={`tag-link ${tagName === tag.title ? 'active' : ''}`}
                  onClick={handleLinkClick}
                >
                  {tag.title}
                </Link>
              </li>
            ))}
          </ul>
        )}
      </div>

      <div className="feed-section">
        <h4 onClick={toggleFeeds} className="section-header">
          <span className={`caret ${feedsExpanded ? 'expanded' : ''}`}>▶</span> Feeds
        </h4>
        {feedsExpanded &&
          (feeds.length === 0 ? (
            <p>No feeds found.</p>
          ) : (
            <ul className="feed-list-items">
              {feeds.map((feed) => (
                <li key={feed._id} className="sidebar-feed-item">
                  <Link
                    to={getNavPath(`/feed/${feed._id}`)}
                    className={`feed-title ${feedId === String(feed._id) ? 'active' : ''}`}
                    onClick={handleLinkClick}
                  >
                    {feed.title || feed.url}
                  </Link>
                </li>
              ))}
            </ul>
          ))}
      </div>

      <div className="nav-section">
        <ul className="nav-list">
          <li>
            <Link to="/settings" className="nav-link" onClick={handleLinkClick}>
              settings
            </Link>
          </li>
          <li>
            <button onClick={handleLogout} className="logout-link">
              logout
            </button>
          </li>
        </ul>
      </div>

      <div className="theme-section">
        <div className="theme-selector">
          <button
            onClick={() => setTheme('light')}
            className={theme === 'light' ? 'active' : ''}
            title="Light Theme"
          >
            ☀️
          </button>
          <button
            onClick={() => setTheme('dark')}
            className={theme === 'dark' ? 'active' : ''}
            title="Dark Theme"
          >
            🌙
          </button>
        </div>
      </div>
    </div>
  );
}