import { useEffect, useState, useRef } from 'react';
import { useParams, useNavigate, useLocation } from 'react-router-dom';
import './ComicReader.css';

interface ComicImage {
  index: number;
  imageUrl: string;
}

interface ChapterInfo {
  slug: string;
  chapter: string;
}

interface ReaderData {
  slug: string;
  title: string;
  images: ComicImage[];
  totalImages: number;
  prevChapter?: ChapterInfo | null;
  nextChapter?: ChapterInfo | null;
  allChapters?: ChapterInfo[];
}

export function ComicReader() {
  const { sessionId } = useParams();
  const navigate = useNavigate();
  const location = useLocation();

  const [data, setData] = useState<ReaderData | null>(null);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState('');
  const [currentPage, setCurrentPage] = useState(1);
  const [showMenu, setShowMenu] = useState(false);
  const [showControls, setShowControls] = useState(true);
  const [showPageJump, setShowPageJump] = useState(false);
  const [jumpPage, setJumpPage] = useState('');
  const [loadingChapter, setLoadingChapter] = useState(false);
  const [password, setPassword] = useState<string>('');
  const [originalSessionId, setOriginalSessionId] = useState<string>('');

  const imageRefs = useRef<{ [key: number]: HTMLImageElement | null }>({});
  const controlsTimeout = useRef<number | null>(null);
  const scrollContainerRef = useRef<HTMLDivElement | null>(null);
  const wsRef = useRef<WebSocket | null>(null);
  const chapterData = location.state?.chapterData;
  useEffect(() => {
    const statePassword = location.state?.password;
    const stateSessionId = location.state?.sessionId;

    if (statePassword) {
      setPassword(statePassword);
    }

    if (stateSessionId) {
      setOriginalSessionId(stateSessionId);
    }
  }, [location.state]);

  useEffect(() => {
    if (!password || !originalSessionId) return;

    const protocol = window.location.protocol === 'https:' ? 'wss:' : 'ws:';
    const wsUrl = `${protocol}//${window.location.host}/ws`;
   
    const ws = new WebSocket(wsUrl);
    let isConnected = false;
    wsRef.current = ws;

    ws.onopen = () => {      
      isConnected = true;
    };

    ws.onmessage = (event) => {
      try {
        const message = JSON.parse(event.data);

        if (message.type === 'chapter_data_response') {
          setLoadingChapter(false);

          if (message.success && message.data) {
            const newData = {
              ...message.data,
              allChapters: message.data.allChapters || data?.allChapters || []
            };

            setData(newData);
            setCurrentPage(1);
            scrollContainerRef.current?.scrollTo({ top: 0 });
          } else {
            setError(message.error || 'Failed to load chapter');
            setTimeout(() => setError(''), 3000);
          }
        }
        
        if (message.type === 'session_force_closed') {
          setError('Session dihapus oleh admin. Silakan buat session baru.');
          sessionStorage.removeItem(`comic_${sessionId}`);
          setTimeout(() => {
            navigate('/');
          }, 3000);
        }
      } catch (err) {
        console.error('[Reader WS] Parse error:', err);
      }
    };

    ws.onerror = (err) => {
      console.error('[Reader WS] Error:', err);
      setLoadingChapter(false);
      if (!isConnected) {
        setError('Failed to connect to server');
      }
    };

    ws.onclose = () => {
      wsRef.current = null;
    };

    return () => {
      if (ws.readyState === WebSocket.OPEN) {
        ws.close();
      }
    };
  }, [password, originalSessionId]);

  useEffect(() => {
    if (chapterData) {
      setData(chapterData);
      setLoading(false);
      return;
    }

    if (!password || !originalSessionId) {
      setError('Unauthorized access - please open from comic page');
      setLoading(false);
      return;
    }

    setError('Please open chapter from comic page');
    setLoading(false);
  }, [sessionId, password, chapterData, originalSessionId]);

  useEffect(() => {
    const resetTimeout = () => {
      if (controlsTimeout.current) {
        clearTimeout(controlsTimeout.current);
      }
      setShowControls(true);
      controlsTimeout.current = window.setTimeout(() => {
        setShowControls(false);
        setShowMenu(false);
      }, 3000);
    };

    const handleMove = () => resetTimeout();

    window.addEventListener('mousemove', handleMove);
    window.addEventListener('touchstart', handleMove);

    return () => {
      window.removeEventListener('mousemove', handleMove);
      window.removeEventListener('touchstart', handleMove);
      if (controlsTimeout.current) {
        clearTimeout(controlsTimeout.current);
      }
    };
  }, []);

  useEffect(() => {
    const handleScroll = () => {
      if (!scrollContainerRef.current) return;

      const container = scrollContainerRef.current;
      const windowHeight = container.clientHeight;
      let currentIdx = 1;

      for (let i = 1; i <= (data?.totalImages || 0); i++) {
        const img = imageRefs.current[i];
        if (img) {
          const rect = img.getBoundingClientRect();
          const containerRect = container.getBoundingClientRect();
          const imgCenter = rect.top + rect.height / 2 - containerRect.top;
          if (imgCenter > 0 && imgCenter < windowHeight) {
            currentIdx = i;
            break;
          }
        }
      }

      setCurrentPage(currentIdx);
    };

    const container = scrollContainerRef.current;
    if (container) {
      container.addEventListener('scroll', handleScroll);
      return () => container.removeEventListener('scroll', handleScroll);
    }
  }, [data]);

  const scrollToPage = (page: number) => {
    const img = imageRefs.current[page];
    if (img && scrollContainerRef.current) {
      const container = scrollContainerRef.current;
      const containerRect = container.getBoundingClientRect();
      const imgRect = img.getBoundingClientRect();

      const scrollTo = container.scrollTop + (imgRect.top - containerRect.top);
      container.scrollTo({ top: scrollTo, behavior: 'smooth' });
    }
  };

  const nextChapter = () => {
    if (data?.nextChapter) {
      handleChapterNavigation(data.nextChapter.slug);
    }
  };

  const prevChapter = () => {
    if (data?.prevChapter) {
      handleChapterNavigation(data.prevChapter.slug);
    }
  };

  const handlePageJump = () => {
    const page = parseInt(jumpPage);
    if (page >= 1 && page <= (data?.totalImages || 1)) {
      scrollToPage(page);
      setShowPageJump(false);
      setJumpPage('');
    }
  };

  const handleChapterNavigation = (chapterSlug: string) => {
    if (!password || !originalSessionId) {
      setError('Missing authentication data');
      return;
    }

    if (!wsRef.current || wsRef.current.readyState !== WebSocket.OPEN) {
      if (wsRef.current?.readyState === WebSocket.CONNECTING) {
        setTimeout(() => {
          if (wsRef.current?.readyState === WebSocket.OPEN) {
            handleChapterNavigation(chapterSlug);
          } else {
            setError('Connection not ready. Please try again.');
          }
        }, 1000);
        return;
      }

      setError('Connection lost. Please refresh the page.');
      console.error('[Reader] WebSocket not connected. State:', wsRef.current?.readyState);
      return;
    }

    setLoadingChapter(true);
    setShowMenu(false);

    const requestData = {
      type: 'request_chapter_data',
      sessionId: originalSessionId,
      password: password,
      chapterSlug: chapterSlug,
      allChapters: data?.allChapters || []
    };

    wsRef.current.send(JSON.stringify(requestData));
  };

  if (loading) {
    return (
      <div className="reader-loading">
        <div className="spinner"></div>
        <p>Loading chapter...</p>
      </div>
    );
  }

  if (loadingChapter) {
    return (
      <div className="reader-loading">
        <div className="spinner"></div>
        <p>Loading chapter...</p>
      </div>
    );
  }

  if (error || !data) {
    return (
      <div className="reader-error">
        <div className="error-icon">⚠️</div>
        <h2>Error</h2>
        <p>{error || 'Failed to load chapter'}</p>
        <button onClick={() => navigate(-1)}>Go Back</button>
      </div>
    );
  }

  return (
    <div className={`comic-reader ${!showControls ? 'hide-controls' : ''}`}>
      <div className="reader-header">
        <button className="back-btn" onClick={() => navigate(-1)}>
          ← Back
        </button>

        <div className="reader-title">
          <h1>{data.title}</h1>
          <span className="page-indicator">
            {currentPage} / {data.totalImages}
          </span>
        </div>

        <button
          className="menu-btn"
          onClick={() => setShowMenu(!showMenu)}
        >
          ☰
        </button>
      </div>

      {showMenu && (
        <div className="hamburger-menu" onClick={() => setShowMenu(false)}>
          <div className="menu-content" onClick={(e) => e.stopPropagation()}>
            <button onClick={() => setShowMenu(false)} className="close-menu">✕</button>

            <div className="menu-section">
              <h3>Navigation</h3>
              <button onClick={() => { scrollToPage(1); setShowMenu(false); }}>
                ⏮️ First Page
              </button>
              <button onClick={() => { scrollToPage(data.totalImages); setShowMenu(false); }}>
                ⏭️ Last Page
              </button>
              <button onClick={() => { setShowPageJump(true); setShowMenu(false); }}>
                📍 Jump to Page
              </button>
            </div>

            {(data.prevChapter || data.nextChapter) && (
              <div className="menu-section">
                <h3>Chapters</h3>
                {data.prevChapter && (
                  <button onClick={() => handleChapterNavigation(data.prevChapter!.slug)}>
                    ⬅️ {data.prevChapter.chapter}
                  </button>
                )}
                {data.nextChapter && (
                  <button onClick={() => handleChapterNavigation(data.nextChapter!.slug)}>
                    ➡️ {data.nextChapter.chapter}
                  </button>
                )}
              </div>
            )}

            <div className="menu-section">
              <h3>Info</h3>
              <div className="menu-info">
                <p>Total Pages: {data.totalImages}</p>
                <p>Current: Page {currentPage}</p>
              </div>
            </div>
          </div>
        </div>
      )}

      {showPageJump && (
        <div className="page-jump-modal" onClick={() => setShowPageJump(false)}>
          <div className="page-jump-content" onClick={(e) => e.stopPropagation()}>
            <h3>Jump to Page</h3>
            <input
              type="number"
              min="1"
              max={data.totalImages}
              value={jumpPage}
              onChange={(e) => setJumpPage(e.target.value)}
              placeholder={`1-${data.totalImages}`}
              autoFocus
              onKeyPress={(e) => e.key === 'Enter' && handlePageJump()}
            />
            <div className="page-jump-actions">
              <button onClick={handlePageJump}>Go</button>
              <button onClick={() => setShowPageJump(false)}>Cancel</button>
            </div>
          </div>
        </div>
      )}

      <div className="reader-content" ref={scrollContainerRef}>
        <div className="scroll-container">
          {data.images.map((img) => (
            <img
              key={img.index}
              ref={(el) => (imageRefs.current[img.index] = el)}
              src={img.imageUrl}
              alt={`Page ${img.index}`}
              className="comic-page"
              loading="lazy"
              onError={(e) => {
                (e.target as HTMLImageElement).src = 'data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" width="800" height="1200"><rect width="800" height="1200" fill="%23222"/><text x="50%" y="50%" text-anchor="middle" fill="%23666" font-size="20">Failed to load page ' + img.index + '</text></svg>';
              }}
            />
          ))}
        </div>
      </div>

      <div className="reader-footer">
        <div className="page-controls">
          <button
            className="nav-control-btn"
            onClick={prevChapter}
            disabled={!data.prevChapter}
          >
            ← Prev
          </button>

          <div className="page-info">
            <span>{currentPage} / {data.totalImages}</span>
            <input
              type="range"
              min="1"
              max={data.totalImages}
              value={currentPage}
              onChange={(e) => scrollToPage(parseInt(e.target.value))}
              className="page-slider"
            />
          </div>

          <button
            className="nav-control-btn"
            onClick={nextChapter}
            disabled={!data.nextChapter}
          >
            Next →
          </button>
        </div>
      </div>
    </div>
  );
}