import React, { useState } from 'react';
import {
  FileText,
  Image as ImageIcon,
  Download,
  Trash2,
  Eye,
  User as UserIcon,
  Calendar,
  X,
  FileSpreadsheet,
  AlertCircle,
  ZoomIn,
} from 'lucide-react';
import { NoteItem, User } from '../types';

interface NotesViewProps {
  notes: NoteItem[];
  currentUser: User;
  onDeleteNote: (noteId: string) => Promise<void>;
  searchQuery: string;
}

export const NotesView: React.FC<NotesViewProps> = ({
  notes,
  currentUser,
  onDeleteNote,
  searchQuery,
}) => {
  const [selectedImage, setSelectedImage] = useState<NoteItem | null>(null);
  const [deletingId, setDeletingId] = useState<string | null>(null);

  const canDelete = (note: NoteItem) => {
    const isOwner = note.uploadedBy.toLowerCase() === currentUser.username.toLowerCase();
    const isAdmin = currentUser.role === 'admin';
    const hasSpecialPerm =
      currentUser.permissions?.canEditDeleteOthers &&
      (currentUser.permissions.allowedGroups?.includes('ALL') ||
        currentUser.permissions.allowedGroups
          ?.map((g) => g.toLowerCase())
          .includes(note.subject.toLowerCase()));

    return isOwner || isAdmin || hasSpecialPerm;
  };

  const handleDelete = async (noteId: string) => {
    if (!window.confirm('Are you sure you want to delete this archived note?')) return;
    setDeletingId(noteId);
    try {
      await onDeleteNote(noteId);
    } finally {
      setDeletingId(null);
    }
  };

  const formatSize = (bytes: number) => {
    if (bytes < 1024) return `${bytes} B`;
    if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(1)} KB`;
    return `${(bytes / (1024 * 1024)).toFixed(1)} MB`;
  };

  return (
    <div className="space-y-4">
      {/* Header Info */}
      <div className="flex items-center justify-between">
        <h3 className="font-bold text-sm text-slate-800 dark:text-slate-200">
          Archived Documents {searchQuery ? `(Search: "${searchQuery}")` : ''} ({notes.length})
        </h3>
      </div>

      {/* Grid of Notes */}
      {notes.length === 0 ? (
        <div className="p-12 text-center bg-white dark:bg-slate-800/60 rounded-2xl border border-dashed border-slate-300 dark:border-slate-700">
          <FileText className="w-12 h-12 text-slate-300 dark:text-slate-600 mx-auto mb-3" />
          <h4 className="font-bold text-slate-700 dark:text-slate-300 text-sm">No notes found</h4>
          <p className="text-xs text-slate-500 dark:text-slate-400 mt-1 max-w-sm mx-auto">
            {searchQuery
              ? `No archived materials matched your search query "${searchQuery}".`
              : 'There are no notes uploaded in this subject folder yet. Click "Upload Notes" to add materials.'}
          </p>
        </div>
      ) : (
        <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 gap-4">
          {notes.map((note) => {
            const isImg = note.fileType === 'image';
            const userCanDelete = canDelete(note);

            return (
              <div
                key={note.id}
                className="bg-white dark:bg-slate-800 rounded-2xl border border-slate-200 dark:border-slate-700/80 shadow-sm hover:shadow-md transition-all flex flex-col overflow-hidden"
              >
                {/* File Thumbnail / Preview Header */}
                <div className="relative h-40 bg-slate-100 dark:bg-slate-900 overflow-hidden flex items-center justify-center border-b border-slate-100 dark:border-slate-700/60">
                  {isImg ? (
                    <div
                      className="w-full h-full cursor-pointer relative group"
                      onClick={() => setSelectedImage(note)}
                    >
                      <img
                        src={note.fileUrl}
                        alt={note.originalName}
                        className="w-full h-full object-cover group-hover:scale-105 transition-transform duration-300"
                        referrerPolicy="no-referrer"
                      />
                      <div className="absolute inset-0 bg-slate-900/40 opacity-0 group-hover:opacity-100 transition-opacity flex items-center justify-center text-white gap-1.5 font-medium text-xs">
                        <ZoomIn className="w-4 h-4" /> Preview Image
                      </div>
                    </div>
                  ) : (
                    <div className="p-6 text-center flex flex-col items-center">
                      <div className="p-3.5 rounded-2xl bg-blue-100 dark:bg-blue-950/80 text-blue-600 dark:text-blue-400 mb-2">
                        <FileText className="w-8 h-8" />
                      </div>
                      <span className="text-xs font-bold text-slate-700 dark:text-slate-300 uppercase tracking-wider">
                        DOCX Document
                      </span>
                      <span className="text-[10px] text-slate-400 mt-0.5">{formatSize(note.size)}</span>
                    </div>
                  )}

                  {/* Subject Tag Badge */}
                  <div className="absolute top-2.5 left-2.5 flex items-center gap-1">
                    <span className="px-2.5 py-0.5 rounded-full text-[10px] font-bold bg-slate-900/80 text-white backdrop-blur-md">
                      {note.subject}
                    </span>
                    {note.subSubject && (
                      <span className="px-2 py-0.5 rounded-full text-[10px] font-bold bg-indigo-600/90 text-white backdrop-blur-md">
                        {note.subSubject}
                      </span>
                    )}
                  </div>
                </div>

                {/* Body Details */}
                <div className="p-4 flex-1 flex flex-col justify-between space-y-3">
                  <div>
                    <h4
                      className="font-bold text-sm text-slate-900 dark:text-white line-clamp-1"
                      title={note.originalName}
                    >
                      {note.originalName}
                    </h4>
                    {note.description && (
                      <p className="text-xs text-slate-500 dark:text-slate-400 mt-1 line-clamp-2">
                        {note.description}
                      </p>
                    )}
                  </div>

                  {/* Upload Metadata: Uploader + Timestamp */}
                  <div className="pt-2 border-t border-slate-100 dark:border-slate-700/60 text-[11px] text-slate-500 dark:text-slate-400 space-y-1">
                    <div className="flex items-center gap-1.5 font-medium text-slate-700 dark:text-slate-300">
                      <UserIcon className="w-3.5 h-3.5 text-indigo-500" />
                      <span>Uploaded by:</span>
                      <span className="font-bold text-indigo-600 dark:text-indigo-400">
                        {note.uploadedBy}
                      </span>
                    </div>

                    <div className="flex items-center gap-1.5">
                      <Calendar className="w-3.5 h-3.5 text-slate-400" />
                      <span>
                        {new Date(note.uploadedAt).toLocaleDateString(undefined, {
                          year: 'numeric',
                          month: 'short',
                          day: 'numeric',
                          hour: '2-digit',
                          minute: '2-digit',
                        })}
                      </span>
                    </div>
                  </div>

                  {/* Action Buttons */}
                  <div className="flex items-center justify-between pt-1">
                    <a
                      href={note.fileUrl}
                      download={note.originalName}
                      target="_blank"
                      rel="noopener noreferrer"
                      className="flex items-center gap-1.5 px-3 py-1.5 rounded-lg bg-indigo-50 hover:bg-indigo-100 dark:bg-indigo-950/60 dark:hover:bg-indigo-900/60 text-indigo-700 dark:text-indigo-300 font-semibold text-xs transition-colors"
                    >
                      <Download className="w-3.5 h-3.5" />
                      <span>Download</span>
                    </a>

                    {userCanDelete && (
                      <button
                        onClick={() => handleDelete(note.id)}
                        disabled={deletingId === note.id}
                        className="p-1.5 rounded-lg text-rose-600 dark:text-rose-400 hover:bg-rose-50 dark:hover:bg-rose-950/50 transition-colors"
                        title="Delete this note"
                      >
                        {deletingId === note.id ? (
                          <div className="w-4 h-4 border-2 border-rose-500 border-t-transparent rounded-full animate-spin" />
                        ) : (
                          <Trash2 className="w-4 h-4" />
                        )}
                      </button>
                    )}
                  </div>
                </div>
              </div>
            );
          })}
        </div>
      )}

      {/* Image Lightbox Modal */}
      {selectedImage && (
        <div className="fixed inset-0 z-50 bg-slate-950/80 backdrop-blur-md flex items-center justify-center p-4">
          <div className="relative max-w-4xl w-full bg-slate-900 border border-slate-800 rounded-3xl overflow-hidden shadow-2xl p-4">
            <div className="flex items-center justify-between mb-3 pb-2 border-b border-slate-800">
              <div>
                <h3 className="font-bold text-slate-100 text-sm">{selectedImage.originalName}</h3>
                <p className="text-xs text-slate-400">
                  Uploaded by {selectedImage.uploadedBy} in {selectedImage.subject}
                </p>
              </div>
              <button
                onClick={() => setSelectedImage(null)}
                className="p-1.5 rounded-xl text-slate-400 hover:text-white hover:bg-slate-800 transition-colors"
              >
                <X className="w-5 h-5" />
              </button>
            </div>

            <div className="max-h-[75vh] overflow-auto flex items-center justify-center bg-black/60 rounded-xl p-2">
              <img
                src={selectedImage.fileUrl}
                alt={selectedImage.originalName}
                className="max-h-[70vh] object-contain rounded-lg"
              />
            </div>

            <div className="mt-3 flex justify-end gap-2">
              <a
                href={selectedImage.fileUrl}
                download={selectedImage.originalName}
                className="px-4 py-2 bg-indigo-600 hover:bg-indigo-500 text-white font-semibold text-xs rounded-xl flex items-center gap-1.5 shadow"
              >
                <Download className="w-4 h-4" /> Download Image
              </a>
            </div>
          </div>
        </div>
      )}
    </div>
  );
};