'use client';

import React, { useRef, useState } from 'react';
import { Upload, Loader2, Image as ImageIcon } from 'lucide-react';
import { shrinkImage, shrinkRemoteImage, uploadFile } from '@/lib/upload';

interface ImageUploadInputProps {
  label?: string;
  value: string;
  onChange: (url: string) => void;
  placeholder?: string;
  // Voliteľný ručný alt text; prázdny = použije sa automatický (altPlaceholder)
  altValue?: string;
  onAltChange?: (alt: string) => void;
  altPlaceholder?: string;
}

export const ImageUploadInput: React.FC<ImageUploadInputProps> = ({
  label = 'Obrázok',
  value,
  onChange,
  placeholder = 'https://... alebo nahrajte súbor',
  altValue,
  onAltChange,
  altPlaceholder
}) => {
  const fileInputRef = useRef<HTMLInputElement>(null);
  const [isUploading, setIsUploading] = useState(false);

  const uploadImage = async (file: File) => {
    setIsUploading(true);
    try {
      const small = await shrinkImage(file);
      onChange(await uploadFile(small, small.name));
    } catch (err) {
      alert(`Chyba pri nahrávaní obrázka: ${(err as Error).message}`);
    } finally {
      setIsUploading(false);
      if (fileInputRef.current) {
        fileInputRef.current.value = '';
      }
    }
  };

  const handleFileChange = (e: React.ChangeEvent<HTMLInputElement>) => {
    const file = e.target.files?.[0];
    if (file) uploadImage(file);
  };

  // Vložená URL: príliš veľký obrázok sa zmenší a uloží k nám (posledná spracovaná adresa, aby sa nerobilo dvakrát)
  const lastCheckedUrl = useRef('');
  const [urlNote, setUrlNote] = useState<{ tone: 'ok' | 'warn'; text: string } | null>(null);
  const checkUrl = async (url: string) => {
    url = url.trim();
    if (!url || url === lastCheckedUrl.current) return;
    lastCheckedUrl.current = url;
    setIsUploading(true);
    setUrlNote(null);
    try {
      const result = await shrinkRemoteImage(url);
      if (result.status === 'shrunk') {
        lastCheckedUrl.current = result.url;
        onChange(result.url);
        setUrlNote({ tone: 'ok', text: 'Obrázok bol väčší ako 1000 px – zmenšili sme ho a uložili k nám.' });
      } else if (result.status === 'small') {
        setUrlNote({ tone: 'ok', text: 'Obrázok je v poriadku (najviac 1000 px), adresa ostáva.' });
      } else if (result.status === 'login') {
        setUrlNote({
          tone: 'warn',
          text: 'Obrázok je za prihlásením – v e-maile sa nezobrazí. Otvorte ho v prehliadači, pravým klikom „Kopírovať obrázok“ a sem vložte Ctrl+V.'
        });
      } else if (result.status === 'failed') {
        setUrlNote({ tone: 'warn', text: `Obrázok sa nepodarilo stiahnuť (${result.error}). Skontrolujte adresu, prípadne obrázok skopírujte a vložte Ctrl+V.` });
      }
    } catch (err) {
      setUrlNote({ tone: 'warn', text: `Obrázok sa nepodarilo spracovať: ${(err as Error).message}` });
    } finally {
      setIsUploading(false);
    }
  };

  const handlePaste = (e: React.ClipboardEvent<HTMLInputElement>) => {
    // obrázok zo schránky (Ctrl+V) → nahrá sa ako súbor
    const file = [...e.clipboardData.files].find((f) => f.type.startsWith('image/'));
    if (file) {
      e.preventDefault();
      uploadImage(file);
      return;
    }
    const text = e.clipboardData.getData('text');
    if (/^https?:\/\//i.test(text.trim())) setTimeout(() => checkUrl(text), 0);
  };

  return (
    <div className="space-y-1.5">
      {label && <label className="block text-[11px] font-semibold text-gray-700">{label}</label>}

      <div className="flex items-center gap-2">
        {/* Náhľad miniatúry */}
        <div className="w-10 h-10 rounded-lg bg-gray-100 border border-gray-200 flex-shrink-0 flex items-center justify-center overflow-hidden">
          {value ? (
            <img
              src={value}
              alt="Náhľad"
              className="w-full h-full object-contain"
              onError={(e) => {
                (e.target as HTMLElement).style.display = 'none';
              }}
            />
          ) : (
            <ImageIcon className="w-4 h-4 text-gray-400" />
          )}
        </div>

        {/* Textové pole s URL */}
        <input
          type="text"
          value={value || ''}
          onChange={(e) => {
            setUrlNote(null);
            onChange(e.target.value);
          }}
          onKeyDown={(e) => {
            if (e.key === 'Enter') checkUrl(e.currentTarget.value);
          }}
          onPaste={handlePaste}
          onBlur={(e) => checkUrl(e.target.value)}
          placeholder={placeholder}
          className="flex-1 min-w-0 text-xs font-mono border border-gray-300 rounded-lg p-2 bg-white"
        />

        {/* Tlačidlo nahrávania */}
        <input
          type="file"
          ref={fileInputRef}
          onChange={handleFileChange}
          accept="image/*"
          className="hidden"
        />
        <button
          type="button"
          onClick={() => fileInputRef.current?.click()}
          disabled={isUploading}
          className="px-2.5 py-2 text-xs font-bold text-gray-700 bg-gray-100 hover:bg-gray-200 border border-gray-300 rounded-lg flex items-center gap-1 transition-colors whitespace-nowrap disabled:opacity-50"
          title="Nahrať obrázok zo zariadenia"
        >
          {isUploading ? (
            <>
              <Loader2 className="w-3.5 h-3.5 animate-spin text-red-600" />
              <span>Nahrávam...</span>
            </>
          ) : (
            <>
              <Upload className="w-3.5 h-3.5" />
              <span>Nahrať</span>
            </>
          )}
        </button>
      </div>

      {urlNote && (
        <p className={`text-[10px] leading-snug ${urlNote.tone === 'warn' ? 'text-amber-700 bg-amber-50 border border-amber-200 rounded-md px-2 py-1' : 'text-emerald-700'}`}>
          {urlNote.text}
        </p>
      )}

      {onAltChange && (
        <input
          type="text"
          value={altValue || ''}
          onChange={(e) => onAltChange(e.target.value)}
          placeholder={altPlaceholder ? `Alt text (automaticky: ${altPlaceholder})` : 'Alt text'}
          title="Alt text obrázka. Ak ho nevyplníte, doplní sa automaticky."
          className="w-full text-[11px] border border-gray-200 rounded-lg px-2 py-1.5 bg-white placeholder:text-gray-400"
        />
      )}
    </div>
  );
};