import { useState } from 'react';
import toast from 'react-hot-toast';

export default function Downloader() {
  const [url, setUrl] = useState('');
  const [loading, setLoading] = useState(false);
  const [progress, setProgress] = useState('');
  const [downloadLink, setDownloadLink] = useState(null);

  const isValidUrl = (string) => {
    try {
      new URL(string);
      return string.includes('deviantart.com');
    } catch (_) {
      return false;
    }
  };

  const handleProcess = async (e) => {
    e.preventDefault();
    
    if (!url.trim()) {
      toast.error('Please enter a DeviantArt URL');
      return;
    }

    if (!isValidUrl(url)) {
      toast.error('Please enter a valid DeviantArt URL');
      return;
    }

    setLoading(true);
    setProgress('Initializing...');
    setDownloadLink(null);

    try {
      const response = await fetch('/api/process', {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
        },
        body: JSON.stringify({ url }),
      });

      if (!response.ok) {
        const errorData = await response.json();
        throw new Error(errorData.error || 'Failed to process request');
      }

      // Simulate progress updates if the backend is fast
      setProgress('Downloading images...');
      await new Promise(r => setTimeout(r, 800));
      
      setProgress('Creating ZIP archive...');
      await new Promise(r => setTimeout(r, 800));

      setProgress('Uploading to MediaFire...');
      await new Promise(r => setTimeout(r, 800));

      const data = await response.json();
      
      if (data.success) {
        setDownloadLink(data.downloadUrl);
        setProgress('Complete!');
        toast.success('ZIP file generated successfully!');
      } else {
        throw new Error(data.error || 'Unknown error occurred');
      }
    } catch (error) {
      console.error(error);
      toast.error(error.message || 'Something went wrong');
      setProgress('Error occurred');
    } finally {
      setLoading(false);
    }
  };

  return (
    <div className="bg-gray-800/50 border border-gray-700 rounded-2xl p-6 md:p-8 shadow-xl">
      <form onSubmit={handleProcess} className="space-y-6">
        <div>
          <label htmlFor="url" className="block text-sm font-medium text-gray-300 mb-2">
            DeviantArt Artwork URL
          </label>
          <div className="relative">
            <input
              type="url"
              id="url"
              value={url}
              onChange={(e) => setUrl(e.target.value)}
              placeholder="https://www.deviantart.com/username/art/artwork-title"
              disabled={loading}
              className="w-full bg-gray-900 border border-gray-600 rounded-lg px-4 py-3 text-white placeholder-gray-500 focus:outline-none focus:ring-2 focus:ring-brand-500 focus:border-transparent transition-all disabled:opacity-50 disabled:cursor-not-allowed"
            />
            {url && (
              <button
                type="button"
                onClick={() => setUrl('')}
                disabled={loading}
                className="absolute right-3 top-1/2 -translate-y-1/2 text-gray-500 hover:text-white transition-colors"
              >
                ✕
              </button>
            )}
          </div>
          <p className="mt-2 text-xs text-gray-500">
            Paste the direct link to the DeviantArt artwork page.
          </p>
        </div>

        <button
          type="submit"
          disabled={loading}
          className="w-full bg-gradient-to-r from-brand-600 to-brand-500 hover:from-brand-500 hover:to-brand-400 text-white font-semibold py-3 px-6 rounded-lg shadow-lg shadow-brand-500/20 transform hover:-translate-y-0.5 transition-all duration-200 disabled:opacity-50 disabled:cursor-not-allowed disabled:transform-none"
        >
          {loading ? 'Processing...' : 'Download & Zip'}
        </button>
      </form>

      {loading && (
        <div className="mt-8 space-y-4">
          <div className="flex items-center justify-between text-sm">
            <span className="text-gray-400">Status</span>
            <span className="text-brand-400 font-medium animate-pulse">{progress}</span>
          </div>
          <div className="h-2 bg-gray-700 rounded-full overflow-hidden">
            <div className="h-full bg-gradient-to-r from-brand-600 to-purple-500 w-2/3 animate-[shimmer_1.5s_infinite]"></div>
          </div>
        </div>
      )}

      {downloadLink && !loading && (
        <div className="mt-8 p-4 bg-green-900/20 border border-green-700/50 rounded-lg">
          <div className="flex items-start gap-3">
            <div className="flex-shrink-0 w-6 h-6 rounded-full bg-green-500/20 flex items-center justify-center mt-0.5">
              <svg className="w-4 h-4 text-green-400" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M5 13l4 4L19 7" />
              </svg>
            </div>
            <div className="flex-grow">
              <h4 className="text-green-400 font-medium mb-1">Ready for Download</h4>
              <p className="text-sm text-gray-400 mb-3">
                Your image has been packaged and is ready to be downloaded.
              </p>
              <a
                href={downloadLink}
                download="deviantart-image.zip"
                className="inline-flex items-center gap-2 bg-green-600 hover:bg-green-500 text-white text-sm font-medium py-2 px-4 rounded transition-colors"
              >
                <svg className="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                  <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M4 16v1a3 3 0 003 3h10a3 3 0 003-3v-1m-4-4l-4 4m0 0l-4-4m4 4V4" />
                </svg>
                Download ZIP
              </a>
            </div>
          </div>
        </div>
      )}
    </div>
  );
}