import { useState, useCallback } from 'react';
import { useDropzone } from 'react-dropzone';
import { motion } from 'framer-motion';
import toast from 'react-hot-toast';
import { ingestUrl, ingestUpload, getSessionStatus } from '../api/client';

export default function VideoInput({ onVideoLoaded }) {
  const [url, setUrl] = useState('');
  const [loading, setLoading] = useState(false);
  const [progress, setProgress] = useState(0);
  const [statusMessage, setStatusMessage] = useState('');

  const handleUrlSubmit = async (e) => {
    e.preventDefault();
    if (!url.trim()) return;
    
    setLoading(true);
    setStatusMessage('Starting download...');
    
    try {
      const result = await ingestUrl(url.trim());
      
      // Poll for download completion
      const sessionId = result.session_id;
      let attempts = 0;
      const maxAttempts = 120; // 10 minutes max
      
      const pollStatus = async () => {
        while (attempts < maxAttempts) {
          await new Promise(r => setTimeout(r, 5000));
          attempts++;
          setProgress(Math.min(attempts * 2, 90));
          
          try {
            const status = await getSessionStatus(sessionId);
            
            if (status.status === 'downloaded') {
              setProgress(100);
              setStatusMessage('Download complete!');
              toast.success('Video downloaded successfully!');
              onVideoLoaded(status);
              return;
            } else if (status.status === 'error') {
              throw new Error(status.error || 'Download failed');
            }
            
            setStatusMessage(`Downloading... (${attempts * 5}s)`);
          } catch (err) {
            if (err.message !== 'Download failed') continue;
            throw err;
          }
        }
        throw new Error('Download timed out');
      };
      
      await pollStatus();
    } catch (err) {
      toast.error(err.response?.data?.detail || err.message || 'Failed to download video');
      setStatusMessage('');
    } finally {
      setLoading(false);
      setProgress(0);
    }
  };

  const onDrop = useCallback(async (acceptedFiles) => {
    const file = acceptedFiles[0];
    if (!file) return;
    
    // Validate size
    if (file.size > 2 * 1024 * 1024 * 1024) {
      toast.error('File too large. Maximum size is 2GB.');
      return;
    }
    
    setLoading(true);
    setStatusMessage('Uploading...');
    
    try {
      const result = await ingestUpload(file, (percent) => {
        setProgress(percent);
        setStatusMessage(`Uploading... ${percent}%`);
      });
      
      toast.success('Video uploaded successfully!');
      onVideoLoaded(result);
    } catch (err) {
      toast.error(err.response?.data?.detail || 'Upload failed');
      setStatusMessage('');
    } finally {
      setLoading(false);
      setProgress(0);
    }
  }, [onVideoLoaded]);

  const { getRootProps, getInputProps, isDragActive } = useDropzone({
    onDrop,
    accept: {
      'video/*': ['.mp4', '.mov', '.mkv', '.avi', '.webm']
    },
    maxFiles: 1,
    disabled: loading,
  });

  return (
    <div className="max-w-3xl mx-auto">
      {/* Hero */}
      <div className="text-center mb-12">
        <motion.h2 
          className="text-5xl font-black mb-4 gradient-text"
          initial={{ opacity: 0, y: -20 }}
          animate={{ opacity: 1, y: 0 }}
        >
          Turn Long Videos Into Viral Clips
        </motion.h2>
        <p className="text-lg text-white/50">
          Drop a video or paste a URL. We'll AI-generate multiple viral-ready short clips with 
          voiceover, captions, sound effects, and more.
        </p>
      </div>

      {/* URL Input */}
      <div className="card mb-6">
        <h3 className="text-sm font-semibold text-white/60 uppercase tracking-wider mb-4">
          🔗 Paste Video URL
        </h3>
        <form onSubmit={handleUrlSubmit} className="flex gap-3">
          <input
            type="url"
            value={url}
            onChange={(e) => setUrl(e.target.value)}
            placeholder="https://youtube.com/watch?v=... or any video URL"
            className="flex-1 bg-dark-900 border border-white/10 rounded-xl px-4 py-3 text-white
                     placeholder:text-white/30 focus:outline-none focus:border-primary-500/50 transition-colors"
            disabled={loading}
          />
          <button 
            type="submit" 
            className="btn-primary whitespace-nowrap disabled:opacity-50"
            disabled={loading || !url.trim()}
          >
            {loading ? '⏳ Processing...' : '🚀 Analyze Video'}
          </button>
        </form>
        <p className="text-xs text-white/30 mt-2">
          Supports YouTube, Vimeo, Twitter/X, and most public video URLs
        </p>
      </div>

      {/* Divider */}
      <div className="flex items-center gap-4 my-8">
        <div className="flex-1 h-px bg-white/10" />
        <span className="text-white/30 text-sm font-medium">OR</span>
        <div className="flex-1 h-px bg-white/10" />
      </div>

      {/* File Upload Dropzone */}
      <div
        {...getRootProps()}
        className={`card cursor-pointer transition-all duration-300 border-2 border-dashed
          ${isDragActive ? 'border-primary-500 bg-primary-500/5' : 'border-white/10 hover:border-white/20'}
          ${loading ? 'opacity-50 cursor-not-allowed' : ''}`}
      >
        <input {...getInputProps()} />
        <div className="text-center py-12">
          <div className="text-5xl mb-4">
            {isDragActive ? '📥' : '🎥'}
          </div>
          <h3 className="text-xl font-semibold mb-2">
            {isDragActive ? 'Drop it here!' : 'Drag & Drop Video File'}
          </h3>
          <p className="text-white/40 mb-4">
            or click to browse • MP4, MOV, MKV, AVI, WebM up to 2GB
          </p>
          <div className="inline-flex items-center gap-2 px-4 py-2 bg-dark-900 rounded-lg text-sm text-white/50">
            <span>📋</span> Requirements: 60 seconds – 3 hours duration
          </div>
        </div>
      </div>

      {/* Progress Bar */}
      {loading && (
        <motion.div 
          className="mt-6 card"
          initial={{ opacity: 0, height: 0 }}
          animate={{ opacity: 1, height: 'auto' }}
        >
          <div className="flex items-center justify-between mb-2">
            <span className="text-sm text-white/60">{statusMessage}</span>
            <span className="text-sm font-mono text-primary-500">{progress}%</span>
          </div>
          <div className="w-full h-2 bg-dark-900 rounded-full overflow-hidden">
            <motion.div
              className="h-full bg-gradient-to-r from-primary-500 to-accent-500 rounded-full"
              initial={{ width: 0 }}
              animate={{ width: `${progress}%` }}
              transition={{ duration: 0.3 }}
            />
          </div>
        </motion.div>
      )}
    </div>
  );
}