import React, { useState, useRef, useEffect, useCallback } from 'react';
import { Upload, Play, Pause, Image as ImageIcon, Video, Settings2, Loader2, StopCircle, Sparkles, Monitor, ImagePlus } from 'lucide-react';

export default function App() {
  const canvasRef = useRef(null);
  const audioRef = useRef(null);
  const audioCtxRef = useRef(null);
  const analyserRef = useRef(null);
  const sourceRef = useRef(null);
  const destRef = useRef(null);
  const reqIdRef = useRef(null);
  const mediaRecorderRef = useRef(null);
  const chunksRef = useRef([]);
  const bgImgRef = useRef(null);

  // State
  const [audioSrc, setAudioSrc] = useState(null);
  const [fileName, setFileName] = useState('');
  const [isPlaying, setIsPlaying] = useState(false);
  const [isExportingVideo, setIsExportingVideo] = useState(false);
  const [exportProgress, setExportProgress] = useState(0);

  // Settings
  const [vizType, setVizType] = useState('bars'); // 'bars', 'wave', 'circle'
  const [color, setColor] = useState('#00ffcc');
  const [thickness, setThickness] = useState(12);
  const [spacing, setSpacing] = useState(8); // NEW
  const [sensitivity, setSensitivity] = useState(1.5); // Changed to Amplitude Multiplier
  const [smoothing, setSmoothing] = useState(0.85); // NEW

  // Transform Settings (NEW)
  const [offsetX, setOffsetX] = useState(0);
  const [offsetY, setOffsetY] = useState(0);
  const [scale, setScale] = useState(1.0);
  const [rotation, setRotation] = useState(0);

  // Advanced Settings
  const [colorMode, setColorMode] = useState('solid'); 
  const [color2, setColor2] = useState('#b829ff');
  const [glow, setGlow] = useState(false);
  const [resolution, setResolution] = useState('4k_16_9');
  const [bgType, setBgType] = useState('transparent'); 
  const [bgColor, setBgColor] = useState('#0f172a');
  const [bgImageSrc, setBgImageSrc] = useState(null);

  const RESOLUTIONS = {
    '4k_16_9': { w: 3840, h: 2160, label: '4K (16:9)', isVertical: false },
    '1080p_16_9': { w: 1920, h: 1080, label: '1080p (16:9)', isVertical: false },
    '4k_9_16': { w: 2160, h: 3840, label: '4K Vertical (9:16)', isVertical: true },
    '1080p_9_16': { w: 1080, h: 1920, label: '1080p Vertical (9:16)', isVertical: true }
  };

  // Load background image
  useEffect(() => {
    if (bgImageSrc) {
      const img = new Image();
      img.onload = () => { bgImgRef.current = img; };
      img.src = bgImageSrc;
    } else {
      bgImgRef.current = null;
    }
  }, [bgImageSrc]);

  const handleBgUpload = (e) => {
    const file = e.target.files[0];
    if (file) {
      if (bgImageSrc) URL.revokeObjectURL(bgImageSrc);
      setBgImageSrc(URL.createObjectURL(file));
      setBgType('image');
    }
  };

  // Initialize Web Audio API
  const initAudio = useCallback(() => {
    if (!audioCtxRef.current) {
      const AudioContext = window.AudioContext || window.webkitAudioContext;
      audioCtxRef.current = new AudioContext();
      analyserRef.current = audioCtxRef.current.createAnalyser();
      destRef.current = audioCtxRef.current.createMediaStreamDestination();

      // We only want to create the source once for the audio element
      if (!sourceRef.current && audioRef.current) {
        sourceRef.current = audioCtxRef.current.createMediaElementSource(audioRef.current);
        sourceRef.current.connect(analyserRef.current);
        analyserRef.current.connect(audioCtxRef.current.destination); // to speakers
        analyserRef.current.connect(destRef.current); // to recording destination
      }
    }
    
    // Resume context if suspended (browser autoplay policy)
    if (audioCtxRef.current.state === 'suspended') {
      audioCtxRef.current.resume();
    }
  }, []);

  const handleFileUpload = (e) => {
    const file = e.target.files[0];
    if (file) {
      if (audioSrc) URL.revokeObjectURL(audioSrc);
      const url = URL.createObjectURL(file);
      setAudioSrc(url);
      setFileName(file.name);
      setIsPlaying(false);
      if (audioRef.current) {
        audioRef.current.pause();
        audioRef.current.currentTime = 0;
      }
    }
  };

  const togglePlay = () => {
    if (!audioSrc) return;
    initAudio();

    if (isPlaying) {
      audioRef.current.pause();
    } else {
      audioRef.current.play();
    }
    setIsPlaying(!isPlaying);
  };

  // The Animation Loop
  const draw = useCallback(() => {
    if (!canvasRef.current || !analyserRef.current) {
      reqIdRef.current = requestAnimationFrame(draw);
      return;
    }

    const canvas = canvasRef.current;
    const ctx = canvas.getContext('2d');
    const res = RESOLUTIONS[resolution] || RESOLUTIONS['4k_16_9'];
    
    // Update canvas native resolution if changed
    if (canvas.width !== res.w || canvas.height !== res.h) {
       canvas.width = res.w;
       canvas.height = res.h;
    }
    
    const width = canvas.width;
    const height = canvas.height;

    // Background handling
    ctx.clearRect(0, 0, width, height);
    if (bgType === 'color') {
      ctx.fillStyle = bgColor;
      ctx.fillRect(0, 0, width, height);
    } else if (bgType === 'image' && bgImgRef.current) {
      const img = bgImgRef.current;
      const imgRatio = img.width / img.height;
      const canvasRatio = width / height;
      let drawW, drawH, drawX, drawY;
      if (imgRatio > canvasRatio) {
        drawH = height;
        drawW = height * imgRatio;
        drawX = (width - drawW) / 2;
        drawY = 0;
      } else {
        drawW = width;
        drawH = width / imgRatio;
        drawX = 0;
        drawY = (height - drawH) / 2;
      }
      ctx.drawImage(img, drawX, drawY, drawW, drawH);
    }

    // Dynamic smoothing and fixed FFT for better reactivity control
    analyserRef.current.smoothingTimeConstant = smoothing;
    analyserRef.current.fftSize = 2048;
    
    const bufferLength = analyserRef.current.frequencyBinCount;
    const dataArray = new Uint8Array(bufferLength);

    ctx.save(); // Save context before applying transforms

    // Apply Transformations (Position, Scale, Rotation)
    const centerX = width / 2 + (width * (offsetX / 100));
    const centerY = height / 2 + (height * (offsetY / 100));
    ctx.translate(centerX, centerY);
    ctx.scale(scale, scale);
    ctx.rotate((rotation * Math.PI) / 180);

    // Color and Glow logic (Coordinates adapted to centered origin)
    let activeColor = color;
    if (colorMode === 'gradient') {
      const grad = ctx.createLinearGradient(-width/2, -height/2, width/2, height/2);
      grad.addColorStop(0, color);
      grad.addColorStop(1, color2);
      activeColor = grad;
    } else if (colorMode === 'rainbow') {
      const grad = ctx.createLinearGradient(-width/2, 0, width/2, 0);
      grad.addColorStop(0, '#ff0000');
      grad.addColorStop(0.16, '#ffff00');
      grad.addColorStop(0.33, '#00ff00');
      grad.addColorStop(0.5, '#00ffff');
      grad.addColorStop(0.66, '#0000ff');
      grad.addColorStop(0.83, '#ff00ff');
      grad.addColorStop(1, '#ff0000');
      activeColor = grad;
    }

    ctx.lineWidth = thickness;
    ctx.strokeStyle = activeColor;
    ctx.fillStyle = activeColor;
    ctx.lineCap = 'round';
    ctx.lineJoin = 'round';

    if (glow) {
      ctx.shadowBlur = thickness * 2;
      ctx.shadowColor = colorMode === 'solid' ? color : (colorMode === 'gradient' ? color2 : '#ffffff');
    } else {
      ctx.shadowBlur = 0;
    }

    if (vizType === 'bars') {
      analyserRef.current.getByteFrequencyData(dataArray);
      
      const step = thickness + spacing;
      // Calculate exactly how many bars can fit in half the screen
      const maxBars = Math.floor((width / 2) / step);
      const usefulLength = Math.floor(bufferLength * 0.75); // Skip extreme silent highs
      const numBars = Math.min(maxBars, usefulLength);

      for (let i = 0; i < numBars; i++) {
        const dataIndex = Math.floor((i / numBars) * usefulLength);
        
        // Progressively boost higher frequencies
        const boost = Math.pow(1 + (i / numBars), 1.5);
        
        const value = dataArray[dataIndex] * boost * sensitivity; 
        
        // Minimum height ensures a nice dot/line is drawn even at complete silence
        const barHeight = Math.max(thickness / 2, (value / 255) * height * 0.8);
        const xOffset = i * step + (step / 2);
        
        // Draw Right Side (Centered at 0,0 where bottom is height/2)
        ctx.beginPath();
        ctx.moveTo(xOffset, height / 2 - (thickness / 2));
        ctx.lineTo(xOffset, height / 2 - barHeight);
        ctx.stroke();
        
        // Draw Left Side (Mirrored)
        ctx.beginPath();
        ctx.moveTo(-xOffset, height / 2 - (thickness / 2));
        ctx.lineTo(-xOffset, height / 2 - barHeight);
        ctx.stroke();
      }
    } else if (vizType === 'wave') {
      analyserRef.current.getByteTimeDomainData(dataArray);
      
      ctx.beginPath();
      const sliceWidth = width / bufferLength;
      let x = -width / 2; // Start from left edge relative to center

      for (let i = 0; i < bufferLength; i++) {
        // Apply sensitivity to the wave
        const normalized = (dataArray[i] / 128.0) - 1;
        const y = normalized * sensitivity * (height / 2); // Centered on Y axis

        if (i === 0) {
          ctx.moveTo(x, y);
        } else {
          ctx.lineTo(x, y);
        }
        x += sliceWidth;
      }
      ctx.stroke();
    } else if (vizType === 'circle') {
      analyserRef.current.getByteFrequencyData(dataArray);
      
      const radius = height / 4;

      ctx.beginPath();
      // Calculate number of bars based on thickness and spacing
      const circumference = 2 * Math.PI * radius;
      const stepSize = thickness + spacing;
      const bars = Math.min(180, Math.floor(circumference / stepSize));
      const step = (Math.PI * 2) / bars;

      for (let i = 0; i < bars; i++) {
        const dataIndex = Math.floor((i / bars) * (bufferLength / 2));
        
        const value = (dataArray[dataIndex] / 255) * sensitivity;
        
        const barHeight = Math.max(thickness / 2, value * (height / 3));
        const angle = i * step;
        
        const x1 = Math.cos(angle) * radius;
        const y1 = Math.sin(angle) * radius;
        const x2 = Math.cos(angle) * (radius + barHeight);
        const y2 = Math.sin(angle) * (radius + barHeight);

        ctx.moveTo(x1, y1);
        ctx.lineTo(x2, y2);
      }
      ctx.stroke();
      
      // Inner solid circle
      ctx.beginPath();
      ctx.arc(0, 0, radius - thickness, 0, Math.PI * 2);
      ctx.lineWidth = thickness / 2;
      ctx.stroke();
    }

    ctx.restore(); // Restore context to original state for next frame
    reqIdRef.current = requestAnimationFrame(draw);
  }, [vizType, color, thickness, spacing, sensitivity, smoothing, colorMode, color2, glow, resolution, bgType, bgColor, offsetX, offsetY, scale, rotation]);

  // Handle Play/Pause side effects and loop
  useEffect(() => {
    reqIdRef.current = requestAnimationFrame(draw);
    return () => cancelAnimationFrame(reqIdRef.current);
  }, [draw]);

  const handleAudioEnded = () => {
    setIsPlaying(false);
    if (isExportingVideo) {
      stopVideoExport();
    }
  };

  // Export Image (PNG)
  const exportImage = () => {
    if (!canvasRef.current) return;
    const link = document.createElement('a');
    link.download = `visualizer_${Date.now()}.png`;
    link.href = canvasRef.current.toDataURL('image/png');
    link.click();
  };

  // Export 4K Transparent Video
  const startVideoExport = async () => {
    if (!audioSrc || !canvasRef.current || !audioCtxRef.current) {
      alert("Please upload an audio file and press play at least once to initialize.");
      return;
    }

    setIsExportingVideo(true);
    setExportProgress(0);
    chunksRef.current = [];

    // Reset audio to start
    audioRef.current.pause();
    audioRef.current.currentTime = 0;

    // Capture Canvas Stream at 60fps
    const canvasStream = canvasRef.current.captureStream(60);
    
    // Get Audio Stream from destination
    const audioStream = destRef.current.stream;
    
    // Combine Streams
    const combinedTracks = [...canvasStream.getTracks(), ...audioStream.getAudioTracks()];
    const combinedStream = new MediaStream(combinedTracks);

    // Setup MediaRecorder for Transparent Video (WebM VP9/VP8)
    let options = { mimeType: 'video/webm; codecs=vp9' };
    if (!MediaRecorder.isTypeSupported(options.mimeType)) {
      options = { mimeType: 'video/webm; codecs=vp8' }; // Fallback
    }
    
    if (!MediaRecorder.isTypeSupported(options.mimeType)) {
      alert("Your browser does not support transparent video export (WebM with VP8/VP9 codecs). Export will proceed but may not be transparent.");
      options = {}; // Use browser default
    }

    try {
      mediaRecorderRef.current = new MediaRecorder(combinedStream, options);
    } catch (e) {
      console.error(e);
      alert("Error starting video recorder. See console.");
      setIsExportingVideo(false);
      return;
    }

    mediaRecorderRef.current.ondataavailable = (e) => {
      if (e.data && e.data.size > 0) {
        chunksRef.current.push(e.data);
      }
    };

    mediaRecorderRef.current.onstop = () => {
      const blob = new Blob(chunksRef.current, { type: mediaRecorderRef.current.mimeType });
      const url = URL.createObjectURL(blob);
      const link = document.createElement('a');
      link.download = `visualizer_4k_${Date.now()}.webm`;
      link.href = url;
      link.click();
      URL.revokeObjectURL(url);
      setIsExportingVideo(false);
      setExportProgress(0);
    };

    // Progress timer
    const duration = audioRef.current.duration;
    const progressInterval = setInterval(() => {
      if (audioRef.current && !audioRef.current.paused) {
        setExportProgress((audioRef.current.currentTime / duration) * 100);
      } else {
        clearInterval(progressInterval);
      }
    }, 500);

    // Start Recording & Playback
    mediaRecorderRef.current.start(100); // collect data every 100ms
    await audioRef.current.play();
    setIsPlaying(true);
  };

  const stopVideoExport = () => {
    if (mediaRecorderRef.current && mediaRecorderRef.current.state !== 'inactive') {
      mediaRecorderRef.current.stop();
    }
    audioRef.current.pause();
    setIsPlaying(false);
  };

  return (
    <div className="min-h-screen bg-slate-950 text-slate-200 font-sans selection:bg-cyan-500/30">
      {/* Header */}
      <header className="border-b border-slate-800 bg-slate-900/50 p-6 flex items-center justify-between">
        <div className="flex items-center gap-3">
          <div className="bg-cyan-500/20 p-2 rounded-lg">
            <Video className="w-6 h-6 text-cyan-400" />
          </div>
          <h1 className="text-xl font-bold tracking-tight text-white">4K Transparent Visualizer</h1>
        </div>
        <div className="text-sm text-slate-400 hidden sm:block">
          All processing is strictly local.
        </div>
      </header>

      <main className="container mx-auto p-6 grid lg:grid-cols-12 gap-8">
        
        {/* Left Column: Controls */}
        <div className="lg:col-span-4 space-y-6">
          
          {/* Upload Section */}
          <section className="bg-slate-900 p-6 rounded-2xl border border-slate-800 shadow-xl">
            <h2 className="text-sm font-semibold uppercase tracking-wider text-slate-500 mb-4 flex items-center gap-2">
              <Upload className="w-4 h-4" /> Audio Input
            </h2>
            <label className="block w-full cursor-pointer bg-slate-800 hover:bg-slate-700 transition-colors border-2 border-dashed border-slate-600 rounded-xl p-8 text-center group">
              <input 
                type="file" 
                accept="audio/*" 
                onChange={handleFileUpload} 
                className="hidden" 
                disabled={isExportingVideo}
              />
              <div className="mx-auto w-12 h-12 bg-slate-900 rounded-full flex items-center justify-center mb-3 group-hover:scale-110 transition-transform">
                <Upload className="w-6 h-6 text-cyan-400" />
              </div>
              <p className="font-medium text-slate-300">
                {fileName ? fileName : 'Click to browse audio file'}
              </p>
              <p className="text-xs text-slate-500 mt-2">MP3, WAV, FLAC</p>
            </label>

            {/* Hidden Audio Element */}
            <audio 
              ref={audioRef} 
              src={audioSrc} 
              onEnded={handleAudioEnded}
              onPlay={() => setIsPlaying(true)}
              onPause={() => setIsPlaying(false)}
            />

            {/* Playback Controls */}
            {audioSrc && (
              <div className="mt-4 flex gap-3">
                <button 
                  onClick={togglePlay}
                  disabled={isExportingVideo}
                  className="flex-1 bg-cyan-500 hover:bg-cyan-400 text-slate-950 font-bold py-3 px-4 rounded-xl flex items-center justify-center gap-2 transition-colors disabled:opacity-50"
                >
                  {isPlaying ? <Pause className="w-5 h-5" /> : <Play className="w-5 h-5" />}
                  {isPlaying ? 'Pause' : 'Play Audio'}
                </button>
              </div>
            )}
          </section>

          {/* Settings Section */}
          <section className="bg-slate-900 p-6 rounded-2xl border border-slate-800 shadow-xl">
            <h2 className="text-sm font-semibold uppercase tracking-wider text-slate-500 mb-4 flex items-center gap-2">
              <Settings2 className="w-4 h-4" /> Visual Settings
            </h2>
            
            <div className="space-y-5">
              {/* Type */}
              <div>
                <label className="block text-sm font-medium text-slate-400 mb-2">Style</label>
                <div className="grid grid-cols-3 gap-2">
                  {['bars', 'wave', 'circle'].map(type => (
                    <button
                      key={type}
                      onClick={() => setVizType(type)}
                      className={`py-2 px-3 rounded-lg text-sm font-medium capitalize transition-all ${
                        vizType === type 
                          ? 'bg-slate-700 text-white shadow-inner border border-slate-600' 
                          : 'bg-slate-950 text-slate-400 border border-slate-800 hover:border-slate-600'
                      }`}
                    >
                      {type}
                    </button>
                  ))}
                </div>
              </div>

              {/* Color & Style */}
              <div>
                <div className="flex justify-between items-center mb-2">
                  <label className="text-sm font-medium text-slate-400">Color Style</label>
                  <select 
                    value={colorMode} 
                    onChange={(e) => setColorMode(e.target.value)}
                    className="bg-slate-950 border border-slate-700 text-slate-300 text-xs rounded px-2 py-1 outline-none"
                  >
                    <option value="solid">Solid</option>
                    <option value="gradient">Gradient</option>
                    <option value="rainbow">Rainbow</option>
                  </select>
                </div>
                
                <div className="flex items-center gap-3">
                  {colorMode !== 'rainbow' && (
                    <input 
                      type="color" 
                      value={color} 
                      onChange={(e) => setColor(e.target.value)}
                      className="h-10 w-14 rounded cursor-pointer bg-slate-950 border border-slate-700 shrink-0"
                    />
                  )}
                  {colorMode === 'gradient' && (
                    <>
                      <span className="text-slate-500 text-xs font-medium">to</span>
                      <input 
                        type="color" 
                        value={color2} 
                        onChange={(e) => setColor2(e.target.value)}
                        className="h-10 w-14 rounded cursor-pointer bg-slate-950 border border-slate-700 shrink-0"
                      />
                    </>
                  )}
                  {colorMode === 'solid' && (
                    <input 
                      type="text" 
                      value={color}
                      onChange={(e) => setColor(e.target.value)}
                      className="flex-1 bg-slate-950 border border-slate-800 rounded-lg px-3 py-2 text-sm focus:ring-1 focus:ring-cyan-500 outline-none uppercase font-mono"
                    />
                  )}
                </div>
              </div>

              {/* Glow Effect */}
              <div className="flex items-center justify-between bg-slate-950 p-3 rounded-xl border border-slate-800">
                <div className="flex items-center gap-2">
                  <Sparkles className="w-4 h-4 text-amber-400" />
                  <span className="text-sm font-medium text-slate-300">Neon Glow Effect</span>
                </div>
                <label className="relative inline-flex items-center cursor-pointer">
                  <input type="checkbox" checked={glow} onChange={(e) => setGlow(e.target.checked)} className="sr-only peer" />
                  <div className="w-11 h-6 bg-slate-700 peer-focus:outline-none rounded-full peer peer-checked:after:translate-x-full peer-checked:after:border-white after:content-[''] after:absolute after:top-[2px] after:left-[2px] after:bg-white after:border-gray-300 after:border after:rounded-full after:h-5 after:w-5 after:transition-all peer-checked:bg-cyan-500"></div>
                </label>
              </div>

              {/* Thickness */}
              <div>
                <label className="flex justify-between text-sm font-medium text-slate-400 mb-2">
                  <span>Line Thickness</span>
                  <span className="text-slate-500">{thickness}px</span>
                </label>
                <input 
                  type="range" 
                  min="2" max="64" 
                  value={thickness} 
                  onChange={(e) => setThickness(Number(e.target.value))}
                  className="w-full accent-cyan-500 cursor-pointer"
                />
              </div>

              {/* Spacing */}
              <div>
                <label className="flex justify-between text-sm font-medium text-slate-400 mb-2">
                  <span>Space Between Lines</span>
                  <span className="text-slate-500">{spacing}px</span>
                </label>
                <input 
                  type="range" 
                  min="0" max="64" 
                  value={spacing} 
                  onChange={(e) => setSpacing(Number(e.target.value))}
                  className="w-full accent-cyan-500 cursor-pointer"
                />
              </div>

              {/* Amplitude (Sensitivity) */}
              <div>
                <label className="flex justify-between text-sm font-medium text-slate-400 mb-2">
                  <span>Amplitude (Height)</span>
                  <span className="text-slate-500">{sensitivity.toFixed(1)}x</span>
                </label>
                <input 
                  type="range" 
                  min="0.5" max="3.0" step="0.1"
                  value={sensitivity} 
                  onChange={(e) => setSensitivity(Number(e.target.value))}
                  className="w-full accent-cyan-500 cursor-pointer"
                />
              </div>

              {/* Smoothing */}
              <div>
                <label className="flex justify-between text-sm font-medium text-slate-400 mb-2">
                  <span>Motion Smoothing</span>
                  <span className="text-slate-500">{Math.round(smoothing * 100)}%</span>
                </label>
                <input 
                  type="range" 
                  min="0.1" max="0.99" step="0.01"
                  value={smoothing} 
                  onChange={(e) => setSmoothing(Number(e.target.value))}
                  className="w-full accent-cyan-500 cursor-pointer"
                />
              </div>

              {/* Transform Settings */}
              <div className="pt-4 mt-4 border-t border-slate-800 space-y-5">
                <h3 className="text-xs font-semibold uppercase tracking-wider text-slate-500 mb-2">Transform & Position</h3>
                
                {/* Scale */}
                <div>
                  <label className="flex justify-between text-sm font-medium text-slate-400 mb-2">
                    <span>Size (Scale)</span>
                    <span className="text-slate-500">{scale.toFixed(2)}x</span>
                  </label>
                  <input 
                    type="range" 
                    min="0.1" max="3.0" step="0.1"
                    value={scale} 
                    onChange={(e) => setScale(Number(e.target.value))}
                    className="w-full accent-cyan-500 cursor-pointer"
                  />
                </div>

                {/* Rotation */}
                <div>
                  <label className="flex justify-between text-sm font-medium text-slate-400 mb-2">
                    <span>Rotation</span>
                    <span className="text-slate-500">{rotation}°</span>
                  </label>
                  <input 
                    type="range" 
                    min="0" max="360" step="1"
                    value={rotation} 
                    onChange={(e) => setRotation(Number(e.target.value))}
                    className="w-full accent-cyan-500 cursor-pointer"
                  />
                </div>

                {/* Offset X */}
                <div>
                  <label className="flex justify-between text-sm font-medium text-slate-400 mb-2">
                    <span>Horizontal Position</span>
                    <span className="text-slate-500">{offsetX}%</span>
                  </label>
                  <input 
                    type="range" 
                    min="-50" max="50" step="1"
                    value={offsetX} 
                    onChange={(e) => setOffsetX(Number(e.target.value))}
                    className="w-full accent-cyan-500 cursor-pointer"
                  />
                </div>

                {/* Offset Y */}
                <div>
                  <label className="flex justify-between text-sm font-medium text-slate-400 mb-2">
                    <span>Vertical Position</span>
                    <span className="text-slate-500">{offsetY}%</span>
                  </label>
                  <input 
                    type="range" 
                    min="-50" max="50" step="1"
                    value={offsetY} 
                    onChange={(e) => setOffsetY(Number(e.target.value))}
                    className="w-full accent-cyan-500 cursor-pointer"
                  />
                </div>
              </div>

            </div>
          </section>

          {/* Advanced Layout Section */}
          <section className="bg-slate-900 p-6 rounded-2xl border border-slate-800 shadow-xl">
            <h2 className="text-sm font-semibold uppercase tracking-wider text-slate-500 mb-4 flex items-center gap-2">
              <Monitor className="w-4 h-4" /> Output Setup
            </h2>

            <div className="space-y-5">
              {/* Resolution */}
              <div>
                <label className="block text-sm font-medium text-slate-400 mb-2">Aspect Ratio & Resolution</label>
                <select 
                  value={resolution}
                  onChange={(e) => setResolution(e.target.value)}
                  className="w-full bg-slate-950 border border-slate-700 text-slate-300 text-sm rounded-lg px-3 py-2.5 outline-none focus:ring-1 focus:ring-cyan-500"
                >
                  <option value="4k_16_9">4K Landscape (3840x2160)</option>
                  <option value="1080p_16_9">1080p Landscape (1920x1080)</option>
                  <option value="4k_9_16">4K Vertical / Reels (2160x3840)</option>
                  <option value="1080p_9_16">1080p Vertical / Reels (1080x1920)</option>
                </select>
              </div>

              {/* Background */}
              <div>
                <label className="block text-sm font-medium text-slate-400 mb-2">Background Type</label>
                <div className="flex gap-2 mb-3">
                  {['transparent', 'color', 'image'].map(type => (
                    <button
                      key={type}
                      onClick={() => setBgType(type)}
                      className={`flex-1 py-2 px-2 rounded-lg text-xs font-medium capitalize transition-all ${
                        bgType === type 
                          ? 'bg-slate-700 text-white shadow-inner border border-slate-600' 
                          : 'bg-slate-950 text-slate-400 border border-slate-800 hover:border-slate-600'
                      }`}
                    >
                      {type}
                    </button>
                  ))}
                </div>

                {bgType === 'color' && (
                  <div className="flex items-center gap-3 mt-2 bg-slate-950 p-2 rounded-lg border border-slate-800">
                    <input type="color" value={bgColor} onChange={(e) => setBgColor(e.target.value)} className="h-8 w-12 rounded cursor-pointer bg-slate-950 border border-slate-700" />
                    <span className="text-sm font-mono text-slate-400 uppercase">{bgColor}</span>
                  </div>
                )}

                {bgType === 'image' && (
                  <div className="mt-2">
                    <label className="flex items-center justify-center gap-2 w-full cursor-pointer bg-slate-950 hover:bg-slate-800 transition-colors border border-dashed border-slate-600 rounded-lg p-3 text-center text-sm text-slate-300">
                      <ImagePlus className="w-4 h-4" />
                      {bgImageSrc ? 'Change Image' : 'Upload Background Image'}
                      <input type="file" accept="image/*" onChange={handleBgUpload} className="hidden" />
                    </label>
                  </div>
                )}
              </div>
            </div>
          </section>

          {/* Export Section */}
          <section className="bg-slate-900 p-6 rounded-2xl border border-slate-800 shadow-xl">
            <h2 className="text-sm font-semibold uppercase tracking-wider text-slate-500 mb-4">Export Options</h2>
            
            <div className="grid grid-cols-2 gap-3">
              <button 
                onClick={exportImage}
                disabled={isExportingVideo}
                className="col-span-2 bg-slate-800 hover:bg-slate-700 text-white font-medium py-3 px-4 rounded-xl flex items-center justify-center gap-2 transition-colors disabled:opacity-50"
              >
                <ImageIcon className="w-4 h-4" />
                Save Snapshot (PNG)
              </button>

              {isExportingVideo ? (
                <div className="col-span-2 space-y-3">
                  <button 
                    onClick={stopVideoExport}
                    className="w-full bg-red-500/10 hover:bg-red-500/20 text-red-500 border border-red-500/20 font-bold py-3 px-4 rounded-xl flex items-center justify-center gap-2 transition-colors"
                  >
                    <StopCircle className="w-5 h-5" />
                    Stop & Save
                  </button>
                  <div className="w-full bg-slate-950 rounded-full h-2.5 border border-slate-800 overflow-hidden">
                    <div className="bg-cyan-500 h-2.5 rounded-full transition-all duration-300" style={{ width: `${exportProgress}%` }}></div>
                  </div>
                  <p className="text-xs text-center text-slate-400">Recording transparent 4K video... {Math.round(exportProgress)}%</p>
                </div>
              ) : (
                <button 
                  onClick={startVideoExport}
                  disabled={!audioSrc}
                  className="col-span-2 bg-gradient-to-r from-indigo-500 to-cyan-500 hover:from-indigo-400 hover:to-cyan-400 text-white font-bold py-3 px-4 rounded-xl flex items-center justify-center gap-2 transition-all shadow-lg shadow-cyan-500/20 disabled:opacity-50 disabled:shadow-none"
                >
                  <Video className="w-5 h-5" />
                  Export 4K Video (WebM)
                </button>
              )}
            </div>
            <p className="text-xs text-slate-500 mt-4 leading-relaxed">
              * Video export records in real-time. Background will be transparent. WebM VP9 format is used for alpha channel support.
            </p>
          </section>

        </div>

        {/* Right Column: Preview */}
        <div className="lg:col-span-8 flex flex-col">
          <div className="bg-slate-900 rounded-2xl border border-slate-800 shadow-xl overflow-hidden flex-1 relative flex flex-col">
            
            <div className="p-4 border-b border-slate-800 bg-slate-900/80 flex justify-between items-center z-10">
              <span className="text-sm font-semibold text-slate-300 flex items-center gap-2">
                Live Preview 
                <span className="bg-slate-800 text-xs px-2 py-0.5 rounded text-slate-400 border border-slate-700">
                  {RESOLUTIONS[resolution]?.w}x{RESOLUTIONS[resolution]?.h}
                </span>
              </span>
              <span className="text-xs text-slate-500">
                {bgType === 'transparent' ? 'Checkerboard denotes transparency' : 'Background included in export'}
              </span>
            </div>

            {/* Checkerboard Background for Transparency check */}
            <div 
              className="flex-1 w-full relative flex items-center justify-center p-4 sm:p-8 overflow-hidden bg-black/50"
              style={ bgType === 'transparent' ? {
                backgroundImage: 'repeating-linear-gradient(45deg, #0f172a 25%, transparent 25%, transparent 75%, #0f172a 75%, #0f172a), repeating-linear-gradient(45deg, #0f172a 25%, #1e293b 25%, #1e293b 75%, #0f172a 75%, #0f172a)',
                backgroundPosition: '0 0, 10px 10px',
                backgroundSize: '20px 20px'
              } : {}}
            >
              {/* Actual Canvas */}
              <canvas 
                ref={canvasRef}
                width={RESOLUTIONS[resolution]?.w || 3840}
                height={RESOLUTIONS[resolution]?.h || 2160}
                className={`max-w-full max-h-full object-contain drop-shadow-2xl rounded-lg ring-1 ring-white/10 bg-transparent ${RESOLUTIONS[resolution]?.isVertical ? 'aspect-[9/16]' : 'aspect-video'}`}
              />

              {!audioSrc && (
                <div className="absolute inset-0 flex flex-col items-center justify-center pointer-events-none bg-slate-900/60 backdrop-blur-sm z-20">
                  <Loader2 className="w-12 h-12 text-slate-500 animate-spin mb-4 opacity-50" />
                  <p className="text-slate-400 font-medium">Awaiting Audio Input</p>
                </div>
              )}
            </div>

          </div>
        </div>

      </main>
    </div>
  );
}