import { useState, useRef } from 'react';
import { motion, AnimatePresence } from 'framer-motion';
import { Eye, EyeOff, ZoomIn, ZoomOut, RotateCcw, Layers, Info } from 'lucide-react';
import styles from './MediaPanel.module.css';

function HeatmapLayer({ regions, opacity }) {
  return (
    <div
      className={styles.heatmapOverlay}
      style={{
        opacity: 0.24 + opacity * 0.76,
        '--heatmap-strength': opacity,
      }}
    >
      {regions.map((region, i) => {
        const isHigh = region.intensity > 0.8;
        const isMedium = region.intensity > 0.5;
        const color = isHigh
          ? 'var(--ai-generated)'
          : isMedium
            ? 'var(--suspect)'
            : 'var(--authentic)';

        const baseAlpha = 0.22 + region.intensity * 0.58;
        const scaledAlpha = Math.min(0.98, baseAlpha * (0.55 + opacity * 1.2));
        const blur = Math.max(10, 28 - opacity * 14 - region.intensity * 8);
        const scale = 1 + region.intensity * 0.2 + opacity * 0.08;

        return (
          <motion.div
            key={i}
            className={styles.heatmapRegion}
            style={{
              left: `${region.x}%`,
              top: `${region.y}%`,
              width: `${region.w}%`,
              height: `${region.h}%`,
              '--region-color': color,
              '--region-alpha': scaledAlpha,
              '--region-blur': `${blur}px`,
              '--region-scale': scale,
              '--region-ring': `${8 + opacity * 20}px`,
              '--region-border-alpha': Math.min(1, 0.35 + opacity * 0.55),
              '--region-glow-alpha': Math.min(1, 0.3 + region.intensity * 0.7),
            }}
            initial={{ opacity: 0, scale: 0.82 }}
            animate={{ opacity: scaledAlpha, scale: scale }}
            transition={{ duration: 0.4, delay: i * 0.08 }}
            title={region.label}
          />
        );
      })}
    </div>
  );
}

export default function MediaPanel({ result, previewUrl }) {
  const [heatmapOn, setHeatmapOn] = useState(false);
  const [heatmapOpacity, setHeatmapOpacity] = useState(0.78);
  const [zoom, setZoom] = useState(1);
  const imgRef = useRef(null);

  const isVideo = result.type === 'video';
  const regions = result.gradcam?.regions || [];

  const handleZoomIn = () => setZoom((value) => Math.min(value + 0.25, 2.5));
  const handleZoomOut = () => setZoom((value) => Math.max(value - 0.25, 0.5));
  const handleReset = () => { setZoom(1); };

  return (
    <div className={styles.panel}>
      <div className={styles.toolbar}>
        <div className={styles.toolbarLeft}>
          <button
            className={`${styles.toolBtn} ${heatmapOn ? styles.toolBtnActive : ''}`}
            onClick={() => setHeatmapOn(!heatmapOn)}
            title={heatmapOn ? 'Hide Grad-CAM heatmap' : 'Show Grad-CAM heatmap'}
          >
            {heatmapOn ? <Eye size={14} /> : <EyeOff size={14} />}
            <span>Grad-CAM</span>
          </button>
          <div className={styles.toolbarDivider} />
          <button className={styles.iconBtn} onClick={handleZoomIn} title="Zoom in" disabled={zoom >= 2.5}>
            <ZoomIn size={14} />
          </button>
          <span className={`${styles.zoomLabel} font-mono`}>{Math.round(zoom * 100)}%</span>
          <button className={styles.iconBtn} onClick={handleZoomOut} title="Zoom out" disabled={zoom <= 0.5}>
            <ZoomOut size={14} />
          </button>
          <button className={styles.iconBtn} onClick={handleReset} title="Reset zoom">
            <RotateCcw size={14} />
          </button>
        </div>

        <AnimatePresence>
          {heatmapOn && (
            <motion.div
              className={styles.opacityControl}
              initial={{ opacity: 0, x: 8 }}
              animate={{ opacity: 1, x: 0 }}
              exit={{ opacity: 0, x: 8 }}
            >
              <Layers size={12} />
              <span>Intensity</span>
              <input
                type="range"
                min={0}
                max={1}
                step={0.01}
                value={heatmapOpacity}
                onChange={(event) => setHeatmapOpacity(parseFloat(event.target.value))}
                className={styles.opacitySlider}
              />
              <span className="font-mono">{Math.round(heatmapOpacity * 100)}%</span>
            </motion.div>
          )}
        </AnimatePresence>
      </div>

      <div className={styles.mediaFrame}>
        <div
          className={`${styles.mediaContainer} ${heatmapOn ? styles.mediaContainerHeatmapOn : ''}`}
          style={{
            transform: `scale(${zoom})`,
            transformOrigin: 'center center',
            '--media-heatmap-strength': heatmapOpacity,
          }}
        >
          {isVideo ? (
            <video
              src={previewUrl}
              controls
              muted
              className={styles.mediaEl}
              ref={imgRef}
            />
          ) : (
            <img
              src={previewUrl}
              alt="Analysed media"
              className={styles.mediaEl}
              ref={imgRef}
            />
          )}

          <AnimatePresence>
            {heatmapOn && (
              <motion.div
                className={styles.heatmapWrap}
                initial={{ opacity: 0 }}
                animate={{ opacity: 1 }}
                exit={{ opacity: 0 }}
                transition={{ duration: 0.25 }}
              >
                <HeatmapLayer regions={regions} opacity={heatmapOpacity} />
              </motion.div>
            )}
          </AnimatePresence>
        </div>

        <AnimatePresence>
          {heatmapOn && (
            <motion.div
              className={styles.heatmapLegend}
              initial={{ opacity: 0, y: 8 }}
              animate={{ opacity: 1, y: 0 }}
              exit={{ opacity: 0 }}
            >
              <span className={styles.legendTitle}>Artifact Intensity</span>
              <div className={styles.legendItems}>
                <div className={styles.legendItem}><span className={`${styles.legendDot} ${styles.dotHigh}`} />High (&gt;80%)</div>
                <div className={styles.legendItem}><span className={`${styles.legendDot} ${styles.dotMed}`} />Medium (50–80%)</div>
                <div className={styles.legendItem}><span className={`${styles.legendDot} ${styles.dotLow}`} />Low (&lt;50%)</div>
              </div>
            </motion.div>
          )}
        </AnimatePresence>
      </div>

      <AnimatePresence>
        {heatmapOn && regions.length > 0 && (
          <motion.div
            className={styles.regionAnnotations}
            initial={{ opacity: 0, y: 8 }}
            animate={{ opacity: 1, y: 0 }}
            exit={{ opacity: 0 }}
          >
            <div className={styles.regionHeader}>
              <Info size={13} />
              <span>Localised Artifact Regions</span>
            </div>
            <div className={styles.regionGrid}>
              {regions.map((region, index) => (
                <div key={index} className={styles.regionItem}>
                  <span
                    className={styles.regionDot}
                    style={{
                      background: region.intensity > 0.8
                        ? 'var(--ai-generated)'
                        : region.intensity > 0.5
                          ? 'var(--suspect)'
                          : 'var(--authentic)',
                    }}
                  />
                  <span className={styles.regionLabel}>{region.label}</span>
                  <span className={`${styles.regionScore} font-mono`}>{Math.round(region.intensity * 100)}%</span>
                </div>
              ))}
            </div>
          </motion.div>
        )}
      </AnimatePresence>

      <div className={styles.fileInfo}>
        <div className={styles.fileInfoItem}>
          <span>Format</span>
          <span className="font-mono">{result.format}</span>
        </div>
        <div className={styles.fileInfoItem}>
          <span>Resolution</span>
          <span className="font-mono">{result.resolution}</span>
        </div>
        <div className={styles.fileInfoItem}>
          <span>Size</span>
          <span className="font-mono">{result.filesize}</span>
        </div>
        {result.type === 'video' && (
          <>
            <div className={styles.fileInfoItem}>
              <span>Duration</span>
              <span className="font-mono">{result.duration}</span>
            </div>
            <div className={styles.fileInfoItem}>
              <span>Frames</span>
              <span className="font-mono">{result.totalFrames}</span>
            </div>
          </>
        )}
      </div>
    </div>
  );
}