import { useCallback, useEffect, useRef, useState } from 'react';
import GlassSurface from '../ui/GlassSurface.js';
import ScannerToast from './ScannerToast.js';
import ScannerCountPill from './ScannerCountPill.js';
import ScannerScanPeek from './ScannerScanPeek.js';
import ScannerDisambiguation from './ScannerDisambiguation.js';
import { useScannerSound } from '../../lib/use-scanner-sound.js';
import { useScannerFlash } from '../../lib/use-scanner-flash.js';

const TOAST_DURATION_MS = 2500;

function DetectionFrame({ card, videoMetrics }) {
  return (
    <div
      className="absolute pointer-events-none scan-frame"
      style={{
        left: `${(card.bounds.x / videoMetrics.width) * 100}%`,
        top: `${(card.bounds.y / videoMetrics.height) * 100}%`,
        width: `${(card.bounds.width / videoMetrics.width) * 100}%`,
        height: `${(card.bounds.height / videoMetrics.height) * 100}%`,
      }}
    >
      <span className="scan-bracket scan-bracket-tl" aria-hidden="true" />
      <span className="scan-bracket scan-bracket-tr" aria-hidden="true" />
      <span className="scan-bracket scan-bracket-bl" aria-hidden="true" />
      <span className="scan-bracket scan-bracket-br" aria-hidden="true" />
      <span className="scan-line" aria-hidden="true" />
      <style jsx>{`
        .scan-bracket {
          position: absolute;
          width: 22px;
          height: 22px;
          border-color: var(--accent-ember);
          border-style: solid;
          filter: drop-shadow(0 0 6px color-mix(in srgb, var(--accent-flame) 55%, transparent));
        }
        .scan-bracket-tl { top: 0; left: 0; border-width: 3px 0 0 3px; }
        .scan-bracket-tr { top: 0; right: 0; border-width: 3px 3px 0 0; }
        .scan-bracket-bl { bottom: 0; left: 0; border-width: 0 0 3px 3px; }
        .scan-bracket-br { bottom: 0; right: 0; border-width: 0 3px 3px 0; }
        .scan-line {
          position: absolute;
          left: 8%;
          right: 8%;
          height: 2px;
          top: 0;
          background: linear-gradient(
            90deg,
            transparent,
            var(--accent-ember),
            var(--accent-flame),
            var(--accent-ember),
            transparent
          );
          box-shadow: 0 0 10px color-mix(in srgb, var(--accent-flame) 70%, transparent);
          animation: scan-sweep 1.6s var(--motion-ease-linear, linear) infinite;
        }
        @keyframes scan-sweep {
          0% { top: 8%; opacity: 0.35; }
          50% { top: 88%; opacity: 1; }
          100% { top: 8%; opacity: 0.35; }
        }
        @media (prefers-reduced-motion: reduce) {
          .scan-line {
            animation: none;
            top: 50%;
            opacity: 0.85;
          }
        }
      `}</style>
    </div>
  );
}

function ChromeIconButton({
  onClick,
  label,
  pressed,
  busy,
  children,
  className = '',
}) {
  return (
    <button
      type="button"
      onClick={onClick}
      className={`w-11 h-11 rounded-full flex items-center justify-center transition-transform active:scale-95 focus:outline-none focus-visible:ring-2 focus-visible:ring-offset-2 ${className}`}
      style={{
        minWidth: 44,
        minHeight: 44,
        '--tw-ring-color': 'var(--accent-ember)',
        '--tw-ring-offset-color': 'transparent',
      }}
      aria-label={label}
      aria-pressed={pressed}
      aria-busy={busy || undefined}
      disabled={busy}
    >
      <GlassSurface
        as="span"
        tint="mid"
        rim="subtle"
        blur="mid"
        className="w-full h-full rounded-full flex items-center justify-center"
        style={{ color: 'var(--text-primary)' }}
      >
        {children}
      </GlassSurface>
    </button>
  );
}

export default function ScannerCamera({
  queue,
  camera,
  identification,
  onBack = () => {},
  onOpenCheckout = () => {},
  onGalleryIdentify,
  latestPeekCard = null,
  cartCount,
  isCheckoutOpen = false,
  verificationPausedRef,
}) {
  const [toast, setToast] = useState({ message: '', visible: false, type: 'success' });
  const [galleryBusy, setGalleryBusy] = useState(false);
  const toastTimerRef = useRef(null);
  const prevCountRef = useRef(queue.scannedCards?.length ?? 0);
  const galleryInputRef = useRef(null);

  const {
    videoRef,
    canvasRef,
    detectionCanvasRef,
    isStreaming,
    trackedCards,
    videoMetrics,
    startCamera,
    streamRef,
    facingMode,
    switchFacingMode,
  } = camera;

  const sound = useScannerSound();
  const flash = useScannerFlash(streamRef);

  const resolvedCartCount = cartCount ?? queue.scannedCards?.length ?? 0;

  useEffect(() => {
    startCamera();
    // eslint-disable-next-line react-hooks/exhaustive-deps -- one-shot mount
  }, []);

  const currentCount = queue.scannedCards?.length ?? 0;
  useEffect(() => {
    if (currentCount > prevCountRef.current) {
      const newest = queue.scannedCards[0];
      const cardName = newest?.name || newest?.card?.name || 'Card';

      navigator.vibrate?.(50);
      sound.playSuccess();

      clearTimeout(toastTimerRef.current);
      setToast({ message: `${cardName} added`, visible: true, type: 'success' });
      toastTimerRef.current = setTimeout(() => {
        setToast((t) => ({ ...t, visible: false }));
      }, TOAST_DURATION_MS);
    }
    prevCountRef.current = currentCount;
  }, [currentCount]); // eslint-disable-line react-hooks/exhaustive-deps -- intentionally only reacts to count

  useEffect(() => {
    return () => clearTimeout(toastTimerRef.current);
  }, []);

  useEffect(() => {
    if (facingMode === 'user' && flash.flashOn) {
      flash.toggleFlash();
    }
    // eslint-disable-next-line react-hooks/exhaustive-deps -- only react to facing mode changes
  }, [facingMode]);

  const handleGalleryClick = useCallback(() => {
    galleryInputRef.current?.click();
  }, []);

  const handleGalleryChange = useCallback(
    async (event) => {
      const file = event.target.files?.[0];
      event.target.value = '';
      if (!file) return;

      const identify =
        onGalleryIdentify ||
        identification.identifyFromGalleryFile?.bind(identification);

      if (!identify) return;

      setGalleryBusy(true);
      try {
        await identify(file);
      } finally {
        setGalleryBusy(false);
      }
    },
    [identification, onGalleryIdentify]
  );

  const foundCards = trackedCards.filter(
    (c) => c.status === 'confirmed' || c.status === 'scanned'
  );

  const hasMetrics = videoMetrics.width > 0 && videoMetrics.height > 0;
  const showFlash = flash.flashSupported && facingMode === 'environment';
  const scanStatus = isCheckoutOpen
    ? 'Checkout open'
    : isStreaming
      ? 'Scanning…'
      : 'Starting camera…';

  const switchCameraLabel =
    facingMode === 'environment' ? 'Switch to front camera' : 'Switch to rear camera';

  return (
    <div className="relative w-full min-h-[100dvh] max-md:rounded-none max-md:min-h-[100dvh] overflow-hidden">
      <div
        className="absolute inset-0"
        style={{ backgroundColor: 'var(--bg-tertiary)' }}
      >
        <video
          ref={videoRef}
          className="absolute inset-0 w-full h-full object-cover"
          style={{ display: isStreaming ? 'block' : 'none' }}
          autoPlay
          playsInline
          muted
          aria-label="Card scanner camera feed"
        />

        {isStreaming &&
          hasMetrics &&
          foundCards.map((card) => (
            <DetectionFrame key={card.id} card={card} videoMetrics={videoMetrics} />
          ))}

        {isStreaming && (
          <div className="absolute top-3 right-3 z-10 md:hidden">
            <GlassSurface
              tint="mid"
              rim="subtle"
              blur="mid"
              className="flex items-center gap-1.5 px-2.5 py-1 rounded-full text-xs font-semibold shadow-lg"
              style={{ color: 'var(--text-primary)' }}
            >
              <span
                className="w-1.5 h-1.5 rounded-full animate-pulse"
                style={{ backgroundColor: 'var(--color-error)' }}
                aria-hidden="true"
              />
              LIVE
            </GlassSurface>
          </div>
        )}

        <ScannerToast
          message={toast.message}
          visible={toast.visible}
          type={toast.type}
        />

        <ScannerScanPeek
          key={latestPeekCard?.id ?? latestPeekCard?.name ?? 'peek'}
          card={latestPeekCard}
          onOpenCheckout={onOpenCheckout}
        />

        {!isStreaming && (
          <div className="absolute inset-0 flex items-center justify-center">
            <div className="flex flex-col items-center gap-3">
              <div
                className="w-10 h-10 rounded-full border-2 border-t-transparent animate-spin"
                style={{ borderColor: 'var(--accent-ember)', borderTopColor: 'transparent' }}
                aria-hidden="true"
              />
              <span
                className="text-sm font-medium"
                style={{ color: 'var(--text-secondary)' }}
              >
                Starting camera…
              </span>
            </div>
          </div>
        )}
      </div>

      <div
        className="absolute top-0 left-0 right-0 z-30 px-3 pb-2"
        style={{ paddingTop: 'calc(0.75rem + env(safe-area-inset-top, 0px))' }}
      >
        <GlassSurface
          tint="mid"
          rim="subtle"
          blur="mid"
          className="flex items-center justify-between gap-2 rounded-2xl px-2 py-2"
        >
          <ChromeIconButton onClick={onBack} label="Leave scanner">
            <svg
              width="18"
              height="18"
              viewBox="0 0 24 24"
              fill="none"
              stroke="currentColor"
              strokeWidth="2"
              strokeLinecap="round"
              strokeLinejoin="round"
              aria-hidden="true"
            >
              <path d="M19 12H5" />
              <path d="M12 19l-7-7 7-7" />
            </svg>
          </ChromeIconButton>

          <h1
            className="text-base font-semibold truncate"
            style={{ color: 'var(--text-primary)' }}
          >
            Scan Cards
          </h1>

          <ChromeIconButton
            onClick={handleGalleryClick}
            label="Choose image from gallery"
            busy={galleryBusy}
          >
            {galleryBusy ? (
              <div
                className="w-4 h-4 rounded-full border-2 border-t-transparent animate-spin"
                style={{ borderColor: 'var(--accent-ember)', borderTopColor: 'transparent' }}
                aria-hidden="true"
              />
            ) : (
              <svg
                width="18"
                height="18"
                viewBox="0 0 24 24"
                fill="none"
                stroke="currentColor"
                strokeWidth="2"
                strokeLinecap="round"
                strokeLinejoin="round"
                aria-hidden="true"
              >
                <rect x="3" y="3" width="18" height="18" rx="2" />
                <circle cx="8.5" cy="8.5" r="1.5" />
                <path d="M21 15l-5-5L5 21" />
              </svg>
            )}
          </ChromeIconButton>
        </GlassSurface>
      </div>

      <input
        ref={galleryInputRef}
        type="file"
        accept="image/*"
        className="sr-only"
        tabIndex={-1}
        onChange={handleGalleryChange}
      />

      {isStreaming && (
        <div
          className="absolute bottom-0 left-0 right-0 z-30 px-3 pt-2"
          style={{ paddingBottom: 'calc(0.75rem + env(safe-area-inset-bottom, 0px))' }}
        >
          <GlassSurface
            tint="mid"
            rim="subtle"
            blur="mid"
            className="flex items-center justify-between gap-2 rounded-2xl px-2 py-2"
          >
            <div className="flex items-center gap-2">
              {showFlash ? (
                <ChromeIconButton
                  onClick={flash.toggleFlash}
                  label={flash.flashOn ? 'Turn off flash' : 'Turn on flash'}
                  pressed={flash.flashOn}
                  className={flash.flashOn ? 'ring-2' : ''}
                >
                  <svg width="18" height="18" viewBox="0 0 24 24" fill="currentColor" aria-hidden="true">
                    <path d="M13 2L3 14h9l-1 8 10-12h-9l1-8z" />
                  </svg>
                </ChromeIconButton>
              ) : (
                <ChromeIconButton onClick={switchFacingMode} label={switchCameraLabel}>
                  <svg
                    width="18"
                    height="18"
                    viewBox="0 0 24 24"
                    fill="none"
                    stroke="currentColor"
                    strokeWidth="2"
                    strokeLinecap="round"
                    strokeLinejoin="round"
                    aria-hidden="true"
                  >
                    <path d="M11 19H5a2 2 0 0 1-2-2V7a2 2 0 0 1 2-2h6" />
                    <path d="M13 5h6a2 2 0 0 1 2 2v10a2 2 0 0 1-2 2h-6" />
                    <path d="M8 12h8" />
                    <path d="m16 9 3 3-3 3" />
                    <path d="m8 15-3-3 3-3" />
                  </svg>
                </ChromeIconButton>
              )}

              {showFlash && (
                <ChromeIconButton onClick={switchFacingMode} label={switchCameraLabel}>
                  <svg
                    width="18"
                    height="18"
                    viewBox="0 0 24 24"
                    fill="none"
                    stroke="currentColor"
                    strokeWidth="2"
                    strokeLinecap="round"
                    strokeLinejoin="round"
                    aria-hidden="true"
                  >
                    <path d="M11 19H5a2 2 0 0 1-2-2V7a2 2 0 0 1 2-2h6" />
                    <path d="M13 5h6a2 2 0 0 1 2 2v10a2 2 0 0 1-2 2h-6" />
                    <path d="M8 12h8" />
                    <path d="m16 9 3 3-3 3" />
                    <path d="m8 15-3-3 3-3" />
                  </svg>
                </ChromeIconButton>
              )}
            </div>

            <p
              className="text-xs font-medium truncate text-center flex-1 px-1"
              style={{ color: 'var(--text-secondary)' }}
              aria-live="polite"
            >
              {scanStatus}
            </p>

            <ScannerCountPill
              count={resolvedCartCount}
              onOpenCheckout={onOpenCheckout}
            />
          </GlassSurface>
        </div>
      )}

      <canvas ref={canvasRef} className="hidden" aria-hidden="true" />
      <canvas ref={detectionCanvasRef} className="hidden" aria-hidden="true" />

      {identification.disambiguation && (
        <ScannerDisambiguation
          disambiguation={identification.disambiguation}
          submittingReview={identification.submittingReview}
          onPick={identification.handleDisambiguationPick}
          onNotInCatalog={identification.handleNotInCatalog}
          onCancel={identification.cancelDisambiguation}
        />
      )}
    </div>
  );
}