import React, { useEffect, useRef, useState } from 'react';

export default function Preview({ snapshot }) {
  const { mockup, designLayers, artwork } = snapshot;
  const wrapperRef = useRef(null);
  const [scale, setScale] = useState(1);

  useEffect(() => {
    if (!mockup || !wrapperRef.current) return;
    const el = wrapperRef.current;
    const update = () => {
      const w = el.clientWidth - 32;
      const h = el.clientHeight - 32;
      const s = Math.min(w / mockup.width, h / mockup.height);
      setScale(s > 0 ? s : 1);
    };
    update();
    const ro = new ResizeObserver(update);
    ro.observe(el);
    return () => ro.disconnect();
  }, [mockup?.width, mockup?.height]);

  if (!mockup) {
    return <div className="preview-empty">No mockup data</div>;
  }

  return (
    <div ref={wrapperRef} className="preview-canvas">
      <div
        style={{
          position: 'relative',
          width: mockup.width,
          height: mockup.height,
          transform: `scale(${scale})`,
          transformOrigin: 'center center',
          background: '#fff',
          boxShadow: '0 0 0 1px #334155',
        }}
      >
        {(mockup.layers || []).map((layer, i) => (
          <MockupLayer
            key={layer.id ?? i}
            layer={layer}
            designLayers={designLayers}
            artwork={artwork}
            printAreas={snapshot.printAreas}
          />
        ))}
      </div>
      <div className="position-debug">
        mockup {mockup.width}×{mockup.height} @ scale {scale.toFixed(2)} ·
        {artwork && ` artwork ${artwork.width}×${artwork.height} ·`}
        {' '}design layers: {designLayers.length}
      </div>
    </div>
  );
}

function MockupLayer({ layer, designLayers, artwork, printAreas }) {
  const baseStyle = {
    position: 'absolute',
    top: layer.top || 0,
    left: layer.left || 0,
    width: layer.width,
    height: layer.height,
    opacity: layer.opacity ?? 1,
    zIndex: layer.position ?? 'auto',
    transform: layer.rotate ? `rotate(${layer.rotate}deg)` : undefined,
    transformOrigin: 'center center',
  };

  if (layer.type === 'image') {
    return (
      <img
        src={layer.src || layer.url}
        alt=""
        style={{ ...baseStyle, pointerEvents: 'none', objectFit: 'fill' }}
      />
    );
  }

  if (layer.type === 'printarea') {
    return (
      <PrintAreaLayer
        layer={layer}
        designLayers={layer.layers || designLayers}
        artwork={artwork}
        printAreas={printAreas}
      />
    );
  }

  return null;
}

function PrintAreaLayer({ layer, designLayers, artwork, printAreas }) {
  // Ưu tiên kích thước artwork theo print area cụ thể, fallback về artwork chung
  const printAreaInfo = (printAreas || []).find((p) => p.id === layer.id);
  const aw = printAreaInfo?.artwork?.width || artwork?.width || layer.width;
  const ah = printAreaInfo?.artwork?.height || artwork?.height || layer.height;

  // Tỉ lệ scale từ artwork-coords về printarea-coords (mockup).
  const sx = layer.width / aw;
  const sy = layer.height / ah;

  const clipPath = layer.masked_enable ? buildClipPath(layer) : undefined;

  return (
    <div
      style={{
        position: 'absolute',
        top: layer.top || 0,
        left: layer.left || 0,
        width: layer.width,
        height: layer.height,
        opacity: layer.opacity ?? 1,
        zIndex: layer.position ?? 'auto',
        transform: layer.rotate ? `rotate(${layer.rotate}deg)` : undefined,
        transformOrigin: 'center center',
        overflow: 'hidden',
        clipPath,
        // Outline để dễ thấy print area khi debug
        outline: '1px dashed rgba(99, 102, 241, 0.3)',
      }}
    >
      <div
        style={{
          position: 'absolute',
          top: 0,
          left: 0,
          width: aw,
          height: ah,
          transformOrigin: 'top left',
          transform: `scale(${sx}, ${sy})`,
        }}
      >
        {(designLayers || []).map((dl, i) => (
          <DesignLayer key={dl.id ?? i} layer={dl} />
        ))}
      </div>
    </div>
  );
}

function buildClipPath(layer) {
  const clipTop = layer.masked_top || 0;
  const clipLeft = layer.masked_left || 0;
  const clipWidth = layer.masked_width || layer.width;
  const clipHeight = layer.masked_height || layer.height;
  const insetTop = clipTop;
  const insetLeft = clipLeft;
  const insetBottom = layer.height - clipTop - clipHeight;
  const insetRight = layer.width - clipLeft - clipWidth;
  return `inset(${insetTop}px ${insetRight}px ${insetBottom}px ${insetLeft}px)`;
}

function DesignLayer({ layer }) {
  const baseStyle = {
    position: 'absolute',
    top: layer.top || 0,
    left: layer.left || 0,
    width: layer.width,
    height: layer.height,
    opacity: layer.opacity ?? 1,
    zIndex: layer.order ?? 'auto',
    transform: layer.rotate ? `rotate(${layer.rotate}deg)` : undefined,
    transformOrigin: 'center center',
    pointerEvents: 'none',
  };

  if (layer.type === 'image') {
    const maskStyles =
      layer.masked_enable && layer.masked_image
        ? {
            WebkitMaskImage: `url(${layer.masked_image})`,
            maskImage: `url(${layer.masked_image})`,
            WebkitMaskSize: 'contain',
            maskSize: 'contain',
            WebkitMaskRepeat: 'no-repeat',
            maskRepeat: 'no-repeat',
            WebkitMaskPosition: 'center',
            maskPosition: 'center',
          }
        : {};

    return (
      <img
        src={layer.src || layer.url}
        alt=""
        style={{
          ...baseStyle,
          objectFit: 'fill',
          ...maskStyles,
        }}
      />
    );
  }

  if (layer.type === 'text') {
    const fontFamily =
      layer.typography_type === 'custom'
        ? layer.custom_font?.family || 'sans-serif'
        : layer.typography?.family || 'sans-serif';
    const fontSize =
      layer.typography_type === 'custom'
        ? layer.custom_font?.size || 16
        : layer.typography?.size || 16;
    const variant = layer.typography?.variant;
    const fontWeight =
      variant === 'bold' || (typeof variant === 'string' && variant.includes('700'))
        ? 700
        : variant === 'regular'
        ? 400
        : Number(variant) || 400;

    const justifyContent =
      layer.align === 'left'
        ? 'flex-start'
        : layer.align === 'right'
        ? 'flex-end'
        : 'center';

    return (
      <div
        style={{
          ...baseStyle,
          color: layer.color || '#000',
          fontFamily: `"${fontFamily}", sans-serif`,
          fontSize,
          fontWeight,
          display: 'flex',
          alignItems: 'center',
          justifyContent,
          textAlign: layer.align || 'center',
          whiteSpace: 'nowrap',
          overflow: 'hidden',
          WebkitTextStroke: layer.stroke_enabled
            ? `${layer.stroke_width}px ${layer.stroke_color}`
            : undefined,
        }}
      >
        {layer.text}
      </div>
    );
  }

  return null;
}