const sharp = require('sharp');

// Source anchors read off the image, mapped by ROLE to MyBazaar tokens.
// Anti-aliased pixels are blended between the two nearest anchors so edges stay smooth
// instead of snapping — a straight nearest-colour swap would leave jagged rims.
const MAP = [
  { from: [255,255,255], to: [234,246,243] },  // ground        -> peacock.10
  { from: [228,228,228], to: [207,229,224] },  // shoe / shade   -> peacock.20
  { from: [197,207,214], to: [215,236,232] },  // jacket         -> pine.20
  { from: [175,185,197], to: [186,214,208] },  // jacket shade   -> between pine.20/peacock.20
  { from: [177,186,192], to: [200,224,218] },  // jacket mid
  { from: [219,39,33],   to: [1,98,88]     },  // trouser shade  -> pine.80
  { from: [255,65,51],   to: [1,121,111]   },  // trousers       -> pine.70  (the primary)
  { from: [178,139,103], to: [215,236,232] },  // skin           -> pine.20  (no skin tones)
  { from: [153,118,89],  to: [186,214,208] },  // skin shade
  { from: [16,16,48],    to: [17,56,51]    },  // hair           -> peacock.90
];

(async () => {
  const src = '/tmp/moodboard/recolor-src.png', out = '/tmp/moodboard/recolor-out.png';
  const { data, info } = await sharp(src).raw().toBuffer({ resolveWithObject: true });
  const { width: W, height: H, channels: C } = info;
  const d2 = (p, q) => (p[0]-q[0])**2 + (p[1]-q[1])**2 + (p[2]-q[2])**2;

  for (let i = 0; i < data.length; i += C) {
    const px = [data[i], data[i+1], data[i+2]];
    let a = 0, b = 1, da = Infinity, db = Infinity;
    for (let k = 0; k < MAP.length; k++) {
      const dist = d2(px, MAP[k].from);
      if (dist < da) { db = da; b = a; da = dist; a = k; }
      else if (dist < db) { db = dist; b = k; }
    }
    if (da === 0) { [data[i], data[i+1], data[i+2]] = MAP[a].to; continue; }
    // weight by inverse distance to the two closest anchors
    const wa = 1 / Math.sqrt(da), wb = 1 / Math.sqrt(db), s = wa + wb;
    for (let c = 0; c < 3; c++) data[i+c] = Math.round((MAP[a].to[c]*wa + MAP[b].to[c]*wb) / s);
  }
  await sharp(data, { raw: { width: W, height: H, channels: C } }).png().toFile(out);
  console.log('->', out);
})();