import sharp from "sharp";
import fs from "node:fs";
const maskPath = "data/media/assets/9a/9a2d060c5d49f72fda4d97c25ff4639acc850724758f43f1783218e533585b4a.mask.png";
console.log("mask exists:", fs.existsSync(maskPath));
if (fs.existsSync(maskPath)) {
  const m = await sharp(maskPath).metadata();
  console.log("mask", m.width, m.height);
  // nakładka: maska jako czerwony overlay na masterze
  const master = "data/media/assets/9a/9a2d060c5d49f72fda4d97c25ff4639acc850724758f43f1783218e533585b4a.png";
  const mw = 1200, mh = Math.round(mw*(m.height!/m.width!));
  const maskRes = await sharp(maskPath).resize(mw,mh).threshold(128).toColourspace("b-w").raw().toBuffer();
  const rgb = await sharp(master).resize(mw,mh).raw().toBuffer({resolveWithObject:true});
  const out = Buffer.from(rgb.data);
  for (let i=0;i<maskRes.length;i++) if (maskRes[i]<128) { out[i*3]=Math.round(out[i*3]*0.4); out[i*3+1]=Math.round(out[i*3+1]*0.4); out[i*3+2]=Math.round(out[i*3+2]*0.4+140); }
  await sharp(out,{raw:{width:mw,height:mh,channels:3}}).png().toFile("tmp/mask-overlay.png");
  console.log("overlay saved");
}