// Rebuild the email-safe PNG from the app's SVG tracks and background palette.
// Run from backend: node scripts/generate-email-background.mjs
import { readFile, writeFile } from 'node:fs/promises';
import sharp from 'sharp';
const css = await readFile(new URL('../../frontend/src/index.css', import.meta.url), 'utf8');
const encoded = css.match(/background-image: url\("data:image\/svg\+xml,([^"\n]+)"\)/)?.[1];
if (!encoded) throw new Error('App bird-track background was not found');
const tracks = decodeURIComponent(encoded);
const gradients = `<defs><linearGradient id="wash" x2="0" y2="1"><stop stop-color="#fef5e7"/><stop offset=".46" stop-color="#e9ddba"/><stop offset="1" stop-color="#d9eadf"/></linearGradient>${[[14,10,22,'#de7c3a',.28],[82,12,20,'#35886e',.26],[24,84,22,'#ddb34e',.2],[86,78,24,'#2b765c',.24],[62,54,16,'#3072a0',.14]].map(([x,y,r,color,opacity],i)=>`<radialGradient id="glow${i}" cx="${x}%" cy="${y}%" r="${r}%"><stop stop-color="${color}" stop-opacity="${opacity}"/><stop offset="1" stop-color="${color}" stop-opacity="0"/></radialGradient>`).join('')}</defs>`;
const svg = `<svg xmlns="http://www.w3.org/2000/svg" width="800" height="1100" viewBox="0 0 1600 2200">${gradients}<rect width="1600" height="2200" fill="url(#wash)"/>${[0,1,2,3,4].map(i=>`<rect width="1600" height="2200" fill="url(#glow${i})"/>`).join('')}<g opacity=".42">${tracks.replace(/^<svg[^>]*>/,'').replace(/<\/svg>$/,'')}</g></svg>`;
await writeFile(new URL('../assets/email-background.png', import.meta.url), await sharp(Buffer.from(svg)).png().toBuffer());

await writeFile(new URL('../../frontend/public/email-background.png', import.meta.url), await readFile(new URL('../assets/email-background.png', import.meta.url)));