"use strict";
/**
 * Generates /public/og-image.png from the brand logo with the project
 * colours and name baked in. Run with `node scripts/build-og-image.mjs`.
 * Requires `sharp` (already a transitive Next.js dependency).
 *
 * The SVG embeds the Inter font directly via base64 so the image is
 * identical on every machine regardless of which fonts are installed.
 * If the font fetch fails we fall back to the system sans-serif at a
 * conservatively smaller size so the wordmark still fits.
 */
import { promises as fs } from "node:fs";
import path from "node:path";
import sharp from "sharp";

const ROOT = path.resolve(process.cwd());

const W = 1200;
const H = 630;

const palette = {
  bg: "#0f172a",
  bgAccent: "#1c2433",
  orange: "#fdb13c",
  teal: "#006672",
  gridLine: "rgba(255,255,255,0.04)",
};

async function loadFontBase64() {
  // Check for a local font file first (committed to the repo so Docker
  // builds work offline).
  const localPath = path.join(ROOT, "public/fonts/inter-800.woff");
  let buffer;
  try {
    buffer = await fs.readFile(localPath);
  } catch {
    // Fall back to Google Fonts.
    const url =
      "https://fonts.gstatic.com/s/inter/v20/UcCO3FwrK3iLTeHuS_nVMrMxCp50SjIw2boKoduKmMEVuDyYMZtrib2Ai-4.woff";
    const res = await fetch(url);
    if (!res.ok) throw new Error(`Failed to fetch Inter: ${res.status}`);
    buffer = Buffer.from(await res.arrayBuffer());
  }
  return buffer.toString("base64");
}

const fontB64 = await loadFontBase64();

const svg = `
<svg xmlns="http://www.w3.org/2000/svg" width="${W}" height="${H}" viewBox="0 0 ${W} ${H}">
  <defs>
    <style type="text/css">
      @font-face {
        font-family: 'Inter';
        font-style: normal;
        font-weight: 800;
        src: url(data:font/woff;base64,${fontB64}) format('woff');
      }
    </style>
    <linearGradient id="bg" x1="0" y1="0" x2="1" y2="1">
      <stop offset="0%" stop-color="${palette.bg}"/>
      <stop offset="100%" stop-color="${palette.bgAccent}"/>
    </linearGradient>
    <radialGradient id="glow" cx="0.85" cy="0.15" r="0.6">
      <stop offset="0%" stop-color="${palette.orange}" stop-opacity="0.35"/>
      <stop offset="60%" stop-color="${palette.orange}" stop-opacity="0.05"/>
      <stop offset="100%" stop-color="${palette.orange}" stop-opacity="0"/>
    </radialGradient>
    <pattern id="grid" width="48" height="48" patternUnits="userSpaceOnUse">
      <path d="M 48 0 L 0 0 0 48" fill="none" stroke="${palette.gridLine}" stroke-width="1"/>
    </pattern>
  </defs>

  <!-- Background -->
  <rect width="${W}" height="${H}" fill="url(#bg)"/>
  <rect width="${W}" height="${H}" fill="url(#grid)"/>
  <rect width="${W}" height="${H}" fill="url(#glow)"/>

  <!-- Brand mark (rounded square on the left) -->
  <g transform="translate(80, 215)">
    <rect x="0" y="0" width="200" height="200" rx="40" fill="${palette.orange}"/>
    <g transform="translate(50, 50)">
      <rect x="0" y="0" width="100" height="100" rx="16" fill="#0f172a"/>
      <rect x="12" y="12" width="76" height="76" rx="10" fill="${palette.orange}"/>
      <path d="M 50 22 L 78 50 L 50 78 L 22 50 Z" fill="#0f172a"/>
      <circle cx="50" cy="50" r="10" fill="${palette.orange}"/>
    </g>
  </g>

  <!-- Wordmark + tagline -->
  <g transform="translate(320, 0)">
    <text x="0" y="220" font-family="Inter, system-ui, sans-serif" font-size="22" font-weight="700" letter-spacing="6" fill="rgba(255,255,255,0.55)">
      CONSTRUCTION OPERATIONS
    </text>
    <text x="0" y="334" font-family="Inter, system-ui, sans-serif" font-size="64" font-weight="800" letter-spacing="-1">
      <tspan fill="${palette.orange}">MEGA</tspan><tspan fill="#ffffff">INFRASTRUCTURE</tspan>
    </text>
    <text x="0" y="400" font-family="Inter, system-ui, sans-serif" font-size="26" font-weight="500" fill="rgba(255,255,255,0.78)">
      Site operations dashboard · fuel · orders · workforce · sites
    </text>
  </g>

  <!-- Bottom accent bars -->
  <g transform="translate(120, 575)">
    <rect width="180" height="6" rx="3" fill="${palette.orange}"/>
    <rect x="200" width="180" height="6" rx="3" fill="#a1ae3b"/>
    <rect x="400" width="180" height="6" rx="3" fill="#4f9c5b"/>
    <rect x="600" width="180" height="6" rx="3" fill="${palette.teal}"/>
  </g>
</svg>
`;

const out = path.join(ROOT, "public", "og-image.png");

const buf = Buffer.from(svg);
await sharp(buf, { density: 144 })
  .resize({ width: W, height: H })
  .png({ compressionLevel: 9 })
  .toFile(out);

const stat = await fs.stat(out);
console.log(`Wrote ${out} (${(stat.size / 1024).toFixed(1)} KB, ${W}x${H})`);