/**
 * Weekly newsletter cover generator.
 *
 * Uses the existing Drop #006 cover as the visual foundation: the same black /
 * orange palette, the urban sunset photography and the route-line motif. Only
 * the issue number, headline, date and copy change. Output is 1200×630 PNG.
 */
import { join } from 'node:path';
import sharp from 'sharp';

const SOURCE = join(process.cwd(), 'public/images/drop-006-cover.png');

function esc(value: string): string {
  return value
    .replaceAll('&', '&')
    .replaceAll('<', '&lt;')
    .replaceAll('>', '&gt;')
    .replaceAll('"', '&quot;');
}

function lines(text: string, maxChars: number, maxLines = 3): string[] {
  const words = text.toUpperCase().split(/\s+/);
  const out: string[] = [];
  let current = '';
  for (const word of words) {
    const next = current ? `${current} ${word}` : word;
    if (next.length > maxChars && current) {
      out.push(current);
      current = word;
      if (out.length === maxLines - 1) break;
    } else {
      current = next;
    }
  }
  if (current && out.length < maxLines) out.push(current);
  return out;
}

export async function generateNewsletterCover(params: {
  number: number;
  dateLabel: string;
  coverTitle: string;
  outputPath: string;
}): Promise<string> {
  const { number, dateLabel, coverTitle, outputPath } = params;
  const issue = `#${String(number).padStart(3, '0')}`;
  const titleLines = lines(coverTitle, 15, 3);

  const source = sharp(SOURCE);
  const meta = await source.metadata();
  const width = meta.width ?? 1059;
  const height = meta.height ?? 537;
  // Take the city/sunset side of the old cover, away from the big old headline.
  const cropWidth = Math.max(320, Math.min(width - 640, 520));
  const hero = await sharp(SOURCE)
    .extract({
      left: Math.max(0, width - cropWidth - 20),
      top: Math.max(0, Math.floor(height * 0.2)),
      width: cropWidth,
      height: Math.floor(height * 0.62),
    })
    .resize(560, 340, { fit: 'cover' })
    .modulate({ brightness: 0.82, saturation: 0.9 })
    .toBuffer();

  const titleSvg = titleLines
    .map(
      (line, i) =>
        `<text x="56" y="${272 + i * 76}" font-family="DejaVu Sans, sans-serif" font-size="62" font-weight="900" fill="#ffffff">${esc(line)}</text>`,
    )
    .join('');

  const overlay = `
  <svg width="1200" height="630" viewBox="0 0 1200 630" xmlns="http://www.w3.org/2000/svg">
    <defs>
      <linearGradient id="fade" x1="0" y1="0" x2="1" y2="0">
        <stop offset="0" stop-color="#080808" stop-opacity="1"/>
        <stop offset="0.58" stop-color="#080808" stop-opacity="0.35"/>
        <stop offset="1" stop-color="#080808" stop-opacity="0.08"/>
      </linearGradient>
      <linearGradient id="bottom" x1="0" y1="0" x2="0" y2="1">
        <stop offset="0" stop-color="#080808" stop-opacity="0"/>
        <stop offset="1" stop-color="#080808" stop-opacity="0.92"/>
      </linearGradient>
    </defs>
    <rect width="1200" height="630" fill="url(#fade)"/>
    <rect x="560" y="120" width="600" height="380" fill="url(#bottom)"/>
    <g font-family="DejaVu Sans, sans-serif">
      <text x="56" y="62" font-size="13" font-weight="700" letter-spacing="4" fill="#ff5a1f">SKATESPOTS</text>
      <text x="56" y="88" font-size="30" font-weight="900" fill="#ffffff">NEWSLETTER</text>
      <text x="760" y="62" font-size="12" font-weight="700" letter-spacing="2" fill="#bdbdbd">REAL SPOTS</text>
      <text x="760" y="82" font-size="12" font-weight="700" letter-spacing="2" fill="#bdbdbd">REAL PEOPLE</text>
      <text x="760" y="102" font-size="12" font-weight="700" letter-spacing="2" fill="#bdbdbd">REAL SKATEBOARDING</text>
      <rect x="978" y="42" width="168" height="40" rx="20" fill="none" stroke="#ff5a1f" stroke-width="2"/>
      <text x="1062" y="68" text-anchor="middle" font-size="14" font-weight="900" fill="#ff5a1f">DROP ${issue}</text>
      <text x="56" y="160" font-size="12" font-weight="700" letter-spacing="4" fill="#ff5a1f">THIS WEEK</text>
      <text x="56" y="190" font-size="13" font-weight="700" fill="#a3a3a3">${esc(dateLabel)}</text>
      ${titleSvg}
      <line x1="56" y1="510" x2="520" y2="510" stroke="#ff5a1f" stroke-width="3"/>
      <text x="56" y="548" font-size="12" font-weight="700" letter-spacing="2" fill="#bdbdbd">SPOTS</text>
      <text x="160" y="548" font-size="12" font-weight="700" letter-spacing="2" fill="#bdbdbd">SHOPS</text>
      <text x="270" y="548" font-size="12" font-weight="700" letter-spacing="2" fill="#bdbdbd">PEOPLE</text>
      <text x="390" y="548" font-size="12" font-weight="700" letter-spacing="2" fill="#bdbdbd">MORE SPOTS</text>
      <polyline points="58,530 115,530 170,500 235,515 300,490 375,505 445,470 510,480" fill="none" stroke="#ff5a1f" stroke-width="3" stroke-linecap="round" stroke-linejoin="round"/>
      <circle cx="58" cy="530" r="6" fill="#ff5a1f"/>
      <circle cx="510" cy="480" r="6" fill="#ff5a1f"/>
      <text x="1144" y="590" text-anchor="end" font-size="11" font-weight="700" fill="#737373">skate-spots.org/newsletter</text>
    </g>
  </svg>`;

  const svgBuffer = Buffer.from(overlay);
  await sharp({
    create: { width: 1200, height: 630, channels: 4, background: '#080808' },
  })
    .composite([
      { input: hero, left: 620, top: 130, blend: 'over' },
      { input: svgBuffer, left: 0, top: 0, blend: 'over' },
    ])
    .png({ quality: 92 })
    .toFile(outputPath);

  return outputPath;
}

if (process.argv[1]?.endsWith('newsletter-cover.ts')) {
  const out = process.argv[2] ?? '/tmp/opencode/newsletter-cover.png';
  await generateNewsletterCover({
    number: 7,
    dateLabel: '28 OCTOBER 2026',
    coverTitle: 'THE PRIVATE CHAT GROWS UP',
    outputPath: out,
  });
  console.log(out);
}