note-articles/scripts/generate-banner.js
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Add: OGPバナー画像自動生成 (node-canvas) + 全記事一括生成
2026-02-28 01:03:39 +00:00

219 lines
6.8 KiB
JavaScript

#!/usr/bin/env node
// Banner image generator for docs.techswan.online
// Usage:
// node scripts/generate-banner.js <slug> # single article
// node scripts/generate-banner.js --all # all missing
// node scripts/generate-banner.js --all --force # regenerate all
const { createCanvas, registerFont } = require('canvas');
const matter = require('gray-matter');
const fs = require('fs');
const path = require('path');
// --- Config ---
const W = 1200, H = 630;
const MAX_TITLE_WIDTH = 1000;
const FONT_SIZES = [52, 44, 38];
const MAX_LINES = 3;
const FONT_PATH = '/usr/share/fonts/opentype/noto/NotoSansCJK-Bold.ttc';
if (fs.existsSync(FONT_PATH)) {
registerFont(FONT_PATH, { family: 'Noto Sans CJK JP', weight: 'bold' });
}
const FONT_REGULAR = '/usr/share/fonts/opentype/noto/NotoSansCJK-Regular.ttc';
if (fs.existsSync(FONT_REGULAR)) {
registerFont(FONT_REGULAR, { family: 'Noto Sans CJK JP', weight: 'normal' });
}
const CATEGORIES = {
'docs': { label: 'Blog', color: '#0ea5e9' },
'docs-tech': { label: 'Tech', color: '#10b981' },
};
const ROOT = path.resolve(__dirname, '..');
// --- Text wrapping ---
function tokenize(text) {
// Split into tokens: consecutive ASCII word chars as one token, each CJK char as one token
const tokens = [];
const re = /([A-Za-z0-9._\-]+)|(\s+)|([\s\S])/g;
let m;
while ((m = re.exec(text)) !== null) {
if (m[1]) tokens.push({ text: m[1], breakable: false });
else if (m[2]) tokens.push({ text: ' ', breakable: true });
else if (m[3]) tokens.push({ text: m[3], breakable: true });
}
return tokens;
}
function wrapText(ctx, text, maxWidth, fontSize, fontFamily) {
ctx.font = `bold ${fontSize}px "${fontFamily}", sans-serif`;
const tokens = tokenize(text);
const lines = [];
let currentLine = '';
for (const token of tokens) {
if (token.text === ' ' && currentLine === '') continue; // skip leading space
const testLine = currentLine + token.text;
const metrics = ctx.measureText(testLine);
if (metrics.width > maxWidth && currentLine !== '') {
lines.push(currentLine);
currentLine = token.breakable && token.text === ' ' ? '' : token.text;
} else {
currentLine = testLine;
}
}
if (currentLine) lines.push(currentLine);
return lines;
}
// --- Drawing ---
function drawBanner(title, category) {
const canvas = createCanvas(W, H);
const ctx = canvas.getContext('2d');
const cat = CATEGORIES[category] || CATEGORIES['docs'];
// Background gradient
const grad = ctx.createLinearGradient(0, 0, W, H);
grad.addColorStop(0, '#1a1a2e');
grad.addColorStop(1, '#16213e');
ctx.fillStyle = grad;
ctx.fillRect(0, 0, W, H);
// Decorative circles
ctx.fillStyle = 'rgba(233,69,96,0.15)';
ctx.beginPath(); ctx.arc(1100, 100, 150, 0, Math.PI * 2); ctx.fill();
ctx.fillStyle = 'rgba(14,165,233,0.1)';
ctx.beginPath(); ctx.arc(1050, 500, 200, 0, Math.PI * 2); ctx.fill();
// Accent line
ctx.fillStyle = '#e94560';
ctx.fillRect(60, 80, 6, 120);
// Title - try font sizes until it fits
ctx.fillStyle = '#ffffff';
ctx.textBaseline = 'top';
let lines, fontSize;
for (fontSize of FONT_SIZES) {
lines = wrapText(ctx, title, MAX_TITLE_WIDTH, fontSize, 'Noto Sans CJK JP');
if (lines.length <= MAX_LINES) break;
}
// If still too many lines, truncate
if (lines.length > MAX_LINES) {
lines = lines.slice(0, MAX_LINES);
lines[MAX_LINES - 1] = lines[MAX_LINES - 1].replace(/.$/, '…');
}
const lineHeight = Math.round(fontSize * 1.35);
const titleStartY = 90;
ctx.font = `bold ${fontSize}px "Noto Sans CJK JP", sans-serif`;
lines.forEach((line, i) => {
ctx.fillText(line, 90, titleStartY + i * lineHeight);
});
// Category badge
const badgeY = Math.max(titleStartY + lines.length * lineHeight + 40, 350);
ctx.fillStyle = cat.color;
ctx.beginPath();
ctx.roundRect(60, badgeY, 100, 36, 8);
ctx.fill();
ctx.fillStyle = '#ffffff';
ctx.font = 'bold 18px "Noto Sans CJK JP", sans-serif';
ctx.textBaseline = 'middle';
ctx.fillText(cat.label, 60 + 50 - ctx.measureText(cat.label).width / 2, badgeY + 18);
// Footer
ctx.textBaseline = 'top';
ctx.fillStyle = 'rgba(255,255,255,0.6)';
ctx.font = '20px "Noto Sans CJK JP", sans-serif';
ctx.fillText('雑記 by swallow', 60, 550);
ctx.fillStyle = 'rgba(255,255,255,0.3)';
const siteText = 'docs.techswan.online';
ctx.fillText(siteText, W - 60 - ctx.measureText(siteText).width, 550);
return canvas.toBuffer('image/png');
}
// --- Article discovery ---
function findArticle(slug) {
for (const dir of ['docs-tech', 'docs']) {
const mdPath = path.join(ROOT, dir, slug, 'index.md');
if (fs.existsSync(mdPath)) return { mdPath, category: dir };
}
return null;
}
function getAllArticles() {
const articles = [];
for (const dir of ['docs-tech', 'docs']) {
const dirPath = path.join(ROOT, dir);
if (!fs.existsSync(dirPath)) continue;
for (const slug of fs.readdirSync(dirPath)) {
const mdPath = path.join(dirPath, slug, 'index.md');
if (fs.existsSync(mdPath)) {
articles.push({ slug, mdPath, category: dir });
}
}
}
return articles;
}
// --- Frontmatter update ---
function ensureFrontmatterImage(mdPath) {
const raw = fs.readFileSync(mdPath, 'utf-8');
const parsed = matter(raw);
if (parsed.data.image) return false; // already set
parsed.data.image = './banner.png';
const updated = matter.stringify(parsed.content, parsed.data);
fs.writeFileSync(mdPath, updated);
return true;
}
// --- Main ---
function generateOne(slug, force = false) {
const article = findArticle(slug);
if (!article) {
console.error(`❌ Article not found: ${slug}`);
return false;
}
const { mdPath, category } = article;
const bannerPath = path.join(path.dirname(mdPath), 'banner.png');
if (fs.existsSync(bannerPath) && !force) {
console.log(`⏭️ Skip (exists): ${slug}`);
return true;
}
const parsed = matter(fs.readFileSync(mdPath, 'utf-8'));
const title = parsed.data.title || slug;
const buf = drawBanner(title, category);
fs.writeFileSync(bannerPath, buf);
const updated = ensureFrontmatterImage(mdPath);
console.log(`${slug} → banner.png (${(buf.length / 1024).toFixed(0)}KB)${updated ? ' + frontmatter updated' : ''}`);
return true;
}
// --- CLI ---
const args = process.argv.slice(2);
const force = args.includes('--force');
const all = args.includes('--all');
if (all) {
const articles = getAllArticles();
console.log(`Found ${articles.length} articles`);
let generated = 0;
for (const { slug } of articles) {
if (generateOne(slug, force)) generated++;
}
console.log(`\nDone: ${generated}/${articles.length}`);
} else {
const slug = args.find(a => !a.startsWith('--'));
if (!slug) {
console.log('Usage: node scripts/generate-banner.js <slug> | --all [--force]');
process.exit(1);
}
generateOne(slug, force);
}