feat(blog): add automated PostHog tiles update workflow

.github/workflows/blog-posthog-tiles.yml

@@ -0,0 +1,38 @@
+name: Blog PostHog Tiles
+
+# Re-bakes the static "Blog posts published per month" and "Blog library age"
+# PostHog tiles from frontmatter publish dates whenever blog content changes,
+# so they stay current with no manual refresh. See
+# apps/blog/scripts/update-posthog-blog-tiles.mjs.
+
+on:
+  workflow_dispatch:
+  push:
+    branches: [main]
+    paths: [apps/blog/content/blog/**/*.mdx]
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+permissions: {}
+
+jobs:
+  update-tiles:
+    name: Update PostHog blog tiles
+    timeout-minutes: 10
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: "20"
+
+      - name: Re-bake PostHog tiles from frontmatter
+        run: node apps/blog/scripts/update-posthog-blog-tiles.mjs
+        env:
+          POSTHOG_API_KEY: ${{ secrets.POSTHOG_API_KEY }}

apps/blog/scripts/update-posthog-blog-tiles.mjs

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+// Re-bakes the static PostHog blog tiles from blog frontmatter so they stay
+// current with no manual refresh.
+//
+// Tiles updated (PostHog project 60295, dashboard "Blog SEO & Performance"):
+//   - "Blog posts published per month"            (insight 9555387 / 1eGn424G)
+//   - "Blog library age — older vs younger 12mo"  (insight 9555402 / IasjsfXT)
+//   - "Recent posts ranked by pageviews"          (insight 9497434 / D2eDZ3eq)
+//
+// Run by .github/workflows/blog-posthog-tiles.yml on every push to main that
+// touches apps/blog/content/blog/**. The first two tiles are driven by a
+// publish-month histogram (frontmatter `date`); the recent-posts tile is driven
+// by the list of posts published OR updated in the last 30 days (frontmatter
+// `date` / `updatedAt`).
+//
+// Local dry run (prints the queries, no API call):
+//   node apps/blog/scripts/update-posthog-blog-tiles.mjs --dry-run
+
+import { readFileSync, readdirSync } from "node:fs";
+import { fileURLToPath } from "node:url";
+import { dirname, join } from "node:path";
+
+const PROJECT_ID = 60295;
+const HOST = "https://us.posthog.com";
+
+// Numeric insight ids (short ids in comments) on the Blog SEO & Performance dashboard.
+const INSIGHTS = {
+  postsPerMonth: 9555387, // 1eGn424G
+  libraryAge: 9555402, // IasjsfXT
+  recentPosts: 9497434, // D2eDZ3eq
+};
+
+const RECENT_DAYS = 30;
+
+const CONTENT_DIR = join(dirname(fileURLToPath(import.meta.url)), "..", "content", "blog");
+
+/** Read the frontmatter block of every post: { slug, date, updatedAt }. */
+function readPosts() {
+  const posts = [];
+  for (const entry of readdirSync(CONTENT_DIR, { withFileTypes: true })) {
+    if (!entry.isDirectory()) continue;
+    let raw;
+    try {
+      raw = readFileSync(join(CONTENT_DIR, entry.name, "index.mdx"), "utf8");
+    } catch {
+      continue; // directory without an index.mdx
+    }
+    const fm = raw.startsWith("---") ? (raw.split(/^---\s*$/m)[1] ?? "") : raw;
+    const date = (fm.match(/^date:\s*["']?(\d{4}-\d{2}-\d{2})/m) ?? [])[1] ?? null;
+    const updatedAt = (fm.match(/^updatedAt:\s*["']?(\d{4}-\d{2}-\d{2})/m) ?? [])[1] ?? null;
+    posts.push({ slug: entry.name, date, updatedAt });
+  }
+  return posts;
+}
+
+/** Sorted [ ['YYYY-MM', count], ... ] histogram of publish months. */
+function publishHistogram(posts) {
+  const counts = new Map();
+  for (const { date } of posts) {
+    if (!date) continue;
+    const month = date.slice(0, 7);
+    counts.set(month, (counts.get(month) ?? 0) + 1);
+  }
+  return [...counts.entries()].sort((a, b) => (a[0] < b[0] ? -1 : 1));
+}
+
+/** Slugs of posts published OR updated within the last RECENT_DAYS days. */
+function recentSlugs(posts) {
+  const cutoff = new Date(Date.now() - RECENT_DAYS * 86400000).toISOString().slice(0, 10);
+  return posts
+    .filter((p) => (p.date && p.date > cutoff) || (p.updatedAt && p.updatedAt > cutoff))
+    .map((p) => p.slug)
+    .sort();
+}
+
+function tuplesLiteral(hist) {
+  return hist.map(([month, count]) => `tuple('${month}',${count})`).join(",");
+}
+
+function postsPerMonthQuery(tuples) {
+  return {
+    kind: "DataVisualizationNode",
+    display: "ActionsBar",
+    source: {
+      kind: "HogQLQuery",
+      query: `SELECT toDate(concat(t.1, '-01')) AS month, t.2 AS posts FROM (SELECT arrayJoin([${tuples}]) AS t) ORDER BY month`,
+    },
+    chartSettings: {
+      xAxis: { column: "month" },
+      yAxis: [{ column: "posts", settings: { display: { label: "Posts published" } } }],
+    },
+  };
+}
+
+function libraryAgeQuery(tuples) {
+  const query =
+    `WITH hist AS (SELECT toDate(concat(t.1, '-01')) AS pub, t.2 AS cnt FROM (SELECT arrayJoin([${tuples}]) AS t)) ` +
+    `SELECT M AS month, ` +
+    `sumIf(cnt, pub > M - toIntervalMonth(12) AND pub <= M) AS younger_than_12mo, ` +
+    `sumIf(cnt, pub <= M - toIntervalMonth(12)) AS older_than_12mo ` +
+    `FROM (SELECT arrayJoin(arrayMap(i -> toStartOfMonth(today()) - toIntervalMonth(i), range(0, 36))) AS M) months ` +
+    `CROSS JOIN hist GROUP BY M ORDER BY M`;
+  return {
+    kind: "DataVisualizationNode",
+    display: "ActionsStackedBar",
+    source: { kind: "HogQLQuery", query },
+    chartSettings: {
+      xAxis: { column: "month" },
+      yAxis: [
+        { column: "younger_than_12mo", settings: { display: { label: "< 12 months" } } },
+        { column: "older_than_12mo", settings: { display: { label: "> 12 months" } } },
+      ],
+    },
+  };
+}
+
+function recentPostsQuery(slugs) {
+  const quote = (s) => `'${s.replace(/\\/g, "\\\\").replace(/'/g, "\\'")}'`;
+  const arr = slugs.length ? `[${slugs.map(quote).join(",")}]` : "CAST([] AS Array(String))";
+  const query =
+    `WITH recent AS (SELECT arrayJoin(${arr}) AS slug), ` +
+    `pv AS (SELECT properties.$pathname AS path, count() AS pageviews, count(DISTINCT person_id) AS visitors ` +
+    `FROM events WHERE event = '$pageview' AND properties.$host = 'www.prisma.io' ` +
+    `AND timestamp >= now() - INTERVAL 30 DAY AND properties.$pathname LIKE '/blog/%' GROUP BY path) ` +
+    `SELECT path, pageviews, visitors, rank, multiIf(rank <= 3, 'Top 3', rank > total - 3, 'Bottom 3', '') AS tier ` +
+    `FROM (SELECT concat('/blog/', recent.slug) AS path, coalesce(pv.pageviews, 0) AS pageviews, ` +
+    `coalesce(pv.visitors, 0) AS visitors, row_number() OVER (ORDER BY coalesce(pv.pageviews, 0) DESC) AS rank, ` +
+    `count() OVER () AS total FROM recent LEFT JOIN pv ON pv.path = concat('/blog/', recent.slug)) ` +
+    `ORDER BY rank LIMIT 100`;
+  return { kind: "DataVisualizationNode", display: "ActionsTable", source: { kind: "HogQLQuery", query } };
+}
+
+async function patchInsight(id, query) {
+  const res = await fetch(`${HOST}/api/projects/${PROJECT_ID}/insights/${id}/`, {
+    method: "PATCH",
+    headers: {
+      "Content-Type": "application/json",
+      Authorization: `Bearer ${process.env.POSTHOG_API_KEY}`,
+    },
+    body: JSON.stringify({ query }),
+  });
+  if (!res.ok) {
+    throw new Error(`PATCH insight ${id} failed: ${res.status} ${await res.text()}`);
+  }
+}
+
+const posts = readPosts();
+const hist = publishHistogram(posts);
+const tuples = tuplesLiteral(hist);
+const total = hist.reduce((sum, [, count]) => sum + count, 0);
+const recent = recentSlugs(posts);
+console.log(
+  `Blog posts: ${total} across ${hist.length} months (${hist[0]?.[0]} – ${hist.at(-1)?.[0]}); ${recent.length} recent (≤${RECENT_DAYS}d).`,
+);
+
+if (process.argv.includes("--dry-run")) {
+  console.log("\nDRY RUN — queries that would be written (no API call):\n");
+  console.log("posts-per-month:\n" + postsPerMonthQuery(tuples).source.query + "\n");
+  console.log("library-age:\n" + libraryAgeQuery(tuples).source.query + "\n");
+  console.log("recent slugs (" + recent.length + "): " + recent.join(", ") + "\n");
+  console.log("recent-posts:\n" + recentPostsQuery(recent).source.query);
+  process.exit(0);
+}
+
+if (!process.env.POSTHOG_API_KEY) {
+  console.error("Error: POSTHOG_API_KEY is not set. Set the repo secret, or pass --dry-run to preview.");
+  process.exit(1);
+}
+
+await patchInsight(INSIGHTS.postsPerMonth, postsPerMonthQuery(tuples));
+console.log(`Updated posts-per-month insight (${INSIGHTS.postsPerMonth}).`);
+await patchInsight(INSIGHTS.libraryAge, libraryAgeQuery(tuples));
+console.log(`Updated library-age insight (${INSIGHTS.libraryAge}).`);
+await patchInsight(INSIGHTS.recentPosts, recentPostsQuery(recent));
+console.log(`Updated recent-posts insight (${INSIGHTS.recentPosts}).`);
+console.log("Done.");