Make metrics reflect autoscaling policies (Refs #137)

src/lib/server/reports/revisions.ts

@@ -1,5 +1,21 @@
 import type Database from 'better-sqlite3';
 
+/** Current policy settings are inputs to historical metrics advice. */
+export function installMetricsPolicyRevisions(handle: Database.Database) {
+    for (const table of ['autoscaling_policies', 'settings'])
+        for (const action of ['INSERT', 'UPDATE', 'DELETE']) {
+            const versions =
+                action === 'INSERT' ? ['NEW'] : action === 'DELETE' ? ['OLD'] : ['OLD', 'NEW'];
+            const condition =
+                table === 'settings'
+                    ? `WHEN ${versions.map((row) => `${row}.key='autoscaling_paused'`).join(' OR ')}`
+                    : '';
+            handle.exec(`CREATE TRIGGER IF NOT EXISTS report_metrics_${table}_${action}
+                AFTER ${action} ON ${table} ${condition}
+                BEGIN UPDATE report_revisions SET revision=revision+1 WHERE topic='metrics'; END;`);
+        }
+}
+
 export function installReportRevisions(handle: Database.Database) {
     handle.exec(`CREATE TABLE IF NOT EXISTS report_revisions (topic TEXT PRIMARY KEY, revision INTEGER NOT NULL DEFAULT 0);
         INSERT OR IGNORE INTO report_revisions(topic) VALUES ('metrics'), ('leaderboard');`);