{master} start bin/cron DB maintenance jobs

bin/cron/mongodb-report-score-decay.js

@@ -0,0 +1,47 @@
+// Makes report scores decay with time.
+// This script is meant to run once per day.
+// It's ok to run it more than that once a day.
+// It's ok to run it less than that once a day.
+// It's ok to run it several times in a row.
+// The script is expected to complete within a couple seconds.
+//
+// Run it with:
+// mongo <IP>:27017/lichess mongodb-report-score-decay.js
+
+const atomMinScore = 5;
+
+db.report2.find(
+  {open:true,'atoms.score':{$gt: atomMinScore}}, // selector
+  {score:1,'atoms.score':1,'atoms.initScore':1,'atoms.at':1} // projection
+).hint('best_open').forEach(report => {
+
+  // what to update in the report
+  const set = {
+    score: 0
+  };
+
+  report.atoms.forEach((atom, index) => {
+    if (!atom.initScore) {
+      // save original score if not yet present
+      atom.initScore = set[`atoms.${index}.initScore`] = atom.score;
+    }
+    atom.score = set[`atoms.${index}.score`] = newScore(atom);
+    set.score += atom.score;
+  });
+
+  if (set.score != report.score) {
+    db.report2.update({ _id: report._id}, {$set:set});
+  }
+});
+
+function newScore(atom) {
+  const minScore = Math.min(atom.initScore, atomMinScore);
+  return Math.max(minScore, atom.initScore - scoreDecay(atom.at));
+}
+
+function scoreDecay(date) {
+  return daysSince(date);
+}
+function daysSince(date) {
+  return Math.floor((new Date().getTime()  - date.getTime() ) / 86400000);
+}