init claude-code

utils/suggestions/skillUsageTracking.ts

@@ -0,0 +1,55 @@
+import { getGlobalConfig, saveGlobalConfig } from '../config.js'
+
+const SKILL_USAGE_DEBOUNCE_MS = 60_000
+
+// Process-lifetime debounce cache — avoids lock + read + parse on debounced
+// calls. Same pattern as lastConfigStatTime / globalConfigWriteCount in config.ts.
+const lastWriteBySkill = new Map<string, number>()
+
+/**
+ * Records a skill usage for ranking purposes.
+ * Updates both usage count and last used timestamp.
+ */
+export function recordSkillUsage(skillName: string): void {
+  const now = Date.now()
+  const lastWrite = lastWriteBySkill.get(skillName)
+  // The ranking algorithm uses a 7-day half-life, so sub-minute granularity
+  // is irrelevant. Bail out before saveGlobalConfig to avoid lock + file I/O.
+  if (lastWrite !== undefined && now - lastWrite < SKILL_USAGE_DEBOUNCE_MS) {
+    return
+  }
+  lastWriteBySkill.set(skillName, now)
+  saveGlobalConfig(current => {
+    const existing = current.skillUsage?.[skillName]
+    return {
+      ...current,
+      skillUsage: {
+        ...current.skillUsage,
+        [skillName]: {
+          usageCount: (existing?.usageCount ?? 0) + 1,
+          lastUsedAt: now,
+        },
+      },
+    }
+  })
+}
+
+/**
+ * Calculates a usage score for a skill based on frequency and recency.
+ * Higher scores indicate more frequently and recently used skills.
+ *
+ * The score uses exponential decay with a half-life of 7 days,
+ * meaning usage from 7 days ago is worth half as much as usage today.
+ */
+export function getSkillUsageScore(skillName: string): number {
+  const config = getGlobalConfig()
+  const usage = config.skillUsage?.[skillName]
+  if (!usage) return 0
+
+  // Recency decay: halve score every 7 days
+  const daysSinceUse = (Date.now() - usage.lastUsedAt) / (1000 * 60 * 60 * 24)
+  const recencyFactor = Math.pow(0.5, daysSinceUse / 7)
+
+  // Minimum recency factor of 0.1 to avoid completely dropping old but heavily used skills
+  return usage.usageCount * Math.max(recencyFactor, 0.1)
+}