/**
* Cache management for intent analysis results
*
* Provides an LRU-style cache with automatic cleanup of stale entries.
* Results are cached based on prompt + skills hash to invalidate when
* skill definitions change.
*/
import {
readFileSync,
writeFileSync,
existsSync,
mkdirSync,
readdirSync,
unlinkSync,
statSync
} from "fs";
import { join } from "path";
import { CACHE_TTL_MS, CACHE_CLEANUP_AGE_MS } from "./constants.js";
import type { CacheEntry } from "./types.js";
// Use project root for cache directory, not hooks cwd
const CACHE_DIR = join(
process.env.CLAUDE_PROJECT_DIR || process.cwd(),
".cache",
"intent-analysis"
);
/**
* Read cached intent analysis result
*
* @param key - MD5 hash of prompt + skills configuration
* @returns Cached result if found and not expired, null otherwise
*/
export function readCache(
key: string
): { required: string[]; suggested: string[] } | null {
const cachePath = join(CACHE_DIR, `${key}.json`);
if (!existsSync(cachePath)) {
return null;
}
try {
const data: CacheEntry = JSON.parse(readFileSync(cachePath, "utf-8"));
const age = Date.now() - data.timestamp;
if (age > CACHE_TTL_MS) {
return null; // Expired
}
return data.result;
} catch {
return null;
}
}
/**
* Write intent analysis result to cache
*
* Automatically cleans up cache entries older than 24 hours to prevent unbounded growth.
*
* @param key - MD5 hash of prompt + skills configuration
* @param result - Analysis result to cache
*/
export function writeCache(
key: string,
result: { required: string[]; suggested: string[] }
): void {
// Ensure cache directory exists
if (!existsSync(CACHE_DIR)) {
mkdirSync(CACHE_DIR, { recursive: true });
}
// Cleanup old cache entries (>24 hours)
cleanupOldCacheEntries();
const cachePath = join(CACHE_DIR, `${key}.json`);
const entry: CacheEntry = {
timestamp: Date.now(),
result
};
writeFileSync(cachePath, JSON.stringify(entry));
}
/**
* Remove cache entries older than 24 hours
*
* Runs automatically during writeCache to prevent unbounded cache growth.
* Failures are logged in debug mode but don't fail the operation.
*/
function cleanupOldCacheEntries(): void {
try {
if (!existsSync(CACHE_DIR)) {
return;
}
const files = readdirSync(CACHE_DIR);
const now = Date.now();
files.forEach((file) => {
const filePath = join(CACHE_DIR, file);
try {
const stats = statSync(filePath);
const age = now - stats.mtimeMs;
if (age > CACHE_CLEANUP_AGE_MS) {
unlinkSync(filePath);
}
} catch (err) {
// Log in debug mode for troubleshooting
if (process.env.AIDB_SKILL_DEBUG === "true") {
console.warn(`Cache cleanup: failed to process ${file}:`, err);
}
}
});
} catch (err) {
// Log directory-level errors in debug mode
if (process.env.AIDB_SKILL_DEBUG === "true") {
console.warn("Cache cleanup failed:", err);
}
}
}
