feat(cache): implement regex101 cache table and queries for API response caching

src/lib/server/db/migrations.ts

@@ -18,6 +18,7 @@ import { migration as migration013 } from './migrations/013_add_upgrade_dry_run.
 import { migration as migration014 } from './migrations/014_create_ai_settings.ts';
 import { migration as migration015 } from './migrations/015_create_arr_sync_tables.ts';
 import { migration as migration016 } from './migrations/016_add_should_sync_flags.ts';
+import { migration as migration017 } from './migrations/017_create_regex101_cache.ts';
 
 export interface Migration {
 	version: number;
@@ -251,7 +252,8 @@ export function loadMigrations(): Migration[] {
 		migration013,
 		migration014,
 		migration015,
-		migration016
+		migration016,
+		migration017
 	];
 
 	// Sort by version number

src/lib/server/db/migrations/017_create_regex101_cache.ts

@@ -0,0 +1,18 @@
+import type { Migration } from '../migrations.ts';
+
+export const migration: Migration = {
+	version: 17,
+	name: 'Create regex101 cache table',
+
+	up: `
+		CREATE TABLE IF NOT EXISTS regex101_cache (
+			regex101_id TEXT PRIMARY KEY,
+			response TEXT NOT NULL,
+			fetched_at DATETIME DEFAULT CURRENT_TIMESTAMP
+		);
+	`,
+
+	down: `
+		DROP TABLE IF EXISTS regex101_cache;
+	`
+};

src/lib/server/db/queries/regex101Cache.ts

@@ -0,0 +1,54 @@
+import { db } from '../db.ts';
+
+/**
+ * Types for regex101_cache table
+ */
+export interface Regex101Cache {
+	regex101_id: string;
+	response: string;
+	fetched_at: string;
+}
+
+/**
+ * All queries for regex101_cache table
+ */
+export const regex101CacheQueries = {
+	/**
+	 * Get cached response by regex101 ID
+	 */
+	get(regex101Id: string): Regex101Cache | undefined {
+		return db.queryFirst<Regex101Cache>(
+			'SELECT * FROM regex101_cache WHERE regex101_id = ?',
+			regex101Id
+		);
+	},
+
+	/**
+	 * Store response in cache (insert or replace)
+	 */
+	set(regex101Id: string, response: string): void {
+		db.execute(
+			'INSERT OR REPLACE INTO regex101_cache (regex101_id, response) VALUES (?, ?)',
+			regex101Id,
+			response
+		);
+	},
+
+	/**
+	 * Delete a cached entry
+	 */
+	delete(regex101Id: string): boolean {
+		const affected = db.execute(
+			'DELETE FROM regex101_cache WHERE regex101_id = ?',
+			regex101Id
+		);
+		return affected > 0;
+	},
+
+	/**
+	 * Clear all cached entries
+	 */
+	clear(): number {
+		return db.execute('DELETE FROM regex101_cache');
+	}
+};

src/lib/server/db/schema.sql

@@ -383,3 +383,15 @@ CREATE INDEX idx_upgrade_configs_arr_instance ON upgrade_configs(arr_instance_id
 -- Arr sync indexes (Migration: 015_create_arr_sync_tables.ts)
 CREATE INDEX idx_arr_sync_quality_profiles_instance ON arr_sync_quality_profiles(instance_id);
 CREATE INDEX idx_arr_sync_delay_profiles_instance ON arr_sync_delay_profiles(instance_id);
+
+-- ==============================================================================
+-- TABLE: regex101_cache
+-- Purpose: Cache regex101 API responses to avoid redundant fetches
+-- Migration: 017_create_regex101_cache.ts
+-- ==============================================================================
+
+CREATE TABLE regex101_cache (
+    regex101_id TEXT PRIMARY KEY,           -- Versioned ID (e.g., "ABC123/1")
+    response TEXT NOT NULL,                 -- Full JSON response with test results
+    fetched_at DATETIME DEFAULT CURRENT_TIMESTAMP
+);

src/routes/api/regex101/[id]/+server.ts

@@ -1,6 +1,7 @@
 import { json, error } from '@sveltejs/kit';
 import type { RequestHandler } from './$types';
 import { logger } from '$logger/logger';
+import { regex101CacheQueries } from '$db/queries/regex101Cache.ts';
 
 export interface Regex101UnitTest {
 	description: string;
@@ -89,6 +90,16 @@ export const GET: RequestHandler = async ({ params, fetch }) => {
 		throw error(400, 'Missing regex101 ID');
 	}
 
+	// Check cache first
+	const cached = regex101CacheQueries.get(id);
+	if (cached) {
+		await logger.debug('regex101 cache hit', {
+			source: 'Regex101API',
+			meta: { id }
+		});
+		return json(JSON.parse(cached.response));
+	}
+
 	// Handle ID with optional version (e.g., "ABC123" or "ABC123/1")
 	const [regexId, version] = id.split('/');
 
@@ -136,6 +147,9 @@ export const GET: RequestHandler = async ({ params, fetch }) => {
 			unitTests: testedUnitTests
 		};
 
+		// Cache the result
+		regex101CacheQueries.set(id, JSON.stringify(result));
+
 		return json(result);
 	} catch (err) {
 		if (err && typeof err === 'object' && 'status' in err) {