Implement Enterprise Logic (Redis, Phone Auth, Full Schema)

backend/app/Core/RedisClient.php

@@ -0,0 +1,62 @@
+<?php
+
+namespace App\Core;
+
+/**
+ * Core Redis Client for managing connections.
+ * Handles Sessions, Rate Limiting, and caching using PHP Redis extension.
+ */
+class RedisClient
+{
+    private static ?\Redis $instance = null;
+
+    /**
+     * Get the singleton Redis connection instance
+     */
+    public static function getInstance(): \Redis
+    {
+        if (self::$instance === null) {
+            try {
+                $redis = new \Redis();
+                
+                $host = getenv('REDIS_HOST') ?: '127.0.0.1';
+                $port = (int)(getenv('REDIS_PORT') ?: 6379);
+                $password = getenv('REDIS_PASSWORD') ?: null;
+                
+                // Connect with a 2 second timeout
+                if (!$redis->connect($host, $port, 2.0)) {
+                    throw new \RuntimeException("Could not connect to Redis server at $host:$port");
+                }
+
+                // Authenticate if password is provided
+                if ($password) {
+                    if (!$redis->auth($password)) {
+                        throw new \RuntimeException("Redis authentication failed.");
+                    }
+                }
+
+                // Set prefix for Saqel to avoid collisions
+                $redis->setOption(\Redis::OPT_PREFIX, 'saqel:');
+
+                self::$instance = $redis;
+            } catch (\Exception $e) {
+                // In production, fallback gracefully or throw HTTP 500
+                error_log("Redis Connection Error: " . $e->getMessage());
+                throw new \RuntimeException("Redis is unavailable. Please ensure the Redis server is running.");
+            }
+        }
+
+        return self::$instance;
+    }
+    
+    /**
+     * Helper to close the connection explicitly
+     */
+    public static function close(): void
+    {
+        if (self::$instance !== null) {
+            self::$instance->close();
+            self::$instance = null;
+        }
+    }
+}