Add caching layer and database helper

- Add CacheHelper for file-based caching with TTL support - Add Database helper for centralized connection management - Update WorkflowModel to cache status transitions (10 min TTL) - Update UserPreferencesModel to cache user prefs (5 min TTL) - Update manage_workflows.php to clear cache on changes - Update get_users.php to use Database helper (example migration) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
2026-01-29 10:53:26 -05:00
parent 1101558fca
commit d2a8c73e2c
6 changed files with 504 additions and 91 deletions
--- a/helpers/Database.php
+++ b/helpers/Database.php
@@ -0,0 +1,174 @@
+<?php
+/**
+ * Database Connection Factory
+ *
+ * Centralizes database connection creation and management.
+ * Provides a singleton connection for the request lifecycle.
+ */
+class Database {
+    private static $connection = null;
+
+    /**
+     * Get database connection (singleton pattern)
+     *
+     * @return mysqli Database connection
+     * @throws Exception If connection fails
+     */
+    public static function getConnection() {
+        if (self::$connection === null) {
+            self::$connection = self::createConnection();
+        }
+
+        // Check if connection is still alive
+        if (!self::$connection->ping()) {
+            self::$connection = self::createConnection();
+        }
+
+        return self::$connection;
+    }
+
+    /**
+     * Create a new database connection
+     *
+     * @return mysqli Database connection
+     * @throws Exception If connection fails
+     */
+    private static function createConnection() {
+        // Ensure config is loaded
+        if (!isset($GLOBALS['config'])) {
+            require_once dirname(__DIR__) . '/config/config.php';
+        }
+
+        $conn = new mysqli(
+            $GLOBALS['config']['DB_HOST'],
+            $GLOBALS['config']['DB_USER'],
+            $GLOBALS['config']['DB_PASS'],
+            $GLOBALS['config']['DB_NAME']
+        );
+
+        if ($conn->connect_error) {
+            throw new Exception("Database connection failed: " . $conn->connect_error);
+        }
+
+        // Set charset to utf8mb4 for proper Unicode support
+        $conn->set_charset('utf8mb4');
+
+        return $conn;
+    }
+
+    /**
+     * Close the database connection
+     */
+    public static function close() {
+        if (self::$connection !== null) {
+            self::$connection->close();
+            self::$connection = null;
+        }
+    }
+
+    /**
+     * Begin a transaction
+     *
+     * @return bool Success
+     */
+    public static function beginTransaction() {
+        return self::getConnection()->begin_transaction();
+    }
+
+    /**
+     * Commit a transaction
+     *
+     * @return bool Success
+     */
+    public static function commit() {
+        return self::getConnection()->commit();
+    }
+
+    /**
+     * Rollback a transaction
+     *
+     * @return bool Success
+     */
+    public static function rollback() {
+        return self::getConnection()->rollback();
+    }
+
+    /**
+     * Execute a query and return results
+     *
+     * @param string $sql SQL query with placeholders
+     * @param string $types Parameter types (i=int, s=string, d=double, b=blob)
+     * @param array $params Parameters to bind
+     * @return mysqli_result|bool Query result
+     */
+    public static function query($sql, $types = '', $params = []) {
+        $conn = self::getConnection();
+
+        if (empty($types) || empty($params)) {
+            return $conn->query($sql);
+        }
+
+        $stmt = $conn->prepare($sql);
+        if (!$stmt) {
+            throw new Exception("Query preparation failed: " . $conn->error);
+        }
+
+        $stmt->bind_param($types, ...$params);
+        $stmt->execute();
+
+        $result = $stmt->get_result();
+        $stmt->close();
+
+        return $result;
+    }
+
+    /**
+     * Execute an INSERT/UPDATE/DELETE and return affected rows
+     *
+     * @param string $sql SQL query with placeholders
+     * @param string $types Parameter types
+     * @param array $params Parameters to bind
+     * @return int Affected rows (-1 on failure)
+     */
+    public static function execute($sql, $types = '', $params = []) {
+        $conn = self::getConnection();
+
+        $stmt = $conn->prepare($sql);
+        if (!$stmt) {
+            throw new Exception("Query preparation failed: " . $conn->error);
+        }
+
+        if (!empty($types) && !empty($params)) {
+            $stmt->bind_param($types, ...$params);
+        }
+
+        if ($stmt->execute()) {
+            $affected = $stmt->affected_rows;
+            $stmt->close();
+            return $affected;
+        }
+
+        $error = $stmt->error;
+        $stmt->close();
+        throw new Exception("Query execution failed: " . $error);
+    }
+
+    /**
+     * Get the last insert ID
+     *
+     * @return int Last insert ID
+     */
+    public static function lastInsertId() {
+        return self::getConnection()->insert_id;
+    }
+
+    /**
+     * Escape a string for use in queries (prefer prepared statements)
+     *
+     * @param string $string String to escape
+     * @return string Escaped string
+     */
+    public static function escape($string) {
+        return self::getConnection()->real_escape_string($string);
+    }
+}