Update: 2026-05-08 02:11:29

app/Core/AI.php

@@ -103,6 +103,71 @@ class AI
             return null;
         }
 
+        // Track token usage from Gemini response
+        $usage = $result['usageMetadata'] ?? [];
+        if (!empty($usage)) {
+            self::logTokenUsage($usage);
+        }
+
         return $data;
     }
+
+    /**
+     * Log AI token usage to the database for cost tracking
+     */
+    private static function logTokenUsage(array $usage): void
+    {
+        try {
+            $db = Database::getInstance();
+
+            $inputTokens  = (int)($usage['promptTokenCount'] ?? 0);
+            $outputTokens = (int)($usage['candidatesTokenCount'] ?? 0);
+            $totalTokens  = (int)($usage['totalTokenCount'] ?? ($inputTokens + $outputTokens));
+
+            // Gemini Flash Lite pricing: $0.075/1M input, $0.30/1M output
+            $inputCost  = ($inputTokens / 1000000) * 0.075;
+            $outputCost = ($outputTokens / 1000000) * 0.30;
+            $totalCostUsd = $inputCost + $outputCost;
+            $totalCostJod = $totalCostUsd * 0.709; // 1 USD ≈ 0.709 JOD
+
+            $db->prepare("
+                INSERT INTO ai_usage_log (id, input_tokens, output_tokens, total_tokens, cost_usd, cost_jod, model, created_at)
+                VALUES (UUID(), ?, ?, ?, ?, ?, 'gemini-flash-lite', NOW())
+            ")->execute([
+                $inputTokens,
+                $outputTokens,
+                $totalTokens,
+                round($totalCostUsd, 8),
+                round($totalCostJod, 8),
+            ]);
+        } catch (\Exception $e) {
+            // Never crash the main flow for logging
+            error_log("[AI] Token usage log failed: " . $e->getMessage());
+        }
+    }
+
+    /**
+     * Get aggregated AI usage stats
+     */
+    public static function getUsageStats(?string $tenantId = null): array
+    {
+        try {
+            $db = Database::getInstance();
+            $stmt = $db->query("
+                SELECT 
+                    COUNT(*) as total_requests,
+                    COALESCE(SUM(input_tokens), 0) as total_input_tokens,
+                    COALESCE(SUM(output_tokens), 0) as total_output_tokens,
+                    COALESCE(SUM(total_tokens), 0) as total_tokens,
+                    COALESCE(SUM(cost_usd), 0) as total_cost_usd,
+                    COALESCE(SUM(cost_jod), 0) as total_cost_jod,
+                    COALESCE(AVG(total_tokens), 0) as avg_tokens_per_request,
+                    COALESCE(AVG(cost_jod), 0) as avg_cost_jod_per_request
+                FROM ai_usage_log
+            ");
+            return $stmt->fetch() ?: [];
+        } catch (\Exception $e) {
+            return [];
+        }
+    }
 }