Add ai functionality

src/services/ai/ai.ts

@@ -0,0 +1,44 @@
+import { GoogleGenAI } from "@google/genai";
+import { config } from "../../config.js";
+
+const googleAI = new GoogleGenAI({
+    apiKey: config.app.ai.api.key,
+});
+
+const getTextGemini = async (input: string): Promise<string> => {
+    const response = await googleAI.models.generateContent({
+        model: "gemini-3-flash-preview",
+        contents: input,
+    });
+
+    return response.text ?? "AI Error";
+};
+
+const getImageNanoBanana = async (
+    input: string,
+): Promise<Buffer<ArrayBuffer> | undefined> => {
+    const response = await googleAI.models.generateContent({
+        model: "gemini-2.5-flash-image",
+        contents: input,
+    });
+
+    const firstCandidate = (response.candidates ?? [])[0];
+    const parts = firstCandidate?.content?.parts ?? [];
+
+    let buffer: Buffer<ArrayBuffer> | undefined = undefined;
+
+    parts.forEach((part) => {
+        if (part.inlineData) {
+            const imageData = part.inlineData.data;
+            if (!imageData) {
+                return;
+            }
+
+            buffer = Buffer.from(imageData, "base64");
+        }
+    });
+
+    return buffer;
+};
+
+export { getTextGemini, getImageNanoBanana };