added google vision caption support

src/endpoints/google.js

@@ -0,0 +1,56 @@
+const { readSecret, SECRET_KEYS } = require('./secrets');
+const fetch = require('node-fetch').default;
+const express = require('express');
+const { jsonParser } = require('../express-common');
+const { MAKERSUITE_SAFETY } = require('../constants');
+
+const router = express.Router();
+
+router.post('/caption-image', jsonParser, async (request, response) => {
+    try {
+        const url = `https://generativelanguage.googleapis.com/v1beta/models/gemini-pro-vision:generateContent?key=${readSecret(SECRET_KEYS.MAKERSUITE)}`;
+        const body = {
+            contents: [{
+                parts: [
+                    { text: request.body.prompt },
+                    { inlineData: {
+                        mimeType: 'image/png',
+                        data: request.body.image,
+                    },
+                    }],
+            }],
+            safetySettings: MAKERSUITE_SAFETY,
+            generationConfig: { maxOutputTokens: 1000 },
+        };
+
+        const result = await fetch(url, {
+            body: JSON.stringify(body),
+            method: 'POST',
+            headers: {
+                'Content-Type': 'application/json',
+            },
+            timeout: 0,
+        });
+
+        console.log('Multimodal captioning request', body);
+
+        if (!result.ok) {
+            console.log(`MakerSuite API returned error: ${result.status} ${result.statusText} ${await result.text()}`);
+            return response.status(result.status).send({ error: true });
+        }
+
+        const data = await result.json();
+
+        const caption = data?.candidates[0].content.parts[0].text;
+        if (!caption) {
+            return response.status(500).send('No caption found');
+        }
+
+        return response.json({ caption });
+    } catch (error) {
+        console.error(error);
+        response.status(500).send('Internal server error');
+    }
+});
+
+module.exports = { router };