📝 Add docstrings to gemini-image-generation-function

node/image-generation-with-gemini/src/setup.js

@@ -0,0 +1,36 @@
+import dotenv from 'dotenv';
+import AppwriteService from './appwrite.js';
+
+dotenv.config();
+
+/**
+ * Ensures an Appwrite bucket for generated images exists, creating it if necessary.
+ *
+ * Reads APPWRITE_FUNCTION_API_KEY from environment and uses APPWRITE_BUCKET_ID (defaulting to "Generated_Images")
+ * as the target bucket name. If the API key is missing the function throws an error; any failure is logged
+ * and causes the process to exit with code 1.
+ */
+async function setup() {
+  try {
+    const apiKey = process.env.APPWRITE_FUNCTION_API_KEY;
+    if (!apiKey) {
+      throw new Error("APPWRITE_FUNCTION_API_KEY is not set in environment variables");
+    }
+
+    const bucketId = process.env.APPWRITE_BUCKET_ID ?? 'Generated_Images';
+
+    const appwrite = new AppwriteService(apiKey);
+
+    if (await appwrite.doesGeneratedImageBucketExist(bucketId)) {
+      console.log(`Bucket exists.`);
+    } else {
+      await appwrite.setupGeneratedImageBucket(bucketId);
+      console.log(`Bucket created.`);
+    }
+  } catch (error) {
+    console.error("Setup failed:", error.message);
+    process.exit(1);
+  }
+}
+
+setup();

node/image-generation-with-gemini/src/utils.js

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+import { GoogleGenAI,Modality } from "@google/genai";
+import fs from "node:fs";
+import path from "path";
+import { fileURLToPath } from 'url';
+import dotenv from 'dotenv'
+import AppwriteService from './appwrite.js';
+dotenv.config();
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+
+
+
+const ai = new GoogleGenAI({
+apiKey:process.env.GEMINI_API_KEY
+});
+
+// Ensure output directory exists
+const outputDir = path.resolve(__dirname, "../output");
+if (!fs.existsSync(outputDir)) {
+  fs.mkdirSync(outputDir);
+}
+
+/**
+ * Compute the next sequential image index for files with the given base name in the output directory.
+ * @param {string} [baseName="gemini-image"] - Filename prefix to match (files must end with `.png`).
+ * @returns {number} The next image number: one greater than the largest numeric suffix among matching PNG files, or 1 if none are found.
+ */
+function getNextImageNumber(baseName = "gemini-image") {
+  const files = fs.readdirSync(outputDir)
+    .filter(f => f.startsWith(baseName) && f.endsWith(".png"));
+  const numbers = files.map(f => {
+    const match = f.match(/(\d+)\.png$/);
+    return match ? parseInt(match[1], 10) : 0;
+  });
+  return numbers.length ? Math.max(...numbers) + 1 : 1;
+}
+
+/**
+ * Generate an image from a text prompt using Gemini and save it to the output directory.
+ * @param {string} prompt - The text prompt used to generate the image.
+ * @returns {string} The filesystem path to the saved PNG image.
+ * @throws {Error} If the Gemini API returns no candidates, the response structure is invalid, or no image data is present.
+ */
+export async function generateImage(prompt) {
+    const imageNumber = getNextImageNumber();
+    const outputName = path.join(outputDir, `gemini-image-${imageNumber}.png`);
+  try {
+    const response = await ai.models.generateContent({
+    model: process.env.GEMINI_MODEL || 'gemini-2.0-flash-preview-image-generation',
+      contents: prompt,
+      config: { responseModalities: [Modality.TEXT, Modality.IMAGE] }
+    });
+
+    // Validate that we got at least one candidate back
+    if (!response.candidates || response.candidates.length === 0) {
+      throw new Error("No candidates returned from Gemini API");
+    }
+
+    const candidate = response.candidates[0];
+    // Validate structure of the first candidate
+    if (!candidate.content || !candidate.content.parts) {
+      throw new Error("Invalid response structure from Gemini API");
+    }
+
+    for (const part of candidate.content.parts) {
+      if (part.inlineData) {
+        const buffer = Buffer.from(part.inlineData.data, "base64");
+        fs.writeFileSync(outputName, buffer);
+        console.log(`Image saved as ${outputName}`);
+        return outputName;
+      }
+    }
+
+    throw new Error("No image data returned from Gemini API");
+  } catch (err) {
+    console.error("Error generating image:", err);
+    throw err;
+  }
+}
+
+/**
+ * Upload a local image file to an Appwrite bucket, creating the bucket if it does not exist.
+ * @param {string} imagePath - Local filesystem path of the image to upload.
+ * @returns {object} The Appwrite file creation result object (includes `$id` and file metadata).
+ * @throws {Error} If `APPWRITE_FUNCTION_API_KEY` is not set or if the upload operation fails.
+ */
+export async function uploadImageToAppwrite(imagePath) {
+  try {
+    const bucketId = process.env.APPWRITE_BUCKET_ID ?? 'Generated_Images';
+    const apiKey = process.env.APPWRITE_FUNCTION_API_KEY;
+
+    if (!apiKey) {
+      throw new Error("APPWRITE_FUNCTION_API_KEY is not set in environment variables");
+    }
+
+    const appwrite = new AppwriteService(apiKey);
+
+    // Check if bucket exists, create if it doesn't
+    if (!(await appwrite.doesGeneratedImageBucketExist(bucketId))) {
+      await appwrite.setupGeneratedImageBucket(bucketId);
+      console.log(`Bucket '${bucketId}' created`);
+    }
+
+    // Upload the file
+    const result = await appwrite.createFileFromPath(bucketId, imagePath);
+    console.log(`Image uploaded to Appwrite with file ID: ${result.$id}`);
+
+    return result;
+  } catch (err) {
+    console.error("Error uploading image to Appwrite:", err.message);
+    throw err;
+  }
+}