Added automatic image resizing

packages/coding-agent/src/utils/image-resize.ts

@@ -0,0 +1,136 @@
+import type { ImageContent } from "@mariozechner/pi-ai";
+
+export interface ImageResizeOptions {
+	maxWidth?: number; // Default: 2000
+	maxHeight?: number; // Default: 2000
+	jpegQuality?: number; // Default: 80
+}
+
+export interface ResizedImage {
+	data: string; // base64
+	mimeType: string;
+	originalWidth: number;
+	originalHeight: number;
+	width: number;
+	height: number;
+	wasResized: boolean;
+}
+
+const DEFAULT_OPTIONS: Required<ImageResizeOptions> = {
+	maxWidth: 2000,
+	maxHeight: 2000,
+	jpegQuality: 80,
+};
+
+/**
+ * Resize an image to fit within the specified max dimensions.
+ * Returns the original image if it already fits within the limits.
+ *
+ * Uses sharp for image processing. If sharp is not available (e.g., in some
+ * environments), returns the original image unchanged.
+ */
+export async function resizeImage(img: ImageContent, options?: ImageResizeOptions): Promise<ResizedImage> {
+	const opts = { ...DEFAULT_OPTIONS, ...options };
+	const buffer = Buffer.from(img.data, "base64");
+
+	let sharp: typeof import("sharp") | undefined;
+	try {
+		sharp = (await import("sharp")).default;
+	} catch {
+		// Sharp not available - return original image
+		// We can't get dimensions without sharp, so return 0s
+		return {
+			data: img.data,
+			mimeType: img.mimeType,
+			originalWidth: 0,
+			originalHeight: 0,
+			width: 0,
+			height: 0,
+			wasResized: false,
+		};
+	}
+
+	const sharpImg = sharp(buffer);
+	const metadata = await sharpImg.metadata();
+
+	const width = metadata.width ?? 0;
+	const height = metadata.height ?? 0;
+	const format = metadata.format ?? img.mimeType?.split("/")[1] ?? "png";
+
+	// Check if already within limits
+	if (width <= opts.maxWidth && height <= opts.maxHeight) {
+		return {
+			data: img.data,
+			mimeType: img.mimeType ?? `image/${format}`,
+			originalWidth: width,
+			originalHeight: height,
+			width,
+			height,
+			wasResized: false,
+		};
+	}
+
+	// Calculate new dimensions maintaining aspect ratio
+	let newWidth = width;
+	let newHeight = height;
+
+	if (newWidth > opts.maxWidth) {
+		newHeight = Math.round((newHeight * opts.maxWidth) / newWidth);
+		newWidth = opts.maxWidth;
+	}
+	if (newHeight > opts.maxHeight) {
+		newWidth = Math.round((newWidth * opts.maxHeight) / newHeight);
+		newHeight = opts.maxHeight;
+	}
+
+	// Resize the image
+	const resized = await sharp(buffer)
+		.resize(newWidth, newHeight, { fit: "inside", withoutEnlargement: true })
+		.toBuffer();
+
+	// Determine output format - preserve original if possible, otherwise use JPEG
+	let outputMimeType: string;
+	let outputBuffer: Buffer;
+
+	if (format === "jpeg" || format === "jpg") {
+		outputBuffer = await sharp(resized).jpeg({ quality: opts.jpegQuality }).toBuffer();
+		outputMimeType = "image/jpeg";
+	} else if (format === "png") {
+		outputBuffer = resized;
+		outputMimeType = "image/png";
+	} else if (format === "gif") {
+		// GIF resize might not preserve animation; convert to PNG for quality
+		outputBuffer = resized;
+		outputMimeType = "image/png";
+	} else if (format === "webp") {
+		outputBuffer = resized;
+		outputMimeType = "image/webp";
+	} else {
+		// Default to JPEG for unknown formats
+		outputBuffer = await sharp(resized).jpeg({ quality: opts.jpegQuality }).toBuffer();
+		outputMimeType = "image/jpeg";
+	}
+
+	return {
+		data: outputBuffer.toString("base64"),
+		mimeType: outputMimeType,
+		originalWidth: width,
+		originalHeight: height,
+		width: newWidth,
+		height: newHeight,
+		wasResized: true,
+	};
+}
+
+/**
+ * Format a dimension note for resized images.
+ * This helps the model understand the coordinate mapping.
+ */
+export function formatDimensionNote(result: ResizedImage): string | undefined {
+	if (!result.wasResized) {
+		return undefined;
+	}
+
+	const scale = result.originalWidth / result.width;
+	return `[Image: original ${result.originalWidth}x${result.originalHeight}, displayed at ${result.width}x${result.height}. Multiply coordinates by ${scale.toFixed(2)} to map to original image.]`;
+}