fix: sanitize oversized image payloads

src/agents/tool-images.ts

@@ -1,5 +1,7 @@
 import type { AgentToolResult } from "@mariozechner/pi-agent-core";
+import type { ImageContent } from "@mariozechner/pi-ai";
 
+import { createSubsystemLogger } from "../logging.js";
 import { getImageMetadata, resizeToJpeg } from "../media/image-ops.js";
 
 type ToolContentBlock = AgentToolResult<unknown>["content"][number];
@@ -14,6 +16,7 @@ type TextContentBlock = Extract<ToolContentBlock, { type: "text" }>;
 // and recompress base64 image blocks when they exceed these limits.
 const MAX_IMAGE_DIMENSION_PX = 2000;
 const MAX_IMAGE_BYTES = 5 * 1024 * 1024;
+const log = createSubsystemLogger("agents/tool-images");
 
 function isImageBlock(block: unknown): block is ImageContentBlock {
   if (!block || typeof block !== "object") return false;
@@ -41,26 +44,41 @@ async function resizeImageBase64IfNeeded(params: {
   mimeType: string;
   maxDimensionPx: number;
   maxBytes: number;
-}): Promise<{ base64: string; mimeType: string; resized: boolean }> {
+  label?: string;
+}): Promise<{
+  base64: string;
+  mimeType: string;
+  resized: boolean;
+  width?: number;
+  height?: number;
+}> {
   const buf = Buffer.from(params.base64, "base64");
   const meta = await getImageMetadata(buf);
   const width = meta?.width;
   const height = meta?.height;
   const overBytes = buf.byteLength > params.maxBytes;
-  const maxDim = Math.max(width ?? 0, height ?? 0);
-  if (typeof width !== "number" || typeof height !== "number") {
-    if (!overBytes) {
-      return {
-        base64: params.base64,
-        mimeType: params.mimeType,
-        resized: false,
-      };
-    }
-  } else if (!overBytes && width <= params.maxDimensionPx && height <= params.maxDimensionPx) {
-    return { base64: params.base64, mimeType: params.mimeType, resized: false };
+  const hasDimensions = typeof width === "number" && typeof height === "number";
+  if (hasDimensions && !overBytes && width <= params.maxDimensionPx && height <= params.maxDimensionPx) {
+    return {
+      base64: params.base64,
+      mimeType: params.mimeType,
+      resized: false,
+      width,
+      height,
+    };
+  }
+  if (hasDimensions && (width > params.maxDimensionPx || height > params.maxDimensionPx || overBytes)) {
+    log.warn("Image exceeds limits; resizing", {
+      label: params.label,
+      width,
+      height,
+      maxDimensionPx: params.maxDimensionPx,
+      maxBytes: params.maxBytes,
+    });
   }
 
   const qualities = [85, 75, 65, 55, 45, 35];
+  const maxDim = hasDimensions ? Math.max(width ?? 0, height ?? 0) : params.maxDimensionPx;
   const sideStart = maxDim > 0 ? Math.min(params.maxDimensionPx, maxDim) : params.maxDimensionPx;
   const sideGrid = [sideStart, 1800, 1600, 1400, 1200, 1000, 800]
     .map((v) => Math.min(params.maxDimensionPx, v))
@@ -80,10 +98,23 @@ async function resizeImageBase64IfNeeded(params: {
         smallest = { buffer: out, size: out.byteLength };
       }
       if (out.byteLength <= params.maxBytes) {
+        log.info("Image resized", {
+          label: params.label,
+          width,
+          height,
+          maxDimensionPx: params.maxDimensionPx,
+          maxBytes: params.maxBytes,
+          originalBytes: buf.byteLength,
+          resizedBytes: out.byteLength,
+          quality,
+          side,
+        });
         return {
           base64: out.toString("base64"),
           mimeType: "image/jpeg",
           resized: true,
+          width,
+          height,
         };
       }
     }
@@ -127,6 +158,7 @@ export async function sanitizeContentBlocksImages(
         mimeType,
         maxDimensionPx,
         maxBytes,
+        label,
       });
       out.push({
         ...block,
@@ -144,6 +176,17 @@ export async function sanitizeContentBlocksImages(
   return out;
 }
 
+export async function sanitizeImageBlocks(
+  images: ImageContent[],
+  label: string,
+  opts: { maxDimensionPx?: number; maxBytes?: number } = {},
+): Promise<{ images: ImageContent[]; dropped: number }> {
+  if (images.length === 0) return { images, dropped: 0 };
+  const sanitized = await sanitizeContentBlocksImages(images as ToolContentBlock[], label, opts);
+  const next = sanitized.filter(isImageBlock) as ImageContent[];
+  return { images: next, dropped: Math.max(0, images.length - next.length) };
+}
+
 export async function sanitizeToolResultImages(
   result: AgentToolResult<unknown>,
   label: string,