refactor(media): share image resize side grid and quality steps

src/agents/tool-images.ts

@@ -1,7 +1,12 @@
 import type { AgentToolResult } from "@mariozechner/pi-agent-core";
 import type { ImageContent } from "@mariozechner/pi-ai";
 import { createSubsystemLogger } from "../logging/subsystem.js";
-import { getImageMetadata, resizeToJpeg } from "../media/image-ops.js";
+import {
+  buildImageResizeSideGrid,
+  getImageMetadata,
+  IMAGE_REDUCE_QUALITY_STEPS,
+  resizeToJpeg,
+} from "../media/image-ops.js";
 import {
   DEFAULT_IMAGE_MAX_BYTES,
   DEFAULT_IMAGE_MAX_DIMENSION_PX,
@@ -101,17 +106,13 @@ async function resizeImageBase64IfNeeded(params: {
     };
   }
 
-  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]
-    .filter((v) => v > 0 && v <= params.maxDimensionPx)
-    .filter((v, i, arr) => v > 0 && arr.indexOf(v) === i)
-    .toSorted((a, b) => b - a);
+  const sideGrid = buildImageResizeSideGrid(params.maxDimensionPx, sideStart);
 
   let smallest: { buffer: Buffer; size: number } | null = null;
   for (const side of sideGrid) {
-    for (const quality of qualities) {
+    for (const quality of IMAGE_REDUCE_QUALITY_STEPS) {
       const out = await resizeToJpeg({
         buffer: buf,
         maxSide: side,

src/browser/screenshot.ts

@@ -1,4 +1,9 @@
-import { getImageMetadata, resizeToJpeg } from "../media/image-ops.js";
+import {
+  buildImageResizeSideGrid,
+  getImageMetadata,
+  IMAGE_REDUCE_QUALITY_STEPS,
+  resizeToJpeg,
+} from "../media/image-ops.js";
 
 export const DEFAULT_BROWSER_SCREENSHOT_MAX_SIDE = 2000;
 export const DEFAULT_BROWSER_SCREENSHOT_MAX_BYTES = 5 * 1024 * 1024;
@@ -22,17 +27,13 @@ export async function normalizeBrowserScreenshot(
     return { buffer };
   }
 
-  const qualities = [85, 75, 65, 55, 45, 35];
   const sideStart = maxDim > 0 ? Math.min(maxSide, maxDim) : maxSide;
-  const sideGrid = [sideStart, 1800, 1600, 1400, 1200, 1000, 800]
-    .map((v) => Math.min(maxSide, v))
-    .filter((v, i, arr) => v > 0 && arr.indexOf(v) === i)
-    .toSorted((a, b) => b - a);
+  const sideGrid = buildImageResizeSideGrid(maxSide, sideStart);
 
   let smallest: { buffer: Buffer; size: number } | null = null;
 
   for (const side of sideGrid) {
-    for (const quality of qualities) {
+    for (const quality of IMAGE_REDUCE_QUALITY_STEPS) {
       const out = await resizeToJpeg({
         buffer,
         maxSide: side,

src/media/image-ops.helpers.test.ts

@@ -0,0 +1,18 @@
+import { describe, expect, it } from "vitest";
+import { buildImageResizeSideGrid, IMAGE_REDUCE_QUALITY_STEPS } from "./image-ops.js";
+
+describe("buildImageResizeSideGrid", () => {
+  it("returns descending unique sides capped by maxSide", () => {
+    expect(buildImageResizeSideGrid(1200, 900)).toEqual([1200, 1000, 900, 800]);
+  });
+
+  it("keeps only positive side values", () => {
+    expect(buildImageResizeSideGrid(0, 0)).toEqual([]);
+  });
+});
+
+describe("IMAGE_REDUCE_QUALITY_STEPS", () => {
+  it("keeps expected quality ladder", () => {
+    expect([...IMAGE_REDUCE_QUALITY_STEPS]).toEqual([85, 75, 65, 55, 45, 35]);
+  });
+});

src/media/image-ops.ts

@@ -10,6 +10,15 @@ export type ImageMetadata = {
   height: number;
 };
 
+export const IMAGE_REDUCE_QUALITY_STEPS = [85, 75, 65, 55, 45, 35] as const;
+
+export function buildImageResizeSideGrid(maxSide: number, sideStart: number): number[] {
+  return [sideStart, 1800, 1600, 1400, 1200, 1000, 800]
+    .map((value) => Math.min(maxSide, value))
+    .filter((value, idx, arr) => value > 0 && arr.indexOf(value) === idx)
+    .toSorted((a, b) => b - a);
+}
+
 function isBun(): boolean {
   return typeof (process.versions as { bun?: unknown }).bun === "string";
 }