fix(agent): clamped provider context images

Dropped oldest outgoing image blocks above the active provider budget so umans requests honor the shipped 10-image cap even when snapcompact is disabled. Added regression coverage for preserving text and newest images.\n\nFixes #3230
2026-06-22 05:57:30 +00:00
parent 320261fca9
commit eb88ecd7bb
4 changed files with 179 additions and 10 deletions
@@ -0,0 +1,80 @@
+import type {
+	Context,
+	DeveloperMessage,
+	ImageContent,
+	Model,
+	TextContent,
+	ToolResultMessage,
+	UserMessage,
+} from "@oh-my-pi/pi-ai";
+import { providerImageBudget } from "@oh-my-pi/snapcompact";
+
+function countImages(context: Context): number {
+	let count = 0;
+	for (const message of context.messages) {
+		if (!Array.isArray(message.content)) continue;
+		for (const part of message.content) {
+			if (part.type === "image") count++;
+		}
+	}
+	return count;
+}
+
+function clampContent(
+	content: readonly (TextContent | ImageContent)[],
+	state: { remainingDrops: number },
+): (TextContent | ImageContent)[] | undefined {
+	let changed = false;
+	const clamped: (TextContent | ImageContent)[] = [];
+	for (const part of content) {
+		if (part.type === "image" && state.remainingDrops > 0) {
+			state.remainingDrops--;
+			changed = true;
+			continue;
+		}
+		clamped.push(part);
+	}
+	return changed ? clamped : undefined;
+}
+
+function clampUserMessage(message: UserMessage, state: { remainingDrops: number }): UserMessage {
+	if (!Array.isArray(message.content) || state.remainingDrops <= 0) return message;
+	const content = clampContent(message.content, state);
+	return content ? { ...message, content } : message;
+}
+
+function clampDeveloperMessage(message: DeveloperMessage, state: { remainingDrops: number }): DeveloperMessage {
+	if (!Array.isArray(message.content) || state.remainingDrops <= 0) return message;
+	const content = clampContent(message.content, state);
+	return content ? { ...message, content } : message;
+}
+
+function clampToolResultMessage(message: ToolResultMessage, state: { remainingDrops: number }): ToolResultMessage {
+	if (state.remainingDrops <= 0) return message;
+	const content = clampContent(message.content, state);
+	return content ? { ...message, content } : message;
+}
+
+/** Drops oldest transient image blocks so outgoing vision requests fit the active provider's image cap. */
+export function clampProviderContextImages(context: Context, model: Model): Context {
+	if (!model.input.includes("image")) return context;
+	const limit = providerImageBudget(model.provider);
+	const totalImages = countImages(context);
+	if (totalImages <= limit) return context;
+
+	const state = { remainingDrops: totalImages - limit };
+	const messages = context.messages.map(message => {
+		switch (message.role) {
+			case "user":
+				return clampUserMessage(message, state);
+			case "developer":
+				return clampDeveloperMessage(message, state);
+			case "toolResult":
+				return clampToolResultMessage(message, state);
+			case "assistant":
+				return message;
+		}
+		return message;
+	});
+	return { ...context, messages };
+}