import type { AgentMessage } from "@earendil-works/pi-agent-core";
import type { AssistantMessage, TextContent } from "@earendil-works/pi-ai";

export function isAssistantMessage(m: AgentMessage): m is AssistantMessage {
	return m.role === "assistant" && Array.isArray(m.content);
}

export function getMessageText(message: AgentMessage): string {
	if (!("content" in message)) return "";
	const content = message.content;
	if (typeof content === "string") return content;
	if (!Array.isArray(content)) return "";
	return content
		.filter((block): block is TextContent => block.type === "text")
		.map((block) => block.text)
		.join("\n");
}

export function truncateText(text: string, limit = 500): string {
	const normalized = text.replace(/\s+/g, " ").trim();
	return normalized.length > limit ? `${normalized.slice(0, limit - 1)}…` : normalized;
}

export function getTextContent(content: Array<{ type: string; text?: string }>): string {
	return content.filter((item) => item.type === "text" && typeof item.text === "string").map((item) => item.text).join("\n");
}