const DEFAULT_TOOL_NAMESPACE = "functions";

function isRecord(value: unknown): value is Record<string, unknown> {
	return typeof value === "object" && value !== null && !Array.isArray(value);
}

function isDefaultNamespace(value: unknown): value is Record<string, unknown> & { tools: unknown[] } {
	return isRecord(value)
		&& value["type"] === "namespace"
		&& value["name"] === DEFAULT_TOOL_NAMESPACE
		&& Array.isArray(value["tools"]);
}

export function namespaceResponsesLiteTools(tools: readonly unknown[]): unknown[] {
	const children: unknown[] = [];
	const output: unknown[] = [];
	let insertionIndex: number | undefined;
	let description = "";

	for (const tool of tools) {
		if (isRecord(tool) && (tool["type"] === "function" || tool["type"] === "custom")) {
			insertionIndex ??= output.length;
			children.push(tool);
			continue;
		}
		if (isDefaultNamespace(tool)) {
			insertionIndex ??= output.length;
			children.push(...tool.tools);
			if (typeof tool["description"] === "string" && tool["description"].trim()) {
				description = tool["description"];
			}
			continue;
		}
		output.push(tool);
	}

	if (children.length === 0) return output;
	output.splice(insertionIndex ?? output.length, 0, {
		type: "namespace",
		name: DEFAULT_TOOL_NAMESPACE,
		description,
		tools: children,
	});
	return output;
}

export function namespaceResponsesLiteInputTools(input: readonly unknown[]): unknown[] {
	return input.map((item) => {
		if (!isRecord(item) || !Array.isArray(item["tools"])) return item;
		if (item["type"] !== "additional_tools" && item["type"] !== "tool_search_output") return item;
		return { ...item, tools: namespaceResponsesLiteTools(item["tools"]) };
	});
}