type ExternalIdArgumentCommandName = "identify" | "page" | "screen" | "track";
type ExternalIdArgumentValueName = "traits" | "properties";
type ExternalIdsCallShape =
	| "identify(userId, traits, { externalIds })"
	| "identify(traits, { externalIds })"
	| "page(name, properties, { externalIds })"
	| "screen(name, properties, { externalIds })"
	| "track(eventName, properties, { externalIds })";

const isObjectRecord = (value: unknown): value is Record<string, unknown> =>
	value !== null && typeof value === "object" && !Array.isArray(value);

const hasSegmentExternalIdsProperty = (value: unknown): boolean => {
	if (!isObjectRecord(value)) {
		return false;
	}

	const externalIds = Object.entries(value).find(
		([key]) => key === "externalIds",
	)?.[1];
	return (
		Array.isArray(externalIds) &&
		externalIds.length > 0 &&
		externalIds.every(isSegmentExternalIdLike)
	);
};

const isSegmentExternalIdLike = (
	value: unknown,
): value is {
	id: string;
	type: string;
	collection: "users";
	encoding: "none";
} => {
	if (!isObjectRecord(value)) {
		return false;
	}
	return (
		typeof value.id === "string" &&
		typeof value.type === "string" &&
		value.collection === "users" &&
		value.encoding === "none"
	);
};

export const assertNoSegmentExternalIdsInValueArgument = ({
	argument,
	commandName,
	valueArgumentName,
	callShape,
}: {
	argument: unknown;
	commandName: ExternalIdArgumentCommandName;
	valueArgumentName: ExternalIdArgumentValueName;
	callShape: ExternalIdsCallShape;
}): void => {
	if (!hasSegmentExternalIdsProperty(argument)) {
		return;
	}

	throw new Error(
		`${commandName} received externalIds in the ${valueArgumentName} argument. Use ${callShape} instead.`,
	);
};