import { createCommandRequestId } from "./request-id.js";
import type {
	ClientMeta,
	CommandEnvelope,
	CommandEnvelopeWithInstanceId,
	PublicCommandPayload,
} from "./sdk-types.js";

export type CreateCommandEnvelopeInput<
	Command extends PublicCommandPayload = PublicCommandPayload,
> = {
	command: Command;
	requestId?: string | undefined;
	idempotencyKey?: string | undefined;
	instanceId?: string | undefined;
	clientMeta?: ClientMeta | undefined;
};

const normalizeOptionalString = (value?: string): string | undefined => {
	if (value === undefined) {
		return undefined;
	}
	const normalized = value.trim();
	return normalized.length > 0 ? normalized : undefined;
};

export const createCommandEnvelope = <Command extends PublicCommandPayload>(
	input: CreateCommandEnvelopeInput<Command>,
): Omit<CommandEnvelope, "command"> & { command: Command } => {
	const requestId =
		normalizeOptionalString(input.requestId) ?? createCommandRequestId();
	const idempotencyKey =
		normalizeOptionalString(input.idempotencyKey) ?? requestId;
	const instanceId = normalizeOptionalString(input.instanceId);

	return {
		version: "1",
		command: input.command,
		requestId,
		idempotencyKey,
		...(instanceId !== undefined ? { instanceId } : {}),
		...(input.clientMeta !== undefined ? { clientMeta: input.clientMeta } : {}),
	};
};

export const createCommandEnvelopeWithInstanceId = <
	Command extends PublicCommandPayload,
>(
	input: CreateCommandEnvelopeInput<Command> & { instanceId: string },
): Omit<CommandEnvelopeWithInstanceId, "command"> & { command: Command } => {
	const envelope = createCommandEnvelope(input);
	if (envelope.instanceId === undefined) {
		throw new Error("instanceId must be a non-empty string");
	}
	return {
		...envelope,
		instanceId: envelope.instanceId,
	};
};

export type { CommandEnvelope, CommandEnvelopeWithInstanceId };