// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0

import { amplifyUuid } from '../../../utils/amplifyUuid';
import { PinpointRecordInput, PinpointSession } from '../types';
import { resolveEndpointId } from '../utils';
import {
	SESSION_START_EVENT,
	SESSION_STOP_EVENT,
} from '../../../utils/sessionListener';
import {
	BUFFER_SIZE,
	FLUSH_INTERVAL,
	FLUSH_SIZE,
	RESEND_LIMIT,
} from '../utils/constants';
import { getEventBuffer } from '../utils/getEventBuffer';

let session: PinpointSession | undefined;

/**
 * @internal
 */
export const record = async ({
	appId,
	category,
	channelType,
	credentials,
	event,
	identityId,
	region,
	userAgentValue,
	bufferSize,
	flushInterval,
	flushSize,
	resendLimit,
}: PinpointRecordInput): Promise<void> => {
	let eventSession = session;
	const currentTime = new Date();
	const timestampISOString = currentTime.toISOString();
	const eventId = amplifyUuid();

	// Prepare event buffer if required
	const buffer = getEventBuffer({
		appId,
		region,
		credentials,
		bufferSize: bufferSize ?? BUFFER_SIZE,
		flushInterval: flushInterval ?? FLUSH_INTERVAL,
		flushSize: flushSize ?? FLUSH_SIZE,
		resendLimit: resendLimit ?? RESEND_LIMIT,
		identityId,
		userAgentValue,
	});

	const endpointId = await resolveEndpointId({
		appId,
		category,
		channelType,
		credentials,
		identityId,
		region,
		userAgentValue,
	});

	// Generate session if required
	if (!eventSession || event.name === SESSION_START_EVENT) {
		const sessionId = amplifyUuid();

		session = {
			Id: sessionId,
			StartTimestamp: timestampISOString,
		};
		eventSession = session;
	}

	// Terminate session when required
	if (session && event.name === SESSION_STOP_EVENT) {
		eventSession = {
			...session,
			StopTimestamp: timestampISOString,
			Duration:
				currentTime.getTime() - new Date(session.StartTimestamp).getTime(),
		};
		session = undefined;
	}

	// Push event to buffer
	buffer.push({
		eventId,
		endpointId,
		event,
		session: eventSession!,
		timestamp: timestampISOString,
		resendLimit: resendLimit ?? RESEND_LIMIT,
	});
};