import { json, type RequestHandler } from '@sveltejs/kit';
import { ConversionControl } from './control.ts';
import type {
	ConversionErrorResponseBody,
	ConversionEventParams,
	ConversionRequestBody,
	ConversionUserData
} from '$lib/types/conversion.js';

import { StatusCodes } from 'http-status-codes';

const getEventIP = (request: Request, getClientAddress: () => string) => {
	return (
		request.headers.get('x-forwarded-for') ||
		request.headers.get('cf-connecting-ip') ||
		request.headers.get('x-real-ip') ||
		request.headers.get('x-client-ip') ||
		request.headers.get('x-cluster-client-ip') ||
		request.headers.get('x-original-forwarded-for') ||
		request.headers.get('forwarded-for') ||
		request.headers.get('forwarded') ||
		getClientAddress()
	);
};

export const createConversionRequestHandler: (control: ConversionControl) => RequestHandler = (
	control
) => {
	const handle: RequestHandler = async ({ request, getClientAddress }) => {
		try {
			const body = (await request.json()) as ConversionRequestBody;

			// Build user data with IP and user agent
			const ip = getEventIP(request, getClientAddress);
			const ua = request.headers.get('user-agent');

			const userData: ConversionUserData = {
				...body.user,
				ip,
				ua: ua ?? body.user?.ua ?? undefined
			};

			// Build custom data with UTM params if applicable
			let customData: ConversionEventParams = body.customData ?? {};
			if (body.eventName === 'PageView' && body.utms) {
				// For PageView events, automatically include UTM params if provided
				customData = {
					...customData,
					...body.utms
				};
			}

			// Send the event via the control
			const response = await control.trackEvent(
				body.eventName,
				{
					eventID: body.eventID,
					eventSourceURL: body.eventSourceURL,
					actionSource: 'website',
					userData
				},
				customData
			);

			return json(response, { status: StatusCodes.OK });
		} catch (e) {
			return json(
				{ error: e instanceof Error ? e.message : String(e) } as ConversionErrorResponseBody,
				{ status: StatusCodes.INTERNAL_SERVER_ERROR }
			);
		}
	};
	return handle;
};