/* Amplify Params - DO NOT EDIT
	API_GRAPHQL_GRAPHQLAPIENDPOINTOUTPUT
	API_GRAPHQL_GRAPHQLAPIIDOUTPUT
	API_GRAPHQL_GRAPHQLAPIKEYOUTPUT
	API_GRAPHQL_LOTTERYPOOLTABLE_ARN
	API_GRAPHQL_LOTTERYPOOLTABLE_NAME
	API_GRAPHQL_PARTICIPANTTABLE_ARN
	API_GRAPHQL_PARTICIPANTTABLE_NAME
	API_GRAPHQL_TICKETTABLE_ARN
	API_GRAPHQL_TICKETTABLE_NAME
	API_GRAPHQL_TRANSACTIONTABLE_ARN
	API_GRAPHQL_TRANSACTIONTABLE_NAME
	API_GRAPHQL_WINNERTABLE_ARN
	API_GRAPHQL_WINNERTABLE_NAME
	ENV
	REGION
Amplify Params - DO NOT EDIT */

const axios = require('axios');
const graphql = require('graphql');
const { print } = graphql;
const query = require('./query');
const rand = require('random-seed').create();

// uncomment below for local testing for env variables
require('dotenv').config();

const callGraphQL = async (query, input) => {
	const graphqlData = await axios({
		url: process.env.API_GRAPHQL_GRAPHQLAPIENDPOINTOUTPUT,
		method: 'post',
		headers: {
			'x-api-key': process.env.API_GRAPHQL_GRAPHQLAPIKEYOUTPUT
		},
		data: {
			query: print(query),
			variables: input
		}
	});
	const body = {
		graphqlData: graphqlData.data.data,
		errors: graphqlData.data.errors
	};
	return body;
}

const checkForError = (body) => {
	if (body.errors) {
		throw body.errors;
	}
}

exports.handler = async (event) => {
	try {
		let response;
		const currentLotteryPoolBody = await callGraphQL(query.lotteryPoolByStatus, null);
		checkForError(currentLotteryPoolBody);

		if (currentLotteryPoolBody.graphqlData.lotteryPoolByStatus.items.length === 0) {
			response = {
				statusCode: 400,
				body: JSON.stringify('No lotteryPool with OPEN status')
			}
		} else {
			const lotteryPoolId = currentLotteryPoolBody.graphqlData.lotteryPoolByStatus.items[0].id;
			const tickets = currentLotteryPoolBody.graphqlData.lotteryPoolByStatus.items[0].tickets.items;
			let transactions = await callGraphQL(query.transactionsByLotteryPoolByAmount, { lotteryPoolID: lotteryPoolId });
			checkForError(transactions);
			transactions = transactions.graphqlData.transactionsByLotteryPoolByAmount.items;
			let finalPotAmount = 0;
			if (transactions.length > 0) {
				transactions.forEach((transaction) => {
					finalPotAmount += parseInt(transaction.amount);
				});
			}
			
			const updateLotteryPoolInput =  {
				id: lotteryPoolId,
				finalPotAmount: finalPotAmount,
				status: 'CLOSED'
			};
			const updateLotteryPoolBody = await callGraphQL(query.updateLotteryPool, { input: updateLotteryPoolInput });
			checkForError(updateLotteryPoolBody);
			
			let createWinnerBody;
			if (tickets.length > 0) {
				let ticketPool = [];
				tickets.forEach((ticket) => {
					ticketPool.push(...Array(ticket.weight).fill(ticket.id));
				});
				const winningTicket = ticketPool[rand(ticketPool.length)];
				console.log('winningTicketID: ', winningTicket);
				const createWinnerInput =  {
					lotteryPoolID: lotteryPoolId,
					ticketID: winningTicket,
					amount: (finalPotAmount / 2).toString()
				};
				createWinnerBody = await callGraphQL(query.createWinner, { input: createWinnerInput });
				checkForError(createWinnerBody);
			}

			response = {
				statusCode: 200,
				body: JSON.stringify({
					updateLotteryPoolBody: updateLotteryPoolBody.graphqlData,
					createWinnerBody: createWinnerBody ? createWinnerBody.graphqlData : 'No winner created'
				}),
			};
		}
		console.log(response.body);
		return response;

	} catch (err) {
		console.log('error posting to appsync: ', err);
		return {
			statusCode: 500,
			body: JSON.stringify(err)
		}
	}
}