const AWS = require(`aws-sdk`);
const shortid = require(`shortid`);
const commonSchemas = require(`../validation/commonSchemas`);
const validation = require(`../validation`);

const dynamodb = new AWS.DynamoDB.DocumentClient({
	region: process.env.AWS_REGION,
});

const defaultParams = {
	TableName: process.env.db,
};

const put = async (kind, item) => {
	const params = {
		...defaultParams,
		Item: {
			...item,
			sk: kind,
			sk2: shortid.generate(),
			createdAt: Date.now(),
			updatedAt: Date.now(),
		},
	};

	await dynamodb.put(params).promise();
};

const getByKey = async (key) => {
	const params = {
		...defaultParams,
		KeyConditionExpression: `hk = :hk`,
		ExpressionAttributeValues: { ":hk": key },
	};

	const obj = await dynamodb.query(params).promise();
	return obj.Items && obj.Items[0] ? obj.Items[0] : null;
};

const getById = async (kind, id) => {
	validation.validateOrThrow(commonSchemas.id, id);

	const params = {
		...defaultParams,
		IndexName: process.env.dbIndex1,
		KeyConditionExpression: `sk2 = :sk2 and sk = :sk`,
		ExpressionAttributeValues: {
			":sk2": id,
			":sk": kind,
		},
	};

	const obj = await dynamodb.query(params).promise();	
	return obj.Items && obj.Items[0] ? obj.Items[0] : null;
};

module.exports = {
	put,
	getByKey,
	getById,
};