"use strict";
/**
 * Model: Users
 */

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

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

/**
 * Register user
 * @param {string} user.email User email
 * @param {string} user.password User password
 */
const register = async (user = {}) => {

	// Validate
	if (!user.email) throw new Error(`"email" is required`);
	if (!user.password) {
		throw new Error(`"password" is required`);
	}
	if (!utils.validateEmailAddress(user.email)) {
		throw new Error(`"${user.email}" is not a valid email address`);
	}

	// Check if user is already registered
	const existingUser = await getByEmail(user.email);
	if (existingUser) {
		throw new Error(`A user with email "${user.email}" is already registered`);
	}

	user.password = utils.hashPassword(user.password);

	// Save
	const params = {
		TableName: process.env.db,
		Item: {
			hk: user.email,
			sk: `user`,
			sk2: shortid.generate(),
			createdAt: Date.now(),
			updatedAt: Date.now(),
			password: user.password,
		}
	};

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

/**
 * Get user by email address
 * @param {string} email
 */

const getByEmail = async (email) => {

	// Validate
	if (!email) {
		throw new Error(`"email" is required`);
	}
	if (!utils.validateEmailAddress(email)) {
		throw new Error(`"${email}" is not a valid email address`);
	}

	// Query
	const params = {
		TableName: process.env.db,
		KeyConditionExpression: `hk = :hk`,
		ExpressionAttributeValues: { ':hk': email }
	};

	let user = await dynamodb.query(params).promise();

	user = user.Items && user.Items[0] ? user.Items[0] : null;
	if (user) {
		user.id = user.sk2;
		user.email = user.hk;
	}
	return user;
};

/**
 * Get user by id
 * @param {string} id
 */

const getById = async (id) => {

	// Validate
	if (!id) {
		throw new Error(`"id" is required`);
	}

	// Query
	const params = {
		TableName: process.env.db,
		IndexName: process.env.dbIndex1,
		KeyConditionExpression: `sk2 = :sk2 and sk = :sk`,
		ExpressionAttributeValues: { ':sk2': id,
			':sk': `user` }
	};
	let user = await dynamodb.query(params).promise();

	user = user.Items && user.Items[0] ? user.Items[0] : null;
	if (user) {
		user.id = user.sk2;
		user.email = user.hk;
	}
	return user;
};

/**
 * Convert user record to public format
 * This hides the keys used for the dynamodb's single table design and returns human-readable properties.
 * @param {*} user
 */
const convertToPublicFormat = (user = {}) => {
	user.email = user.hk || null;
	user.id = user.sk2 || null;
	if (user.hk) delete user.hk;
	if (user.sk) delete user.sk;
	if (user.sk2) delete user.sk2;
	if (user.password) delete user.password;
	return user;
};

module.exports = {
	register,
	getByEmail,
	getById,
	convertToPublicFormat,
};