'use strict';

const Util = require('util');
const Jwt = require('@hapi/jwt');
const Schmervice = require('@hapipal/schmervice');
const SecurePassword = require('secure-password');

/** Class for methods used in the User plugin */
module.exports = class UserService extends Schmervice.Service {
    /**
     * Unsure of what our constructor does
     * @param  {...any} args
     */
    constructor(...args) {
        super(...args)
        const pwd = new SecurePassword()
        this.pwd = {
            hash: Util.promisify(pwd.hash.bind(pwd)),
            verify: Util.promisify(pwd.verify.bind(pwd))
        }
    }

    /**
     * Use knex to find users with id column
     * @param {number} id
     * @param {*} txn
     * @returns
     */
    async findById(id, txn) {
        const { User } = this.server.models()
        return await User.query(txn).throwIfNotFound().findById(id)
    }

    /**
     * Use knew to find first user with username
     * @param {*} username
     * @param {*} txn
     * @returns
     */
    async findByUsername(username, txn) {
        const { User } = this.server.models()

        return await User.query(txn).throwIfNotFound().first().where({ username })
    }

    /**
     * Signup function
     * @param {*} param0
     * @param {*} txn
     * @returns
     */
    async signup({ password, ...userInfo }, txn) {
        const { User } = this.server.models()
        const { id } = await User.query(txn).insert(userInfo)
        await this.changePassword(id, password, txn)
        return id
    }

    /**
     * Updates user's info
     * @param {number} id
     * @param {*} param1
     * @param {*} txn
     * @returns
     */
    async update(id, { password, ...userInfo }, txn) {
        const { User } = this.server.models()

        if (Object.keys(userInfo).length > 0) {
            await User.query(txn).throwIfNotFound().where({ id }).patch(userInfo)
        }

        if (password) {
            await this.changePassword(id, password, txn)
        }

        return id
    }

    /**
     * Self explanatory
     * @param {*} param0
     * @param {*} txn
     * @returns
     */
    async login({ email, password }, txn) {
        const { User } = this.server.models()

        const user = await User.query(txn)
            .throwIfNotFound()
            .first()
            .where({ user_email: email })


        /** Uncomment to run password check using SecurePassword */
        // const passwordCheck = await this.pwd.verify(Buffer.from(password), user.password)
        // if (passwordCheck === SecurePassword.VALID_NEEDS_REHASH) {
        //     await this.changePassword(user.id, password, txn)
        // }
        // else if (passwordCheck !== SecurePassword.VALID) {
        //     throw User.createNotFoundError()
        // }

        return user
    }

    /**
     * Create a token to be sent in request headers
     * @param {User} user
     * @returns {Token}
     */
    createToken(user) {
        const key = this.server.registrations['main-app-plugin'].options.jwtKey

        return Jwt.token.generate({
            aud: 'urn:audience:test',
            iss: 'urn:issuer:test',
            email: user.user_email
        },
        {
            key: key,
            algorithm: 'HS256'
        }, {
            ttlSec: 4 * 60 * 60 // 7 days
        })
    }

    /**
     * Use knex to try to change password entry
     * @param {number} id
     * @param {string} password
     * @param {*} txn
     * @returns {number}
     */
    async changePassword(id, password, txn) {
        const { User } = this.server.models()

        await User.query(txn).throwIfNotFound().where({ id }).patch({
            password: await this.pwd.hash(Buffer.from(password))
        })
        return id
    }
}