'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()
            .first()
            .where({ user_id: 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({ user_name: username })
    }

    /**
     * Signup function
     * @param {*} param0
     * @param {*} txn
     * @returns
     */
    async signup({ password, userInfo }, txn) {
        const { User } = this.server.models()
        const matchingEmails = await User.query().where('user_email', userInfo.user_email)

        if(matchingEmails.length > 0) { 
            throw `User ${userInfo.user_email} already exists: Cannot create a user without a unique email`
        }
        const user = await User.query(txn).insert(userInfo)
        user.user_id = user.id
        delete user.id
        // await this.changePassword(id, password, txn)
        return user
    }

    /**
     * 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()
        return 'done'

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