ModelCredentialsAuthenticatable.swift

//
//  ModelCredentialsAuthenticatable.swift
//  
//
//  Created by Dmytro on 12.02.2022.
//

import Vapor
import Bridges

public protocol ModelCredentialsAuthenticatable: Table, Authenticatable {
    static var usernameKey: KeyPath<Self, Column<String>> { get }
    static var passwordHashKey: KeyPath<Self, Column<String>> { get }
    func verify(password: String) throws -> Bool
}

extension ModelCredentialsAuthenticatable {
    public static func credentialsAuthenticator(
        database: DatabaseIdentifier
    ) -> Authenticator {
        ModelCredentialsAuthenticator<Self>(database: database)
    }

    var _$username: Column<String> {
        self[keyPath: Self.usernameKey]
    }

    var _$passwordHash: Column<String> {
        self[keyPath: Self.passwordHashKey]
    }
}

public struct ModelCredentials: Content {
    public let username: String
    public let password: String

    public init(username: String, password: String) {
        self.username = username
        self.password = password
    }
}

private struct ModelCredentialsAuthenticator<User>: CredentialsAuthenticator
    where User: ModelCredentialsAuthenticatable
{
    typealias Credentials = ModelCredentials

    public let database: DatabaseIdentifier

    func authenticate(credentials: ModelCredentials, for request: Request) -> EventLoopFuture<Void> {
        User.query(on: database, on: request)
            .where(\User._$username == credentials.username)
            .first()
            .flatMapThrowing
        {
            guard let user = $0 else {
                return
            }
            guard try user.verify(password: credentials.password) else {
                return
            }
            request.auth.login(user)
        }
    }
}