AuthenticationService.kt

package gems.user.service

import com.google.inject.ImplementedBy
import com.google.inject.Inject
import gems.user.dao.UserDao
import gems.user.dao.entity.User
import gems.user.service.dto.Credentials
import gems.user.service.session.Session
import gems.user.service.session.SessionManager

@ImplementedBy(DefaultAuthenticationService::class)
interface AuthenticationService {

    fun login(credentials: Credentials, sessionManager: SessionManager): Boolean

    fun logout(sessionManager: SessionManager)

}

class DefaultAuthenticationService @Inject constructor(private val userDao: UserDao) :
    AuthenticationService {

    override fun login(credentials: Credentials, sessionManager: SessionManager): Boolean {
        val user = userDao.findByEmail(credentials.email)

        if (user == null) {
            return false
        }

        if (authenticate(user, credentials)) {
            sessionManager.beginSession(Session(user.id))
            return true
        } else {
            return false
        }
    }

    private fun authenticate(user: User, credentials: Credentials) = doesPasswordMatchHash(credentials.password, user.passwordHash)

    override fun logout(sessionManager: SessionManager) = sessionManager.endSession()

}