package be.vandewalleh.services

import be.vandewalleh.entities.User
import be.vandewalleh.tables.Users
import me.liuwj.ktorm.database.Database
import me.liuwj.ktorm.dsl.*
import me.liuwj.ktorm.entity.add
import me.liuwj.ktorm.entity.sequenceOf
import org.kodein.di.Kodein
import org.kodein.di.KodeinAware
import org.kodein.di.generic.instance
import java.time.LocalDateTime

/**
 * service to handle database queries for users.
 */
class UserService(override val kodein: Kodein) : KodeinAware {
    private val db by instance<Database>()

    /**
     * returns a user ID if present or null
     */
    fun getUserId(userEmail: String): Int? {
        return db.from(Users)
            .select(Users.id)
            .where { Users.email eq userEmail }
            .limit(0, 1)
            .map { it[Users.id] }
            .firstOrNull()
    }

    /**
     * returns a user email and password from it's email if found or null
     */
    fun getEmailAndPasswordFromUsername(username: String): Pair<String, String>? {
        return db.from(Users)
            .select(Users.email, Users.password)
            .where { Users.username eq username }
            .limit(0, 1)
            .map { row -> row[Users.email]!! to row[Users.password]!! }
            .firstOrNull()
    }

    fun userExists(username: String, email: String): Boolean {
        return db.from(Users)
            .select(Users.id)
            .where { (Users.username eq username) or (Users.email eq email) }
            .limit(0, 1)
            .firstOrNull() != null
    }

    /**
     * create a new user
     * password should already be hashed
     */
    fun createUser(user: UserRegistrationDto) {
        db.useTransaction {
            val newUser = User {
                this.username = user.username
                this.email = user.email
                this.password = user.password
                this.createdAt = LocalDateTime.now()
            }

            db.sequenceOf(Users).add(newUser)
        }
    }

}

data class UserRegistrationDto(val username: String, val email: String, val password: String)