output-service-rdb/src/database/DatabaseFactory.kt

package com.kmalbz.database

import com.typesafe.config.ConfigFactory
import com.zaxxer.hikari.*
import io.ktor.config.HoconApplicationConfig
import io.ktor.util.KtorExperimentalAPI
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.withContext
import org.jetbrains.exposed.sql.*
import org.jetbrains.exposed.sql.transactions.transaction

object DatabaseFactory {

    @KtorExperimentalAPI
    private val appConfig = HoconApplicationConfig(ConfigFactory.load())
    @KtorExperimentalAPI
    private val dbUrl = appConfig.property("ktor.db.jdbc").getString()
    @KtorExperimentalAPI
    private val dbUser = appConfig.property("ktor.db.user").getString()
    @KtorExperimentalAPI
    private val dbPassword = appConfig.property("ktor.db.password").getString()

    @KtorExperimentalAPI
    fun init() {
        Database.connect(hikari())
    }

    @KtorExperimentalAPI
    private fun hikari(): HikariDataSource {
        val config = HikariConfig()
        config.driverClassName = "org.postgresql.Driver"
        config.jdbcUrl = dbUrl
        config.username = dbUser
        config.password = dbPassword
        config.maximumPoolSize = 3
        config.isAutoCommit = false
        config.transactionIsolation = "TRANSACTION_REPEATABLE_READ"
        config.validate()
        return HikariDataSource(config)
    }

    suspend fun <T> dbQuery(block: () -> T): T =
        withContext(Dispatchers.IO) {
            transaction { block() }
        }
}