m.kt

package io.helidon.kotlin.examples.quickstart.se

import healthSupport
import io.helidon.common.LogConfig
import io.helidon.config.Config
import io.helidon.health.checks.HealthChecks
import io.helidon.media.jsonp.JsonpSupport
import io.helidon.metrics.MetricsSupport
import io.helidon.webserver.Routing
import io.helidon.webserver.WebServer
import routing


/**
 * Application main entry point.
 * @param args command line arguments.
 */
fun main(args: Array<String>) {
    startServer()
}

/**
 * Start the server.
 * @return the created [WebServer] instance
 */
fun startServer(): WebServer {

    // load logging configuration
    LogConfig.configureRuntime()

    // By default this will pick up application.yaml from the classpath
    val config = Config.create()
    val server = WebServer.builder(createRouting(config))
        .config(config["server"])
        .addMediaSupport(JsonpSupport.create())
        .build()

    // Try to start the server. If successful, print some info and arrange to
    // print a message at shutdown. If unsuccessful, print the exception.
    server.start()
        .thenAccept { ws: WebServer ->
            println(
                "WEB server is up! http://localhost:" + ws.port() + "/greet"
            )
            ws.whenShutdown().thenRun { println("WEB server is DOWN. Good bye!") }
        }
        .exceptionally { t: Throwable ->
            System.err.println("Startup failed: " + t.message)
            t.printStackTrace(System.err)
            null
        }

    // Server threads are not daemon. No need to block. Just react.
    return server
}

/**
 * Creates new [Routing].
 *
 * @return routing configured with JSON support, a health check, and a service
 * @param config configuration of this server
 */
private fun createRouting(config: Config): Routing {
    val metrics = MetricsSupport.create()
    val greetService = GreetService(config)


    val health = healthSupport {
        addLiveness(*HealthChecks.healthChecks())
    }
    return routing {
        register(health) // Health at "/health"
        register(metrics) // Metrics at "/metrics"
        register("/greet", greetService)
    }
}