package com.anaplan.definitionservice.handlers

import com.anaplan.definitionservice.extensions.endWithJson
import io.vertx.core.json.JsonObject
import io.vertx.ext.mongo.MongoClient
import io.vertx.ext.web.RoutingContext
import io.vertx.kotlin.core.json.json
import io.vertx.kotlin.core.json.obj
import kotlinx.coroutines.experimental.*

fun health(mongo: MongoClient): (RoutingContext) -> Unit =
    {
        launch { withTimeout(500) {
            try {
                val result = pingMongo(mongo)
                it.response().endWithJson(result)
            } catch (throwable: Throwable) {
                val errorObj = json { obj("error" to throwable.message) }

                it.response().statusCode = 500
                it.response().endWithJson(errorObj)
            }
        } }
    }

private suspend fun pingMongo(mongoClient: MongoClient): JsonObject =
    runCommandAsync(mongoClient, "ping", json { obj("ping" to 1) })

private suspend fun runCommandAsync(mongoClient: MongoClient, commandName: String, command: JsonObject): JsonObject =
    suspendCancellableCoroutine { cont ->
        try {
            mongoClient.runCommand(commandName, command, {
                if (it.succeeded())
                    cont.resume(it.result())
                else
                    cont.resumeWithException(it.cause())
            })
        } catch (throwable: Throwable) {
            cont.resumeWithException(throwable)
        }
    }