add server utils

ktor/server/src/jvmMain/kotlin/com/insanusmokrassar/postssystem/ktor/server/ServerRoutingShortcuts.kt

@@ -0,0 +1,36 @@
+package com.insanusmokrassar.postssystem.ktor.server
+
+import com.insanusmokrassar.postssystem.ktor.standardKtorSerialFormat
+import io.ktor.application.ApplicationCall
+import io.ktor.application.call
+import io.ktor.http.HttpStatusCode
+import io.ktor.response.respond
+import io.ktor.response.respondBytes
+import io.ktor.util.toByteArray
+import kotlinx.serialization.DeserializationStrategy
+import kotlinx.serialization.SerializationStrategy
+
+suspend fun <T> ApplicationCall.unianswer(
+    answerSerializer: SerializationStrategy<T>,
+    answer: T
+) {
+    respondBytes(
+        standardKtorSerialFormat.dump(answerSerializer, answer),
+        standardKtorSerialFormatContentType
+    )
+}
+
+suspend fun <T> ApplicationCall.uniload(
+    deserializer: DeserializationStrategy<T>
+) = standardKtorSerialFormat.load(
+    deserializer,
+    request.receiveChannel().toByteArray()
+)
+
+suspend fun ApplicationCall.getParameterOrSendError(
+    field: String
+) = parameters[field].also {
+    if (it == null) {
+        respond(HttpStatusCode.BadRequest, "request must contains $field")
+    }
+}