feat: factory function for RSocket transport engine

rsocket-engine/src/commonMain/kotlin/io/timemates/api/rsocket/RSocketTimeMatesRequestsEngine.kt

@@ -1,11 +1,17 @@
 package io.timemates.api.rsocket
 
 import io.ktor.client.HttpClient
+import io.ktor.client.HttpClientConfig
+import io.ktor.client.plugins.websocket.WebSockets
 import io.rsocket.kotlin.ExperimentalMetadataApi
 import io.rsocket.kotlin.RSocket
+import io.rsocket.kotlin.core.WellKnownMimeType
+import io.rsocket.kotlin.keepalive.KeepAlive
+import io.rsocket.kotlin.ktor.client.RSocketSupport
 import io.rsocket.kotlin.ktor.client.rSocket
 import io.rsocket.kotlin.metadata.RoutingMetadata
 import io.rsocket.kotlin.metadata.compositeMetadata
+import io.rsocket.kotlin.payload.PayloadMimeType
 import io.rsocket.kotlin.payload.buildPayload
 import io.timemates.api.rsocket.common.markers.RSocketRequest
 import io.timemates.api.rsocket.common.metadata.AuthorizationMetadata
@@ -25,17 +31,65 @@ import kotlinx.coroutines.async
 import kotlinx.serialization.DeserializationStrategy
 import kotlinx.serialization.SerializationStrategy
 import kotlinx.serialization.serializer
+import kotlin.time.Duration.Companion.minutes
+import kotlin.time.Duration.Companion.seconds
 import io.timemates.api.rsocket.timers.requests.RSocketEditTimerRequest as RSocketEditTimerRequest
 import io.timemates.api.rsocket.timers.requests.RSocketGetTimerRequest as RSocketGetTimerRequest
 
+/**
+ * Creates an RSocket-based TimeMates request engine.
+ *
+ * This function configures and creates an RSocket-based TimeMates request engine
+ * that communicates with the TimeMates API over WebSockets. You can customize the
+ * WebSocket endpoint, coroutine scope, and HTTP client configuration using the
+ * provided parameters.
+ *
+ * **Note**: You should implement ktor client engine to use it.
+ *
+ * @param endpoint The WebSocket endpoint URL for the TimeMates API.
+ * @param coroutineScope The coroutine scope used for RSocket lifecycle.
+ * @param config Configuration lambda for customizing the underlying HTTP client.
+ * @return An instance of the RSocketTimeMatesRequestsEngine.
+ */
+public fun RSocketTimeMatesRequestsEngine(
+    endpoint: String = "wss://api.timemates.io/v0/rsocket",
+    coroutineScope: CoroutineScope,
+    config: HttpClientConfig<*>.() -> Unit = {},
+): RSocketTimeMatesRequestsEngine {
+    val client = HttpClient {
+        install(RSocketSupport) {
+            connector {
+                maxFragmentSize = 1024
+
+                connectionConfig {
+                    keepAlive = KeepAlive(
+                        interval = 30.seconds,
+                        maxLifetime = 2.minutes
+                    )
+
+                    payloadMimeType = PayloadMimeType(
+                        data = WellKnownMimeType.ApplicationJson,
+                        metadata = WellKnownMimeType.MessageRSocketCompositeMetadata,
+                    )
+                }
+            }
+        }
+        config()
+    }
+
+    return RSocketTimeMatesRequestsEngine(
+        client, endpoint, coroutineScope,
+    )
+}
+
 /**
  * Represents an engine for making requests using RSocket.
  *
  * @property client An instance of [HttpClient] for making HTTP requests.
  * @param endpoint The RSocket endpoint URL. Defaults to "wss://api.timemates.io/v0/rsocket".
  * @param coroutineScope A [CoroutineScope] tied to the RSocket lifecycle.
  */
-public class RSocketTimeMatesRequestsEngine private constructor(
+public class RSocketTimeMatesRequestsEngine internal constructor(
     private val client: HttpClient,
     endpoint: String = "wss://api.timemates.io/v0/rsocket",
     coroutineScope: CoroutineScope,