From 85d2ab1c118b69d9ffebd6049a68ec1ef74906ba Mon Sep 17 00:00:00 2001
From: Dmitriy Berdnikov <d.k.berdnikov@tinkoff.ru>
Date: Mon, 5 Feb 2024 15:45:49 +0300
Subject: [PATCH] make switch extension for Flow inside Actors

---
 .../money/vivid/elmslie/core/store/Actor.kt   | 24 +++++++++++++++++++
 .../coroutines/timer/elm/TimerActor.kt        | 23 +++++++++++-------
 2 files changed, 39 insertions(+), 8 deletions(-)

diff --git a/elmslie-core/src/main/kotlin/money/vivid/elmslie/core/store/Actor.kt b/elmslie-core/src/main/kotlin/money/vivid/elmslie/core/store/Actor.kt
index c59efce6..652c8708 100644
--- a/elmslie-core/src/main/kotlin/money/vivid/elmslie/core/store/Actor.kt
+++ b/elmslie-core/src/main/kotlin/money/vivid/elmslie/core/store/Actor.kt
@@ -3,9 +3,13 @@ package money.vivid.elmslie.core.store
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.catch
 import kotlinx.coroutines.flow.mapNotNull
+import money.vivid.elmslie.core.switcher.Switcher
+import kotlin.reflect.KClass
 
 abstract class Actor<Command : Any, Event : Any> {
 
+    private val switchers = mutableMapOf<KClass<out Any>, Switcher>()
+
     /**
      * Executes a command. This method is performed on the [Dispatchers.IO]
      * [kotlinx.coroutines.Dispatchers.IO] which is set by ElmslieConfig.ioDispatchers()
@@ -17,4 +21,24 @@ abstract class Actor<Command : Any, Event : Any> {
         errorMapper: (error: Throwable) -> Event? = { null },
     ) = mapNotNull { eventMapper(it) }
         .catch { errorMapper(it)?.let { event -> emit(event) } ?: throw it }
+
+    protected fun <T : Any> switchFlow(
+        command: Command,
+        delayMillis: Long = 0,
+        flow: () -> Flow<T>
+    ): Flow<T> {
+        val switcher = switchers.getOrPut(command::class) {
+            Switcher()
+        }
+        return switcher.switch(delayMillis) {
+            flow.invoke()
+        }
+    }
+
+    protected fun <T : Any, Command : Any> Flow<T>.switchOnEach(command: Command, delayMillis: Long = 0): Flow<T> {
+        val switcher = switchers.getOrPut(command::class) {
+            Switcher()
+        }
+        return switcher.switch(delayMillis) { this }
+    }
 }
diff --git a/samples/coroutines-loader/src/main/kotlin/money/vivid/elmslie/samples/coroutines/timer/elm/TimerActor.kt b/samples/coroutines-loader/src/main/kotlin/money/vivid/elmslie/samples/coroutines/timer/elm/TimerActor.kt
index ce9c076a..87cb1efc 100644
--- a/samples/coroutines-loader/src/main/kotlin/money/vivid/elmslie/samples/coroutines/timer/elm/TimerActor.kt
+++ b/samples/coroutines-loader/src/main/kotlin/money/vivid/elmslie/samples/coroutines/timer/elm/TimerActor.kt
@@ -1,6 +1,7 @@
 package money.vivid.elmslie.samples.coroutines.timer.elm
 
 import kotlinx.coroutines.delay
+import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.flow
 import money.vivid.elmslie.core.store.Actor
 import money.vivid.elmslie.core.switcher.Switcher
@@ -11,18 +12,24 @@ internal object TimerActor : Actor<Command, Event>() {
 
     override fun execute(command: Command) =
         when (command) {
-            is Command.Start ->
-                switcher
-                    .switch { secondsFlow() }
-                    .mapEvents(
-                        eventMapper = { Event.OnTimeTick },
-                        errorMapper = { Event.OnTimeError(it) },
-                    )
+//            is Command.Start -> switchFlow(command) {
+//                secondsFlow()
+//            }.mapEvents(
+//                eventMapper = { Event.OnTimeTick },
+//                errorMapper = { Event.OnTimeError(it) },
+//            )
+            is Command.Start -> secondsFlow()
+                .switchOnEach(command)
+                .mapEvents(
+                    eventMapper = { Event.OnTimeTick },
+                    errorMapper = { Event.OnTimeError(it) },
+                )
+
             is Command.Stop -> switcher.cancel()
         }
 
     @Suppress("MagicNumber")
-    private fun secondsFlow() = flow {
+    private fun secondsFlow(): Flow<Int> = flow {
         repeat(10) {
             delay(1000)
             emit(it)