start add fsm

fsm/common/build.gradle

@@ -0,0 +1,17 @@
+plugins {
+    id "org.jetbrains.kotlin.multiplatform"
+    id "org.jetbrains.kotlin.plugin.serialization"
+    id "com.android.library"
+}
+
+apply from: "$mppProjectWithSerializationPresetPath"
+
+kotlin {
+    sourceSets {
+        commonMain {
+            dependencies {
+                api project(":micro_utils.coroutines")
+            }
+        }
+    }
+}

fsm/common/src/commonMain/kotlin/dev/inmo/micro_utils/fsm/common/State.kt

@@ -0,0 +1,5 @@
+package dev.inmo.micro_utils.fsm.common
+
+interface State {
+    val context: Any
+}

fsm/common/src/commonMain/kotlin/dev/inmo/micro_utils/fsm/common/StateHandlerHolder.kt

@@ -0,0 +1,15 @@
+package dev.inmo.micro_utils.fsm.common
+
+import kotlin.reflect.KClass
+
+class StateHandlerHolder<I : State>(
+    private val inputKlass: KClass<I>,
+    private val strict: Boolean = false,
+    private val delegateTo: StatesHandler<I>
+) : StatesHandler<State> {
+    fun checkHandleable(state: State) = state::class == inputKlass || (!strict && inputKlass.isInstance(state))
+
+    override suspend fun StatesMachine.handleState(state: State): State? {
+        return delegateTo.run { handleState(state as I) }
+    }
+}

fsm/common/src/commonMain/kotlin/dev/inmo/micro_utils/fsm/common/StatesHandler.kt

@@ -0,0 +1,5 @@
+package dev.inmo.micro_utils.fsm.common
+
+fun interface StatesHandler<I : State> {
+    suspend fun StatesMachine.handleState(state: I): State?
+}

fsm/common/src/commonMain/kotlin/dev/inmo/micro_utils/fsm/common/StatesMachine.kt

@@ -0,0 +1,46 @@
+package dev.inmo.micro_utils.fsm.common
+
+import dev.inmo.micro_utils.coroutines.*
+import kotlinx.coroutines.*
+import kotlinx.coroutines.flow.asFlow
+
+private suspend fun <I : State> StatesMachine.launchStateHandling(
+    state: State,
+    handlers: List<StateHandlerHolder<out I>>
+): State? {
+    return handlers.firstOrNull { it.checkHandleable(state) } ?.run {
+        handleState(state)
+    }
+}
+
+class StatesMachine (
+    private val statesManager: StatesManager,
+    private val handlers: List<StateHandlerHolder<*>>
+) : StatesHandler<State> {
+    override suspend fun StatesMachine.handleState(state: State): State? = launchStateHandling(state, handlers)
+
+    fun start(scope: CoroutineScope): Job = scope.launchSafelyWithoutExceptions {
+        val statePerformer: suspend (State) -> Unit = { state: State ->
+            val newState = launchStateHandling(state, handlers)
+            if (newState != null) {
+                statesManager.update(state, newState)
+            } else {
+                statesManager.endChain(state)
+            }
+        }
+        statesManager.onStartChain.subscribeSafelyWithoutExceptions(this) {
+            launch { statePerformer(it) }
+        }
+        statesManager.onChainStateUpdated.subscribeSafelyWithoutExceptions(this) {
+            launch { statePerformer(it.second) }
+        }
+
+        statesManager.getActiveStates().forEach {
+            launch { statePerformer(it) }
+        }
+    }
+
+    suspend fun startChain(state: State) {
+        statesManager.startChain(state)
+    }
+}

fsm/common/src/commonMain/kotlin/dev/inmo/micro_utils/fsm/common/StatesManager.kt

@@ -0,0 +1,92 @@
+package dev.inmo.micro_utils.fsm.common
+
+import kotlinx.coroutines.flow.*
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+
+interface StatesManager {
+    val onChainStateUpdated: Flow<Pair<State, State>>
+    val onStartChain: Flow<State>
+    val onEndChain: Flow<State>
+
+
+    /**
+     * Must set current set using [State.context]
+     */
+    suspend fun update(old: State, new: State)
+
+    /**
+     * Starts chain with [state] as first [State]. May returns false in case of [State.context] of [state] is already
+     * busy by the other [State]
+     */
+    suspend fun startChain(state: State)
+
+    /**
+     * Ends chain with context from [state]. In case when [State.context] of [state] is absent, [state] should be just
+     * ignored
+     */
+    suspend fun endChain(state: State)
+
+    suspend fun getActiveStates(): List<State>
+}
+
+/**
+ * @param onContextsConflictResolver Receive old [State], new one and the state currently placed on new [State.context]
+ * key. In case when this callback will returns true, the state placed on [State.context] of new will be replaced by
+ * new state by using [endChain] with that state
+ */
+class InMemoryStatesManager(
+    private val onContextsConflictResolver: suspend (old: State, new: State, currentNew: State) -> Boolean = { _, _, _ -> true }
+) : StatesManager {
+    private val _onChainStateUpdated = MutableSharedFlow<Pair<State, State>>(0)
+    override val onChainStateUpdated: Flow<Pair<State, State>> = _onChainStateUpdated.asSharedFlow()
+    private val _onStartChain = MutableSharedFlow<State>(0)
+    override val onStartChain: Flow<State> = _onStartChain.asSharedFlow()
+    private val _onEndChain = MutableSharedFlow<State>(0)
+    override val onEndChain: Flow<State> = _onEndChain.asSharedFlow()
+
+    private val contextsToStates = mutableMapOf<Any, State>()
+    private val mapMutex = Mutex()
+
+    override suspend fun update(old: State, new: State) = mapMutex.withLock {
+        when {
+            contextsToStates[old.context] != old -> return@withLock
+            old.context == new.context || !contextsToStates.containsKey(new.context) -> {
+                contextsToStates[old.context] = new
+                _onChainStateUpdated.emit(old to new)
+            }
+            else -> {
+                val stateOnNewOneContext = contextsToStates.getValue(new.context)
+                if (onContextsConflictResolver(old, new, stateOnNewOneContext)) {
+                    endChainWithoutLock(stateOnNewOneContext)
+                    contextsToStates.remove(old.context)
+                    contextsToStates[new.context] = new
+                    _onChainStateUpdated.emit(old to new)
+                }
+            }
+        }
+    }
+
+    override suspend fun startChain(state: State) = mapMutex.withLock {
+        if (!contextsToStates.containsKey(state.context)) {
+            contextsToStates[state.context] = state
+            _onStartChain.emit(state)
+        }
+    }
+
+    private suspend fun endChainWithoutLock(state: State) {
+        if (contextsToStates[state.context] == state) {
+            contextsToStates.remove(state.context)
+            _onEndChain.emit(state)
+        }
+    }
+
+    override suspend fun endChain(state: State) {
+        mapMutex.withLock {
+            endChainWithoutLock(state)
+        }
+    }
+
+    override suspend fun getActiveStates(): List<State> = contextsToStates.values.toList()
+
+}

fsm/common/src/commonMain/kotlin/dev/inmo/micro_utils/fsm/common/dsl/FSMBuilder.kt

@@ -0,0 +1,35 @@
+package dev.inmo.micro_utils.fsm.common.dsl
+
+import dev.inmo.micro_utils.fsm.common.*
+import kotlin.reflect.KClass
+
+class FSMBuilder(
+    var statesManager: StatesManager = InMemoryStatesManager()
+) {
+    private var states = mutableListOf<StateHandlerHolder<*>>()
+
+    fun <I : State> add(kClass: KClass<I>, handler: StatesHandler<I>) {
+        states.add(StateHandlerHolder(kClass, false, handler))
+    }
+
+    fun <I : State> addStrict(kClass: KClass<I>, handler: StatesHandler<I>) {
+        states.add(StateHandlerHolder(kClass, true, handler))
+    }
+
+    fun build() = StatesMachine(
+        statesManager,
+        states.toList()
+    )
+}
+
+inline fun <reified I : State> FSMBuilder.onStateOrSubstate(handler: StatesHandler<I>) {
+    add(I::class, handler)
+}
+
+inline fun <reified I : State> FSMBuilder.strictlyOn(handler: StatesHandler<I>) {
+    addStrict(I::class, handler)
+}
+
+fun buildFSM(
+    block: FSMBuilder.() -> Unit
+): StatesMachine = FSMBuilder().apply(block).build()

fsm/common/src/jvmTest/kotlin/PlayableMain.kt

@@ -0,0 +1,53 @@
+import dev.inmo.micro_utils.fsm.common.*
+import dev.inmo.micro_utils.fsm.common.dsl.buildFSM
+import dev.inmo.micro_utils.fsm.common.dsl.strictlyOn
+import kotlinx.coroutines.*
+
+sealed interface TrafficLightState : State {
+    val trafficLightNumber: Int
+    override val context: Int
+        get() = trafficLightNumber
+}
+data class GreenCommon(override val trafficLightNumber: Int) : TrafficLightState
+data class YellowCommon(override val trafficLightNumber: Int) : TrafficLightState
+data class RedCommon(override val trafficLightNumber: Int) : TrafficLightState
+
+class PlayableMain {
+//    @Test
+    fun test() {
+        runBlocking {
+            val countOfTrafficLights = 10
+            val initialStates = (0 until countOfTrafficLights).map {
+                when (0/*Random.nextInt(3)*/) {
+                    0 -> GreenCommon(it)
+                    1 -> YellowCommon(it)
+                    else -> RedCommon(it)
+                }
+            }
+
+            val statesManager = InMemoryStatesManager()
+
+            val machine = buildFSM {
+                strictlyOn<GreenCommon> {
+                    delay(1000L)
+                    YellowCommon(it.context).also(::println)
+                }
+                strictlyOn<YellowCommon> {
+                    delay(1000L)
+                    RedCommon(it.context).also(::println)
+                }
+                strictlyOn<RedCommon> {
+                    delay(1000L)
+                    GreenCommon(it.context).also(::println)
+                }
+                this.statesManager = statesManager
+            }
+
+            initialStates.forEach { machine.startChain(it) }
+
+            val scope = CoroutineScope(Dispatchers.Default)
+            machine.start(scope).join()
+
+        }
+    }
+}

fsm/common/src/main/AndroidManifest.xml

@@ -0,0 +1 @@
+<manifest package="dev.inmo.micro_utils.fsm.common"/>

fsm/repos/build.gradle

@@ -0,0 +1,18 @@
+plugins {
+    id "org.jetbrains.kotlin.multiplatform"
+    id "org.jetbrains.kotlin.plugin.serialization"
+    id "com.android.library"
+}
+
+apply from: "$mppProjectWithSerializationPresetPath"
+
+kotlin {
+    sourceSets {
+        commonMain {
+            dependencies {
+                api project(":micro_utils.fsm.common")
+                api project(":micro_utils.repos.common")
+            }
+        }
+    }
+}

fsm/repos/src/commonMain/kotlin/dev/inmo/micro_utils/fsm/repos/KeyValueBasedStatesManager.kt

@@ -0,0 +1,84 @@
+package dev.inmo.micro_utils.fsm.repos
+
+import dev.inmo.micro_utils.fsm.common.State
+import dev.inmo.micro_utils.fsm.common.StatesManager
+import dev.inmo.micro_utils.repos.*
+import dev.inmo.micro_utils.repos.mappers.withMapper
+import dev.inmo.micro_utils.repos.pagination.getAll
+import kotlinx.coroutines.flow.*
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+import kotlin.reflect.KClass
+
+class KeyValueBasedStatesManager(
+    private val keyValueRepo: KeyValueRepo<Any, State>,
+    private val onContextsConflictResolver: suspend (old: State, new: State, currentNew: State) -> Boolean = { _, _, _ -> true }
+) : StatesManager {
+    private val _onChainStateUpdated = MutableSharedFlow<Pair<State, State>>(0)
+    override val onChainStateUpdated: Flow<Pair<State, State>> = _onChainStateUpdated.asSharedFlow()
+    private val _onEndChain = MutableSharedFlow<State>(0)
+    override val onEndChain: Flow<State> = _onEndChain.asSharedFlow()
+
+    override val onStartChain: Flow<State> = keyValueRepo.onNewValue.map { it.second }
+
+    private val mutex = Mutex()
+
+    override suspend fun update(old: State, new: State) {
+        mutex.withLock {
+            when {
+                keyValueRepo.get(old.context) != old -> return@withLock
+                old.context == new.context || !keyValueRepo.contains(new.context) -> {
+                    keyValueRepo.set(old.context, new)
+                    _onChainStateUpdated.emit(old to new)
+                }
+                else -> {
+                    val stateOnNewOneContext = keyValueRepo.get(new.context)!!
+                    if (onContextsConflictResolver(old, new, stateOnNewOneContext)) {
+                        endChainWithoutLock(stateOnNewOneContext)
+                        keyValueRepo.unset(old.context)
+                        keyValueRepo.set(new.context, new)
+                        _onChainStateUpdated.emit(old to new)
+                    }
+                }
+            }
+
+        }
+    }
+
+    override suspend fun startChain(state: State) {
+        if (!keyValueRepo.contains(state.context)) {
+            keyValueRepo.set(state.context, state)
+        }
+    }
+
+    private suspend fun endChainWithoutLock(state: State) {
+        if (keyValueRepo.get(state.context) == state) {
+            keyValueRepo.unset(state.context)
+            _onEndChain.emit(state)
+        }
+    }
+
+    override suspend fun endChain(state: State) {
+        mutex.withLock { endChainWithoutLock(state) }
+    }
+
+    override suspend fun getActiveStates(): List<State> {
+        return keyValueRepo.getAll { keys(it) }.map { it.second }
+    }
+
+}
+
+inline fun <reified TargetContextType, reified TargetStateType> createStatesManager(
+    targetKeyValueRepo: KeyValueRepo<TargetContextType, TargetStateType>,
+    noinline contextToOutTransformer: suspend Any.() -> TargetContextType,
+    noinline stateToOutTransformer: suspend State.() -> TargetStateType,
+    noinline outToContextTransformer: suspend TargetContextType.() -> Any,
+    noinline outToStateTransformer: suspend TargetStateType.() -> State,
+) = KeyValueBasedStatesManager(
+    targetKeyValueRepo.withMapper<Any, State, TargetContextType, TargetStateType>(
+        contextToOutTransformer,
+        stateToOutTransformer,
+        outToContextTransformer,
+        outToStateTransformer
+    )
+)

fsm/repos/src/main/AndroidManifest.xml

@@ -0,0 +1 @@
+<manifest package="dev.inmo.micro_utils.fsm.repos"/>

settings.gradle

@@ -28,6 +28,9 @@ String[] includes = [
     ":serialization:encapsulator",
     ":serialization:typed_serializer",
 
+    ":fsm:common",
+    ":fsm:repos",
+
     ":dokka"
 ]