init: add project

Assets/_Project/Develop/Runtime/Utilities/StateMachine/StateMachine.cs

@@ -0,0 +1,79 @@
+using System;
+using System.Collections.Generic;
+
+namespace _Project.Develop.Runtime.Utilities.StateMachine
+{
+    public abstract class StateMachine : IStateChanger
+    {
+        public event Action<State> Changed;
+        
+        public State Current { get; private set; }
+
+        private readonly Dictionary<Type, State> _states = new();
+        private bool _isRunning;
+        
+        public StateMachine(params State[] states)
+        {
+            foreach (State state in states)
+                Add(state);
+        }
+
+        public void Update(float deltaTime)
+        {
+            if (_isRunning == false)
+                return;
+            
+            Current?.Update(deltaTime);
+        }
+        
+        public StateMachine Add(State state)
+        {
+            if (state == null)
+                throw new ArgumentNullException(nameof(state));
+            
+            Type type = state.GetType();
+            
+            if (_states.TryAdd(type, state) == false)
+                throw new InvalidOperationException($"[StateMachine] State {type.Name} is already registered");
+
+            return this;
+        }
+        
+        public StateMachine Remove<TState>() where TState : State
+        {
+            Type type = typeof(TState);
+            
+            if (_states.Remove(type) == false)
+                throw new InvalidOperationException($"[StateMachine] State {type.Name} is not registered");
+
+            return this;
+        }
+        
+        public StateMachine ChangeState<TState>() where TState : State
+        {
+            Type type = typeof(TState);
+            
+            if (_states.TryGetValue(type, out State state) == false)
+                throw new InvalidOperationException($"[StateMachine] State {type.Name} is not registered");
+            
+            SwitchState(state);
+            
+            return this;
+        }
+        
+        private void SwitchState(State newState)
+        {
+            if (newState == null)
+                throw new ArgumentNullException(nameof(newState));
+            
+            if (Current != null)
+                Current.OnExit();
+            else
+                _isRunning = true;
+            
+            Current = newState;
+            Changed?.Invoke(Current);
+            Current.OnEnter();
+        }
+    }
+}