// IState.swift
// The interface for implementing states in a StateMachine
// Ported from Android implementation

import Foundation

/// Protocol defining the interface for implementing states in a state machine
public protocol IState {
    
    /// Called when a state is entered
    /// - Parameters:
    ///   - from: State we are coming from
    ///   - params: Optional parameters for state transition
    func enter(from: IState?, params: Any?)
    
    /// Called when a state is exited
    /// - Parameter to: State we are transitioning to
    func exit(to: IState?)
    
    /// Process a message sent to the state machine
    /// - Parameter msg: The message to process
    /// - Returns: HANDLED if processing has completed or NOT_HANDLED if the message wasn't processed
    func processMessage(_ msg: Message) -> Bool
    
    /// Name of State for debugging purposes
    /// - Returns: name of state
    var name: String { get }
}