Class StateMachine

packages/fsm/src/StateMachine.ts:54–426

 * @en State machine implementation
 */
export class StateMachine<TState extends string = string, TContext = unknown>
    implements IStateMachine<TState, TContext>
{
    private _current: TState;
    private _previous: TState | null = null;
    private _context: TContext;
    private _isTransitioning = false;
    private _stateStartTime = 0;

    private states: Map<TState, StateConfig<TState, TContext>> = new Map();
    private transitions: Map<TState, TransitionConfig<TState, TContext>[]> = new Map();

    private enterListeners: Map<TState, Set<(from: TState | null) => void>> = new Map();
    private exitListeners: Map<TState, Set<(to: TState) => void>> = new Map();
    private changeListeners: Set<StateChangeListener<TState>> = new Set();

    private history: StateChangeEvent<TState>[] = [];
    private maxHistorySize: number;
    private enableHistory: boolean;

    constructor(initialState: TState, options: StateMachineOptions<TContext> = {}) {
        this._current = initialState;
        this._context = (options.context ?? {}) as TContext;
        this.maxHistorySize = options.maxHistorySize ?? 100;
        this.enableHistory = options.enableHistory ?? true;
        this._stateStartTime = Date.now();

        // Auto-define initial state if not defined
        this.defineState(initialState);
    }

    // =========================================================================
    // 属性 | Properties
    // =========================================================================

    get current(): TState {
        return this._current;
    }

    get previous(): TState | null {
        return this._previous;
    }

    get context(): TContext {
        return this._context;
    }

    get isTransitioning(): boolean {
        return this._isTransitioning;
    }

    get currentStateDuration(): number {
        return Date.now() - this._stateStartTime;
    }

    // =========================================================================
    // 状态定义 | State Definition
    // =========================================================================