import {
  UndoManager,
  ArrayList,
} from "../internal";

export class UndoManagerObserver {
  protected _onPerformRedoListeners: ArrayList<UndoManagerObserver.OnPerformRedoListener>;
  protected _onPerformUndoListeners: ArrayList<UndoManagerObserver.OnPerformUndoListener>;
  protected _onPerformCommandListeners: ArrayList<UndoManagerObserver.OnPerformCommandListener>;

  public addPerformRedoListener(listener: UndoManagerObserver.OnPerformRedoListener): void {
    if (this._onPerformRedoListeners == null) {
      this._onPerformRedoListeners = new ArrayList<UndoManagerObserver.OnPerformRedoListener>();
    }
    this._onPerformRedoListeners.add(listener);
  }

  public addPerformUndoListener(listener: UndoManagerObserver.OnPerformUndoListener): void {
    if (this._onPerformUndoListeners == null) {
      this._onPerformUndoListeners = new ArrayList<UndoManagerObserver.OnPerformUndoListener>();
    }
    this._onPerformUndoListeners.add(listener);
  }

  public addPerformCommandListener(listener: UndoManagerObserver.OnPerformCommandListener): void {
    if (this._onPerformCommandListeners == null) {
      this._onPerformCommandListeners = new ArrayList<UndoManagerObserver.OnPerformCommandListener>();
    }
    this._onPerformCommandListeners.add(listener);
  }

  public removePerformRedoListener(listener: UndoManagerObserver.OnPerformRedoListener): void {
    if (this._onPerformRedoListeners == null) {
      return;
    }
    this._onPerformRedoListeners.remove(listener);
  }

  public removePerformUndoListener(listener: UndoManagerObserver.OnPerformUndoListener): void {
    if (this._onPerformUndoListeners == null) {
      return;
    }
    this._onPerformUndoListeners.remove(listener);
  }

  public removePerformCommandListener(listener: UndoManagerObserver.OnPerformCommandListener): void {
    if (this._onPerformCommandListeners == null) {
      return;
    }
    this._onPerformCommandListeners.remove(listener);
  }

  public dispatchPerformRedo(wrapped: UndoManager.Wrapped): void {
    let listeners = this._onPerformRedoListeners;
    if (listeners != null) {
      const sizeof = listeners.sizeof();
      for (let i = 0; i < sizeof; i++) {
        const listener = listeners.get(i);
        listener.onPerformRedo(wrapped);
      }
    }
  }

  public dispatchPerformUndo(wrapped: UndoManager.Wrapped): void {
    let listeners = this._onPerformUndoListeners;
    if (listeners != null) {
      const sizeof = listeners.sizeof();
      for (let i = 0; i < sizeof; i++) {
        const listener = listeners.get(i);
        listener.onPerformUndo(wrapped);
      }
    }
  }

  public dispatchPerformCommand(wrapped: UndoManager.Wrapped): void {
    let listeners = this._onPerformCommandListeners;
    if (listeners != null) {
      const sizeof = listeners.sizeof();
      for (let i = 0; i < sizeof; i++) {
        const listener = listeners.get(i);
        listener.onPerformCommand(wrapped);
      }
    }
  }
}

export namespace UndoManagerObserver {
  export interface OnPerformRedoListener {
    onPerformRedo(wrapped: UndoManager.Wrapped): void
  }

  export interface OnPerformUndoListener {
    onPerformUndo(wrapped: UndoManager.Wrapped): void
  }

  export interface OnPerformCommandListener {
    onPerformCommand(wrapped: UndoManager.Wrapped): void
  }
}