Design Circular Deque

export class MyCircularDeque {
  public size: number;
  private readonly maxSize: number;
  private head: CircularNode;
  private tail: CircularNode;
 
  constructor(k: number) {
    this.maxSize = k;
    this.size = 0;
    this.head = new CircularNode(-1);
    this.tail = new CircularNode(-1);
    this.head.next = this.tail;
    this.tail.prev = this.head;
  }
 
  insertFront(value: number): boolean {
    if (this.isFull()) {
      return false;
    }
    const newNode = new CircularNode(value, this.head, this.head.next);
    if (this.head.next) {
      this.head.next.prev = newNode;
    }
    this.head.next = newNode;
    this.size += 1;
    return true;
  }
 
  insertLast(value: number): boolean {
    if (this.isFull()) {
      return false;
    }
    const newNode = new CircularNode(value, this.tail.prev, this.tail);
    if (this.tail.prev) {
      this.tail.prev.next = newNode;
    }
    this.tail.prev = newNode;
    this.size += 1;
    return true;
  }
 
  deleteFront(): boolean {
    if (this.isEmpty()) {
      return false;
    }
    this.head.next = this.head.next?.next;
    if (this.head.next) {
      this.head.next.prev = this.head;
    }
    this.size -= 1;
    return true;
  }
 
  deleteLast(): boolean {
    if (this.isEmpty()) {
      return false;
    }
    this.tail.prev = this.tail.prev?.prev;
    if (this.tail.prev) {
      this.tail.prev.next = this.tail;
    }
    this.size -= 1;
    return true;
  }
 
  getFront(): number {
    return this.head.next?.value ?? -1;
  }
 
  getRear(): number {
    return this.tail.prev?.value ?? -1;
  }
 
  isEmpty(): boolean {
    return this.size === 0;
  }
 
  isFull(): boolean {
    return this.size === this.maxSize;
  }
}
 
class CircularNode {
  public value: number;
  public prev: CircularNode | undefined;
  public next: CircularNode | undefined;
 
  constructor(value: number, prev?: CircularNode, next?: CircularNode) {
    this.value = value;
    this.prev = prev;
    this.next = next;
  }
}