using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace Composite
{
    class Program
    {
        static void Main(string[] args)
        {
            // 创建根节点
            Composite root = new Composite("root");
            root.add(new Leaf("Leaf A"));
            root.add(new Leaf("Leaf B"));
            // 创建第二层节点
            Composite branch = new Composite("branch");
            branch.add(new Leaf("branch BX"));
            branch.add(new Leaf("branch BY"));
            root.add(branch);
            // 创建第三层节点
            Composite branch2 = new Composite("branch2");
            branch2.add(new Leaf("branch2 BBX"));
            branch2.add(new Leaf("branch2 BBY"));
            root.add(branch2);
            // 叶子节点操作
            Composite branch3 = new Composite("branch3");
            Leaf leaf = new Leaf("Leaf L");
            Leaf leaf1 = new Leaf("Leaf L1");
            leaf.add(leaf1);
            leaf.delete(leaf1);
            branch3.add(leaf);
            branch3.add(leaf1);
            branch3.delete(leaf);
            root.add(branch3);
            // 显示
            root.show(1);
            Console.Read();
        }
    }
    /// <summary>
    /// 抽象构件
    /// </summary>
    public abstract class Component
    {
        public string Name { get; set; }
        public Component(string name)
        {
            this.Name = name;
        }
        // 添加一个叶子构件或树枝构件
        public abstract void add(Component component);
        // 删除一个叶子构件或树枝构件
        public abstract void delete(Component component);
        // 获取分支下的所有叶子构件和树枝构件
        public abstract void show(int depth);
    }
    /// <summary>
    /// 叶子构件
    /// </summary>
    public class Leaf : Component
    {
        public Leaf(string name):base(name)
        { }
        // 如果是叶子节点，则不允许进行添加节点，因为叶子节点下再没有节点了
        public override void add(Component component)
        {
            Console.WriteLine("叶子节点不能添加其他内容");
        }
        
        // 如果是叶子节点，则不允许进行删除节点，因为叶子节点下再没有节点了
        public override void delete(Component component)
        {
            Console.WriteLine("叶子节点不能删除内容");
        }
        public override void show(int depth)
        {
            // 输出叶子节点
            for (int i = 0; i < depth; i++)
            {
                Console.Write("-");
            }
            Console.WriteLine(this.Name);
        }
    }
    /// <summary>
    /// 树构件
    /// </summary>
    public class Composite : Component
    {
        protected List<Component> _children = new List<Component>();
        public Composite(string name) : base(name)
        { }
        public override void add(Component component)
        {
            _children.Add(component);
        }
        public override void delete(Component component)
        {
            _children.Remove(component);
        }
        public override void show(int depth)
        {
            // 输出树形结构层次
            for (int i=0; i<depth; i++)
            {
                Console.Write("-");
            }
            Console.WriteLine(this.Name);
            // 向下遍历
            foreach (Component compontent in _children)
            {
                compontent.show(depth + 1);
            }
        }
    }
}

叶子节点不能添加其他内容
叶子节点不能删除内容
-root
--Leaf A
--Leaf B
--branch
---branch BX
---branch BY
--branch2
---branch2 BBX
---branch2 BBY
--branch3
---Leaf L1