using System;
using System.Collections.Generic;
using System.Linq;
using System.Collections;

namespace Cosmos.Compiler.Assembler {

  public class StackContents: IEnumerable<StackContents.Item> {
    #region class Item
    public sealed class Item {
      public Item(int aSize) {
        Size = aSize;
      }

      public Item(int aSize, Type aType)
        : this(aSize) {
        IsNumber = (aType == typeof(byte)
            || aType == typeof(sbyte)
            || aType == typeof(Boolean)
            || aType == typeof(short)
            || aType == typeof(ushort)
            || aType == typeof(int)
            || aType == typeof(uint)
            || aType == typeof(long)
            || aType == typeof(ulong)
            || aType == typeof(Single)
            || aType == typeof(Double));
        IsFloat = (aType == typeof(Single) || aType == typeof(Double));
        IsSigned = (aType == typeof(sbyte)
            || aType == typeof(short)
            || aType == typeof(int)
            || aType == typeof(long)
            || aType == typeof(Single)
            || aType == typeof(Double));
        ContentType = aType;
      }

      public Item(int aSize, bool aIsNumber, bool aIsFloat, bool aIsSigned)
        : this(aSize) {
        IsNumber = aIsNumber;
        IsFloat = aIsFloat;
        IsSigned = aIsSigned;
      }
      public readonly int Size;
      public readonly bool IsNumber = false;
      public readonly bool IsFloat = false;
      public readonly bool IsSigned = false;
      public readonly Type ContentType = null;
      public readonly bool IsBox = false;
    }
    #endregion

    public StackContents() {
    }

    private Stack<Item> mStack = new Stack<Item>();

    public int Count { get { return mStack.Count; } }
    public Item Peek() {
      return mStack.Peek();
    }

    public void Clear() {
      mStack.Clear();
    }

    public Item Pop() {
      return mStack.Pop();
    }

    public void Push(Item aItem) {
      mStack.Push(aItem);
    }

    public void Push(int aSize) {
      mStack.Push(new Item(aSize));
    }

    public void Push(int aSize, Type aType) {
      mStack.Push(new Item(aSize, aType));
    }

    public void Push(int aSize, bool aIsNumber, bool aIsFloat, bool aIsSigned) {
      mStack.Push(new Item(aSize, aIsNumber, aIsFloat, aIsSigned));
    }

    public IEnumerator<Item> GetEnumerator() {
      foreach (var item in mStack) {
        yield return item;
      }
    }

    IEnumerator IEnumerable.GetEnumerator() {
      foreach (var xItem in mStack) {
        yield return xItem;
      }
    }
  }
}