using System;
using System.Collections.Generic;

namespace AspClassic.Parser;

/// <summary>
/// A parse tree for a binary operator expression.
/// </summary>
public sealed class BinaryOperatorExpression : Expression
{
	private readonly Expression _LeftOperand;

	private readonly OperatorType _Operator;

	private readonly Location _OperatorLocation;

	private readonly Expression _RightOperand;

	/// <summary>
	/// The left operand expression.
	/// </summary>
	public Expression LeftOperand => _LeftOperand;

	/// <summary>
	/// The operator.
	/// </summary>
	public OperatorType Operator => _Operator;

	/// <summary>
	/// The location of the operator.
	/// </summary>
	public Location OperatorLocation => _OperatorLocation;

	/// <summary>
	/// The right operand expression.
	/// </summary>
	public Expression RightOperand => _RightOperand;

	public override bool IsConstant => LeftOperand.IsConstant && RightOperand.IsConstant;

	/// <summary>
	/// Constructs a new parse tree for a binary operation.
	/// </summary>
	/// <param name="leftOperand">The left operand expression.</param>
	/// <param name="operator">The operator.</param>
	/// <param name="operatorLocation">The location of the operator.</param>
	/// <param name="rightOperand">The right operand expression.</param>
	/// <param name="span">The location of the parse tree.</param>
	public BinaryOperatorExpression(Expression leftOperand, OperatorType @operator, Location operatorLocation, Expression rightOperand, Span span)
		: base(TreeType.BinaryOperatorExpression, span)
	{
		if (@operator < OperatorType.Plus || @operator > OperatorType.GreaterThanEquals)
		{
			throw new ArgumentOutOfRangeException("operator");
		}
		if (leftOperand == null)
		{
			throw new ArgumentNullException("leftOperand");
		}
		if (rightOperand == null)
		{
			throw new ArgumentNullException("rightOperand");
		}
		SetParent(leftOperand);
		SetParent(rightOperand);
		_LeftOperand = leftOperand;
		_Operator = @operator;
		_OperatorLocation = operatorLocation;
		_RightOperand = rightOperand;
	}

	protected override void GetChildTrees(IList<Tree> childList)
	{
		Tree.AddChild(childList, LeftOperand);
		Tree.AddChild(childList, RightOperand);
	}
}