using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ShintenScript
{
    public abstract class ASTNodeBinaryNumericOperator : IASTNode
    {
        public IASTNode lhs, rhs;

        protected ASTNodeBinaryNumericOperator(IASTNode lhs, IASTNode rhs)
        {
            this.lhs = lhs;
            this.rhs = rhs;
        }

        public bool Const()
        {
            return lhs.Const() && rhs.Const();
        }

        public object CreateFunction()
        {
            SSType lhst = lhs.Type();
            SSType rhst = rhs.Type();

            if (lhst == SSType.real && rhst == SSType.real)
            {
                Func<ExecutionContext, float> left = (Func<ExecutionContext, float>)lhs.CreateFunction();
                Func<ExecutionContext, float> right = (Func<ExecutionContext, float>)rhs.CreateFunction();
                return CreateFunction11(left, right);
            }

            throw new Exception("This should be unreachable");
        }

        public SSType Type()
        {
            SSType lhst = lhs.Type();
            SSType rhst = rhs.Type();

            if (lhst == SSType.real && rhst == SSType.real)
                return SSType.real;

            throw new TypeException($"Unsupported types for operator '{Op()}': {lhst} and {rhst}");
        }

        public abstract string Op();
        public abstract object CreateFunction11(Func<ExecutionContext, float> left, Func<ExecutionContext, float> right);
    }
}