using System.Diagnostics;
using System.Text;
using Intromat.Model;
using Intromat.Model.Compiler;

namespace Intromat.Nodes.Code
{
    public class ForLoopValue : ExecutionValueBase
    {
        public IStatement? LoopBody { get; set; }

        public ITypedExpression<int>? LowerBound { get; set; }
        public ITypedExpression<int>? UpperBound { get; set; }

        public InlineVariableDefinition<int> CurrentIndex { get; } = new();

        public override void Compile(CompilerContext context, StringBuilder sb)
        {
            Debug.Assert(UpperBound != null, nameof(UpperBound) + " != null");

            context.EnterNewScope("For loop");

            CurrentIndex.Value = LowerBound;
            sb.Append("for (");
            CurrentIndex.Compile(context, sb);
            sb.Append("; ");
            sb.Append(CurrentIndex.VariableName);
            sb.Append(" <= ");
            UpperBound.Compile(context, sb);
            sb.Append("; ++");
            sb.Append(CurrentIndex.VariableName);
            sb.Append(")\n{\n");
            LoopBody?.Compile(context, sb);
            sb.Append("\n}\n");

            context.LeaveScope();

            base.Compile(context, sb);
        }

        public override void CompileHeader(CompilerContext context, StringBuilder sb)
        {
            LoopBody?.CompileHeader(context, sb);

            base.CompileHeader(context, sb);
        }
    }
}