using Connected.Expressions.Visitors;
using System.Linq.Expressions;

namespace Connected.Expressions.Translation.Rewriters;

public class ParameterRewriter : DatabaseVisitor
{
    private ParameterRewriter(ExpressionCompilationContext context)
    {
        Context = context;
    }

    private ExpressionCompilationContext Context { get; }

    public static Expression Rewrite(ExpressionCompilationContext context, Expression expression)
    {
        return new ParameterRewriter(context).Visit(expression);
    }

    protected override Expression VisitBinary(BinaryExpression expression)
    {
        return base.VisitBinary(expression);
    }
    protected override Expression VisitConstant(ConstantExpression expression)
    {
        var parameter = Context.Parameters.FirstOrDefault(f => f.Value == expression);

        if (parameter.Value is not null)
            return Expression.Constant($"@{parameter.Key}");

        return base.VisitConstant(expression);
    }
}