using Microsoft.SqlServer.TransactSql.ScriptDom;
using SQLLinter.Common;

namespace SQLLinter.Infrastructure.Rules;

public class SelectStarRule : BaseRuleVisitor, IRule
{
    private int expressionCounter;

    public override string Text => "Ожидаются имена столбцов в SELECT";

    public override void Visit(ExistsPredicate node)
    {
        var childVisitor = new ChildVisitor();
        node.AcceptChildren(childVisitor);
        expressionCounter += childVisitor.SelectStarExpressionCount;
    }

    public override void Visit(SelectStarExpression node)
    {
        if (expressionCounter > 0)
        {
            expressionCounter--;
            return;
        }

        AddViolation(node);
    }

    public class ChildVisitor : TSqlFragmentVisitor
    {
        public int SelectStarExpressionCount { get; set; }

        public override void Visit(SelectStarExpression node)
        {
            SelectStarExpressionCount++;
        }
    }
}