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

namespace SQLLinter.Infrastructure.Rules;

public class CountStarRule : BaseRuleVisitor, IRule
{
    public override string Text => "COUNT(*) запрещен. Используйте COUNT(1) или COUNT(<PK>)";

    public override void Visit(FunctionCall node)
    {
        var functionName = node.FunctionName?.Value;
        if (functionName == null || !functionName.ToUpper().Equals("COUNT"))
        {
            return;
        }
        foreach (ScalarExpression param in node.Parameters)
        {
            var paramVisitor = new ParameterVisitor();
            param.Accept(paramVisitor);
            if (paramVisitor.IsWildcard)
            {
                AddViolation(node);
            }
        }
    }

    public override void FixViolation(List<string> fileLines, IRuleViolation ruleViolation, FileLineActions actions)
    {
        var node = FixHelpers.FindViolatingNode<FunctionCall>(fileLines, ruleViolation);

        foreach (ScalarExpression param in node.Parameters)
        {
            var paramVisitor = new ParameterVisitor();
            param.Accept(paramVisitor);
            if (paramVisitor.IsWildcard)
            {
                var whileCard = paramVisitor.Expression;
                actions.RepaceInlineAt(whileCard.StartLine - 1, whileCard.StartColumn - 1, "1");
            }
        }
    }

    private class ParameterVisitor : TSqlFragmentVisitor
    {
        public bool IsWildcard { get; private set; }
        public ColumnReferenceExpression Expression { get; private set; }

        public ParameterVisitor()
        {
            IsWildcard = false;
        }

        public override void Visit(ColumnReferenceExpression node)
        {
            IsWildcard = node.ColumnType.Equals(ColumnType.Wildcard);
            Expression = node;
        }
    }
}