using Microsoft.SqlServer.TransactSql.ScriptDom;
using SQLLinter.Common;
using SQLLinter.Common.Helpers;
using System.Text.RegularExpressions;

namespace SQLLinter.Infrastructure.Rules;

/// <summary>
/// Ожидается наличие BEGIN - END в блоке IF
/// </summary>
public class ConditionalBeginEndRule : BaseRuleVisitor, IRule
{
    private readonly Regex IsWhiteSpaceOrSemiColon = new Regex(@"\s|;", RegexOptions.Compiled);


    public override string Text => "Ожидается наличие BEGIN - END в блоке IF";

    public override void Visit(IfStatement node)
    {
        if (node.ThenStatement != null && node.ThenStatement is not BeginEndBlockStatement)
        {
            if (node.ThenStatement.StartLine != node.StartLine || node.ScriptTokenStream.Where(t => t.Offset <= node.ThenStatement.StartOffset + node.ThenStatement.FragmentLength).Max(t => t.Line) != node.StartLine)
            {
                AddViolation(node.ThenStatement);
            }
        }

        if (node.ElseStatement != null && node.ElseStatement is not BeginEndBlockStatement && node.ElseStatement is not IfStatement)
        {
            if (node.ElseStatement.StartLine != node.StartLine || node.ScriptTokenStream.Where(t => t.Offset <= node.ElseStatement.StartOffset + node.ElseStatement.FragmentLength).Max(t => t.Line) != node.StartLine)
            {
                AddViolation(node.ElseStatement);
            }
        }
    }

    public override void FixViolation(List<string> fileLines, IRuleViolation ruleViolation, FileLineActions actions)
    {
        var ifNode = FixHelpers.FindViolatingNode<IfStatement>(fileLines, ruleViolation);
        TSqlStatement statement;

        if (ifNode == null)
        {
            (statement, ifNode) = FindElse(fileLines, ruleViolation);
        }
        else
        {
            statement = ifNode.ThenStatement;
        }

        var stream = statement.ScriptTokenStream;
        var indent = FixHelpers.GetIndent(fileLines, ifNode);
        var beingLine = stream[statement.FirstTokenIndex].Line - 1;
        var ifNodeLastToken = stream[statement.LastTokenIndex];
        var endLine = stream[statement.LastTokenIndex].Line;

        if (statement.StartLine == ifNodeLastToken.Line)
        {
            var index = statement.LastTokenIndex;
            actions.InsertInLine(statement.StartLine - 1, stream[index].Column, " END");
            actions.InsertInLine(statement.StartLine - 1, statement.StartColumn - 1, "BEGIN ");
        }
        else
        {
            actions.Insert(endLine, $"{indent}END");
            actions.Insert(beingLine, $"{indent}BEGIN");
        }

        static (TSqlStatement, IfStatement) FindElse(List<string> fileLines, IRuleViolation ruleViolation)
        {
            return FixHelpers.FindViolatingNode<IfStatement, TSqlStatement>(
                fileLines, ruleViolation, x => x.ElseStatement);
        }
    }
}