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

namespace SQLLinter.Infrastructure.Rules;

public class SemicolonTerminationRule : BaseRuleVisitor, IRule
{
    private readonly IList<TSqlFragment> waitForStatements = new List<TSqlFragment>();
    private readonly IList<TSqlFragment> functionReturnTypeSelectStatements = new List<TSqlFragment>();
    private static Regex WhiteSpaceRegex = new Regex(@"\s", RegexOptions.Compiled);
    private static Regex AllWhiteSpaceRegex = new Regex(@"^\s$", RegexOptions.Compiled);


    // не принудительно завершать эти операторы точкой с запятой
    private readonly Type[] typesToSkip =
    {
        typeof(BeginEndBlockStatement),
        typeof(GoToStatement),
        typeof(IndexDefinition),
        typeof(LabelStatement),
        typeof(WhileStatement),
        typeof(IfStatement),
        typeof(CreateViewStatement)
    };

    public override string Text => "Оператор не заканчивается точкой с запятой";

    public override void Visit(WaitForStatement node)
    {
        waitForStatements.Add(node.Statement);
    }

    public override void Visit(CreateFunctionStatement node)
    {
        if (node.ReturnType is SelectFunctionReturnType returnType)
        {
            functionReturnTypeSelectStatements.Add(returnType.SelectStatement);
        }
    }

    public override void Visit(TSqlStatement node)
    {
        if (Array.IndexOf(typesToSkip, node.GetType()) > -1 ||
            EndsWithSemicolon(node) ||
            waitForStatements.Contains(node) ||
            functionReturnTypeSelectStatements.Contains(node))
        {
            return;
        }

        var dynamicSqlColumnOffset = GetDynamicSqlColumnOffset(node);

        var (lastToken, column) = GetLastTokenAndColumn(node);
        AddViolation(Name, Text, GetLineNumber(lastToken), column + dynamicSqlColumnOffset);
    }

    private static (TSqlParserToken, int) GetLastTokenAndColumn(TSqlStatement node)
    {
        var lastToken = node.ScriptTokenStream[node.LastTokenIndex];
        var tabsOnLine = ColumnNumberCalculator.CountTabsBeforeToken(lastToken.Line, node.LastTokenIndex, node.ScriptTokenStream);
        var column = ColumnNumberCalculator.GetColumnNumberAfterToken(tabsOnLine, lastToken);

        return (lastToken, column);
    }

    private static bool EndsWithSemicolon(TSqlFragment node)
    {
        return node.ScriptTokenStream[node.LastTokenIndex].TokenType == TSqlTokenType.Semicolon
            || node.ScriptTokenStream[node.LastTokenIndex + 1].TokenType == TSqlTokenType.Semicolon;
    }
}