content: /*
   * This file is a part of BSL Language Server.
   *
   * Copyright (c) 2018-2025
   * Alexey Sosnoviy <labotamy@gmail.com>, Nikita Fedkin <nixel2007@gmail.com> and contributors
   *
   * SPDX-License-Identifier: LGPL-3.0-or-later
   *
   * BSL Language Server is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 3.0 of the License, or (at your option) any later version.
   *
   * BSL Language Server is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with BSL Language Server.
   */
  package com.github._1c_syntax.bsl.languageserver.diagnostics;
  
  import com.github._1c_syntax.bsl.languageserver.diagnostics.metadata.DiagnosticMetadata;
  import com.github._1c_syntax.bsl.languageserver.diagnostics.metadata.DiagnosticParameter;
  import com.github._1c_syntax.bsl.languageserver.diagnostics.metadata.DiagnosticScope;
  import com.github._1c_syntax.bsl.languageserver.diagnostics.metadata.DiagnosticSeverity;
  import com.github._1c_syntax.bsl.languageserver.diagnostics.metadata.DiagnosticTag;
  import com.github._1c_syntax.bsl.languageserver.diagnostics.metadata.DiagnosticType;
  import com.github._1c_syntax.bsl.languageserver.utils.Trees;
  import com.github._1c_syntax.bsl.parser.SDBLParser;
  import edu.umd.cs.findbugs.annotations.Nullable;
  import org.antlr.v4.runtime.tree.ParseTree;
  
  @DiagnosticMetadata(
    type = DiagnosticType.CODE_SMELL,
    severity = DiagnosticSeverity.MAJOR,
    minutesToFix = 5,
    tags = {
      DiagnosticTag.STANDARD,
      DiagnosticTag.SQL,
      DiagnosticTag.SUSPICIOUS
    },
    scope = DiagnosticScope.BSL
  )
  public class SelectTopWithoutOrderByDiagnostic extends AbstractSDBLVisitorDiagnostic {
  
    // for skip queries with 'TOP 1' limitation without 'ORDER BY'
    private static final boolean SKIP_SELECT_TOP_ONE = true;
    @DiagnosticParameter(
      type = Boolean.class,
      defaultValue = "" + SKIP_SELECT_TOP_ONE
    )
    private boolean skipSelectTopOne = SKIP_SELECT_TOP_ONE;
  
    @Override
    public ParseTree visitSubquery(SDBLParser.SubqueryContext ctx) {
      if (!ctx.union().isEmpty()) {
        // always presence of 'top' is a mistake
        checkQuery(ctx.query(), false);
        ctx.union().forEach(unionCtx -> checkQuery(unionCtx.query(), false));
      } else {
        // missing order by
        if (!Trees.nodeContains(ctx.getParent(), SDBLParser.RULE_orderBy)) {
          checkQuery(ctx.query(), skipSelectTopOne);
        }
      }
      return super.visitSubquery(ctx);
    }
  
    private void checkQuery(@Nullable SDBLParser.QueryContext ctx, boolean canTopOne) {
  
      if (ctx == null) {
        // для битых запросов, чтобы не ронять
        return;
      }
  
      SDBLParser.LimitationsContext limitations = ctx.limitations();
  
      // limitations or top is missing
      if (limitations == null || limitations.top() == null) {
        return;
      }
  
      var topCtx = ctx.limitations().top();
      if (topCtx.DECIMAL() == null) {
        // why? it's error!
        return;
      }
  
      var topLimit = topCtx.DECIMAL().getText();
      boolean allowedTopNumber = "1".equals(topLimit) || "0".equals(topLimit);
      if (!(allowedTopNumber && (canTopOne || ctx.where != null))) {
        diagnosticStorage.addDiagnostic(topCtx);
      }
    }
  }
  