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.context.DocumentContext;
  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.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.providers.CodeActionProvider;
  import com.github._1c_syntax.bsl.languageserver.utils.Ranges;
  import com.github._1c_syntax.bsl.parser.BSLLexer;
  import org.antlr.v4.runtime.Token;
  import org.eclipse.lsp4j.CodeAction;
  import org.eclipse.lsp4j.CodeActionParams;
  import org.eclipse.lsp4j.Diagnostic;
  import org.eclipse.lsp4j.Range;
  import org.eclipse.lsp4j.TextEdit;
  
  import java.util.List;
  import java.util.stream.Collectors;
  
  @DiagnosticMetadata(
    type = DiagnosticType.CODE_SMELL,
    severity = DiagnosticSeverity.INFO,
    minutesToFix = 1,
    tags = {
      DiagnosticTag.BADPRACTICE
    }
  )
  public class ConsecutiveEmptyLinesDiagnostic extends AbstractDiagnostic implements QuickFixProvider {
  
    private static final int DEFAULT_ALLOWED_EMPTY_LINES_COUNT = 1;
  
    @DiagnosticParameter(
      type = Integer.class,
      defaultValue = "" + DEFAULT_ALLOWED_EMPTY_LINES_COUNT
    )
    private int allowedEmptyLinesCount = DEFAULT_ALLOWED_EMPTY_LINES_COUNT;
  
    @Override
    protected void check() {
  
      final var tokens = documentContext.getTokens();
      if (tokens.isEmpty()) {
        return;
      }
  
      final int[] prevLineStorage = {0};
      // без EOF, т.к. его проще и чуть быстрее обработать вне цикла
      tokens.subList(0, tokens.size() - 1)
        .stream()
        .filter(token -> token.getType() != BSLLexer.WHITE_SPACE)
        .mapToInt(Token::getLine)
        .distinct()
        .forEachOrdered((int currentLine) -> {
          checkEmptyLines(currentLine - 1, prevLineStorage[0]);
          prevLineStorage[0] = currentLine;
        });
  
      checkEmptyLines(getEofTokenLine(tokens), prevLineStorage[0]);
    }
  
    private void checkEmptyLines(int currentLine, int previousLine) {
      if (currentLine - previousLine > allowedEmptyLinesCount) {
        addIssue(previousLine, currentLine);
      }
    }
  
    private static int getEofTokenLine(List<Token> tokens) {
      return tokens.get(tokens.size() - 1).getLine();
    }
  
    private void addIssue(int startEmptyLine, int lastEmptyLine) {
      diagnosticStorage.addDiagnostic(startEmptyLine, 0, lastEmptyLine - 1, 0);
    }
  
    @Override
    public List<CodeAction> getQuickFixes(
      List<Diagnostic> diagnostics, CodeActionParams params, DocumentContext documentContext) {
  
      var eofTokenLine = getEofTokenLine(documentContext.getTokens());
  
      var textEdits = diagnostics.stream()
        .map(diagnostic -> getQuickFixText(diagnostic, eofTokenLine))
        .collect(Collectors.toList());
  
      return CodeActionProvider.createCodeActions(
        textEdits,
        info.getResourceString("quickFixMessage"),
        documentContext.getUri(),
        diagnostics
      );
    }
  
    private static TextEdit getQuickFixText(Diagnostic diagnostic, int eofTokenLine) {
      Range range = diagnostic.getRange();
  
      int endLine = range.getEnd().getLine() + 1;
      String newText = "\n";
      if (endLine == eofTokenLine) {
        endLine--;
        newText = "";
      }
      Range newRange = Ranges.create(range.getStart().getLine(), 0, endLine, 0);
      return new TextEdit(newRange, newText);
    }
  }
  