/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
    * with the License.  You may obtain a copy of the License at
    *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  package org.apache.maven.doxia.module.markdown;
  
  import java.io.IOException;
  
  import org.apache.commons.io.output.NullWriter;
  import org.junit.jupiter.api.BeforeEach;
  import org.junit.jupiter.api.Test;
  import org.junit.jupiter.params.ParameterizedTest;
  import org.junit.jupiter.params.provider.ValueSource;
  
  import static org.junit.jupiter.api.Assertions.assertFalse;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  class LastTwoLinesBufferingWriterTest {
  
      private LastTwoLinesBufferingWriter writer;
  
      @BeforeEach
      void setup() {
          writer = new LastTwoLinesBufferingWriter(NullWriter.INSTANCE);
      }
  
      @Test
      void testEmptyWriter() {
          assertTrue(writer.isWriterAfterBlankLine());
          assertTrue(writer.isWriterAtStartOfNewLine());
      }
  
      @Test
      void testWriterWithOneBlankLine() throws IOException {
          writer.write("  " + System.lineSeparator());
          assertTrue(writer.isWriterAfterBlankLine());
          assertTrue(writer.isWriterAtStartOfNewLine());
      }
  
      @Test
      void testWriterWithOneNonBlankLine() throws IOException {
          writer.write("not blank  " + System.lineSeparator());
          assertFalse(writer.isWriterAfterBlankLine());
          assertTrue(writer.isWriterAtStartOfNewLine());
      }
  
      @Test
      void testWriterWithTwoBlankLines() throws IOException {
          writer.write("  " + System.lineSeparator());
          writer.write("  " + System.lineSeparator());
          assertTrue(writer.isWriterAfterBlankLine());
          assertTrue(writer.isWriterAtStartOfNewLine());
          // try writing the same two lines in other blocks
          writer.write("  ");
          writer.write(System.lineSeparator());
          writer.write("  ");
          writer.write(System.lineSeparator());
          assertTrue(writer.isWriterAfterBlankLine());
          assertTrue(writer.isWriterAtStartOfNewLine());
      }
  
      @Test
      void testWriterWithNonBlankLineFollowingBlankLine() throws IOException {
          writer.write("\t" + System.lineSeparator());
          writer.write("test");
          assertFalse(writer.isWriterAfterBlankLine());
          assertFalse(writer.isWriterAtStartOfNewLine());
      }
  
      @Test
      void testWriterWithBlankLineFollowingNonBlankLine() throws IOException {
          writer.write("test");
          writer.write(System.lineSeparator());
          writer.write(System.lineSeparator());
          assertTrue(writer.isWriterAfterBlankLine());
          assertTrue(writer.isWriterAtStartOfNewLine());
      }
  
      @ParameterizedTest()
      @ValueSource(strings = {"\n", "\r\n"})
      void testDifferentLineSeparators(String lineSeparator) throws IOException {
          writer = new LastTwoLinesBufferingWriter(NullWriter.INSTANCE, lineSeparator);
          writer.write("text" + lineSeparator);
          assertFalse(writer.isWriterAfterBlankLine());
          assertTrue(writer.isWriterAtStartOfNewLine());
         writer.write("text" + lineSeparator + lineSeparator + " ");
         assertTrue(writer.isWriterAfterBlankLine());
         assertFalse(writer.isWriterAtStartOfNewLine());
     }
 }