/*
    * 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
    *
    *      https://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.commons.io.input.buffer;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertFalse;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  import java.nio.charset.StandardCharsets;
  
  import org.junit.jupiter.api.Test;
  
  /**
   * Tests {@link CircularByteBuffer}.
   */
  class CircularByteBufferTest {
  
      @Test
      void testAddByteSmallestBuffer() {
          final CircularByteBuffer cbb = new CircularByteBuffer(1);
          cbb.add((byte) 1);
          assertEquals(1, cbb.read());
          cbb.add((byte) 2);
          assertEquals(2, cbb.read());
      }
  
      @Test
      void testAddInvalidOffset() {
          final CircularByteBuffer cbb = new CircularByteBuffer();
          assertThrows(IllegalArgumentException.class, () -> cbb.add(new byte[] { 1, 2, 3 }, -1, 3));
      }
  
      @Test
      void testAddNegativeLength() {
          final CircularByteBuffer cbb = new CircularByteBuffer();
          final byte[] targetBuffer = { 1, 2, 3 };
          assertThrows(IllegalArgumentException.class, () -> cbb.add(targetBuffer, 0, -1));
      }
  
      @Test
      void testAddNullBuffer() {
          final CircularByteBuffer cbb = new CircularByteBuffer();
          assertThrows(NullPointerException.class, () -> cbb.add(null, 0, 3));
      }
  
      /**
       * Tests for add function with 3 arguments of type byte[], int and int.
       */
      @Test
      void testAddValidData() {
          final CircularByteBuffer cbb = new CircularByteBuffer();
          final int length = 3;
          cbb.add(new byte[] { 3, 6, 9 }, 0, length);
          assertEquals(length, cbb.getCurrentNumberOfBytes());
      }
  
      @Test
      void testClear() {
         final byte[] data = { 1, 2, 3 };
         final CircularByteBuffer buffer = new CircularByteBuffer(10);
         assertEquals(0, buffer.getCurrentNumberOfBytes());
         assertFalse(buffer.hasBytes());
  
         buffer.add(data, 0, data.length);
         assertEquals(3, buffer.getCurrentNumberOfBytes());
         assertEquals(7, buffer.getSpace());
         assertTrue(buffer.hasBytes());
         assertTrue(buffer.hasSpace());
  
         buffer.clear();
         assertEquals(0, buffer.getCurrentNumberOfBytes());
         assertEquals(10, buffer.getSpace());
         assertFalse(buffer.hasBytes());
         assertTrue(buffer.hasSpace());
      }
  
      @Test
      void testHasSpace() {
          final CircularByteBuffer cbb = new CircularByteBuffer(1);
          assertTrue(cbb.hasSpace());
          cbb.add((byte) 1);
          assertFalse(cbb.hasSpace());
          assertEquals(1, cbb.read());
          assertTrue(cbb.hasSpace());
         cbb.add((byte) 2);
         assertFalse(cbb.hasSpace());
         assertEquals(2, cbb.read());
         assertTrue(cbb.hasSpace());
     }
 
     @Test
     void testHasSpaceInt() {
         final CircularByteBuffer cbb = new CircularByteBuffer(1);
         assertTrue(cbb.hasSpace(1));
         cbb.add((byte) 1);
         assertFalse(cbb.hasSpace(1));
         assertEquals(1, cbb.read());
         assertTrue(cbb.hasSpace(1));
         cbb.add((byte) 2);
         assertFalse(cbb.hasSpace(1));
         assertEquals(2, cbb.read());
         assertTrue(cbb.hasSpace(1));
     }
 
     @Test
     void testPeekWithExcessiveLength() {
         assertFalse(new CircularByteBuffer().peek(new byte[] { 1, 3, 5, 7, 9 }, 0, 6));
     }
 
     @Test
     void testPeekWithInvalidOffset() {
         final CircularByteBuffer cbb = new CircularByteBuffer();
         final IllegalArgumentException e = assertThrows(IllegalArgumentException.class, () -> cbb.peek(new byte[] { 2, 4, 6, 8, 10 }, -1, 5));
         assertEquals("Illegal offset: -1", e.getMessage());
     }
 
     @Test
     void testPeekWithNegativeLength() {
         final CircularByteBuffer cbb = new CircularByteBuffer();
         final IllegalArgumentException e = assertThrows(IllegalArgumentException.class, () -> cbb.peek(new byte[] { 1, 4, 3 }, 0, -1));
         assertEquals("Illegal length: -1", e.getMessage());
     }
 
     // Tests for peek function
     @Test
     void testPeekWithValidArguments() {
         assertFalse(new CircularByteBuffer().peek(new byte[] { 5, 10, 15, 20, 25 }, 0, 5));
     }
 
     @Test
     void testReadByteArray() {
         final CircularByteBuffer cbb = new CircularByteBuffer();
         final String string = "0123456789";
         final byte[] bytesIn = string.getBytes(StandardCharsets.UTF_8);
         cbb.add(bytesIn, 0, 10);
         final byte[] bytesOut = new byte[10];
         cbb.read(bytesOut, 0, 10);
         assertEquals(string, new String(bytesOut, StandardCharsets.UTF_8));
     }
 
     @Test
     void testReadByteArrayIllegalArgumentException() {
         final CircularByteBuffer cbb = new CircularByteBuffer();
         final byte[] bytesOut = new byte[10];
         // targetOffset < 0
         assertThrows(IllegalArgumentException.class, () -> cbb.read(bytesOut, -1, 10));
         // targetOffset >= targetBuffer.length
         assertThrows(IllegalArgumentException.class, () -> cbb.read(bytesOut, 0, bytesOut.length + 1));
     }
 }