/*
    * Copyright (C) 2007 The Guava Authors
    *
    * Licensed 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 com.google.common.io;
  
  import com.google.common.primitives.Bytes;
  
  import junit.framework.TestCase;
  
  import java.io.ByteArrayInputStream;
  import java.io.ByteArrayOutputStream;
  import java.io.DataInput;
  import java.io.DataOutputStream;
  import java.io.EOFException;
  import java.io.IOException;
  
  /**
   * Test class for {@link LittleEndianDataInputStream}.
   *
   * @author Chris Nokleberg
   */
  public class LittleEndianDataInputStreamTest extends TestCase {
    
    private byte[] data;
  
    @Override
    protected void setUp() throws Exception {
      super.setUp();
      
      ByteArrayOutputStream baos = new ByteArrayOutputStream();
      DataOutputStream out = new DataOutputStream(baos);
  
      initializeData(out);
  
      data = baos.toByteArray();
    }
  
    private void initializeData(DataOutputStream out) throws IOException {
      /* Write out various test values NORMALLY */
      out.write(new byte[] { -100, 100 });
      out.writeBoolean(true);
      out.writeBoolean(false);
      out.writeByte(100);
      out.writeByte(-100);
      out.writeByte((byte) 200);
      out.writeChar('a'); 
      out.writeShort((short) -30000);
      out.writeShort((short) 50000);
      out.writeInt(0xCAFEBABE);
      out.writeLong(0xDEADBEEFCAFEBABEL);
      out.writeUTF("Herby Derby");
      out.writeFloat(Float.intBitsToFloat(0xCAFEBABE));
      out.writeDouble(Double.longBitsToDouble(0xDEADBEEFCAFEBABEL));
    }
    
    public void testReadFully() throws IOException {
      DataInput in = new LittleEndianDataInputStream(new ByteArrayInputStream(data));
      byte[] b = new byte[data.length];
      in.readFully(b);
      assertEquals(Bytes.asList(data), Bytes.asList(b));
    }
    
    public void testReadUnsignedByte_eof() throws IOException {
      DataInput in = new LittleEndianDataInputStream(new ByteArrayInputStream(new byte[0]));
      try {
        in.readUnsignedByte();
        fail();
      } catch (EOFException expected) {
      }
    }
    
    public void testReadUnsignedShort_eof() throws IOException {
      byte[] buf = {23};
      DataInput in = new LittleEndianDataInputStream(new ByteArrayInputStream(buf));
      try {
        in.readUnsignedShort();
        fail();
      } catch (EOFException expected) {}
    }
    
    public void testReadLine() throws IOException {
      DataInput in = new LittleEndianDataInputStream(new ByteArrayInputStream(data));
      try {
        in.readLine();
        fail();
      } catch (UnsupportedOperationException expected) {
       assertEquals("readLine is not supported", expected.getMessage()); 
     }
   }
   
   public void testReadLittleEndian() throws IOException {
     DataInput in = new LittleEndianDataInputStream(new ByteArrayInputStream(data));
 
     /* Read in various values in LITTLE ENDIAN FORMAT */
     byte[] b = new byte[2];
     in.readFully(b);
     assertEquals(-100, b[0]);
     assertEquals(100, b[1]);
     assertEquals(true, in.readBoolean());
     assertEquals(false, in.readBoolean());
     assertEquals(100, in.readByte());
     assertEquals(-100, in.readByte());
     assertEquals(200, in.readUnsignedByte());
     assertEquals('\u6100', in.readChar());
     assertEquals(-12150, in.readShort());
     assertEquals(20675, in.readUnsignedShort());
     assertEquals(0xBEBAFECA, in.readInt());
     assertEquals(0xBEBAFECAEFBEADDEL, in.readLong());
     assertEquals("Herby Derby", in.readUTF());
     assertEquals(0xBEBAFECA, Float.floatToIntBits(in.readFloat()));
     assertEquals(0xBEBAFECAEFBEADDEL, Double.doubleToLongBits(in.readDouble()));
   }
   
   public void testSkipBytes() throws IOException {
     ByteArrayOutputStream baos = new ByteArrayOutputStream();
     DataOutputStream out = new DataOutputStream(baos);
 
     /* Write out various test values NORMALLY */
     out.write(new byte[] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9}); // 10 bytes of junk to skip
     initializeData(out);
 
     byte[] data = baos.toByteArray();
 
     DataInput in = new LittleEndianDataInputStream(new ByteArrayInputStream(data));
     int bytesSkipped = 0;
     while (bytesSkipped < 10) {
       bytesSkipped += in.skipBytes(10 - bytesSkipped);
     }
     
     /* Read in various values in LITTLE ENDIAN FORMAT */
     byte[] b = new byte[2];
     in.readFully(b);
     assertEquals(-100, b[0]);
     assertEquals(100, b[1]);
     assertTrue(in.readBoolean());
     assertFalse(in.readBoolean());
   }
 }