package com.github.davidmoten.rx2.buffertofile;
   
   import java.io.ByteArrayInputStream;
   import java.io.ByteArrayOutputStream;
   import java.io.DataInputStream;
   import java.io.DataOutputStream;
   import java.io.IOException;
   import java.io.Serializable;
   import java.nio.charset.Charset;
  
  import com.github.davidmoten.rx2.internal.flowable.buffertofile.SerializerBytes;
  import com.github.davidmoten.rx2.internal.flowable.buffertofile.SerializerJavaIO;
  
  public final class Serializers {
  
      private static final Charset UTF_8 = Charset.forName("UTF-8");
  
      private Serializers() {
          // prevent initialization
      }
  
      public static <T extends Serializable> Serializer<T> javaIO() {
          // TODO use holder
          return new SerializerJavaIO<T>();
      }
  
      public static Serializer<byte[]> bytes() {
          // TODO use holder
          return new SerializerBytes();
      }
  
      public static Serializer<String> utf8() {
          // TODO use holder
          return string(UTF_8);
      }
  
      public static Serializer<String> string(Charset charset) {
          return new SerializerString(charset);
      }
  
      public static <T> Serializer<T> from(DataSerializer<T> ds) {
          return new WrappedDataSerializer<T>(ds);
      }
  
      private static final class WrappedDataSerializer<T> implements Serializer<T> {
  
          private final DataSerializer<T> ds;
  
          WrappedDataSerializer(DataSerializer<T> ds) {
              this.ds = ds;
          }
  
          @Override
          public byte[] serialize(T t) throws IOException {
              ByteArrayOutputStream bytes;
              int cap = ds.sizeHint();
              if (cap > 0)
                  bytes = new ByteArrayOutputStream(ds.sizeHint());
              else
                  bytes = new ByteArrayOutputStream();
              DataOutputStream out = new DataOutputStream(bytes);
              ds.serialize(t, out);
              out.close();
              return bytes.toByteArray();
          }
  
          @Override
          public T deserialize(byte[] bytes) throws IOException, ClassNotFoundException {
              ByteArrayInputStream is = new ByteArrayInputStream(bytes);
              DataInputStream in = new DataInputStream(is);
              T t = ds.deserialize(in);
              in.close();
              return t;
          }
  
      }
  
  }