/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * 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.squareup.okhttp.internal.http;

import com.squareup.okhttp.internal.AbstractOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.ProtocolException;

import static com.squareup.okhttp.internal.Util.checkOffsetAndCount;

/**
 * An HTTP request body that's completely buffered in memory. This allows
 * the post body to be transparently re-sent if the HTTP request must be
 * sent multiple times.
 */
final class RetryableOutputStream extends AbstractOutputStream {
  private final int limit;
  private final ByteArrayOutputStream content;

  public RetryableOutputStream(int limit) {
    this.limit = limit;
    this.content = new ByteArrayOutputStream(limit);
  }

  public RetryableOutputStream() {
    this.limit = -1;
    this.content = new ByteArrayOutputStream();
  }

  @Override public synchronized void close() throws IOException {
    if (closed) {
      return;
    }
    closed = true;
    if (content.size() < limit) {
      throw new ProtocolException(
          "content-length promised " + limit + " bytes, but received " + content.size());
    }
  }

  @Override public synchronized void write(byte[] buffer, int offset, int count)
      throws IOException {
    checkNotClosed();
    checkOffsetAndCount(buffer.length, offset, count);
    if (limit != -1 && content.size() > limit - count) {
      throw new ProtocolException("exceeded content-length limit of " + limit + " bytes");
    }
    content.write(buffer, offset, count);
  }

  public synchronized int contentLength() throws IOException {
    close();
    return content.size();
  }

  public void writeToSocket(OutputStream socketOut) throws IOException {
    content.writeTo(socketOut);
  }
}