content: /*
   * Copyright The OpenTelemetry Authors
   * SPDX-License-Identifier: Apache-2.0
   */
  
  package io.opentelemetry.javaagent.instrumentation.servlet.snippet;
  
  import io.opentelemetry.javaagent.bootstrap.servlet.InjectionState;
  import io.opentelemetry.javaagent.bootstrap.servlet.SnippetInjectingResponseWrapper;
  import java.io.PrintWriter;
  
  public class SnippetInjectingPrintWriter extends PrintWriter {
    private final String snippet;
    private final InjectionState state;
  
    public SnippetInjectingPrintWriter(
        PrintWriter writer, String snippet, SnippetInjectingResponseWrapper wrapper) {
      super(writer);
      state = new InjectionState(wrapper);
      this.snippet = snippet;
    }
  
    @Override
    public void write(String s, int off, int len) {
      if (state.isHeadTagWritten()) {
        super.write(s, off, len);
        return;
      }
      for (int i = off; i < s.length() && i - off < len; i++) {
        write(s.charAt(i));
      }
    }
  
    @Override
    public void write(int b) {
      super.write(b);
      if (state.isHeadTagWritten()) {
        return;
      }
      boolean endOfHeadTagFound = state.processByte(b);
      if (!endOfHeadTagFound) {
        return;
      }
  
      if (state.getWrapper().isNotSafeToInject()) {
        return;
      }
      state.getWrapper().updateContentLengthIfPreviouslySet();
      super.write(snippet);
    }
  
    @Override
    public void write(char[] buf, int off, int len) {
      if (state.isHeadTagWritten()) {
        super.write(buf, off, len);
        return;
      }
      for (int i = off; i < buf.length && i - off < len; i++) {
        write(buf[i]);
      }
    }
  }
  