// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/net/net_log_logger.h"

#include <stdio.h>

#include "base/json/json_writer.h"
#include "base/logging.h"
#include "base/memory/scoped_ptr.h"
#include "base/values.h"
#include "chrome/browser/ui/webui/net_internals/net_internals_ui.h"

NetLogLogger::NetLogLogger(FILE* file) : file_(file), added_events_(false) {
  DCHECK(file);

  // Write constants to the output file.  This allows loading files that have
  // different source and event types, as they may be added and removed
  // between Chrome versions.
  scoped_ptr<Value> value(NetInternalsUI::GetConstants());
  std::string json;
  base::JSONWriter::Write(value.get(), &json);
  fprintf(file_.get(), "{\"constants\": %s,\n", json.c_str());
  fprintf(file_.get(), "\"events\": [\n");
}

NetLogLogger::~NetLogLogger() {
  if (file_.get())
    fprintf(file_.get(), "]}");
}

void NetLogLogger::StartObserving(net::NetLog* net_log) {
  net_log->AddThreadSafeObserver(this, net::NetLog::LOG_ALL_BUT_BYTES);
}

void NetLogLogger::StopObserving() {
  net_log()->RemoveThreadSafeObserver(this);
}

void NetLogLogger::OnAddEntry(const net::NetLog::Entry& entry) {
  // Add a comma and newline for every event but the first.  Newlines are needed
  // so can load partial log files by just ignoring the last line.  For this to
  // work, lines cannot be pretty printed.
  scoped_ptr<Value> value(entry.ToValue());
  std::string json;
  base::JSONWriter::Write(value.get(), &json);
  fprintf(file_.get(), "%s%s",
          (added_events_ ? ",\n" : ""),
          json.c_str());
  added_events_ = true;
}