// 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 "content/browser/devtools/devtools_tracing_handler.h"

#include <cmath>

#include "base/bind.h"
#include "base/callback.h"
#include "base/file_util.h"
#include "base/json/json_reader.h"
#include "base/json/json_writer.h"
#include "base/location.h"
#include "base/memory/ref_counted_memory.h"
#include "base/strings/string_split.h"
#include "base/strings/stringprintf.h"
#include "base/time/time.h"
#include "base/timer/timer.h"
#include "base/values.h"
#include "content/browser/devtools/devtools_http_handler_impl.h"
#include "content/browser/devtools/devtools_protocol_constants.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/tracing_controller.h"

namespace content {

namespace {

const char kRecordUntilFull[]   = "record-until-full";
const char kRecordContinuously[] = "record-continuously";
const char kEnableSampling[] = "enable-sampling";

void ReadFile(
    const base::FilePath& path,
    const base::Callback<void(const scoped_refptr<base::RefCountedString>&)>
        callback) {
  std::string trace_data;
  if (!base::ReadFileToString(path, &trace_data))
    LOG(ERROR) << "Failed to read file: " << path.value();
  base::DeleteFile(path, false);
  BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
      base::Bind(callback, make_scoped_refptr(
          base::RefCountedString::TakeString(&trace_data))));
}

}  // namespace

const char* DevToolsTracingHandler::kDefaultCategories =
    "-*,disabled-by-default-devtools.timeline*";
const double DevToolsTracingHandler::kDefaultReportingInterval = 1000.0;
const double DevToolsTracingHandler::kMinimumReportingInterval = 250.0;

DevToolsTracingHandler::DevToolsTracingHandler(
    DevToolsTracingHandler::Target target)
    : weak_factory_(this), target_(target), is_recording_(false) {
  RegisterCommandHandler(devtools::Tracing::start::kName,
                         base::Bind(&DevToolsTracingHandler::OnStart,
                                    base::Unretained(this)));
  RegisterCommandHandler(devtools::Tracing::end::kName,
                         base::Bind(&DevToolsTracingHandler::OnEnd,
                                    base::Unretained(this)));
  RegisterCommandHandler(devtools::Tracing::getCategories::kName,
                         base::Bind(&DevToolsTracingHandler::OnGetCategories,
                                    base::Unretained(this)));
  RegisterNotificationHandler(devtools::Tracing::started::kName,
                         base::Bind(&DevToolsTracingHandler::OnTracingStarted,
                                    base::Unretained(this)));
  RegisterNotificationHandler(devtools::Tracing::stopped::kName,
                         base::Bind(&DevToolsTracingHandler::OnTracingStopped,
                                    base::Unretained(this)));
}

DevToolsTracingHandler::~DevToolsTracingHandler() {
}

void DevToolsTracingHandler::BeginReadingRecordingResult(
    const base::FilePath& path) {
  BrowserThread::PostTask(
      BrowserThread::FILE, FROM_HERE,
      base::Bind(&ReadFile, path,
                 base::Bind(&DevToolsTracingHandler::ReadRecordingResult,
                            weak_factory_.GetWeakPtr())));
}

void DevToolsTracingHandler::ReadRecordingResult(
    const scoped_refptr<base::RefCountedString>& trace_data) {
  if (trace_data->data().size()) {
    scoped_ptr<base::Value> trace_value(base::JSONReader::Read(
        trace_data->data()));
    base::DictionaryValue* dictionary = NULL;
    bool ok = trace_value->GetAsDictionary(&dictionary);
    DCHECK(ok);
    base::ListValue* list = NULL;
    ok = dictionary->GetList("traceEvents", &list);
    DCHECK(ok);
    std::string buffer;
    for (size_t i = 0; i < list->GetSize(); ++i) {
      std::string item;
      base::Value* item_value;
      list->Get(i, &item_value);
      base::JSONWriter::Write(item_value, &item);
      if (buffer.size())
        buffer.append(",");
      buffer.append(item);
      const size_t kMessageSizeThreshold = 1024 * 1024;
      if (buffer.size() > kMessageSizeThreshold) {
        OnTraceDataCollected(buffer);
        buffer.clear();
      }
    }
    if (buffer.size())
      OnTraceDataCollected(buffer);
  }

  SendNotification(devtools::Tracing::tracingComplete::kName, NULL);
}

void DevToolsTracingHandler::OnTraceDataCollected(
    const std::string& trace_fragment) {
  // Hand-craft protocol notification message so we can substitute JSON
  // that we already got as string as a bare object, not a quoted string.
  std::string message = base::StringPrintf(
      "{ \"method\": \"%s\", \"params\": { \"%s\": [ %s ] } }",
      devtools::Tracing::dataCollected::kName,
      devtools::Tracing::dataCollected::kParamValue,
      trace_fragment.c_str());
  SendRawMessage(message);
}

TracingController::Options DevToolsTracingHandler::TraceOptionsFromString(
    const std::string& options) {
  std::vector<std::string> split;
  std::vector<std::string>::iterator iter;
  int ret = 0;

  base::SplitString(options, ',', &split);
  for (iter = split.begin(); iter != split.end(); ++iter) {
    if (*iter == kRecordUntilFull) {
      ret &= ~TracingController::RECORD_CONTINUOUSLY;
    } else if (*iter == kRecordContinuously) {
      ret |= TracingController::RECORD_CONTINUOUSLY;
    } else if (*iter == kEnableSampling) {
      ret |= TracingController::ENABLE_SAMPLING;
    }
  }
  return static_cast<TracingController::Options>(ret);
}

scoped_refptr<DevToolsProtocol::Response>
DevToolsTracingHandler::OnStart(
    scoped_refptr<DevToolsProtocol::Command> command) {
  is_recording_ = true;

  std::string categories;
  TracingController::Options options = TracingController::DEFAULT_OPTIONS;
  double usage_reporting_interval = 0.0;

  base::DictionaryValue* params = command->params();
  if (params) {
    params->GetString(devtools::Tracing::start::kParamCategories, &categories);
    std::string options_param;
    if (params->GetString(devtools::Tracing::start::kParamOptions,
                          &options_param)) {
      options = TraceOptionsFromString(options_param);
    }
    params->GetDouble(
        devtools::Tracing::start::kParamBufferUsageReportingInterval,
        &usage_reporting_interval);
  }

  SetupTimer(usage_reporting_interval);

  // If inspected target is a render process Tracing.start will be handled by
  // tracing agent in the renderer.
  if (target_ == Renderer) {
    TracingController::GetInstance()->EnableRecording(
        categories, options, TracingController::EnableRecordingDoneCallback());
    return NULL;
  }

  TracingController::GetInstance()->EnableRecording(
      categories, options,
      base::Bind(&DevToolsTracingHandler::OnRecordingEnabled,
                 weak_factory_.GetWeakPtr(),
                 command));
  return command->AsyncResponsePromise();
}

void DevToolsTracingHandler::SetupTimer(double usage_reporting_interval) {
  if (usage_reporting_interval == 0) return;

  if (usage_reporting_interval < kMinimumReportingInterval)
      usage_reporting_interval = kMinimumReportingInterval;

  base::TimeDelta interval = base::TimeDelta::FromMilliseconds(
      std::ceil(usage_reporting_interval));
  buffer_usage_poll_timer_.reset(new base::Timer(
      FROM_HERE,
      interval,
      base::Bind(
          base::IgnoreResult(&TracingController::GetTraceBufferPercentFull),
          base::Unretained(TracingController::GetInstance()),
          base::Bind(&DevToolsTracingHandler::OnBufferUsage,
                     weak_factory_.GetWeakPtr())),
      true));
  buffer_usage_poll_timer_->Reset();
}

void DevToolsTracingHandler::OnRecordingEnabled(
    scoped_refptr<DevToolsProtocol::Command> command) {
  SendAsyncResponse(command->SuccessResponse(NULL));
}

void DevToolsTracingHandler::OnBufferUsage(float usage) {
  base::DictionaryValue* params = new base::DictionaryValue();
  params->SetDouble(devtools::Tracing::bufferUsage::kParamValue, usage);
  SendNotification(devtools::Tracing::bufferUsage::kName, params);
}

scoped_refptr<DevToolsProtocol::Response>
DevToolsTracingHandler::OnEnd(
    scoped_refptr<DevToolsProtocol::Command> command) {
  DisableRecording(
      base::Bind(&DevToolsTracingHandler::BeginReadingRecordingResult,
                 weak_factory_.GetWeakPtr()));
  return command->SuccessResponse(NULL);
}

void DevToolsTracingHandler::DisableRecording(
    const TracingController::TracingFileResultCallback& callback) {
  is_recording_ = false;
  buffer_usage_poll_timer_.reset();
  TracingController::GetInstance()->DisableRecording(base::FilePath(),
                                                     callback);
}

void DevToolsTracingHandler::OnClientDetached() {
  if (is_recording_)
    DisableRecording();
}

scoped_refptr<DevToolsProtocol::Response>
DevToolsTracingHandler::OnGetCategories(
    scoped_refptr<DevToolsProtocol::Command> command) {
  TracingController::GetInstance()->GetCategories(
      base::Bind(&DevToolsTracingHandler::OnCategoriesReceived,
                 weak_factory_.GetWeakPtr(),
                 command));
  return command->AsyncResponsePromise();
}

void DevToolsTracingHandler::OnCategoriesReceived(
    scoped_refptr<DevToolsProtocol::Command> command,
    const std::set<std::string>& category_set) {
  base::DictionaryValue* response = new base::DictionaryValue;
  base::ListValue* category_list = new base::ListValue;
  for (std::set<std::string>::const_iterator it = category_set.begin();
       it != category_set.end(); ++it) {
    category_list->AppendString(*it);
  }

  response->Set(devtools::Tracing::getCategories::kResponseCategories,
                category_list);
  SendAsyncResponse(command->SuccessResponse(response));
}

void DevToolsTracingHandler::OnTracingStarted(
    scoped_refptr<DevToolsProtocol::Notification> notification) {
  if (is_recording_)
    return;
  is_recording_ = true;

  SetupTimer(kDefaultReportingInterval);

  TracingController::GetInstance()->EnableRecording(
      kDefaultCategories,
      TracingController::DEFAULT_OPTIONS,
      TracingController::EnableRecordingDoneCallback());
}

void DevToolsTracingHandler::OnTracingStopped(
    scoped_refptr<DevToolsProtocol::Notification> notification) {
  if (!is_recording_)
    return;
  is_recording_ = false;
  DisableRecording(
      base::Bind(&DevToolsTracingHandler::BeginReadingRecordingResult,
                 weak_factory_.GetWeakPtr()));
}


}  // namespace content