// 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/chrome_browser_field_trials.h"

#include <string>

#include "base/command_line.h"
#include "base/metrics/field_trial.h"
#include "base/prefs/pref_service.h"
#include "base/string_util.h"
#include "base/time.h"
#include "chrome/browser/omnibox/omnibox_field_trial.h"
#include "chrome/common/chrome_switches.h"
#include "chrome/common/chrome_version_info.h"
#include "chrome/common/metrics/variations/uniformity_field_trials.h"
#include "chrome/common/pref_names.h"

#if defined(OS_ANDROID) || defined(OS_IOS)
#include "chrome/browser/chrome_browser_field_trials_mobile.h"
#else
#include "chrome/browser/chrome_browser_field_trials_desktop.h"
#endif

ChromeBrowserFieldTrials::ChromeBrowserFieldTrials(
    const CommandLine& parsed_command_line)
    : parsed_command_line_(parsed_command_line) {
}

ChromeBrowserFieldTrials::~ChromeBrowserFieldTrials() {
}

void ChromeBrowserFieldTrials::SetupFieldTrials(PrefService* local_state) {
  const base::Time install_time = base::Time::FromTimeT(
      local_state->GetInt64(prefs::kInstallDate));
  DCHECK(!install_time.is_null());

  // Field trials that are shared by all platforms.
  chrome_variations::SetupUniformityFieldTrials(install_time);
  SetUpSimpleCacheFieldTrial();
  InstantiateDynamicTrials();

#if defined(OS_ANDROID) || defined(OS_IOS)
  chrome::SetupMobileFieldTrials(
      parsed_command_line_, install_time, local_state);
#else
  chrome::SetupDesktopFieldTrials(
      parsed_command_line_, install_time, local_state);
#endif
}

// Sets up the experiment. The actual cache backend choice is made in the net/
// internals by looking at the experiment state.
void ChromeBrowserFieldTrials::SetUpSimpleCacheFieldTrial() {
  const std::string opt_value = parsed_command_line_.GetSwitchValueASCII(
      switches::kUseSimpleCacheBackend);

  const base::FieldTrial::Probability kDivisor = 100;
  scoped_refptr<base::FieldTrial> trial(
      base::FieldTrialList::FactoryGetFieldTrial("SimpleCacheTrial", kDivisor,
                                                 "ExperimentNo", 2013, 12, 31,
                                                 NULL));
  trial->UseOneTimeRandomization();

  if (LowerCaseEqualsASCII(opt_value, "off")) {
    trial->AppendGroup("ExplicitNo", kDivisor);
    trial->group();
    return;
  }
  if (LowerCaseEqualsASCII(opt_value, "on")) {
    trial->AppendGroup("ExplicitYes", kDivisor);
    trial->group();
    return;
  }

#if defined(OS_ANDROID)
  base::FieldTrial::Probability simple_cache_experiment_probability = 0;
  base::FieldTrial::Probability simple_cache_experiment2_probability = 0;
  base::FieldTrial::Probability simple_cache_control_probability = 0;

  switch (chrome::VersionInfo::GetChannel()) {
    case chrome::VersionInfo::CHANNEL_DEV:
      simple_cache_experiment_probability = 45;
      simple_cache_control_probability = 45;
      break;
    case chrome::VersionInfo::CHANNEL_BETA:
      simple_cache_experiment_probability = 80;
      simple_cache_experiment2_probability = 10;
      simple_cache_control_probability = 10;
      break;
    default:
      break;
  }
  trial->AppendGroup("ExperimentYes", simple_cache_experiment_probability);
  trial->AppendGroup("ExperimentYes2", simple_cache_experiment2_probability);
  trial->AppendGroup("ExperimentControl", simple_cache_control_probability);
#endif
  trial->group();
}

void ChromeBrowserFieldTrials::InstantiateDynamicTrials() {
  // Call |FindValue()| on the trials below, which may come from the server, to
  // ensure they get marked as "used" for the purposes of data reporting.
  base::FieldTrialList::FindValue("UMA-Dynamic-Binary-Uniformity-Trial");
  base::FieldTrialList::FindValue("UMA-Dynamic-Uniformity-Trial");
  base::FieldTrialList::FindValue("InstantDummy");
  base::FieldTrialList::FindValue("InstantChannel");
  base::FieldTrialList::FindValue("Test0PercentDefault");
  // Activate the autocomplete dynamic field trials.
  OmniboxFieldTrial::ActivateDynamicTrials();
}