// Copyright 2016 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 "components/data_reduction_proxy/core/browser/data_reduction_proxy_pingback_client.h"

#include <stdint.h>

#include "base/bind_helpers.h"
#include "base/metrics/histogram_macros.h"
#include "base/optional.h"
#include "base/rand_util.h"
#include "base/threading/thread_task_runner_handle.h"
#include "base/time/time.h"
#include "components/data_reduction_proxy/core/browser/data_reduction_proxy_data.h"
#include "components/data_reduction_proxy/core/common/data_reduction_proxy_page_load_timing.h"
#include "components/data_reduction_proxy/core/common/data_reduction_proxy_params.h"
#include "components/data_reduction_proxy/core/common/data_reduction_proxy_util.h"
#include "components/data_reduction_proxy/proto/client_config.pb.h"
#include "components/data_use_measurement/core/data_use_user_data.h"
#include "net/base/load_flags.h"
#include "net/nqe/effective_connection_type.h"
#include "net/url_request/url_fetcher.h"
#include "net/url_request/url_request_context_getter.h"
#include "net/url_request/url_request_status.h"
#include "url/gurl.h"

namespace data_reduction_proxy {

namespace {

static const char kHistogramSucceeded[] =
    "DataReductionProxy.Pingback.Succeeded";
static const char kHistogramAttempted[] =
    "DataReductionProxy.Pingback.Attempted";

// Adds the relevant information to |request| for this page load based on page
// timing and data reduction proxy state.
void AddDataToPageloadMetrics(const DataReductionProxyData& request_data,
                              const DataReductionProxyPageLoadTiming& timing,
                              PageloadMetrics* request,
                              bool opted_out) {
  request->set_session_key(request_data.session_key());
  // For the timing events, any of them could be zero. Fill the message as a
  // best effort.
  request->set_allocated_first_request_time(
      protobuf_parser::CreateTimestampFromTime(timing.navigation_start)
          .release());
  if (request_data.request_url().is_valid())
    request->set_first_request_url(request_data.request_url().spec());
  if (timing.first_contentful_paint) {
    request->set_allocated_time_to_first_contentful_paint(
        protobuf_parser::CreateDurationFromTimeDelta(
            timing.first_contentful_paint.value())
            .release());
  }
  if (timing.experimental_first_meaningful_paint) {
    request->set_allocated_experimental_time_to_first_meaningful_paint(
        protobuf_parser::CreateDurationFromTimeDelta(
            timing.experimental_first_meaningful_paint.value())
            .release());
  }
  if (timing.first_image_paint) {
    request->set_allocated_time_to_first_image_paint(
        protobuf_parser::CreateDurationFromTimeDelta(
            timing.first_image_paint.value())
            .release());
  }
  if (timing.response_start) {
    request->set_allocated_time_to_first_byte(
        protobuf_parser::CreateDurationFromTimeDelta(
            timing.response_start.value())
            .release());
  }
  if (timing.load_event_start) {
    request->set_allocated_page_load_time(
        protobuf_parser::CreateDurationFromTimeDelta(
            timing.load_event_start.value())
            .release());
  }
  if (timing.parse_blocked_on_script_load_duration) {
    request->set_allocated_parse_blocked_on_script_load_duration(
        protobuf_parser::CreateDurationFromTimeDelta(
            timing.parse_blocked_on_script_load_duration.value())
            .release());
  }
  if (timing.parse_stop) {
    request->set_allocated_parse_stop(
        protobuf_parser::CreateDurationFromTimeDelta(timing.parse_stop.value())
            .release());
  }

  request->set_effective_connection_type(
      protobuf_parser::ProtoEffectiveConnectionTypeFromEffectiveConnectionType(
          request_data.effective_connection_type()));
  request->set_compressed_page_size_bytes(timing.network_bytes);
  request->set_original_page_size_bytes(timing.original_network_bytes);

  if (request_data.page_id()) {
    request->set_page_id(request_data.page_id().value());
  }

  bool was_preview_shown = false;
  if (request_data.lofi_received()) {
    request->set_previews_type(PageloadMetrics_PreviewsType_LOFI);
    was_preview_shown = true;
  } else if (request_data.lite_page_received()) {
    request->set_previews_type(PageloadMetrics_PreviewsType_LITE_PAGE);
    was_preview_shown = true;
  } else {
    request->set_previews_type(PageloadMetrics_PreviewsType_NONE);
  }

  if (!was_preview_shown || timing.app_background_occurred) {
    request->set_previews_opt_out(PageloadMetrics_PreviewsOptOut_UNKNOWN);
    return;
  }

  if (opted_out) {
    request->set_previews_opt_out(PageloadMetrics_PreviewsOptOut_OPT_OUT);
    return;
  }
  request->set_previews_opt_out(PageloadMetrics_PreviewsOptOut_NON_OPT_OUT);
}

// Adds |current_time| as the metrics sent time to |request_data|, and returns
// the serialized request.
std::string AddTimeAndSerializeRequest(
    RecordPageloadMetricsRequest* request_data,
    base::Time current_time) {
  request_data->set_allocated_metrics_sent_time(
      protobuf_parser::CreateTimestampFromTime(current_time).release());
  std::string serialized_request;
  request_data->SerializeToString(&serialized_request);
  return serialized_request;
}

}  // namespace

DataReductionProxyPingbackClient::DataReductionProxyPingbackClient(
    net::URLRequestContextGetter* url_request_context)
    : url_request_context_(url_request_context),
      pingback_url_(util::AddApiKeyToUrl(params::GetPingbackURL())),
      pingback_reporting_fraction_(0.0) {}

DataReductionProxyPingbackClient::~DataReductionProxyPingbackClient() {
  DCHECK(opt_outs_.empty());
  DCHECK(thread_checker_.CalledOnValidThread());
}

void DataReductionProxyPingbackClient::OnURLFetchComplete(
    const net::URLFetcher* source) {
  DCHECK(thread_checker_.CalledOnValidThread());
  DCHECK(source == current_fetcher_.get());
  UMA_HISTOGRAM_BOOLEAN(kHistogramSucceeded, source->GetStatus().is_success());
  current_fetcher_.reset();
  if (metrics_request_.pageloads_size() > 0) {
    CreateFetcherForDataAndStart();
  }
}

void DataReductionProxyPingbackClient::SendPingback(
    const DataReductionProxyData& request_data,
    const DataReductionProxyPageLoadTiming& timing) {
  DCHECK(thread_checker_.CalledOnValidThread());
  bool send_pingback = ShouldSendPingback();
  UMA_HISTOGRAM_BOOLEAN(kHistogramAttempted, send_pingback);
  if (!send_pingback)
    return;

  bool opted_out = false;
  if (request_data.page_id()) {
    auto opt_out = opt_outs_.find(NavigationID(request_data.page_id().value(),
                                               request_data.session_key()));
    opted_out = opt_out != opt_outs_.end();
    if (opted_out)
      opt_outs_.erase(opt_out);
  }

  PageloadMetrics* pageload_metrics = metrics_request_.add_pageloads();
  AddDataToPageloadMetrics(request_data, timing, pageload_metrics, opted_out);
  if (current_fetcher_.get())
    return;
  DCHECK_EQ(1, metrics_request_.pageloads_size());
  CreateFetcherForDataAndStart();
}

void DataReductionProxyPingbackClient::CreateFetcherForDataAndStart() {
  DCHECK(!current_fetcher_);
  DCHECK_GE(metrics_request_.pageloads_size(), 1);
  std::string serialized_request =
      AddTimeAndSerializeRequest(&metrics_request_, CurrentTime());
  metrics_request_.Clear();
  current_fetcher_ =
      net::URLFetcher::Create(pingback_url_, net::URLFetcher::POST, this);
  data_use_measurement::DataUseUserData::AttachToFetcher(
      current_fetcher_.get(),
      data_use_measurement::DataUseUserData::DATA_REDUCTION_PROXY);
  current_fetcher_->SetLoadFlags(net::LOAD_BYPASS_PROXY);
  current_fetcher_->SetUploadData("application/x-protobuf", serialized_request);
  current_fetcher_->SetRequestContext(url_request_context_);
  // |current_fetcher_| should not retry on 5xx errors since the server may
  // already be overloaded.
  static const int kMaxRetries = 5;
  current_fetcher_->SetAutomaticallyRetryOnNetworkChanges(kMaxRetries);
  current_fetcher_->Start();
}

bool DataReductionProxyPingbackClient::ShouldSendPingback() const {
  return params::IsForcePingbackEnabledViaFlags() ||
         GenerateRandomFloat() < pingback_reporting_fraction_;
}

base::Time DataReductionProxyPingbackClient::CurrentTime() const {
  return base::Time::Now();
}

float DataReductionProxyPingbackClient::GenerateRandomFloat() const {
  return static_cast<float>(base::RandDouble());
}

void DataReductionProxyPingbackClient::SetPingbackReportingFraction(
    float pingback_reporting_fraction) {
  DCHECK(thread_checker_.CalledOnValidThread());
  DCHECK_LE(0.0f, pingback_reporting_fraction);
  DCHECK_GE(1.0f, pingback_reporting_fraction);
  pingback_reporting_fraction_ = pingback_reporting_fraction;
}

void DataReductionProxyPingbackClient::AddOptOut(
    const NavigationID& navigation_id) {
  opt_outs_.emplace(navigation_id);
}

void DataReductionProxyPingbackClient::ClearNavigationKeySync(
    const NavigationID& navigation_id) {
  opt_outs_.erase(navigation_id);
}

void DataReductionProxyPingbackClient::ClearNavigationKeyAsync(
    const NavigationID& navigation_id) {
  base::ThreadTaskRunnerHandle::Get()->PostTask(
      FROM_HERE,
      base::Bind(&DataReductionProxyPingbackClient::ClearNavigationKeySync,
                 base::Unretained(this), navigation_id));
}

size_t DataReductionProxyPingbackClient::OptOutsSizeForTesting() const {
  return opt_outs_.size();
}

}  // namespace data_reduction_proxy