// Copyright 2015 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 "google_apis/gcm/engine/instance_id_delete_token_request_handler.h"

#include "base/macros.h"
#include "base/metrics/histogram.h"
#include "base/strings/string_number_conversions.h"
#include "google_apis/gcm/base/gcm_util.h"
#include "net/url_request/url_fetcher.h"
#include "net/url_request/url_request_context_getter.h"

namespace gcm {

namespace {

// Request constants.
const char kGMSVersionKey[] = "gmsv";
const char kInstanceIDKey[] = "appid";
const char kSenderKey[] = "sender";
const char kSubtypeKey[] = "X-subtype";
const char kScopeKey[] = "scope";
const char kExtraScopeKey[] = "X-scope";

// Response constants.
const char kTokenPrefix[] = "token=";
const char kErrorPrefix[] = "Error=";
const char kInvalidParameters[] = "INVALID_PARAMETERS";

}  // namespace

InstanceIDDeleteTokenRequestHandler::InstanceIDDeleteTokenRequestHandler(
    const std::string& instance_id,
    const std::string& authorized_entity,
    const std::string& scope,
    int gcm_version)
    : instance_id_(instance_id),
      authorized_entity_(authorized_entity),
      scope_(scope),
      gcm_version_(gcm_version) {
  DCHECK(!instance_id.empty());
  DCHECK(!authorized_entity.empty());
  DCHECK(!scope.empty());
}

InstanceIDDeleteTokenRequestHandler::~InstanceIDDeleteTokenRequestHandler() {}

void InstanceIDDeleteTokenRequestHandler::BuildRequestBody(std::string* body){
  BuildFormEncoding(kInstanceIDKey, instance_id_, body);
  BuildFormEncoding(kSenderKey, authorized_entity_, body);
  BuildFormEncoding(kScopeKey, scope_, body);
  BuildFormEncoding(kExtraScopeKey, scope_, body);
  BuildFormEncoding(kGMSVersionKey, base::IntToString(gcm_version_), body);
  // TODO(jianli): To work around server bug. To be removed when the server fix
  // is deployed.
  BuildFormEncoding(kSubtypeKey, authorized_entity_, body);
}

UnregistrationRequest::Status
InstanceIDDeleteTokenRequestHandler::ParseResponse(
    const net::URLFetcher* source) {
  std::string response;
  if (!source->GetResponseAsString(&response)) {
    DVLOG(1) << "Failed to get response body.";
    return UnregistrationRequest::NO_RESPONSE_BODY;
  }

  if (response.find(kErrorPrefix) != std::string::npos) {
    std::string error = response.substr(
        response.find(kErrorPrefix) + arraysize(kErrorPrefix) - 1);
    return error == kInvalidParameters ?
        UnregistrationRequest::INVALID_PARAMETERS :
        UnregistrationRequest::UNKNOWN_ERROR;
  }

  if (response.find(kTokenPrefix) == std::string::npos)
    return UnregistrationRequest::RESPONSE_PARSING_FAILED;

  return UnregistrationRequest::SUCCESS;
}

void InstanceIDDeleteTokenRequestHandler::ReportUMAs(
    UnregistrationRequest::Status status,
    int retry_count,
    base::TimeDelta complete_time) {
  UMA_HISTOGRAM_ENUMERATION("InstanceID.DeleteToken.RequestStatus",
                            status,
                            UnregistrationRequest::UNREGISTRATION_STATUS_COUNT);

  // Other UMAs are only reported when the request succeeds.
  if (status != UnregistrationRequest::SUCCESS)
    return;

  UMA_HISTOGRAM_COUNTS("InstanceID.DeleteToken.RetryCount", retry_count);
  UMA_HISTOGRAM_TIMES("InstanceID.DeleteToken.CompleteTime", complete_time);
}

}  // namespace gcm