CRD iOS: Updating remoting service to use oauth and host list fetcher.

remoting/client/ios/facade/host_list_fetcher.cc

+// Copyright 2017 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 "remoting/client/ios/facade/host_list_fetcher.h"
+
+#include <thread>
+
+#include "base/bind.h"
+#include "base/callback_helpers.h"
+#include "base/json/json_reader.h"
+#include "base/logging.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "base/values.h"
+#include "net/http/http_status_code.h"
+#include "net/url_request/url_fetcher.h"
+#include "remoting/base/url_request_context_getter.h"
+
+namespace remoting {
+
+HostListFetcher::HostListFetcher(
+    const scoped_refptr<net::URLRequestContextGetter>&
+        url_request_context_getter)
+    : url_request_context_getter_(url_request_context_getter) {}
+
+HostListFetcher::~HostListFetcher() {}
+
+// TODO(nicholss): This was written assuming only one request at a time. Fix
+// that. For the moment it will work to make progress in the app.
+void HostListFetcher::RetrieveHostlist(const std::string& access_token,
+                                       const HostlistCallback& callback) {
+  DCHECK(!access_token.empty());
+  DCHECK(!callback.is_null());
+  DCHECK(hostlist_callback_.is_null());

[joedow, 2017/04/05 22:30:55]

nit: this was written with the old Callback syntax, you can just check the value
now:
DCHECK(callback);
DCHECK(!hostlist_callback_);

[nicholss, 2017/04/07 18:16:15]

Done.

+
+  hostlist_callback_ = callback;
+
+  request_ = net::URLFetcher::Create(GURL(kHostListProdRequestUrl),
+                                     net::URLFetcher::GET, this);
+  request_->SetRequestContext(url_request_context_getter_.get());
+  request_->AddExtraRequestHeader("Authorization: OAuth " + access_token);
+  request_->SetMaxRetriesOn5xx(0);
+  request_->SetAutomaticallyRetryOnNetworkChanges(3);
+  request_->Start();
+}
+
+bool HostListFetcher::ProcessResponse(
+    std::vector<remoting::HostInfo>* hostlist) {
+  int response_code = request_->GetResponseCode();
+  if (response_code != net::HTTP_OK) {
+    LOG(ERROR) << "Hostlist request failed with error code: " << response_code;
+    return false;
+  }
+
+  std::string response_string;
+  if (!request_->GetResponseAsString(&response_string)) {
+    LOG(ERROR) << "Failed to retrieve Hostlist response data";
+    return false;
+  }
+
+  std::unique_ptr<base::Value> response_value(
+      base::JSONReader::Read(response_string));
+  if (!response_value ||
+      !response_value->IsType(base::Value::Type::DICTIONARY)) {
+    LOG(ERROR) << "Failed to parse response string to JSON";
+    return false;
+  }
+
+  const base::DictionaryValue* response;
+  if (!response_value->GetAsDictionary(&response)) {
+    LOG(ERROR) << "Failed to convert parsed JSON to a dictionary object";
+    return false;
+  }
+
+  const base::DictionaryValue* data = nullptr;
+  if (!response->GetDictionary("data", &data)) {
+    LOG(ERROR) << "Hostlist response data is empty";
+    return false;
+  }
+
+  const base::ListValue* hosts = nullptr;
+  if (!data->GetList("items", &hosts)) {
+    LOG(ERROR) << "Failed to find hosts in Hostlist response data";
+    return false;
+  }
+
+  // Any host_info with malformed data will not be added to the hostlist.
+  base::DictionaryValue* host_dict;
+  for (const auto& host_info : *hosts) {
+    remoting::HostInfo host;
+    if (host_info->GetAsDictionary(&host_dict) &&
+        host.ParseHostInfo(*host_dict)) {
+      hostlist->push_back(host);
+    }
+  }
+  return true;
+}
+
+void HostListFetcher::OnURLFetchComplete(const net::URLFetcher* source) {
+  DCHECK(source);
+
+  std::vector<HostInfo> hostlist;
+  if (!ProcessResponse(&hostlist)) {
+    hostlist.clear();
+  }
+  base::ResetAndReturn(&hostlist_callback_).Run(hostlist);
+}
+
+}  // namespace remoting