Record the initial state of the Physical Web at startup

ios/chrome/browser/physical_web/physical_web_initial_state_recorder.mm

Index: ios/chrome/browser/physical_web/physical_web_initial_state_recorder.mm
diff --git a/ios/chrome/browser/physical_web/physical_web_initial_state_recorder.mm b/ios/chrome/browser/physical_web/physical_web_initial_state_recorder.mm
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+// 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.
+
+#import "ios/chrome/browser/physical_web/physical_web_initial_state_recorder.h"
+
+#import <CoreBluetooth/CoreBluetooth.h>
+#import <CoreLocation/CoreLocation.h>
+
+#include "base/mac/scoped_nsobject.h"
+#include "base/metrics/histogram.h"
+#include "components/prefs/pref_service.h"
+#include "ios/chrome/browser/physical_web/physical_web_constants.h"
+#include "ios/chrome/browser/pref_names.h"
+
+namespace {
+
+// Initial state of settings relevant to the Physical Web feature. These are
+// ordered so that bits 2:0 encode the Bluetooth enabled state, the Location
+// Services enabled state, and whether Chrome has been granted the Location app
+// permission. Bits 4:3 encode the Physical Web preference tristate.
+// This enum is used in a user metrics histogram. The states should not be
+// reordered or removed.
+enum PhysicalWebInitialStateIosChrome {
+  OPTOUT_BTOFF_LOCOFF_UNAUTH,
+  OPTOUT_BTOFF_LOCOFF_AUTH,
+  OPTOUT_BTOFF_LOCON_UNAUTH,
+  OPTOUT_BTOFF_LOCON_AUTH,
+  OPTOUT_BTON_LOCOFF_UNAUTH,
+  OPTOUT_BTON_LOCOFF_AUTH,
+  OPTOUT_BTON_LOCON_UNAUTH,
+  OPTOUT_BTON_LOCON_AUTH,
+  OPTIN_BTOFF_LOCOFF_UNAUTH,
+  OPTIN_BTOFF_LOCOFF_AUTH,
+  OPTIN_BTOFF_LOCON_UNAUTH,
+  OPTIN_BTOFF_LOCON_AUTH,
+  OPTIN_BTON_LOCOFF_UNAUTH,
+  OPTIN_BTON_LOCOFF_AUTH,
+  OPTIN_BTON_LOCON_UNAUTH,
+  OPTIN_BTON_LOCON_AUTH,
+  ONBOARDING_BTOFF_LOCOFF_UNAUTH,
+  ONBOARDING_BTOFF_LOCOFF_AUTH,
+  ONBOARDING_BTOFF_LOCON_UNAUTH,
+  ONBOARDING_BTOFF_LOCON_AUTH,
+  ONBOARDING_BTON_LOCOFF_UNAUTH,
+  ONBOARDING_BTON_LOCOFF_AUTH,
+  ONBOARDING_BTON_LOCON_UNAUTH,
+  ONBOARDING_BTON_LOCON_AUTH,
+  PHYSICAL_WEB_INITIAL_STATE_COUNT,
+
+  // Helper flag values
+  LOCATION_AUTHORIZED_FLAG = 1 << 0,
+  LOCATION_SERVICES_FLAG = 1 << 1,
+  BLUETOOTH_FLAG = 1 << 2,
+  OPTIN_FLAG = 1 << 3,
+  ONBOARDING_FLAG = 1 << 4,
+};
+}  // namespace
+
+@implementation PhysicalWebInitialStateRecorder {
+  int preferenceState_;
+  BOOL recordedState_;
+  base::scoped_nsobject<CBCentralManager> centralManager_;
+}
+
+- (instancetype)initWithPrefService:(PrefService*)prefService {
+  self = [super init];
+  if (self) {
+    preferenceState_ = prefService->GetInteger(prefs::kIosPhysicalWebEnabled);
+  }
+  return self;
+}
+
+- (instancetype)init {
+  NOTREACHED();
+  return nil;
+}
+
+- (void)dealloc {
+  [centralManager_ setDelegate:nil];
+  centralManager_.reset();
+  [super dealloc];
+}
+
+- (void)centralManagerDidUpdateState:(CBCentralManager*)central {
+  // Remove ourselves as a delegate so we won't get notified for later changes
+  // to the Bluetooth enabled state.
+  [centralManager_ setDelegate:nil];
+
+  BOOL bluetoothEnabled = [centralManager_ state] == CBManagerStatePoweredOn;
+
+  BOOL locationServicesEnabled = [CLLocationManager locationServicesEnabled];
+
+  CLAuthorizationStatus authStatus = [CLLocationManager authorizationStatus];
+  BOOL locationAuthorized =
+      authStatus == kCLAuthorizationStatusAuthorizedWhenInUse ||
+      authStatus == kCLAuthorizationStatusAuthorizedAlways;
+
+  [self recordStateWithPreferenceState:preferenceState_
+                      bluetoothEnabled:bluetoothEnabled
+               locationServicesEnabled:locationServicesEnabled
+                    locationAuthorized:locationAuthorized];
+}
+
+- (void)collectAndRecordState {
+  if (recordedState_) {
+    return;
+  }
+  recordedState_ = YES;
+
+  // The Bluetooth enabled state must be checked asynchronously. When the state
+  // is ready, it will call our centralManagerDidUpdateState method.
+  centralManager_.reset([[CBCentralManager alloc]
+      initWithDelegate:self
+                 queue:dispatch_get_main_queue()
+               options:@{
+                 // By default, creating a CBCentralManager object with
+                 // Bluetooth disabled will prompt the user to enable Bluetooth.
+                 // Passing ShowPowerAlert=NO disables the prompt so we can
+                 // check the Bluetooth enabled state silently.
+                 CBCentralManagerOptionShowPowerAlertKey : @NO
+               }]);
+}
+
+- (void)recordStateWithPreferenceState:(int)preferenceState
+                      bluetoothEnabled:(BOOL)bluetoothEnabled
+               locationServicesEnabled:(BOOL)locationServicesEnabled
+                    locationAuthorized:(BOOL)locationAuthorized {
+  int state = 0;
+  if (preferenceState == physical_web::kPhysicalWebOn) {
+    state |= OPTIN_FLAG;
+  } else if (preferenceState == physical_web::kPhysicalWebOnboarding) {
+    state |= ONBOARDING_FLAG;
+  }
+  if (locationServicesEnabled) {
+    state |= LOCATION_SERVICES_FLAG;
+  }
+  if (locationAuthorized) {
+    state |= LOCATION_AUTHORIZED_FLAG;
+  }
+  if (bluetoothEnabled) {
+    state |= BLUETOOTH_FLAG;
+  }
+
+  DCHECK(state < PHYSICAL_WEB_INITIAL_STATE_COUNT);
+  UMA_HISTOGRAM_ENUMERATION("PhysicalWeb.InitialState.IosChrome", state,
+                            PHYSICAL_WEB_INITIAL_STATE_COUNT);
+}
+
+@end