[ios, macos] Add Mapbox Maps SDK metrics manager. (#13997)

Added MGLSDKMetricsManager to keep track of SDK related events such as tile download times.

* [ios, macos] Add tile download performance event.

* [ios, macos] Modify the performance event format.

* [ios, macos] Add Mapbox Maps SDK events manager.

* [ios, macos] Remove events delegate.

* [ios, macos] Remove deprecated macro.

* [ios, macos] Rename MGLEventsManager to MGLMetricsManager.

* [ios, macos] Make MGLMetricsDelegate follow delegate convention.

* [ios, macos] Remove mbgl-filesource target dependency on MGLMetricsManager.

* [ios, macos] Update metrics manager documentation.

* [ios, macos] Add device metadata.

* [ios, macos] Rename MGLMetricsManager to MGLSDKMetricsManager.

1 files changed, 65 insertions, 2 deletions

diff --git a/platform/darwin/src/MGLNetworkConfiguration.m b/platform/darwin/src/MGLNetworkConfiguration.m
index 8262e7eea1..bac4d12ee5 100644
--- a/platform/darwin/src/MGLNetworkConfiguration.m
+++ b/platform/darwin/src/MGLNetworkConfiguration.m
@@ -1,19 +1,33 @@
-#import "MGLNetworkConfiguration.h"
+#import "MGLNetworkConfiguration_Private.h"
+
+static NSString * const MGLStartTime = @"start_time";
+static NSString * const MGLResourceType = @"resource_type";
+NSString * const kMGLDownloadPerformanceEvent = @"mobile.performance_trace";
 
 @interface MGLNetworkConfiguration ()
 
 @property (strong) NSURLSessionConfiguration *sessionConfig;
+@property (nonatomic, strong) NSMutableDictionary<NSString *, NSDictionary*> *events;
+@property (nonatomic, weak) id<MGLNetworkConfigurationMetricsDelegate> metricsDelegate;
 
 @end
 
 @implementation MGLNetworkConfiguration
 
+- (instancetype)init {
+    if (self = [super init]) {
+        self.sessionConfiguration = nil;
+        _events = [NSMutableDictionary dictionary];
+    }
+    
+    return self;
+}
+
 + (instancetype)sharedManager {
     static dispatch_once_t onceToken;
     static MGLNetworkConfiguration *_sharedManager;
     dispatch_once(&onceToken, ^{
         _sharedManager = [[self alloc] init];
-        _sharedManager.sessionConfiguration = nil;
     });
 
     return _sharedManager;
@@ -48,4 +62,53 @@
     return sessionConfiguration;
 }
 
+- (void)startDownloadEvent:(NSString *)urlString type:(NSString *)resourceType {
+    if (urlString && ![self.events objectForKey:urlString]) {
+        [self.events setObject:@{ MGLStartTime: [NSDate date], MGLResourceType: resourceType } forKey:urlString];
+    }
+}
+
+- (void)stopDownloadEvent:(NSString *)urlString {
+    [self sendEventForURL:urlString withAction:nil];
+}
+
+- (void)cancelDownloadEvent:(NSString *)urlString {
+    [self sendEventForURL:urlString withAction:@"cancel"];
+}
+
+- (void)sendEventForURL:(NSString *)urlString withAction:(NSString *)action
+{
+    if (urlString && [self.events objectForKey:urlString]) {
+        NSDictionary *eventAttributes = [self eventAttributesForURL:urlString withAction:action];
+        [self.metricsDelegate networkConfiguration:self didGenerateMetricEvent:eventAttributes];
+        [self.events removeObjectForKey:urlString];
+    }
+}
+
+- (NSDictionary *)eventAttributesForURL:(NSString *)urlString withAction:(NSString *)action
+{
+    NSDictionary *parameters = [self.events objectForKey:urlString];
+    NSDate *startDate = [parameters objectForKey:MGLStartTime];
+    NSDate *endDate = [NSDate date];
+    NSTimeInterval elapsedTime = [endDate timeIntervalSinceDate:startDate];
+    NSDateFormatter* iso8601Formatter = [[NSDateFormatter alloc] init];
+    iso8601Formatter.dateFormat = @"yyyy-MM-dd'T'HH:mm:ssZ";
+    NSString *createdDate = [iso8601Formatter stringFromDate:[NSDate date]];
+    
+    NSMutableArray *attributes = [NSMutableArray array];
+    [attributes addObject:@{ @"name" : @"resource" , @"value" : urlString }];
+    [attributes addObject:@{ @"name" : MGLResourceType , @"value" : [parameters objectForKey:MGLResourceType] }];
+    if (action) {
+        [attributes addObject:@{ @"name" : @"action" , @"value" : action }];
+    }
+
+    return @{
+             @"event" : kMGLDownloadPerformanceEvent,
+             @"created" : createdDate,
+             @"sessionId" : [NSUUID UUID].UUIDString,
+             @"counters" : @[ @{ @"name" : @"elapsed_time" , @"value" : @(elapsedTime) } ],
+             @"attributes" : attributes
+             };
+}
+
 @end