#import <Foundation/Foundation.h>
#import "HockeySDK.h"

#if HOCKEYSDK_FEATURE_METRICS

@class BITPersistence;

#import "HockeySDKNullability.h"
NS_ASSUME_NONNULL_BEGIN

/**
 * Utility class that's responsible for sending a bundle of data to the server
 */
@interface BITSender : NSObject

/**
 * Notification that will be send on the main thread to notifiy observers of finish sending data.
 */
FOUNDATION_EXPORT NSString *const BITSenderFinishSendingDataNotification;

///-----------------------------------------------------------------------------
/// @name Initialize instance
///-----------------------------------------------------------------------------

/**
 *  Initializes a sender instance with a given persistence object.
 *
 *  @param persistence used for loading files before sending them out
 *  @param serverURL the endpoint URL for telemetry data
 *  @return an initialized sender instance
 */
- (instancetype)initWithPersistence:(BITPersistence *)persistence serverURL:(NSURL *)serverURL;

/**
 *  A queue which is used to handle completion blocks.
 */
@property (nonatomic, strong) dispatch_queue_t senderTasksQueue;

/**
 *  The endpoint url of the telemetry server.
 */
@property (nonatomic, copy) NSString *endpointPath;

/**
 *  The max number of request that can run at a time.
 */
@property (nonatomic, assign) NSUInteger maxRequestCount;

/**
 *  The number of requests that are currently running.
 */
@property (atomic, assign) NSUInteger runningRequestsCount;

/**
 *	BaseURL to which relative paths are appended.
 */
@property (nonatomic, strong, readonly) NSURL *serverURL;

/**
 *  The persistence instance used for loading files before sending them out.
 */
@property (nonatomic, strong, readonly) BITPersistence *persistence;

///-----------------------------------------------------------------------------
/// @name Sending data
///-----------------------------------------------------------------------------

/**
 *  Creates a request for the given data and forwards that in order to send it out.
 *
 *  @param data the telemetry data which should be sent
 *  @param filePath a reference of filePath to the file which should be sent (needed to delete it after sending)
 */
- (void)sendData:(NSData *)data withFilePath:(NSString * )filePath;

/**
 *  Triggers sending the saved data on a background thread. Does nothing if nothing has been persisted, yet. This method should be called on app start.
 */
- (void)sendSavedDataAsync;

/**
 *  Triggers sending the saved data.
 */
- (void)sendSavedData;

/**
 *  Creates a HTTP operation/session task and puts it to the queue.
 *
 *  @param request a request for sending a data object to the telemetry server
 *  @param path path to the file which should be sent
 */
- (void)sendRequest:(NSURLRequest *)request filePath:(NSString *)path;

/**
 *  Deletes or unblocks sent file according to the given response code.
 *
 *  @param statusCode the status code of the response
 *  @param responseData the data of the response
 *  @param filePath the path of the file which content has been sent to the server
 *  @param error an error object sent from the server
 */
- (void)handleResponseWithStatusCode:(NSInteger)statusCode responseData:(NSData *)responseData filePath:(NSString *)filePath error:(NSError *)error;

///-----------------------------------------------------------------------------
/// @name Helper
///-----------------------------------------------------------------------------

/**
 *  Returns a request for sending data to the telemetry sender.
 *
 *  @param data the data which should be sent
 *
 *  @return a request which contains the given data
 */
- (NSURLRequest *)requestForData:(NSData *)data;

/**
 *  Returns if data should be deleted based on a given status code.
 *
 *  @param statusCode the status code which is part of the response object
 *
 *  @return YES if data should be deleted, NO if the payload should be sent at a later time again.
 */
- (BOOL)shouldDeleteDataWithStatusCode:(NSInteger)statusCode;

@end
NS_ASSUME_NONNULL_END

#endif /* HOCKEYSDK_FEATURE_METRICS */