Add configuration option to enable tracking for demonstration purposes

This resolves #9.

PrivacyKit/Http.swift

@@ -238,6 +238,15 @@ public class Http {
 		case contentLength = "Content-Length"
 		/// `Content-Type`
 		case contentType = "Content-Type"
+
+		/**
+			A header used to activating bad behaviour of a service provider.
+			This should be used for demonstration purposes only.
+
+			- warning: Do not use this in production systems, as all requests
+				will be logged, if this header is set.
+		*/
+		case badProvider = "X-AppPETs-BadProvider"
 	}
 
 	/**

PrivacyKit/KeyValueStorage.swift

@@ -557,7 +557,7 @@ extension PrivacyService {
 		Key-value storage backend of the P-Service.
 	*/
 	var keyValueStorageBackend: KeyValueStorageBackend {
-		return PrivacyService.KeyValueStorage(baseUrl: baseUrl)
+		return PrivacyService.KeyValueStorage(service: self)
 	}
 
 	/**
@@ -566,26 +566,23 @@ extension PrivacyService {
 	*/
 	class KeyValueStorage {
 
-		/**
-			The base URL of the P-Service.
-		*/
-		let baseUrl: URL
+		weak var service: PrivacyService! = nil
 
 		/**
 			Initialize the key-value storage backend.
 
 			- parameters:
-				- baseUrl: The base URL of the P-Service.
+				- service: The P-Service object.
 		*/
-		init(baseUrl: URL) {
-			self.baseUrl = baseUrl
+		init(service: PrivacyService) {
+			self.service = service
 		}
 
 		/**
 			The entry point of the key-value storage API.
 		*/
 		var entryPoint: URL {
-			return baseUrl
+			return service.baseUrl
 				.appendingPathComponent("storage", isDirectory: true)
 				.appendingPathComponent("v1", isDirectory: true)
 		}
@@ -640,6 +637,10 @@ extension PrivacyService.KeyValueStorage: KeyValueStorageBackend {
 		request.set(method: .post)
 		request.set(contentType: .octetStream)
 
+		if service.options.contains(.activateBadBehavior) {
+			request.add(value: "1", for: .badProvider)
+		}
+
 		Indicators.showNetworkActivity()
 
 		let task = session.uploadTask(with: request, from: Data(value.bytes)) {
@@ -687,6 +688,10 @@ extension PrivacyService.KeyValueStorage: KeyValueStorageBackend {
 
 		request.set(method: .get)
 
+		if service.options.contains(.activateBadBehavior) {
+			request.add(value: "1", for: .badProvider)
+		}
+
 		Indicators.showNetworkActivity()
 
 		let task = session.dataTask(with: request) {
@@ -747,6 +752,10 @@ extension PrivacyService.KeyValueStorage: KeyValueStorageBackend {
 
 		request.set(method: .delete)
 
+		if service.options.contains(.activateBadBehavior) {
+			request.add(value: "1", for: .badProvider)
+		}
+
 		Indicators.showNetworkActivity()
 
 		let task = session.dataTask(with: request) {

PrivacyKit/PrivacyService.swift

@@ -3,19 +3,58 @@
 */
 public class PrivacyService {
 
+	/**
+		These options can be used to configure the behaviour of the service.
+	*/
+	public struct Options: OptionSet {
+
+		/**
+			A bit representing a single option.
+		*/
+		public let rawValue: Int
+
+		/**
+			Initialize a single option with a given value.
+
+			- parameters:
+				- rawValue: The bit representing the option.
+		*/
+		public init(rawValue: Int) {
+			self.rawValue = rawValue
+		}
+
+		/**
+			This option activates bad behaviour of the service. Every request
+			send to a service with activated bad behaviour is logged and
+			available in the visualization API.
+
+			- warning: Do not use this in production system. This is meant for
+				demonstration purposes only. Every reqeust will be logged on the
+				server, including the user's IP address.
+		*/
+		static let activateBadBehavior = Options(rawValue: 1 << 0)
+
+	}
+
 	/**
 		The base URL of the P-Service.
 	*/
 	let baseUrl: URL
 
+	/**
+		Options that configure the behaviour of
+	*/
+	let options: Options
+
 	/**
 		Initializes a `PrivacyService` instance.
 
 		- parameters:
 			- baseUrl: The base URL of the P-Service.
 	*/
-	public init(baseUrl: URL) {
+	public init(baseUrl: URL, options: Options = []) {
 		self.baseUrl = baseUrl
+		self.options = options
 	}
 
 }