Add useragent interceptor

src/main/kotlin/io/github/wulkanowy/api/Api.kt

@@ -2,6 +2,7 @@ package io.github.wulkanowy.api
 
 import io.github.wulkanowy.api.interceptor.ErrorInterceptor
 import io.github.wulkanowy.api.interceptor.NotLoggedInErrorInterceptor
+import io.github.wulkanowy.api.interceptor.UserAgentInterceptor
 import io.github.wulkanowy.api.messages.Folder
 import io.github.wulkanowy.api.messages.Folder.*
 import io.github.wulkanowy.api.messages.Message
@@ -79,6 +80,13 @@ class Api {
 
     var useNewStudent: Boolean = false
 
+    /**
+     * @see <a href="https://deviceatlas.com/blog/most-popular-android-smartphones#poland">The most popular Android phones - 2018</a>
+     * @see <a href="http://www.tera-wurfl.com/explore/?action=wurfl_id&id=samsung_sm_j500h_ver1">Tera-WURFL Explorer - Samsung SM-J500H (Galaxy J5)</a>
+     */
+    var androidVersion: String = "5.1"
+    var buildTag: String = "SM-J500H Build/LMY48B"
+
     enum class LoginType {
         AUTO,
         STANDARD,
@@ -87,11 +95,14 @@ class Api {
         ADFSLight
     }
 
-    private val interceptors: HashMap<Interceptor, Boolean> = hashMapOf(
-            ErrorInterceptor() to false,
-            NotLoggedInErrorInterceptor(loginType) to false,
-            HttpLoggingInterceptor().setLevel(logLevel) to true
-    )
+    private val interceptors by lazy {
+        hashMapOf(
+                UserAgentInterceptor(androidVersion, buildTag) to false,
+                ErrorInterceptor() to false,
+                NotLoggedInErrorInterceptor(loginType) to false,
+                HttpLoggingInterceptor().setLevel(logLevel) to true
+        )
+    }
 
     fun setInterceptor(interceptor: Interceptor, network: Boolean = false) {
         interceptors[interceptor] = network

src/main/kotlin/io/github/wulkanowy/api/interceptor/UserAgentInterceptor.kt

@@ -0,0 +1,27 @@
+package io.github.wulkanowy.api.interceptor
+
+import okhttp3.Interceptor
+import okhttp3.Response
+
+/**
+ * @see <a href="https://github.com/jhy/jsoup/blob/220b77140bce70dcf9c767f8f04758b09097db14/src/main/java/org/jsoup/helper/HttpConnection.java#L59">JSoup default user agent</a>
+ * @see <a href="https://developer.chrome.com/multidevice/user-agent#chrome_for_android_user_agent">User Agent Strings - Google Chrome</a>
+ */
+class UserAgentInterceptor(
+        private val androidVersion: String,
+        private val buildTag: String,
+        private val webKitRev: String = "537.36",
+        private val chromeRev: String = "71.0.3578.98"
+) : Interceptor {
+
+    override fun intercept(chain: Interceptor.Chain): Response {
+        return chain.proceed(chain.request().newBuilder()
+                .addHeader("User-Agent",
+                        "Mozilla/5.0 (Linux; $androidVersion; $buildTag) " +
+                                "AppleWebKit/$webKitRev (KHTML, like Gecko) " +
+                                "Chrome/$chromeRev Mobile " +
+                                "Safari/$webKitRev")
+                .build()
+        )
+    }
+}

src/test/kotlin/io/github/wulkanowy/api/ApiRemoteTest.kt

@@ -49,6 +49,8 @@ class ApiRemoteTest : BaseTest() {
             studentId = 1
             diaryId = 101
             useNewStudent = false
+            androidVersion = "7.1.1"
+            buildTag = "PIXEL"
             setInterceptor(Interceptor {
                 println("Request event ${it.request().url().host()}")
                 it.proceed(it.request())