Add required utils for auth lib (#3)

Author: hitherejoe

lib/src/main/java/org/buffer/android/utils/ConnectivityUtil.kt

@@ -0,0 +1,15 @@
+package org.buffer.android.utils
+
+import android.annotation.SuppressLint
+import android.content.Context
+import android.net.ConnectivityManager
+
+object ConnectivityUtil {
+
+    @SuppressLint("MissingPermission")
+    fun checkConnectivity(context: Context): Boolean {
+        val cm = context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
+        val activeNetwork = cm.activeNetworkInfo
+        return activeNetwork != null && activeNetwork.isConnectedOrConnecting
+    }
+}

lib/src/main/java/org/buffer/android/utils/ErrorUtil.kt

@@ -0,0 +1,38 @@
+package org.buffer.android.utils
+
+import android.content.Context
+import org.buffer.android.utils.model.ErrorResponse
+
+open class ErrorUtil {
+
+    fun extractErrorMessage(
+        context: Context,
+        throwable: Throwable?,
+        fallback: String
+    ): String {
+        return if (throwable is ErrorResponse) {
+            return throwable.getErrorMessage()?.let {
+                if (it.isNotEmpty()) {
+                    it
+                } else {
+                    handleGenericMessage(context, fallback)
+                }
+            } ?: run {
+                handleGenericMessage(context, fallback)
+            }
+        } else {
+            handleGenericMessage(context, fallback)
+        }
+    }
+
+    private fun handleGenericMessage(
+        context: Context,
+        fallback: String
+    ): String {
+        return if (ConnectivityUtil.checkConnectivity(context)) {
+            fallback
+        } else {
+            context.getString(R.string.error_message_internet_connect)
+        }
+    }
+}

lib/src/main/java/org/buffer/android/utils/model/ErrorResponse.kt

@@ -0,0 +1,16 @@
+package org.buffer.android.utils.model
+
+class ErrorResponse @JvmOverloads constructor(
+    var code: String? = null,
+    var error: String? = null,
+    override var message: String? = null
+) : Throwable() {
+
+    fun getErrorMessage(): String? {
+        return if (!error.isNullOrEmpty()) {
+            error
+        } else {
+            message
+        }
+    }
+}

lib/src/main/res/values-es/strings.xml

@@ -0,0 +1,3 @@
+<resources>
+    <string name="error_message_internet_connect">The internet connection appears to be offline.</string>
+</resources>

lib/src/main/res/values/strings.xml

@@ -1,3 +1,5 @@
 <resources>
     <string name="app_name">Android Utils</string>
+
+    <string name="error_message_internet_connect">The internet connection appears to be offline.</string>
 </resources>