Merge pull request #973 from RocketChat/new/login-with-linkedin

[NEW] Login with Linkedin (OAuth).

app/src/main/java/chat/rocket/android/authentication/login/presentation/LoginPresenter.kt

@@ -30,6 +30,7 @@ private const val TYPE_LOGIN_CAS = 1
 private const val TYPE_LOGIN_OAUTH = 2
 private const val SERVICE_NAME_GITHUB = "github"
 private const val SERVICE_NAME_GOOGLE = "google"
+private const val SERVICE_NAME_LINKEDIN = "linkedin"
 private const val SERVICE_NAME_GILAB = "gitlab"
 
 class LoginPresenter @Inject constructor(private val view: LoginView,
@@ -142,8 +143,12 @@ class LoginPresenter @Inject constructor(private val view: LoginView,
                         }
                     }
                     if (settings.isLinkedinAuthenticationEnabled()) {
-                        view.enableLoginByLinkedin()
-                        totalSocialAccountsEnabled++
+                        val clientId = getOauthClientId(services, SERVICE_NAME_LINKEDIN)
+                        if (clientId != null) {
+                            view.setupGoogleButtonListener(UrlHelper.getLinkedinOauthUrl(clientId, currentServer, state), state)
+                            view.enableLoginByLinkedin()
+                            totalSocialAccountsEnabled++
+                        }
                     }
                     if (settings.isMeteorAuthenticationEnabled()) {
                         view.enableLoginByMeteor()

app/src/main/java/chat/rocket/android/authentication/login/presentation/LoginView.kt

@@ -132,9 +132,19 @@ interface LoginView : LoadingView, MessageView, InternetView {
 
     /**
      * Shows the "login by Linkedin" view if it is enable by the server settings.
+     *
+     * REMARK: We must set up the Linkedin button listener before enabling it [setupLinkedinButtonListener].
      */
     fun enableLoginByLinkedin()
 
+    /**
+     * Setups the Linkedin button when tapped.
+     *
+     * @param linkedinUrl The Linkedin OAuth URL to authenticate with.
+     * @param state A random string generated by the app, which you'll verify later (to protect against forgery attacks).
+     */
+    fun setupLinkedinButtonListener(linkedinUrl: String, state: String)
+
     /**
      * Shows the "login by Meteor" view if it is enable by the server settings.
      */

app/src/main/java/chat/rocket/android/authentication/login/ui/LoginFragment.kt

@@ -231,6 +231,13 @@ class LoginFragment : Fragment(), LoginView {
         button_linkedin.isClickable = true
     }
 
+    override fun setupLinkedinButtonListener(linkedinUrl: String, state: String) {
+        button_linkedin.setOnClickListener {
+            startActivityForResult(context?.oauthWebViewIntent(linkedinUrl, state), REQUEST_CODE_FOR_OAUTH)
+            activity?.overridePendingTransition(R.anim.slide_up, R.anim.hold)
+        }
+    }
+
     override fun enableLoginByMeteor() {
         button_meteor.isClickable = true
     }

app/src/main/java/chat/rocket/android/helper/UrlHelper.kt

@@ -56,6 +56,17 @@ object UrlHelper {
     fun getGoogleOauthUrl(clientId: String, serverUrl: String, state: String) =
         "https://accounts.google.com/o/oauth2/v2/auth?client_id=$clientId&redirect_uri=${removeTrailingSlash(serverUrl)}/_oauth/google?close&response_type=code&state=$state&scope=email%20profile"
 
+    /**
+     * Returns the Linkedin Oauth URL.
+     *
+     * @param clientId The Linkedin client ID.
+     * @param serverUrl The server URL.
+     * @param state An unguessable random string used to protect against forgery attacks.
+     * @return The Linkedin Oauth URL.
+     */
+    fun getLinkedinOauthUrl(clientId: String, serverUrl: String, state: String) =
+        "https://www.linkedin.com/oauth/v2/authorization?response_type=code&client_id=$clientId&redirect_uri=${removeTrailingSlash(serverUrl)}/_oauth/linkedin?close&state=$state"
+
     /**
      * Returns the Gitlab Oauth URL.
      *