Convert the LoginClient to kotlin (#5479)

* Convert the result classes to kotlin

* Convert response and callback to kotlin

* Cleanup code-quality warnings before converting

* Converted the LoginClient to kotlin

* Updated the UserExtendedInfoClientTest to be kotlin, and live in the correct spot

app/src/main/java/fr/free/nrw/commons/auth/LoginActivity.java

@@ -31,11 +31,10 @@ import fr.free.nrw.commons.auth.login.LoginResult;
 import fr.free.nrw.commons.databinding.ActivityLoginBinding;
 import fr.free.nrw.commons.utils.ActivityUtils;
 import java.util.Locale;
-import org.wikipedia.AppAdapter;
 import org.wikipedia.dataclient.ServiceFactory;
 import org.wikipedia.dataclient.WikiSite;
 import org.wikipedia.dataclient.mwapi.MwQueryResponse;
-import fr.free.nrw.commons.auth.login.LoginClient.LoginCallback;
+import fr.free.nrw.commons.auth.login.LoginCallback;
 
 import javax.inject.Inject;
 import javax.inject.Named;

app/src/main/java/fr/free/nrw/commons/auth/csrf/CsrfTokenClient.kt

@@ -8,8 +8,8 @@ import org.wikipedia.dataclient.SharedPreferenceCookieManager
 import org.wikipedia.dataclient.WikiSite
 import org.wikipedia.dataclient.mwapi.MwQueryResponse
 import fr.free.nrw.commons.auth.login.LoginClient
-import fr.free.nrw.commons.auth.login.LoginClient.LoginCallback
-import fr.free.nrw.commons.auth.login.LoginClient.LoginFailedException
+import fr.free.nrw.commons.auth.login.LoginCallback
+import fr.free.nrw.commons.auth.login.LoginFailedException
 import fr.free.nrw.commons.auth.login.LoginResult
 import retrofit2.Call
 import retrofit2.Response
@@ -129,7 +129,7 @@ class CsrfTokenClient(
     ) = LoginClient()
         .request(csrfWikiSite, username, password, object : LoginCallback {
         override fun success(loginResult: LoginResult) {
-            if (loginResult.pass()) {
+            if (loginResult.pass) {
                 sessionManager.updateAccount(loginResult)
                 retryCallback()
             } else {

app/src/main/java/fr/free/nrw/commons/auth/login/LoginCallback.kt

@@ -0,0 +1,8 @@
+package fr.free.nrw.commons.auth.login
+
+interface LoginCallback {
+    fun success(loginResult: LoginResult)
+    fun twoFactorPrompt(caught: Throwable, token: String?)
+    fun passwordResetPrompt(token: String?)
+    fun error(caught: Throwable)
+}

app/src/main/java/fr/free/nrw/commons/auth/login/LoginClient.java

@@ -1,259 +0,0 @@
-package fr.free.nrw.commons.auth.login;
-
-import android.annotation.SuppressLint;
-import android.text.TextUtils;
-
-import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
-
-import com.google.gson.annotations.SerializedName;
-
-import org.apache.commons.lang3.StringUtils;
-import org.wikipedia.dataclient.Service;
-import org.wikipedia.dataclient.ServiceFactory;
-import org.wikipedia.dataclient.WikiSite;
-import org.wikipedia.dataclient.mwapi.ListUserResponse;
-import org.wikipedia.dataclient.mwapi.MwQueryResponse;
-import org.wikipedia.dataclient.mwapi.MwServiceError;
-import org.wikipedia.util.log.L;
-
-import java.io.IOException;
-import java.util.List;
-import java.util.Map;
-
-import io.reactivex.android.schedulers.AndroidSchedulers;
-import io.reactivex.schedulers.Schedulers;
-import retrofit2.Call;
-import retrofit2.Callback;
-import retrofit2.Response;
-
-/**
- * Responsible for making login related requests to the server.
- */
-public class LoginClient {
-    @Nullable private Call<MwQueryResponse> tokenCall;
-    @Nullable private Call<LoginResponse> loginCall;
-    /**
-     * userLanguage
-     * It holds the value of the user's device language code.
-     * For example, if user's device language is English it will hold En
-     * The value will be fetched when the user clicks Login Button in the LoginActivity
-     */
-    @NonNull private String userLanguage;
-    
-    public interface LoginCallback {
-        void success(@NonNull LoginResult result);
-        void twoFactorPrompt(@NonNull Throwable caught, @Nullable String token);
-        void passwordResetPrompt(@Nullable String token);
-        void error(@NonNull Throwable caught);
-    }
-
-    public void request(@NonNull final WikiSite wiki, @NonNull final String userName,
-                        @NonNull final String password, @NonNull final LoginCallback cb) {
-        cancel();
-
-        tokenCall = ServiceFactory.get(wiki, LoginInterface.class).getLoginToken();
-        tokenCall.enqueue(new Callback<MwQueryResponse>() {
-            @Override public void onResponse(@NonNull Call<MwQueryResponse> call,
-                                             @NonNull Response<MwQueryResponse> response) {
-                login(wiki, userName, password, null, null, response.body().query().loginToken(),
-                    userLanguage, cb);
-            }
-
-            @Override
-            public void onFailure(@NonNull Call<MwQueryResponse> call, @NonNull Throwable caught) {
-                if (call.isCanceled()) {
-                    return;
-                }
-                cb.error(caught);
-            }
-        });
-    }
-
-    public void login(@NonNull final WikiSite wiki, @NonNull final String userName, @NonNull final String password,
-               @Nullable final String retypedPassword, @Nullable final String twoFactorCode,
-               @Nullable final String loginToken, @NonNull final String userLanguage, @NonNull final LoginCallback cb) {
-        this.userLanguage = userLanguage;
-        loginCall = TextUtils.isEmpty(twoFactorCode) && TextUtils.isEmpty(retypedPassword)
-                ? ServiceFactory.get(wiki, LoginInterface.class).postLogIn(userName, password, loginToken, userLanguage, Service.WIKIPEDIA_URL)
-                : ServiceFactory.get(wiki, LoginInterface.class).postLogIn(userName, password, retypedPassword, twoFactorCode, loginToken,
-                    userLanguage, true);
-        loginCall.enqueue(new Callback<LoginResponse>() {
-            @Override
-            public void onResponse(@NonNull Call<LoginResponse> call, @NonNull Response<LoginResponse> response) {
-                LoginResponse loginResponse = response.body();
-                LoginResult loginResult = loginResponse.toLoginResult(wiki, password);
-                if (loginResult != null) {
-                    if (loginResult.pass() && !TextUtils.isEmpty(loginResult.getUserName())) {
-                        // The server could do some transformations on user names, e.g. on some
-                        // wikis is uppercases the first letter.
-                        String actualUserName = loginResult.getUserName();
-                        getExtendedInfo(wiki, actualUserName, loginResult, cb);
-                    } else if ("UI".equals(loginResult.getStatus())) {
-                        if (loginResult instanceof LoginOAuthResult) {
-                            cb.twoFactorPrompt(new LoginFailedException(loginResult.getMessage()), loginToken);
-                        } else if (loginResult instanceof LoginResetPasswordResult) {
-                            cb.passwordResetPrompt(loginToken);
-                        } else {
-                            cb.error(new LoginFailedException(loginResult.getMessage()));
-                        }
-                    } else {
-                        cb.error(new LoginFailedException(loginResult.getMessage()));
-                    }
-                } else {
-                    cb.error(new IOException("Login failed. Unexpected response."));
-                }
-            }
-
-            @Override
-            public void onFailure(@NonNull Call<LoginResponse> call, @NonNull Throwable t) {
-                if (call.isCanceled()) {
-                    return;
-                }
-                cb.error(t);
-            }
-        });
-    }
-
-    public void loginBlocking(@NonNull final WikiSite wiki, @NonNull final String userName,
-                              @NonNull final String password, @Nullable final String twoFactorCode) throws Throwable {
-        Response<MwQueryResponse> tokenResponse = ServiceFactory.get(wiki, LoginInterface.class).getLoginToken().execute();
-        if (tokenResponse.body() == null || TextUtils.isEmpty(tokenResponse.body().query().loginToken())) {
-            throw new IOException("Unexpected response when getting login token.");
-        }
-        String loginToken = tokenResponse.body().query().loginToken();
-
-        Call<LoginResponse> tempLoginCall = StringUtils.defaultIfEmpty(twoFactorCode, "").isEmpty()
-                ? ServiceFactory.get(wiki, LoginInterface.class).postLogIn(userName, password, loginToken, userLanguage, Service.WIKIPEDIA_URL)
-                : ServiceFactory.get(wiki, LoginInterface.class).postLogIn(userName, password, null, twoFactorCode, loginToken,
-                    userLanguage, true);
-        Response<LoginResponse> response = tempLoginCall.execute();
-        LoginResponse loginResponse = response.body();
-        if (loginResponse == null) {
-            throw new IOException("Unexpected response when logging in.");
-        }
-        LoginResult loginResult = loginResponse.toLoginResult(wiki, password);
-        if (loginResult == null) {
-            throw new IOException("Unexpected response when logging in.");
-        }
-        if ("UI".equals(loginResult.getStatus())) {
-            if (loginResult instanceof LoginOAuthResult) {
-
-                // TODO: Find a better way to boil up the warning about 2FA
-                throw new LoginFailedException(loginResult.getMessage());
-
-            } else {
-                throw new LoginFailedException(loginResult.getMessage());
-            }
-        } else if (!loginResult.pass() || TextUtils.isEmpty(loginResult.getUserName())) {
-            throw new LoginFailedException(loginResult.getMessage());
-        }
-    }
-
-    @SuppressLint("CheckResult")
-    private void getExtendedInfo(@NonNull final WikiSite wiki, @NonNull String userName,
-                                 @NonNull final LoginResult loginResult, @NonNull final LoginCallback cb) {
-        ServiceFactory.get(wiki, LoginInterface.class).getUserInfo(userName)
-                .subscribeOn(Schedulers.io())
-                .observeOn(AndroidSchedulers.mainThread())
-                .subscribe(response -> {
-                    ListUserResponse user = response.query().getUserResponse(userName);
-                    int id = response.query().userInfo().id();
-                    loginResult.setUserId(id);
-                    loginResult.setGroups(user.getGroups());
-                    cb.success(loginResult);
-                    L.v("Found user ID " + id + " for " + wiki.subdomain());
-                }, caught -> {
-                    L.e("Login succeeded but getting group information failed. " + caught);
-                    cb.error(caught);
-                });
-    }
-
-    public void cancel() {
-        cancelTokenRequest();
-        cancelLogin();
-    }
-
-    private void cancelTokenRequest() {
-        if (tokenCall == null) {
-            return;
-        }
-        tokenCall.cancel();
-        tokenCall = null;
-    }
-
-    private void cancelLogin() {
-        if (loginCall == null) {
-            return;
-        }
-        loginCall.cancel();
-        loginCall = null;
-    }
-
-    public static final class LoginResponse {
-        @SuppressWarnings("unused") @SerializedName("error") @Nullable
-        private MwServiceError error;
-
-        @SuppressWarnings("unused") @SerializedName("clientlogin") @Nullable
-        private ClientLogin clientLogin;
-
-        @Nullable public MwServiceError getError() {
-            return error;
-        }
-
-        @Nullable LoginResult toLoginResult(@NonNull WikiSite site, @NonNull String password) {
-            return clientLogin != null ? clientLogin.toLoginResult(site, password) : null;
-        }
-
-        private static class ClientLogin {
-            @SuppressWarnings("unused,NullableProblems") @NonNull private String status;
-            @SuppressWarnings("unused") @Nullable private List<Request> requests;
-            @SuppressWarnings("unused") @Nullable private String message;
-            @SuppressWarnings("unused") @SerializedName("username") @Nullable private String userName;
-
-            LoginResult toLoginResult(@NonNull WikiSite site, @NonNull String password) {
-                String userMessage = message;
-                if ("UI".equals(status)) {
-                    if (requests != null) {
-                        for (Request req : requests) {
-                            if ("MediaWiki\\Extension\\OATHAuth\\Auth\\TOTPAuthenticationRequest".equals(req.id())) {
-                                return new LoginOAuthResult(site, status, userName, password, message);
-                            } else if ("MediaWiki\\Auth\\PasswordAuthenticationRequest".equals(req.id())) {
-                                return new LoginResetPasswordResult(site, status, userName, password, message);
-                            }
-                        }
-                    }
-                } else if (!"PASS".equals(status) && !"FAIL".equals(status)) {
-                    //TODO: String resource -- Looks like needed for others in this class too
-                    userMessage = "An unknown error occurred.";
-                }
-                return new LoginResult(site, status, userName, password, userMessage);
-            }
-        }
-
-        private static class Request {
-            @SuppressWarnings("unused") @Nullable private String id;
-            //@SuppressWarnings("unused") @Nullable private JsonObject metadata;
-            @SuppressWarnings("unused") @Nullable private String required;
-            @SuppressWarnings("unused") @Nullable private String provider;
-            @SuppressWarnings("unused") @Nullable private String account;
-            @SuppressWarnings("unused") @Nullable private Map<String, RequestField> fields;
-
-            @Nullable String id() {
-                return id;
-            }
-        }
-
-        private static class RequestField {
-            @SuppressWarnings("unused") @Nullable private String type;
-            @SuppressWarnings("unused") @Nullable private String label;
-            @SuppressWarnings("unused") @Nullable private String help;
-        }
-    }
-
-    public static class LoginFailedException extends Throwable {
-        public LoginFailedException(String message) {
-            super(message);
-        }
-    }
-}

app/src/main/java/fr/free/nrw/commons/auth/login/LoginClient.kt

@@ -0,0 +1,172 @@
+package fr.free.nrw.commons.auth.login
+
+import android.text.TextUtils
+import fr.free.nrw.commons.auth.login.LoginResult.OAuthResult
+import fr.free.nrw.commons.auth.login.LoginResult.ResetPasswordResult
+import io.reactivex.android.schedulers.AndroidSchedulers
+import io.reactivex.schedulers.Schedulers
+import org.wikipedia.dataclient.Service
+import org.wikipedia.dataclient.ServiceFactory
+import org.wikipedia.dataclient.WikiSite
+import org.wikipedia.dataclient.mwapi.MwQueryResponse
+import retrofit2.Call
+import retrofit2.Callback
+import retrofit2.Response
+import timber.log.Timber
+import java.io.IOException
+
+/**
+ * Responsible for making login related requests to the server.
+ */
+class LoginClient {
+    private var tokenCall: Call<MwQueryResponse?>? = null
+    private var loginCall: Call<LoginResponse?>? = null
+
+    /**
+     * userLanguage
+     * It holds the value of the user's device language code.
+     * For example, if user's device language is English it will hold En
+     * The value will be fetched when the user clicks Login Button in the LoginActivity
+     */
+    private var userLanguage = ""
+
+    fun request(wiki: WikiSite, userName: String, password: String, cb: LoginCallback) {
+        cancel()
+
+        tokenCall = ServiceFactory.get(wiki, LoginInterface::class.java).getLoginToken()
+        tokenCall!!.enqueue(object : Callback<MwQueryResponse?> {
+            override fun onResponse(call: Call<MwQueryResponse?>, response: Response<MwQueryResponse?>) {
+                login(wiki, userName, password, null, null,
+                    response.body()!!.query()!!.loginToken(), userLanguage, cb)
+            }
+
+            override fun onFailure(call: Call<MwQueryResponse?>, caught: Throwable) {
+                if (call.isCanceled) {
+                    return
+                }
+                cb.error(caught)
+            }
+        })
+    }
+
+    fun login(
+        wiki: WikiSite, userName: String, password: String, retypedPassword: String?,
+        twoFactorCode: String?, loginToken: String?, userLanguage: String, cb: LoginCallback
+    ) {
+        this.userLanguage = userLanguage
+
+        loginCall = if (twoFactorCode.isNullOrEmpty() && retypedPassword.isNullOrEmpty()) {
+            ServiceFactory.get(wiki, LoginInterface::class.java)
+                .postLogIn(userName, password, loginToken, userLanguage, Service.WIKIPEDIA_URL)
+        } else {
+            ServiceFactory.get(wiki, LoginInterface::class.java).postLogIn(
+                userName, password, retypedPassword, twoFactorCode, loginToken, userLanguage, true
+            )
+        }
+
+        loginCall!!.enqueue(object : Callback<LoginResponse?> {
+            override fun onResponse(
+                call: Call<LoginResponse?>,
+                response: Response<LoginResponse?>
+            ) {
+                val loginResult = response.body()?.toLoginResult(wiki, password)
+                if (loginResult != null) {
+                    if (loginResult.pass && !loginResult.userName.isNullOrEmpty()) {
+                        // The server could do some transformations on user names, e.g. on some
+                        // wikis is uppercases the first letter.
+                        getExtendedInfo(wiki, loginResult.userName, loginResult, cb)
+                    } else if ("UI" == loginResult.status) {
+                        when (loginResult) {
+                            is OAuthResult -> cb.twoFactorPrompt(
+                                LoginFailedException(loginResult.message),
+                                loginToken
+                            )
+
+                            is ResetPasswordResult -> cb.passwordResetPrompt(loginToken)
+
+                            is LoginResult.Result -> cb.error(
+                                LoginFailedException(loginResult.message)
+                            )
+                        }
+                    } else {
+                        cb.error(LoginFailedException(loginResult.message))
+                    }
+                } else {
+                    cb.error(IOException("Login failed. Unexpected response."))
+                }
+            }
+
+            override fun onFailure(call: Call<LoginResponse?>, t: Throwable) {
+                if (call.isCanceled) {
+                    return
+                }
+                cb.error(t)
+            }
+        })
+    }
+
+    @Throws(Throwable::class)
+    fun loginBlocking(wiki: WikiSite, userName: String, password: String, twoFactorCode: String?) {
+        val tokenResponse = ServiceFactory.get(wiki, LoginInterface::class.java).getLoginToken().execute()
+        if (tokenResponse.body()?.query()?.loginToken().isNullOrEmpty()) {
+            throw IOException("Unexpected response when getting login token.")
+        }
+
+        val loginToken = tokenResponse.body()?.query()?.loginToken()
+        val tempLoginCall = if (twoFactorCode.isNullOrEmpty()) {
+            ServiceFactory.get(wiki, LoginInterface::class.java).postLogIn(
+                userName, password, loginToken, userLanguage, Service.WIKIPEDIA_URL
+            )
+        } else {
+            ServiceFactory.get(wiki, LoginInterface::class.java).postLogIn(
+                userName, password, null, twoFactorCode, loginToken, userLanguage, true
+            )
+        }
+
+        val response = tempLoginCall.execute()
+        val loginResponse = response.body() ?: throw IOException("Unexpected response when logging in.")
+        val loginResult = loginResponse.toLoginResult(wiki, password) ?: throw IOException("Unexpected response when logging in.")
+
+        if ("UI" == loginResult.status) {
+            if (loginResult is OAuthResult) {
+                // TODO: Find a better way to boil up the warning about 2FA
+                throw LoginFailedException(loginResult.message)
+            }
+            throw LoginFailedException(loginResult.message)
+        }
+
+        if (!loginResult.pass || TextUtils.isEmpty(loginResult.userName)) {
+            throw LoginFailedException(loginResult.message)
+        }
+    }
+
+    private fun getExtendedInfo(
+        wiki: WikiSite, userName: String, loginResult: LoginResult, cb: LoginCallback
+    ) = ServiceFactory.get(wiki, LoginInterface::class.java).getUserInfo(userName)
+        .subscribeOn(Schedulers.io()).observeOn(AndroidSchedulers.mainThread())
+        .subscribe({ response: MwQueryResponse? ->
+            loginResult.userId = response?.query()?.userInfo()?.id() ?: 0
+            loginResult.groups = response?.query()?.getUserResponse(userName)?.groups ?: emptySet()
+            cb.success(loginResult)
+            Timber.v(
+                "Found user ID %s for %s",
+                response?.query()?.userInfo()?.id(),
+                wiki.subdomain()
+            )
+        }, { caught: Throwable ->
+            Timber.e(caught, "Login succeeded but getting group information failed. ")
+            cb.error(caught)
+        })
+
+    fun cancel() {
+        tokenCall?.let {
+            it.cancel()
+            tokenCall = null
+        }
+
+        loginCall?.let {
+            it.cancel()
+            loginCall = null
+        }
+    }
+}

app/src/main/java/fr/free/nrw/commons/auth/login/LoginFailedException.kt

@@ -0,0 +1,3 @@
+package fr.free.nrw.commons.auth.login
+
+class LoginFailedException(message: String?) : Throwable(message)

app/src/main/java/fr/free/nrw/commons/auth/login/LoginInterface.kt

@@ -25,7 +25,7 @@ interface LoginInterface {
         @Field("logintoken") token: String?,
         @Field("uselang") userLanguage: String?,
         @Field("loginreturnurl") url: String?
-    ): Call<LoginClient.LoginResponse?>
+    ): Call<LoginResponse?>
 
     @Headers("Cache-Control: no-cache")
     @FormUrlEncoded
@@ -38,7 +38,7 @@ interface LoginInterface {
         @Field("logintoken") token: String?,
         @Field("uselang") userLanguage: String?,
         @Field("logincontinue") loginContinue: Boolean
-    ): Call<LoginClient.LoginResponse?>
+    ): Call<LoginResponse?>
 
     @GET(Service.MW_API_PREFIX + "action=query&meta=userinfo&list=users&usprop=groups|cancreate")
     fun getUserInfo(@Query("ususers") userName: String): Observable<MwQueryResponse?>

app/src/main/java/fr/free/nrw/commons/auth/login/LoginOAuthResult.java

@@ -1,14 +0,0 @@
-package fr.free.nrw.commons.auth.login;
-
-import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
-
-import org.wikipedia.dataclient.WikiSite;
-
-public class LoginOAuthResult extends LoginResult {
-
-    public LoginOAuthResult(@NonNull WikiSite site, @NonNull String status, @Nullable String userName,
-                     @Nullable String password, @Nullable String message) {
-        super(site, status, userName, password, message);
-    }
-}

app/src/main/java/fr/free/nrw/commons/auth/login/LoginResetPasswordResult.java

@@ -1,13 +0,0 @@
-package fr.free.nrw.commons.auth.login;
-
-import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
-
-import org.wikipedia.dataclient.WikiSite;
-
-public class LoginResetPasswordResult extends LoginResult {
-    public LoginResetPasswordResult(@NonNull WikiSite site, @NonNull String status, @Nullable String userName,
-                             @Nullable String password, @Nullable String message) {
-        super(site, status, userName, password, message);
-    }
-}

app/src/main/java/fr/free/nrw/commons/auth/login/LoginResponse.kt

@@ -0,0 +1,64 @@
+package fr.free.nrw.commons.auth.login
+
+import com.google.gson.annotations.SerializedName
+import fr.free.nrw.commons.auth.login.LoginResult.OAuthResult
+import fr.free.nrw.commons.auth.login.LoginResult.ResetPasswordResult
+import fr.free.nrw.commons.auth.login.LoginResult.Result
+import org.wikipedia.dataclient.WikiSite
+import org.wikipedia.dataclient.mwapi.MwServiceError
+
+class LoginResponse {
+    @SerializedName("error")
+    val error: MwServiceError? = null
+
+    @SerializedName("clientlogin")
+    private val clientLogin: ClientLogin? = null
+
+    fun toLoginResult(site: WikiSite, password: String): LoginResult? {
+        return clientLogin?.toLoginResult(site, password)
+    }
+}
+
+internal class ClientLogin {
+    private val status: String? = null
+    private val requests: List<Request>? = null
+    private val message: String? = null
+
+    @SerializedName("username")
+    private val userName: String? = null
+
+    fun toLoginResult(site: WikiSite, password: String): LoginResult {
+        var userMessage = message
+        if ("UI" == status) {
+            if (requests != null) {
+                for (req in requests) {
+                    if ("MediaWiki\\Extension\\OATHAuth\\Auth\\TOTPAuthenticationRequest" == req.id()) {
+                        return OAuthResult(site, status, userName, password, message)
+                    } else if ("MediaWiki\\Auth\\PasswordAuthenticationRequest" == req.id()) {
+                        return ResetPasswordResult(site, status, userName, password, message)
+                    }
+                }
+            }
+        } else if ("PASS" != status && "FAIL" != status) {
+            //TODO: String resource -- Looks like needed for others in this class too
+            userMessage = "An unknown error occurred."
+        }
+        return Result(site, status ?: "", userName, password, userMessage)
+    }
+}
+
+internal class Request {
+    private val id: String? = null
+    private val required: String? = null
+    private val provider: String? = null
+    private val account: String? = null
+    private val fields: Map<String, RequestField>? = null
+
+    fun id(): String? = id
+}
+
+internal class RequestField {
+    private val type: String? = null
+    private val label: String? = null
+    private val help: String? = null
+}

app/src/main/java/fr/free/nrw/commons/auth/login/LoginResult.java

@@ -1,73 +0,0 @@
-package fr.free.nrw.commons.auth.login;
-
-import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
-
-import org.wikipedia.dataclient.WikiSite;
-
-import java.util.Collections;
-import java.util.Set;
-
-public class LoginResult {
-    @NonNull private final WikiSite site;
-    @NonNull private final String status;
-    @Nullable private final String userName;
-    @Nullable private final String password;
-    @Nullable private final String message;
-
-    private int userId;
-    @NonNull private Set<String> groups = Collections.emptySet();
-
-    public LoginResult(@NonNull WikiSite site, @NonNull String status, @Nullable String userName,
-                @Nullable String password, @Nullable String message) {
-        this.site = site;
-        this.status = status;
-        this.userName = userName;
-        this.password = password;
-        this.message = message;
-    }
-
-    @NonNull public WikiSite getSite() {
-        return site;
-    }
-
-    @NonNull public String getStatus() {
-        return status;
-    }
-
-    public boolean pass() {
-        return "PASS".equals(status);
-    }
-
-    public boolean fail() {
-        return "FAIL".equals(status);
-    }
-
-    @Nullable public String getUserName() {
-        return userName;
-    }
-
-    @Nullable public String getPassword() {
-        return password;
-    }
-
-    @Nullable public String getMessage() {
-        return message;
-    }
-
-    public void setUserId(int id) {
-        this.userId = id;
-    }
-
-    public int getUserId() {
-        return userId;
-    }
-
-    public void setGroups(@NonNull Set<String> groups) {
-        this.groups = groups;
-    }
-
-    @NonNull public Set<String> getGroups() {
-        return groups;
-    }
-}

app/src/main/java/fr/free/nrw/commons/auth/login/LoginResult.kt

@@ -0,0 +1,39 @@
+package fr.free.nrw.commons.auth.login
+
+import org.wikipedia.dataclient.WikiSite
+
+sealed class LoginResult(
+    val site: WikiSite,
+    val status: String,
+    val userName: String?,
+    val password: String?,
+    val message: String?
+) {
+    var userId = 0
+    var groups = emptySet<String>()
+    val pass: Boolean get() = "PASS" == status
+
+    class Result(
+        site: WikiSite,
+        status: String,
+        userName: String?,
+        password: String?,
+        message: String?
+    ): LoginResult(site, status, userName, password, message)
+
+    class OAuthResult(
+        site: WikiSite,
+        status: String,
+        userName: String?,
+        password: String?,
+        message: String?
+    ) : LoginResult(site, status, userName, password, message)
+
+    class ResetPasswordResult(
+        site: WikiSite,
+        status: String,
+        userName: String?,
+        password: String?,
+        message: String?
+    ) : LoginResult(site, status, userName, password, message)
+}

app/src/test/kotlin/fr/free/nrw/commons/auth/login/UserExtendedInfoClientTest.kt

@@ -0,0 +1,78 @@
+package fr.free.nrw.commons.auth.login
+
+import android.net.Uri
+import com.google.gson.GsonBuilder
+import com.google.gson.stream.MalformedJsonException
+import fr.free.nrw.commons.MockWebServerTest
+import io.reactivex.observers.TestObserver
+import org.junit.Before
+import org.junit.Test
+import org.wikipedia.dataclient.WikiSite
+import org.wikipedia.dataclient.mwapi.MwQueryResponse
+import org.wikipedia.json.NamespaceTypeAdapter
+import org.wikipedia.json.PostProcessingTypeAdapter
+import org.wikipedia.json.UriTypeAdapter
+import org.wikipedia.json.WikiSiteTypeAdapter
+import org.wikipedia.page.Namespace
+import retrofit2.Retrofit
+import retrofit2.adapter.rxjava2.RxJava2CallAdapterFactory
+import retrofit2.converter.gson.GsonConverterFactory
+
+class UserExtendedInfoClientTest : MockWebServerTest() {
+    private var apiService: LoginInterface? = null
+    private val observer = TestObserver<MwQueryResponse>()
+    private val gson = GsonBuilder()
+        .registerTypeHierarchyAdapter(Uri::class.java, UriTypeAdapter().nullSafe())
+        .registerTypeHierarchyAdapter(Namespace::class.java, NamespaceTypeAdapter().nullSafe())
+        .registerTypeAdapter(WikiSite::class.java, WikiSiteTypeAdapter().nullSafe())
+        .registerTypeAdapterFactory(PostProcessingTypeAdapter())
+        .create()
+
+    @Before
+    @Throws(Throwable::class)
+    override fun setUp() {
+        super.setUp()
+
+        apiService = Retrofit.Builder()
+            .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
+            .addConverterFactory(GsonConverterFactory.create(gson))
+            .baseUrl(server().url)
+            .build()
+            .create(LoginInterface::class.java)
+    }
+
+    @Test
+    @Throws(Throwable::class)
+    fun testRequestSuccess() {
+        enqueueFromFile("user_extended_info.json")
+
+        apiService!!.getUserInfo("USER").subscribe(observer)
+
+        observer
+            .assertComplete()
+            .assertNoErrors()
+            .assertValue { result: MwQueryResponse ->
+                result.query()!!
+                    .userInfo()!!.id() == 24531888 && result.query()!!.getUserResponse("USER")!!
+                    .name() == "USER"
+            }
+    }
+
+    @Test
+    fun testRequestResponse404() {
+        enqueue404()
+
+        apiService!!.getUserInfo("USER").subscribe(observer)
+
+        observer.assertError(Exception::class.java)
+    }
+
+    @Test
+    fun testRequestResponseMalformed() {
+        enqueueMalformed()
+
+        apiService!!.getUserInfo("USER").subscribe(observer)
+
+        observer.assertError(MalformedJsonException::class.java)
+    }
+}

app/src/test/kotlin/fr/free/nrw/commons/login/UserExtendedInfoClientTest.java

@@ -1,84 +0,0 @@
-package fr.free.nrw.commons.login;
-
-import android.net.Uri;
-import com.google.gson.Gson;
-import com.google.gson.GsonBuilder;
-import com.google.gson.stream.MalformedJsonException;
-import fr.free.nrw.commons.MockWebServerTest;
-import fr.free.nrw.commons.auth.login.LoginInterface;
-import io.reactivex.observers.TestObserver;
-import org.junit.Before;
-import org.junit.Test;
-import org.wikipedia.dataclient.WikiSite;
-import org.wikipedia.dataclient.mwapi.MwQueryResponse;
-import org.wikipedia.json.NamespaceTypeAdapter;
-import org.wikipedia.json.PostProcessingTypeAdapter;
-import org.wikipedia.json.UriTypeAdapter;
-import org.wikipedia.json.WikiSiteTypeAdapter;
-import org.wikipedia.page.Namespace;
-import retrofit2.Retrofit;
-import retrofit2.adapter.rxjava2.RxJava2CallAdapterFactory;
-import retrofit2.converter.gson.GsonConverterFactory;
-
-public class UserExtendedInfoClientTest extends MockWebServerTest {
-
-    private LoginInterface apiService;
-
-    @Override
-    @Before
-    public void setUp() throws Throwable {
-        super.setUp();
-
-        apiService = new Retrofit.Builder()
-            .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
-            .addConverterFactory(GsonConverterFactory.create(getGson()))
-            .baseUrl(server().getUrl())
-            .build()
-            .create(LoginInterface.class);
-    }
-
-    @Test
-    public void testRequestSuccess() throws Throwable {
-        enqueueFromFile("user_extended_info.json");
-        TestObserver<MwQueryResponse> observer = new TestObserver<>();
-
-        apiService.getUserInfo("USER").subscribe(observer);
-
-        observer
-            .assertComplete()
-            .assertNoErrors()
-            .assertValue(
-                result -> result.query().userInfo().id() == 24531888
-                && result.query().getUserResponse("USER").name().equals("USER")
-            );
-    }
-
-    @Test
-    public void testRequestResponse404() {
-        enqueue404();
-        TestObserver<MwQueryResponse> observer = new TestObserver<>();
-
-        apiService.getUserInfo("USER").subscribe(observer);
-
-        observer.assertError(Exception.class);
-    }
-
-    @Test
-    public void testRequestResponseMalformed() {
-        enqueueMalformed();
-        TestObserver<MwQueryResponse> observer = new TestObserver<>();
-
-        apiService.getUserInfo("USER").subscribe(observer);
-
-        observer.assertError(MalformedJsonException.class);
-    }
-
-    private Gson getGson() {
-        return new GsonBuilder()
-            .registerTypeHierarchyAdapter(Uri.class, new UriTypeAdapter().nullSafe())
-            .registerTypeHierarchyAdapter(Namespace.class, new NamespaceTypeAdapter().nullSafe())
-            .registerTypeAdapter(WikiSite.class, new WikiSiteTypeAdapter().nullSafe())
-            .registerTypeAdapterFactory(new PostProcessingTypeAdapter())
-            .create();
-    }
-}