add offline account supportHEADtom

I added the offline patch from my MultiMC repo[1]. The only change I
made compared to my fork was adding an extra sentence in the account
adder dialog that the password needs to be blank for an offline
account.

Signed-off-by: Shokara <shokara@snopyta.org>

6 files changed, 136 insertions, 101 deletions

diff --git a/api/logic/minecraft/MinecraftInstance.cpp b/api/logic/minecraft/MinecraftInstance.cpp
index 28073edf..4617b09f 100644
--- a/api/logic/minecraft/MinecraftInstance.cpp
+++ b/api/logic/minecraft/MinecraftInstance.cpp
@@ -821,7 +821,7 @@ shared_qobject_ptr<LaunchTask> MinecraftInstance::createLaunchTask(AuthSessionPt
     }
     else
     {
-        process->appendStep(new Update(pptr, Net::Mode::Offline));
+	process->appendStep(new Update(pptr, Net::Mode::Online));
     }
 
     // if there are any jar mods
diff --git a/api/logic/minecraft/auth/MojangAccount.cpp b/api/logic/minecraft/auth/MojangAccount.cpp
index 657e0009..28f31266 100644
--- a/api/logic/minecraft/auth/MojangAccount.cpp
+++ b/api/logic/minecraft/auth/MojangAccount.cpp
@@ -19,6 +19,7 @@
 #include "flows/RefreshTask.h"
 #include "flows/AuthenticateTask.h"
 
+#include <QCryptographicHash>
 #include <QUuid>
 #include <QJsonObject>
 #include <QJsonArray>
@@ -103,6 +104,20 @@ MojangAccountPtr MojangAccount::createFromUsername(const QString &username)
     return account;
 }
 
+MojangAccountPtr MojangAccount::createFromUsernameOffline(const QString &username)
+{
+    MojangAccountPtr account(new MojangAccount());
+    account->m_clientToken = "ff64ff64ff64ff64ff64ff64ff64ff64";
+    account->m_accessToken = "ff64ff64ff64ff64ff64ff64ff64ff64";
+    account->m_username = username;
+    QList<AccountProfile> profiles;
+    QString uuid = QCryptographicHash::hash(username.toLocal8Bit(), QCryptographicHash::Md5).toHex();
+    profiles.append({uuid, username, false});
+    account->m_profiles = profiles;
+    account->setCurrentProfile(uuid);
+    return account;
+}
+
 QJsonObject MojangAccount::saveToJson() const
 {
     QJsonObject json;
diff --git a/api/logic/minecraft/auth/MojangAccount.h b/api/logic/minecraft/auth/MojangAccount.h
index 7006435e..92679076 100644
--- a/api/logic/minecraft/auth/MojangAccount.h
+++ b/api/logic/minecraft/auth/MojangAccount.h
@@ -77,6 +77,9 @@ public: /* construction */
     //! Creates an empty account for the specified user name.
     static MojangAccountPtr createFromUsername(const QString &username);
 
+    //! Creates an offline account for the specified user name.
+    static MojangAccountPtr createFromUsernameOffline(const QString &username);
+
     //! Loads a MojangAccount from the given JSON object.
     static MojangAccountPtr loadFromJson(const QJsonObject &json);
 
diff --git a/application/LaunchController.cpp b/application/LaunchController.cpp
index e39048f1..b6916027 100644
--- a/application/LaunchController.cpp
+++ b/application/LaunchController.cpp
@@ -78,112 +78,122 @@ void LaunchController::login()
         return;
     }
 
-    // we try empty password first :)
-    QString password;
-    // we loop until the user succeeds in logging in or gives up
-    bool tryagain = true;
-    // the failure. the default failure.
-    const QString needLoginAgain = tr("Your account is currently not logged in. Please enter "
-                            "your password to log in again.");
-    QString failReason = needLoginAgain;
-
-    while (tryagain)
-    {
-        m_session = std::make_shared<AuthSession>();
-        m_session->wants_online = m_online;
-        auto task = account->login(m_session, password);
-        if (task)
+    if(account->clientToken() != "ff64ff64ff64ff64ff64ff64ff64ff64") {
+        // Online
+        // we try empty password first :)
+        QString password;
+        // we loop until the user succeeds in logging in or gives up
+        bool tryagain = true;
+        // the failure. the default failure.
+        const QString needLoginAgain = tr("Your account is currently not logged in. Please enter your password to log in again. <br /> <br /> This could be caused by a password change.");
+        QString failReason = needLoginAgain;
+	while (tryagain)
         {
-            // We'll need to validate the access token to make sure the account
-            // is still logged in.
-            ProgressDialog progDialog(m_parentWidget);
-            if (m_online)
-            {
-                progDialog.setSkipButton(true, tr("Play Offline"));
-            }
-            progDialog.execWithTask(task.get());
-            if (!task->wasSuccessful())
+            m_session = std::make_shared<AuthSession>();
+            m_session->wants_online = m_online;
+            auto task = account->login(m_session, password);
+            if (task)
             {
-                auto failReasonNew = task->failReason();
-                if(failReasonNew == "Invalid token.")
+                // We'll need to validate the access token to make sure the account
+                // is still logged in.
+                ProgressDialog progDialog(m_parentWidget);
+                if (m_online)
                 {
-                    account->invalidateClientToken();
-                    failReason = needLoginAgain;
+                     progDialog.setSkipButton(true, tr("Play Offline"));
                 }
-                else failReason = failReasonNew;
-            }
-        }
-        switch (m_session->status)
-        {
-        case AuthSession::Undetermined:
-        {
-            qCritical() << "Received undetermined session status during login. Bye.";
-            tryagain = false;
-            emitFailed(tr("Received undetermined session status during login."));
-            break;
-        }
-        case AuthSession::RequiresPassword:
-        {
-            EditAccountDialog passDialog(failReason, m_parentWidget, EditAccountDialog::PasswordField);
-            auto username = m_session->username;
-            auto chopN = [](QString toChop, int N) -> QString
-            {
-                if(toChop.size() > N)
+                progDialog.execWithTask(task.get());
+                if (!task->wasSuccessful())
                 {
-                    auto left = toChop.left(N);
-                    left += QString("\u25CF").repeated(toChop.size() - N);
-                    return left;
+                    auto failReasonNew = task->failReason();
+                    if(failReasonNew == "Invalid token.")
+                    {
+                        account->invalidateClientToken();
+                        failReason = needLoginAgain;
+                    }
+                    else failReason = failReasonNew;
                 }
-                return toChop;
-            };
-
-            if(username.contains('@'))
-            {
-                auto parts = username.split('@');
-                auto mailbox = chopN(parts[0],3);
-                QString domain = chopN(parts[1], 3);
-                username = mailbox + '@' + domain;
             }
-            passDialog.setUsername(username);
-            if (passDialog.exec() == QDialog::Accepted)
+            switch (m_session->status)
             {
-                password = passDialog.password();
-            }
-            else
+            case AuthSession::Undetermined:
             {
+                qCritical() << "Received undetermined session status during login. Bye.";
                 tryagain = false;
+                emitFailed(tr("Received undetermined session status during login."));
+                break;
             }
-            break;
-        }
-        case AuthSession::PlayableOffline:
-        {
-            // we ask the user for a player name
-            bool ok = false;
-            QString usedname = m_session->player_name;
-            QString name = QInputDialog::getText(m_parentWidget, tr("Player name"),
-                                                 tr("Choose your offline mode player name."),
-                                                 QLineEdit::Normal, m_session->player_name, &ok);
-            if (!ok)
+            case AuthSession::RequiresPassword:
             {
-                tryagain = false;
+                EditAccountDialog passDialog(failReason, m_parentWidget, EditAccountDialog::PasswordField);
+                auto username = m_session->username;
+                auto chopN = [](QString toChop, int N) -> QString
+                {
+                    if(toChop.size() > N)
+                    {
+                        auto left = toChop.left(N);
+                        left += QString("\u25CF").repeated(toChop.size() - N);
+                        return left;
+                    }
+                    return toChop;
+                };
+
+                if(username.contains('@'))
+                {
+                    auto parts = username.split('@');
+                    auto mailbox = chopN(parts[0],3);
+                    QString domain = chopN(parts[1], 3);
+                    username = mailbox + '@' + domain;
+                }
+                passDialog.setUsername(username);
+                if (passDialog.exec() == QDialog::Accepted)
+                {
+                    password = passDialog.password();
+                }
+                else
+                {
+                    tryagain = false;
+                }
                 break;
             }
-            if (name.length())
+            case AuthSession::PlayableOffline:
             {
-                usedname = name;
+                // we ask the user for a player name
+                bool ok = false;
+                QString usedname = m_session->player_name;
+                QString name = QInputDialog::getText(m_parentWidget, tr("Player name"),
+                                                     tr("Choose your offline mode player name."),
+                                                     QLineEdit::Normal, m_session->player_name, &ok);
+                if (!ok)
+                {
+                    tryagain = false;
+                    break;
+                }
+                if (name.length())
+                {
+                    usedname = name;
+                }
+                m_session->MakeOffline(usedname);
+                // offline flavored game from here :3
+            }
+            case AuthSession::PlayableOnline:
+            {
+                launchInstance();
+                tryagain = false;
+                return;
+            }
             }
-            m_session->MakeOffline(usedname);
-            // offline flavored game from here :3
-        }
-        case AuthSession::PlayableOnline:
-        {
-            launchInstance();
-            tryagain = false;
-            return;
-        }
         }
+        emitFailed(tr("Failed to launch."));
+    }else{
+        // Offline
+        m_session = std::make_shared<AuthSession>();
+        m_session->client_token = account->clientToken();
+        m_session->access_token = account->accessToken();
+        m_session->uuid = account->currentProfile()->id;
+        m_session->status = AuthSession::PlayableOffline;
+        m_session->MakeOffline(account->currentProfile()->name);
+        launchInstance();
     }
-    emitFailed(tr("Failed to launch."));
 }
 
 void LaunchController::launchInstance()
diff --git a/application/dialogs/LoginDialog.cpp b/application/dialogs/LoginDialog.cpp
index 484cb8e2..a74b898d 100644
--- a/application/dialogs/LoginDialog.cpp
+++ b/application/dialogs/LoginDialog.cpp
@@ -41,15 +41,22 @@ void LoginDialog::accept()
     setUserInputsEnabled(false);
     ui->progressBar->setVisible(true);
 
-    // Setup the login task and start it
-    m_account = MojangAccount::createFromUsername(ui->userTextBox->text());
-    m_loginTask = m_account->login(nullptr, ui->passTextBox->text());
-    connect(m_loginTask.get(), &Task::failed, this, &LoginDialog::onTaskFailed);
-    connect(m_loginTask.get(), &Task::succeeded, this,
-            &LoginDialog::onTaskSucceeded);
-    connect(m_loginTask.get(), &Task::status, this, &LoginDialog::onTaskStatus);
-    connect(m_loginTask.get(), &Task::progress, this, &LoginDialog::onTaskProgress);
-    m_loginTask->start();
+    if(!ui->passTextBox->text().isEmpty()){
+        // Online mode
+        // Setup the login task and start it
+        m_account = MojangAccount::createFromUsername(ui->userTextBox->text());
+        m_loginTask = m_account->login(nullptr, ui->passTextBox->text());
+        connect(m_loginTask.get(), &Task::failed, this, &LoginDialog::onTaskFailed);
+        connect(m_loginTask.get(), &Task::succeeded, this,
+                &LoginDialog::onTaskSucceeded);
+        connect(m_loginTask.get(), &Task::status, this, &LoginDialog::onTaskStatus);
+        connect(m_loginTask.get(), &Task::progress, this, &LoginDialog::onTaskProgress);
+        m_loginTask->start();
+    }else{
+        // Offline mode
+        m_account = MojangAccount::createFromUsernameOffline(ui->userTextBox->text());
+        QDialog::accept();
+    }
 }
 
 void LoginDialog::setUserInputsEnabled(bool enable)
@@ -63,12 +70,12 @@ void LoginDialog::setUserInputsEnabled(bool enable)
 void LoginDialog::on_userTextBox_textEdited(const QString &newText)
 {
     ui->buttonBox->button(QDialogButtonBox::Ok)
-        ->setEnabled(!newText.isEmpty() && !ui->passTextBox->text().isEmpty());
+        ->setEnabled(!newText.isEmpty());
 }
 void LoginDialog::on_passTextBox_textEdited(const QString &newText)
 {
     ui->buttonBox->button(QDialogButtonBox::Ok)
-        ->setEnabled(!newText.isEmpty() && !ui->userTextBox->text().isEmpty());
+        ->setEnabled(!ui->userTextBox->text().isEmpty());
 }
 
 void LoginDialog::onTaskFailed(const QString &reason)
diff --git a/application/pages/global/AccountListPage.cpp b/application/pages/global/AccountListPage.cpp
index c14134f3..240fa33a 100644
--- a/application/pages/global/AccountListPage.cpp
+++ b/application/pages/global/AccountListPage.cpp
@@ -104,7 +104,7 @@ void AccountListPage::listChanged()
 void AccountListPage::on_actionAdd_triggered()
 {
     addAccount(tr("Please enter your Mojang or Minecraft account username and password to add "
-                  "your account."));
+                  "your account.\nLeave password blank for an offline account."));
 }
 
 void AccountListPage::on_actionRemove_triggered()