add undo last commit feature

app/src/main/java/me/sheimi/android/activities/SheimiFragmentActivity.java

@@ -159,6 +159,12 @@ public void showMessageDialog(int title, String msg) {
                 .setPositiveButton(R.string.label_ok, new DummyDialogListener()).show();
     }
 
+    public void showMessageDialog(int title, int msg) {
+        AlertDialog.Builder builder = new AlertDialog.Builder(this);
+        builder.setTitle(title).setMessage(getString(msg))
+            .setPositiveButton(R.string.label_ok, new DummyDialogListener()).show();
+    }
+
     public void showOptionsDialog(int title,final int option_names,
                                   final onOptionDialogClicked[] option_listeners) {
         CharSequence[] options_values = getResources().getStringArray(option_names);

app/src/main/java/me/sheimi/sgit/activities/delegate/RepoOperationDelegate.java

@@ -28,6 +28,7 @@
 import me.sheimi.sgit.activities.delegate.actions.RemoveRemoteAction;
 import me.sheimi.sgit.activities.delegate.actions.RepoAction;
 import me.sheimi.sgit.activities.delegate.actions.ResetAction;
+import me.sheimi.sgit.activities.delegate.actions.UndoAction;
 import me.sheimi.sgit.database.models.Repo;
 import me.sheimi.sgit.repo.tasks.SheimiAsyncTask.AsyncTaskPostCallback;
 import me.sheimi.sgit.repo.tasks.repo.AddToStageTask;
@@ -55,6 +56,7 @@ private void initActions() {
         mActions.add(new PushAction(mRepo, mActivity));
         mActions.add(new AddAllAction(mRepo, mActivity));
         mActions.add(new CommitAction(mRepo, mActivity));
+        mActions.add(new UndoAction(mRepo, mActivity));
         mActions.add(new ResetAction(mRepo, mActivity));
         mActions.add(new MergeAction(mRepo, mActivity));
         mActions.add(new FetchAction(mRepo, mActivity));

app/src/main/java/me/sheimi/sgit/activities/delegate/actions/UndoAction.java

@@ -0,0 +1,64 @@
+package me.sheimi.sgit.activities.delegate.actions;
+
+import android.content.DialogInterface;
+
+import org.eclipse.jgit.api.errors.GitAPIException;
+import org.eclipse.jgit.revwalk.RevCommit;
+
+import java.util.Iterator;
+
+import me.sheimi.sgit.R;
+import me.sheimi.sgit.activities.RepoDetailActivity;
+import me.sheimi.sgit.database.models.Repo;
+import me.sheimi.sgit.exception.StopTaskException;
+import me.sheimi.sgit.repo.tasks.SheimiAsyncTask.AsyncTaskPostCallback;
+import me.sheimi.sgit.repo.tasks.repo.UndoCommitTask;
+
+public class UndoAction extends RepoAction {
+
+    public UndoAction(Repo repo, RepoDetailActivity activity) {
+        super(repo, activity);
+    }
+
+    @Override
+    public void execute() {
+        boolean firstCommit = true;
+        boolean noCommit = true;
+        try {
+            Iterator<RevCommit> logIt = mRepo.getGit().log().call().iterator();
+            noCommit = !logIt.hasNext();
+            if (!noCommit) {
+                logIt.next();
+                firstCommit = !logIt.hasNext();
+            }
+        } catch (GitAPIException | StopTaskException e) {
+            e.printStackTrace();
+        }
+        if (noCommit) {
+            mActivity.showMessageDialog(R.string.dialog_undo_commit_title, R.string.dialog_undo_no_commit_msg);
+        } else if (firstCommit) {
+            mActivity.showMessageDialog(R.string.dialog_undo_commit_title, R.string.dialog_undo_first_commit_msg);
+        } else {
+            mActivity.showMessageDialog(R.string.dialog_undo_commit_title,
+                R.string.dialog_undo_commit_msg, R.string.action_undo,
+                new DialogInterface.OnClickListener() {
+                    @Override
+                    public void onClick(DialogInterface dialogInterface, int i) {
+                        undo();
+                    }
+                });
+        }
+        mActivity.closeOperationDrawer();
+    }
+
+    public void undo() {
+        UndoCommitTask undoTask = new UndoCommitTask(mRepo,
+            new AsyncTaskPostCallback() {
+                @Override
+                public void onPostExecute(Boolean isSuccess) {
+                    mActivity.reset();
+                }
+            });
+        undoTask.executeTask();
+    }
+}

app/src/main/java/me/sheimi/sgit/repo/tasks/repo/UndoCommitTask.java

@@ -0,0 +1,44 @@
+package me.sheimi.sgit.repo.tasks.repo;
+
+import org.eclipse.jgit.api.ResetCommand;
+
+import me.sheimi.sgit.R;
+import me.sheimi.sgit.database.models.Repo;
+import me.sheimi.sgit.exception.StopTaskException;
+
+public class UndoCommitTask extends RepoOpTask {
+
+    private AsyncTaskPostCallback mCallback;
+
+    public UndoCommitTask(Repo repo, AsyncTaskPostCallback callback) {
+        super(repo);
+        mCallback = callback;
+        setSuccessMsg(R.string.success_undo);
+    }
+
+    @Override
+    protected Boolean doInBackground(Void... params) {
+        return undo();
+    }
+
+    protected void onPostExecute(Boolean isSuccess) {
+        super.onPostExecute(isSuccess);
+        if (mCallback != null) {
+            mCallback.onPostExecute(isSuccess);
+        }
+    }
+
+    public boolean undo() {
+        try {
+            mRepo.getGit().getRepository().writeMergeCommitMsg(null);
+            mRepo.getGit().getRepository().writeMergeHeads(null);
+            mRepo.getGit().reset().setRef("HEAD~").setMode(ResetCommand.ResetType.SOFT).call();
+        } catch (StopTaskException e) {
+            return false;
+        } catch (Throwable e) {
+            setException(e);
+            return false;
+        }
+        return true;
+    }
+}

app/src/main/res/values-de/arrays.xml

@@ -21,6 +21,7 @@
         <item>Push</item>
         <item>Alles zum Staging-Bereich hinzufügen</item>
         <item>Commit</item>
+        <item>Undo Last Commit</item>
         <item>Reset (HARD)</item>
         <item>Merge</item>
         <item>Fetch</item>

app/src/main/res/values-es/arrays.xml

@@ -19,6 +19,7 @@
         <item>Empujar</item>
         <item>Anadir todo a stage</item>
         <item>Commit</item>
+        <item>Undo Last Commit</item>
         <item>Reset (DURO)</item>
         <item>Merge</item>
         <item>Fetch</item>

app/src/main/res/values-fr/arrays.xml

@@ -21,6 +21,7 @@
         <item>Pousser</item>
         <item>Ajouter tout au stage</item>
         <item>Commit</item>
+        <item>Undo Last Commit</item>
         <item>Reset (HARD)</item>
         <item>Merge</item>
         <item>Fetch</item>

app/src/main/res/values-iw/arrays.xml

@@ -20,7 +20,8 @@
     <item>דחוף</item>
     <item>הוסף את כולם לשלב</item>
     <item>Commit</item>
-    <item>Reset (HARD)</item>
+      <item>Undo Last Commit</item>
+      <item>Reset (HARD)</item>
     <item>מיזוג</item>
     <item>Fetch</item>
     <item>Rebase</item>

app/src/main/res/values-ja/arrays.xml

@@ -21,6 +21,7 @@
         <item>プッシュ</item>
         <item>すべてステージに追加</item>
         <item>コミット</item>
+        <item>Undo Last Commit</item>
         <item>Reset (HARD)</item>
         <item>マージ</item>
         <item>Fetch</item>

app/src/main/res/values-ko/arrays.xml

@@ -19,6 +19,7 @@
         <item>Push</item>
         <item>Add all to stage</item>
         <item>Commit</item>
+        <item>Undo Last Commit</item>
         <item>Reset (HARD)</item>
         <item>Merge</item>
         <item>Fetch</item>

app/src/main/res/values-ru/arrays.xml

@@ -19,6 +19,7 @@
         <item>Загрузить</item>
         <item>Добавить все</item>
         <item>Закоммитить</item>
+        <item>Undo Last Commit</item>
         <item>СБРОС</item>
         <item>Слитие</item>
         <item>Обновить в новую ветку</item>

app/src/main/res/values-zh-rCN/arrays.xml

@@ -21,6 +21,7 @@
         <item>推送</item>
         <item>暂存所有</item>
         <item>提交</item>
+        <item>撤销上次提交</item>
         <item>重置（强制）</item>
         <item>合并</item>
         <item>获取</item>

app/src/main/res/values-zh-rCN/strings.xml

@@ -31,6 +31,7 @@
     <string name="action_share_diff">分享 diff</string>
     <string name="action_save_diff">保存 diff</string>
     <string name="action_send_report">发送报告</string>
+    <string name="action_undo">撤销</string>
 
     <!-- label msg -->
     <string name="label_ok">确定</string>
@@ -192,4 +193,5 @@
     <string name="error_file_not_found">File not found!</string>
     <string name="dialog_access_all_files_title">所有文件的访问</string>
     <string name="dialog_access_all_files_msg">请允许访问所有文件以从外部存储读取/写入存储库。</string>
+
 </resources>

app/src/main/res/values-zh-rCN/strings_dialog.xml

@@ -60,4 +60,9 @@
     <string name="dialog_fetch_positive_button">抓取</string>
     <string name="dialog_fetch_all_button">抓取所有</string>
 
+    <!-- Undo -->
+    <string name="dialog_undo_commit_msg">您确定要撤销上次提交吗？</string>
+    <string name="dialog_undo_commit_title">撤销上次提交</string>
+    <string name="dialog_undo_no_commit_msg">没有历史提交！</string>
+    <string name="dialog_undo_first_commit_msg">首次提交无法撤销！</string>
 </resources>

app/src/main/res/values-zh-rCN/strings_success_msg.xml

@@ -13,5 +13,6 @@
     <string name="success_save">文件成功保存</string>
     <string name="msg_now_you_can_edit">文件可以被编辑</string>
     <string name="msg_commit_str_has_copied">已复制添加的 Hash 值</string>
+    <string name="success_undo">上次提交已被撤销</string>
 
 </resources>

app/src/main/res/values/arrays.xml

@@ -21,6 +21,7 @@
         <item>Push</item>
         <item>Add all to stage</item>
         <item>Commit</item>
+        <item>Undo Last Commit</item>
         <item>Reset (HARD)</item>
         <item>Merge</item>
         <item>Fetch</item>

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

@@ -33,6 +33,7 @@
     <string name="action_share_diff">Share diff</string>
     <string name="action_save_diff">Save diff</string>
     <string name="action_send_report">Send report</string>
+    <string name="action_undo">Undo</string>
 
     <!-- label msg -->
     <string name="label_ok">OK</string>

app/src/main/res/values/strings_dialog.xml

@@ -60,4 +60,10 @@
     <string name="dialog_fetch_positive_button">Fetch</string>
     <string name="dialog_fetch_all_button">Fetch All</string>
 
+    <!-- Undo -->
+    <string name="dialog_undo_commit_title">Undo Last Commit</string>
+    <string name="dialog_undo_commit_msg">Are you sure you want to undo last commit?</string>
+    <string name="dialog_undo_no_commit_msg">No commit to undo!</string>
+    <string name="dialog_undo_first_commit_msg">Cannot undo the initial commit!</string>
+
 </resources>

app/src/main/res/values/strings_success_msg.xml

@@ -13,5 +13,6 @@
     <string name="success_save">File saved Successfully</string>
     <string name="msg_now_you_can_edit">File can be edited</string>
     <string name="msg_commit_str_has_copied">Commit hash has been copied</string>
+    <string name="success_undo">Last commit have been undone</string>
 
 </resources>