From 3d0882295b0298624cedfb7d91769d3d11a3cdb0 Mon Sep 17 00:00:00 2001
From: Patrizio Bekerle <patrizio@bekerle.com>
Date: Thu, 13 Feb 2020 16:31:46 +0100
Subject: [PATCH] Automatically remove duplicate conflicted notes.sqlite
 database files (#1625)

---
 CHANGELOG.md                     |  5 +++++
 src/mainwindow.cpp               | 27 ++++++++++++++++++++-------
 src/services/databaseservice.cpp | 25 +++++++++++++++++++++++++
 src/services/databaseservice.h   |  3 ++-
 src/utils/misc.cpp               | 28 ++++++++++++++++++++++++++++
 src/utils/misc.h                 |  2 ++
 6 files changed, 82 insertions(+), 8 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9720276c0c..1c2391aaf1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 # QOwnNotes Changelog
 
+## 20.2.4
+- conflicted copies of the note folder database `notes.sqlite` are now
+  immediately deleted if they are not different to the current `notes.sqlite`
+  (for [#1625](https://github.com/pbek/QOwnNotes/issues/1625))
+
 ## 20.2.3
 - improved Setext-style headers highlighting with leading spaces
   (for [#101](https://github.com/pbek/qmarkdowntextedit/issues/101), thank you @Waqar144)
diff --git a/src/mainwindow.cpp b/src/mainwindow.cpp
index 9450712913..3706a2d4ea 100644
--- a/src/mainwindow.cpp
+++ b/src/mainwindow.cpp
@@ -3251,9 +3251,28 @@ void MainWindow::removeConflictedNotesDatabaseCopies() {
     QDirIterator it(NoteFolder::currentLocalPath(), filter,
                     QDir::AllEntries | QDir::NoSymLinks | QDir::NoDotAndDotDot);
     auto files = QStringList();
+    const QSignalBlocker blocker(this->noteDirectoryWatcher);
+    Q_UNUSED(blocker)
+
+    // we try to fix problems with the blocker
+    directoryWatcherWorkaround(true);
 
     while (it.hasNext()) {
-        files << it.next();
+        const QString &file = it.next();
+
+        // check if conflicted database copy is the same as the current note
+        // folder database
+        if (Utils::Misc::isSameFile(
+                file, DatabaseService::getNoteFolderDatabasePath())) {
+            showStatusBarMessage(
+                tr(QFile::remove(file)
+                       ? "Removed duplicate conflicted database: %1"
+                       : "Could not remove duplicate conflicted database: %1")
+                    .arg(file),
+                4000);
+        } else {
+            files << file;
+        }
     }
 
     int count = files.count();
@@ -3276,12 +3295,6 @@ void MainWindow::removeConflictedNotesDatabaseCopies() {
         return;
     }
 
-    const QSignalBlocker blocker(this->noteDirectoryWatcher);
-    Q_UNUSED(blocker)
-
-    // we try to fix problems with the blocker
-    directoryWatcherWorkaround(true);
-
     count = 0;
 
     // remove the database files
diff --git a/src/services/databaseservice.cpp b/src/services/databaseservice.cpp
index e6c156c09e..0bd96b309f 100644
--- a/src/services/databaseservice.cpp
+++ b/src/services/databaseservice.cpp
@@ -835,3 +835,28 @@ QString DatabaseService::getAppData(const QString& name,
 
     return QString();
 }
+
+/**
+ * WIP
+ *
+ * @param path
+ * @return
+ */
+bool DatabaseService::mergeNoteFolderDatabase(QString path) {
+    QSqlDatabase mergeDB = QSqlDatabase::addDatabase(
+        QStringLiteral("QSQLITE"), QStringLiteral("note_folder_merge"));
+    mergeDB.setDatabaseName(path);
+
+    if (!mergeDB.open()) {
+        QMessageBox::critical(
+            nullptr, QWidget::tr("Cannot open database"),
+            QWidget::tr("Unable to establish a database connection with "
+                        "note folder database to merge '%1'.\nAre the folder "
+                        "and the file writeable?")
+                .arg(path),
+            QMessageBox::Ok);
+        return false;
+    }
+
+    return true;
+}
diff --git a/src/services/databaseservice.h b/src/services/databaseservice.h
index 2f62f49d77..ddbd82659b 100644
--- a/src/services/databaseservice.h
+++ b/src/services/databaseservice.h
@@ -22,11 +22,12 @@ class DatabaseService {
     static QSqlDatabase getNoteFolderDatabase();
     static void closeDatabaseConnection(const QSqlDatabase& db,
                                         QSqlQuery& query);
+    static QString getNoteFolderDatabasePath();
 
    private:
-    static QString getNoteFolderDatabasePath();
     static bool createMemoryConnection();
     static bool createDiskConnection();
+    static bool mergeNoteFolderDatabase(QString path);
 };
 
 #endif    // DATABASESERVICE_H
diff --git a/src/utils/misc.cpp b/src/utils/misc.cpp
index d4b39834b9..4bef4808f2 100644
--- a/src/utils/misc.cpp
+++ b/src/utils/misc.cpp
@@ -1939,3 +1939,31 @@ QString Utils::Misc::localDictionariesPath() {
     dir.mkpath(path);
     return path;
 }
+
+/**
+ * Generates a SHA1 signature for a file
+ *
+ * @return
+ */
+QByteArray Utils::Misc::generateFileSha1Signature(const QString &path) {
+    QCryptographicHash hash(QCryptographicHash::Sha1);
+    QFile file(path);
+
+    if (file.open(QIODevice::ReadOnly)) {
+        hash.addData(file.readAll());
+    } else {
+        return QByteArray();
+    }
+
+    // retrieve the SHA1 signature of the file
+    return hash.result();
+}
+
+/**
+ * Checks if two files are the same
+ *
+ * @return
+ */
+bool Utils::Misc::isSameFile(const QString &path1, const QString &path2) {
+    return generateFileSha1Signature(path1) == generateFileSha1Signature(path2);
+}
diff --git a/src/utils/misc.h b/src/utils/misc.h
index 0ee43b277f..422f48a974 100644
--- a/src/utils/misc.h
+++ b/src/utils/misc.h
@@ -128,6 +128,8 @@ QString remotePreviewImageTagToInlineImageTag(QString imageTag,
                                               int &imageWidth);
 QString createUuidString();
 QString localDictionariesPath();
+QByteArray generateFileSha1Signature(const QString &path);
+bool isSameFile(const QString &path1, const QString &path2);
 }    // namespace Misc
 }    // namespace Utils