Remove the wrong error message and made the program exit if no session is found

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

src/pilgrim/service/backup_service.py

@@ -0,0 +1,36 @@
+import sqlite3
+import zipfile
+from pathlib import Path
+
+
+from pilgrim.utils.directory_manager import DirectoryManager
+
+
+class BackupService:
+    def __init__(self, session):
+        self.session = session
+
+    def create_backup(self):
+        db_path = DirectoryManager.get_database_path()
+        if not db_path.exists():
+            raise FileNotFoundError("No Database Found")
+
+        with self.session.connection() as conn:
+            raw_conn = conn.connection
+            dump = "\n".join(line for line in raw_conn.iterdump())
+
+        filename = DirectoryManager.get_config_directory() / "backup.zip"
+        diaries_root_path = DirectoryManager.get_diaries_root()
+
+        try:
+            with zipfile.ZipFile(filename, "w",zipfile.ZIP_DEFLATED) as zipf:
+                zipf.writestr("database.sql", dump)
+                if diaries_root_path.exists():
+                    for file_path in diaries_root_path.rglob('*'):
+                        if file_path.is_file():
+                            arcname = file_path.relative_to(diaries_root_path.parent)
+                            zipf.write(file_path, arcname=arcname)
+                return True, filename
+        except Exception as e:
+            return False, str(e)
+

src/pilgrim/ui/screens/diary_list_screen.py

@@ -14,6 +14,8 @@ from pilgrim.ui.screens.edit_diary_modal import EditDiaryModal
 from pilgrim.ui.screens.new_diary_modal import NewDiaryModal
 from pilgrim.ui.screens.edit_entry_screen import EditEntryScreen
 
+from pilgrim.service.backup_service import BackupService
+
 
 class DiaryListScreen(Screen):
     TITLE = "Pilgrim - Main"
@@ -298,3 +300,18 @@ class DiaryListScreen(Screen):
                 self.notify("Invalid diary ID")
         else:
             self.notify("Select a diary to open the settings")
+
+
+    def action_backup(self):
+        session = self.app.service_manager.get_session()
+        if session:
+            backup_service = BackupService(session)
+            result_operation, result_data = backup_service.create_backup()
+            if result_operation:
+                self.notify(f"Backup result: {result_data}")
+            else:
+                self.notify(f"Error performing backup: {result_data}")
+        else:
+            self.notify("Error: Session not found",severity="error")
+            self.app.exit()
+

src/pilgrim/ui/ui.py

@@ -37,6 +37,11 @@ class UIApp(App):
                 "Open About Pilgrim",
                 screen.action_about_cmd
             )
+            yield SystemCommand(
+                "Backup Database",
+                "Backup the Database",
+                screen.action_backup
+            )
 
         elif isinstance(screen, AboutScreen):
             yield SystemCommand(