Implement extracting exactly the selected files.

* src/vorta/borg/extract.py (BorgExtractJob.prepare): Use `patterns-from` to include only the selected items.

src/vorta/borg/extract.py

@@ -1,4 +1,9 @@
-from vorta.views.extract_dialog import ExtractTree
+import tempfile
+
+from PyQt5.QtCore import QModelIndex, Qt
+
+from vorta.views.extract_dialog import ExtractTree, FileData
+from vorta.views.partials.treemodel import FileSystemItem, path_to_str
 
 from .borg_job import BorgJob
 
@@ -15,7 +20,7 @@ def finished_event(self, result):
         self.app.backup_progress_event.emit(self.tr('Restored files from archive.'))
 
     @classmethod
-    def prepare(cls, profile, archive_name, selected_files: ExtractTree, destination_folder):
+    def prepare(cls, profile, archive_name, model: ExtractTree, destination_folder):
         ret = super().prepare(profile)
         if not ret['ok']:
             return ret
@@ -25,8 +30,30 @@ def prepare(cls, profile, archive_name, selected_files: ExtractTree, destination
         cmd = ['borg', 'extract', '--list', '--info', '--log-json']
         cmd.append(f'{profile.repo.url}::{archive_name}')
 
-        for s in selected_files: # TODO
-            cmd.append(s)
+        # process selected items
+        # all items will be excluded beside the one actively selected in the
+        # dialog.
+        # Unselected (and excluded) parent folders will be restored by borg
+        # but without the metadata stored in the archive.
+        pattern_file = tempfile.NamedTemporaryFile('w', delete=False)
+        pattern_file.write("P fm\n")
+
+        indexes = [QModelIndex()]
+        while indexes:
+            index = indexes.pop()
+
+            for i in range(model.rowCount(index)):
+                new_index = model.index(i, 0, index)
+                indexes.append(new_index)
+
+                item: FileSystemItem[FileData] = new_index.internalPointer()
+                if item.data.checkstate == Qt.CheckState.Checked:
+                    pattern_file.write("+ " + path_to_str(item.path) + "\n")
+
+        pattern_file.write("- *\n")
+        pattern_file.flush()
+        pattern_file.close()  # wont delete temp file
+        cmd.extend(['--patterns-from', pattern_file.name])
 
         ret['ok'] = True
         ret['cmd'] = cmd
@@ -34,5 +61,5 @@ def prepare(cls, profile, archive_name, selected_files: ExtractTree, destination
 
         return ret
 
-    def process_result(self, result):
+    def process_result(self, result: dict):
         pass