Make basemap export not fail anymore when package already exists

Update libqfieldsync/offline_converter.py

Co-authored-by: Ivan Ivanov <[email protected]>

Update libqfieldsync/offline_converter.py

Co-authored-by: Ivan Ivanov <[email protected]>

Update libqfieldsync/offline_converter.py

Co-authored-by: Ivan Ivanov <[email protected]>

Apply suggestion from @suricactus

Author: gounux

Diff for: libqfieldsync/offline_converter.py

@@ -607,7 +607,6 @@ def _export_basemap_as_mbtiles(
         """
         Exports a basemap to mbtiles format.
         This method handles several zoom levels.
-        This should be preferred over the legacy `_export_basemap_as_tiff` method.
 
         Args:
             extent (QgsRectangle): extent of the area of interest
@@ -623,12 +622,14 @@ def _export_basemap_as_mbtiles(
             .createAlgorithmById("native:tilesxyzmbtiles")
         )
 
+        basemap_export_path = self._export_filename.with_name("basemap.mbtiles")
+
         params = {
             "EXTENT": extent,
             "ZOOM_MIN": self.project_configuration.base_map_tiles_min_zoom_level,
             "ZOOM_MAX": self.project_configuration.base_map_tiles_max_zoom_level,
             "TILE_SIZE": 256,
-            "OUTPUT_FILE": str(self._export_filename.with_name("basemap.mbtiles")),
+            "OUTPUT_FILE": str(basemap_export_path),
         }
 
         # clone current QGIS project
@@ -686,6 +687,10 @@ def _export_basemap_as_mbtiles(
         # we use a try clause to make sure the feedback's `progressChanged` signal
         # is disconnected in the finally clause.
         try:
+            # if the basemap file already exists on target destination,
+            # the `native:tilesxyzmbtiles` alg will throw an error.
+            basemap_export_path.unlink(missing_ok=True)
+
             results, ok = alg.run(params, context, self._feedback)
 
             if not ok: