enh: warn user about too many resources in a dataset (close #86)

Author: paulmueller

CHANGELOG

@@ -1,6 +1,7 @@
 0.17.2
  - fix: check for existence of DC resources before starting uploads (#85)
  - enh: sort resources according to internal basin dependencies (#79)
+ - enh: warn user about too many resources in a dataset (#86)
  - ref: use more f-strings
  - ref: add `common.is_dc_file` for consistent resource checks
 0.17.1

dcoraid/gui/upload/dlg_upload.py

@@ -121,7 +121,7 @@ def __init__(self, *args, **kwargs):
         # do not allow to proceed without a title
         self.lineEdit_authors.textChanged.connect(self.on_authors_edited)
         self.on_authors_edited("")  # initial state
-        # if the user changes the preset combobox text, offer him
+        # if the user changes the preset combobox text, offer them
         # to save it as a preset
         self.comboBox_preset.editTextChanged.connect(
             self.on_preset_text_edited)
@@ -314,6 +314,24 @@ def on_proceed(self):
                 "resource.")
             return
 
+        # If the user uploads A LOT of resources in a dataset, we should
+        # warn them about possible performance penalties.
+        max_num_res = 100
+        if len(paths) > max_num_res:
+            choice = QtWidgets.QMessageBox.question(
+                self, "Unusually large number of resources specified",
+                f"You are attempting to upload {len(paths)} resources "
+                f"in one single dataset. Be advised that adding more than "
+                f"{max_num_res} resources to a dataset might affect DCOR "
+                f"performance (listing the resources can be slow).\n\n"
+                f"Too many resources in one dataset may also impair the "
+                f"ability of a human to grasp what you are attempting to "
+                f"share.\n\n"
+                f"Are you sure you want to upload {len(paths)} resources to "
+                f"this dataset? Select 'Yes' to continue with the upload.")
+            if choice != QtWidgets.QMessageBox.StandardButton.Yes:
+                return
+
         # Checking for duplicate resources is the responsibility of
         # DCOR-Aid, because we are skipping existing resources in
         # dcoraid.upload.job.UploadJob.task_upload_resources.