frontend: don't send new create project task if project is deleting

wait for the end of the deletion of project to avoid race condition when fork is called immidiatelly after delete

frontend/coprs_frontend/coprs/logic/complex_logic.py

@@ -1,13 +1,14 @@
 # coding: utf-8
-
 import os
 import datetime
 import time
 import fnmatch
 import flask
 import sqlalchemy
 
-from copr_common.enums import StatusEnum
+from sqlalchemy import and_
+
+from copr_common.enums import StatusEnum, ActionTypeEnum, BackendResultEnum, ActionObjectTypeEnum
 from coprs import app
 from coprs import db
 from coprs import helpers
@@ -125,6 +126,47 @@ def delete_expired_projects(cls):
                 print(e)
                 print("project {} postponed".format(copr.full_name))
 
+    @staticmethod
+    def _refresh_waiting_actions(actions_to_refresh):
+        for action_to_refresh in actions_to_refresh:
+            db.session.refresh(action_to_refresh)
+
+        blocking_actions = []
+        for action in actions_to_refresh:
+            if action.result == BackendResultEnum("waiting"):
+                blocking_actions.append(action)
+
+        return blocking_actions
+
+    @classmethod
+    def _wait_for_copr_to_be_deleted(cls, ownername, dirname):
+        actions_to_wait = (
+            models.Action.query
+            .filter(models.Action.object_type == ActionObjectTypeEnum.copr)
+            .filter(models.Action.result == BackendResultEnum("waiting"))
+            .filter(models.Action.action_type == ActionTypeEnum("delete"))
+            .filter(
+                and_(
+                    models.Action.data.contains(ownername),
+                    models.Action.data.contains(dirname)
+                )
+            )
+        ).all()
+
+        # if a project is in deleting state for a day, it's bad, right?
+        for _ in range(3600):
+            blocking_actions = cls._refresh_waiting_actions(actions_to_wait)
+            if not blocking_actions:
+                app.logger.info(
+                    f"No blocking actions for project {ownername}/{dirname} so far. Forking..."
+                )
+                return
+
+            app.logger.info(
+                f"Blocking delete actions: {blocking_actions} to wait for project:"
+                f" {ownername}/{dirname}"
+            )
+            time.sleep(60)
 
     @classmethod
     def fork_copr(cls, copr, user, dstname, dstgroup=None):
@@ -133,6 +175,8 @@ def fork_copr(cls, copr, user, dstname, dstgroup=None):
         created = (not bool(forking.get(copr, dstname)))
         fcopr = forking.fork_copr(copr, dstname)
 
+        cls._wait_for_copr_to_be_deleted(fcopr.owner_name, fcopr.name)
+
         if fcopr.full_name == copr.full_name:
             raise exceptions.DuplicateException("Source project should not be same as destination")