Update exportadmins manage cmd to export write access

app/django/timetables/management/commands/exportadmins.py

@@ -20,10 +20,12 @@
 import csv
 import sys
 import argparse
+import itertools
 
 from django.contrib.auth.models import User
 
 from timetables.utils import manage_commands
+from timetables import models
 
 
 ADMIN_PERM_CODENAME = "is_admin"
@@ -41,10 +43,39 @@ def __init__(self):
             formatter_class=argparse.ArgumentDefaultsHelpFormatter
         )
 
+        subparsers = self.parser.add_subparsers(help="Export type")
+        read_access = subparsers.add_parser(
+            "read-access",
+            help="Export CSV list of CRSIDs with access to view admin area")
+        read_access.set_defaults(func=self.handle_read_access)
+        write_access = subparsers.add_parser(
+            "write-access",
+            help="Export CSV list of CRSIDs with subjects they can edit")
+        write_access.set_defaults(func=self.handle_write_access)
+
     def handle(self, args):
+        # Dispatch to correct handler for subcommand
+        args.func()
+
+    def handle_write_access(self):
+        admin_users = self.get_admins()
+
+        editable_subjects = self.get_editable_subjects_by_crsid(self.get_subjects())
+
+        admin_write_access = (
+            (user.username, subject.get_most_significant_thing().fullpath,
+             unicode(subject))
+            for user in admin_users
+            if user.username in editable_subjects
+            for subject in editable_subjects[user.username])
+
+        csv.writer(sys.stdout).writerows(admin_write_access)
+
+    def handle_read_access(self):
         admin_users = self.get_admins()
 
-        admin_usernames = ((user.username,) for user in admin_users)
+        admin_usernames = ((user.username,)
+            for user in admin_users)
 
         csv.writer(sys.stdout).writerows(admin_usernames)
 
@@ -53,3 +84,39 @@ def get_admins(self):
             user_permissions__codename=ADMIN_PERM_CODENAME,
             user_permissions__content_type__app_label=ADMIN_PERM_APP_LABEL)
             .order_by("username"))
+
+    def get_subjects(self):
+        return models.Subjects.all_subjects()
+
+    @classmethod
+    def subjects_by_thing_id(cls, subjects):
+        return dict(
+            (models.Thing.hash(sub.get_most_significant_thing().fullpath), sub)
+            for sub in subjects)
+
+    def get_editable_subjects_by_crsid(self, subjects):
+        """
+        Get a dict mapping CRSIDs to a set of subjects they can edit.
+        """
+
+        subjects_by_thing = self.subjects_by_thing_id(subjects)
+
+        edit_perms = models.ThingTag.objects.filter(
+                annotation="admin",
+                targetthing__pathid__in=subjects_by_thing.keys()
+            ).values_list('thing__name', 'targetthing__pathid')
+
+        # Map pathids back to subjects
+        user_editable_subjects = (
+            (crsid, subjects_by_thing[pathid])
+            for (crsid, pathid) in edit_perms
+            if pathid in subjects_by_thing
+        )
+
+        # Group subjects
+        by_user = itertools.groupby(sorted(user_editable_subjects),
+                                    lambda (crsid, _): crsid)
+
+        return dict(
+            (crsid, set(sub for (_, sub) in group))
+            for (crsid, group) in by_user)