add more properties to CustomerHostingPackage

- add get_hostingoptions method and property hostingoptions
- add get_package_space method to determine disk space provided by the
  hosting package itself
- add get_databases_flat and property databases to get a list of databases
  assigned to the hosting package
- add may_add_database to determine whether additional databases are allowed
  by the hosting package's options

gnuviechadmin/hostingpackages/models.py

@@ -21,7 +21,10 @@ from osusers.models import (
     Group,
     User as OsUser,
 )
-from userdbs.models import DB_TYPES
+from userdbs.models import (
+    DB_TYPES,
+    UserDatabase,
+)
 
 
 DISK_SPACE_UNITS = Choices(
@@ -236,12 +239,25 @@ class CustomerHostingPackage(HostingPackageBase):
         for attrname in ('diskspace', 'diskspace_unit', 'mailboxcount'):
             setattr(self, attrname, getattr(self.template, attrname))
 
+    def get_hostingoptions(self):
+        opts = []
+        for opt_type in [
+            CustomerDiskSpaceOption,
+            CustomerMailboxOption,
+            CustomerUserDatabaseOption
+        ]:
+            opts.extend(opt_type.objects.filter(hosting_package=self))
+        return opts
+    hostingoptions = property(get_hostingoptions)
+
     def get_disk_space(self, unit=None):
         """
         Get the total disk space reserved for this hosting package and all its
         additional disk space options.
 
-        :return: disk space
+        :param unit: value from :py:data:`DISK_SPACE_UNITS` or :py:const:`None`
+        :return: disk space in unit or bytes (if parameter unit is
+            :py:const:`None`)
         :rtype: int
 
         """
@@ -267,6 +283,25 @@ class CustomerHostingPackage(HostingPackageBase):
             return DISK_SPACE_FACTORS[unit][min_unit] * diskspace
         return DISK_SPACE_FACTORS[min_unit][unit] * diskspace
 
+    def get_package_space(self, unit=None):
+        """
+        Get the total disk space reserved for this package without looking at
+        any additional dis space options.
+
+        :param unit: value from :py:data:`DISK_SPACE_UNITS` or :py:const:`None`
+        :return: disk space in unit or bytes (if parameter unit is
+            :py:const:`None`)
+        :rtype: int
+
+        """
+        if unit is None:
+            return (DISK_SPACE_FACTORS[self.diskspace_unit][0] *
+                    self.diskspace * 1024**2)
+        if unit > self.diskspace_unit:
+            return (DISK_SPACE_FACTORS[unit][self.diskspace_unit] *
+                    self.diskspace)
+        return DISK_SPACE_FACTORS[self.diskspace_unit][unit] * self.diskspace
+
     def get_quota(self):
         soft = 1024 * self.get_disk_space(DISK_SPACE_UNITS.M)
         hard = soft * 105 / 100
@@ -316,6 +351,21 @@ class CustomerHostingPackage(HostingPackageBase):
             number=models.Sum('number')
         ).all()
 
+    def get_databases_flat(self):
+        if self.osuser:
+            return UserDatabase.objects.filter(
+                db_user__osuser=self.osuser).all()
+    databases = property(get_databases_flat)
+
+    def may_add_database(self):
+        return (
+            CustomerUserDatabaseOption.objects.filter(
+            hosting_package=self).count()
+            >
+            UserDatabase.objects.filter(
+                db_user__osuser=self.osuser).count()
+        )
+
     @transaction.atomic
     def save(self, *args, **kwargs):
         """