chore(access): planning work for centurion Tenancy model

ref: #765 #766

app/access/models/tenancy_abstract.py

@@ -0,0 +1,172 @@
+import logging
+
+from django.core.exceptions import (
+    ValidationError,
+)
+from django.db import models
+
+from access.models.tenant import Tenant
+
+
+
+class TenancyManager(
+    models.Manager
+):
+    """Multi-Tennant Object Manager
+
+    This manager specifically caters for the multi-tenancy features of Centurion ERP.
+    """
+
+    def get_queryset(self):
+        """ Fetch the data
+
+        When the model contains the user data, the query is filtered to their
+        and the globally defined Tenancy only.
+
+        Returns:
+            (queryset): **super user**: return unfiltered data.
+            (queryset): **not super user**: return data from the stored unique organizations.
+        """
+
+        # user = None    # When CenturionUser in use
+
+        # if hasattr(self.model, 'context'):
+
+        #     user = self.model.context['user']
+
+
+        # if user:
+
+        #     tencies = user.get_tenancies(int_list = True)
+
+        #     if len(tenancies) > 0 and not request.user.is_superuser:
+
+        #         if hasattr(self.model, 'organization'):
+        #             return super().get_queryset().select_related('organization').filter(
+        #                 models.Q(organization__in = tenancies)
+        #             )
+
+        #         return super().get_queryset().select_related('organization').filter(
+        #             models.Q(organization__in = tenancies)
+        #         )
+
+        request = None
+
+        if hasattr(self.model, 'context'):
+
+            request = self.model.context['request']
+
+        if request is not None:
+
+            tenancies: list(str()) = []
+
+            if request.app_settings.global_organization:
+
+                tenancies += [ request.app_settings.global_organization.id ]
+
+
+            if request.user.is_authenticated:
+
+                for team in request.tenancy._user_teams:
+
+                    if team.organization.id in tenancies:
+                        continue
+
+                    tenancies += [ team.organization.id ]
+
+
+                if len(tenancies) > 0 and not request.user.is_superuser:
+
+                    if hasattr(self.model, 'organization'):
+                        return super().get_queryset().select_related('organization').filter(
+                            models.Q(organization__in = tenancies)
+                        )
+
+                    return super().get_queryset().select_related('organization').filter(
+                        models.Q(organization__in = tenancies)
+                    )
+
+        return super().get_queryset().select_related('organization')
+
+
+
+class TenancyAbstractModel(
+    models.Model,
+):
+    """ Tenancy Model Abstract class.
+
+    This class is for inclusion within **every** model within Centurion ERP.
+    Provides the required fields, functions and methods for multi tennant objects.
+    Unless otherwise stated, **no** object within this class may be overridden.
+
+    Raises:
+        ValidationError: User failed to supply organization
+    """
+
+    objects = TenancyManager()
+    """ Multi-Tenanant Objects """
+
+    class Meta:
+        abstract = True
+
+
+    def validatate_organization_exists(self):
+        """Ensure that the user did provide an organization
+
+        Raises:
+            ValidationError: User failed to supply organization.
+        """
+
+        if not self:
+            raise ValidationError(
+                code = 'required',
+                message = 'You must provide an organization'
+            )
+
+
+    id = models.AutoField(
+        blank=False,
+        help_text = 'ID of the item',
+        primary_key=True,
+        unique=True,
+        verbose_name = 'ID'
+    )
+
+    organization = models.ForeignKey(
+        Tenant,
+        blank = False,
+        help_text = 'Tenant this belongs to',
+        null = False,
+        on_delete = models.CASCADE,
+        related_name = '+',
+        validators = [
+            validatate_organization_exists
+        ],
+        verbose_name = 'Tenant'
+    )
+
+    is_global = models.BooleanField(
+        blank = False,
+        default = False,
+        help_text = 'Is this a global object?',
+        null = False,
+        verbose_name = 'Global Object'
+    )
+
+    model_notes = models.TextField(
+        blank = True,
+        default = None,                            # ToDo: Remove this field
+        help_text = 'Tid bits of information',
+        null = True,
+        verbose_name = 'Notes',
+    )
+
+
+
+    def get_tenant(self) -> Tenant:
+        """ Return the models Tenancy
+
+        This model can be safely over-ridden as long as it returns the models
+        tenancy
+        """
+        return self.organization