Implement payment backends and interaction

Advances #3 (closed)

aleksis/apps/tezor/rules.py

 import rules
+from payments import PaymentStatus
+
+from aleksis.core.util.predicates import has_person, has_global_perm, has_any_object, has_object_perm, is_site_preference_set
 
 from .models.base import Client
 from .models.invoice import Invoice, InvoiceGroup
-
-from aleksis.core.util.predicates import has_person, has_global_perm, has_any_object, has_object_perm
+from .predicates import has_no_payment_variant, is_own_invoice, is_in_payment_status
 
 # View clients
 view_clients_predicate = has_person & (
@@ -65,8 +67,25 @@ delete_invoice_groups_predicate = has_person & (
 )
 rules.add_perm("tezor.delete_invoice_groups_rule", delete_invoice_groups_predicate)
 
+# Display invoice billing information
+display_billing_predicate = has_person & (is_own_invoice | has_global_perm("tezor.display_billing") | has_object_perm("tezor.display_billing"))
+rules.add_perm("tezor.display_billing_rule", display_billing_predicate)
+
+# Display invoice purchased items
+display_purchased_items_predicate = has_person & (is_own_invoice | has_global_perm("tezor.display_purchased_items") | has_object_perm("tezor.display_purchased_items"))
+rules.add_perm("tezor.display_purchased_items_rule", display_purchased_items_predicate)
+
+# Change payment variant
+change_payment_variant_predicate = has_person & is_in_payment_status(PaymentStatus.WAITING) & ((is_own_invoice & has_no_payment_variant) | has_global_perm("tezor.change_payment_variant") | has_object_perm("tezor.change_payment_variant"))
+rules.add_perm("tezor.change_payment_variant", change_payment_variant_predicate)
+
+# Start payment
+do_payment_predicate = has_person & (is_in_payment_status(PaymentStatus.WAITING) | is_in_payment_status(PaymentStatus.INPUT) | is_in_payment_status(PaymentStatus.ERROR) | is_in_payment_status(PaymentStatus.REJECTED)) & ((is_own_invoice | is_site_preference_set("payments", "public_payments")) | has_global_perm("tezor.do_payment") | has_object_perm("tezor.do_payment"))
+rules.add_perm("tezor.do_payment", do_payment_predicate)
+
 # View invoice
-view_invoice_predicate = has_person & (
-    has_global_perm("tezor.view_invoice") | has_object_perm("tezor.view_invoice")
-)
+view_invoice_predicate = has_person & is_own_invoice | is_site_preference_set("payments", "public_payments") | has_global_perm("tezor.view_invoice") | has_object_perm("tezor.view_invoice")
 rules.add_perm("tezor.view_invoice_rule", view_invoice_predicate)
+
+print_invoice_predicate = (view_invoice_predicate & display_billing_predicate & display_purchased_items_predicate)
+rules.add_perm("tezor.print_invoice_rule", print_invoice_predicate)