Add nir control key computation function to utils.

calebasse/utils.py

@@ -53,3 +53,22 @@ def is_validator(user):
     if validator_group in user.groups.all():
         return True
     return False
+
+def get_nir_control_key(nir):
+    try:
+        # Corse dpt 2A et 2B
+        minus = 0
+        if nir[6] in ('A', 'a'):
+            nir = [c for c in nir]
+            nir[6] = '0'
+            nir = ''.join(nir)
+            minus = 1000000
+        elif nir[6] in ('B', 'b'):
+            nir = [c for c in nir]
+            nir[6] = '0'
+            nir = ''.join(nir)
+            minus = 2000000
+        nir = int(nir) - minus
+        return (97 - (nir % 97))
+    except:
+        return None