Add get_counterparty_name utility

crm/utils/counterparty_name.py

@@ -0,0 +1,67 @@
+from email.utils import parseaddr
+from django.db.models import CharField
+from django.db.models import Q
+from django.db.models import Subquery
+from django.db.models import Value
+from django.db.models.functions import Coalesce
+from django.db.models.functions import Concat
+
+from crm.models import Contact
+from crm.models import Company
+from crm.models import CrmEmail
+from crm.models import Lead
+
+
+def get_counterparty_name(email: CrmEmail) -> str:
+    """
+    If the email address (the first one if the address list)
+    does not contain a recipient name, then performs a search
+    and returns the name of the first match among
+    Contact, Lead, and Company.
+    """
+    if email.sent:
+        addresses = email.to or email.cc
+    else:
+        addresses = email.from_field
+    address_list = addresses.split(",")
+    name, email_addr = parseaddr(address_list.pop(0))
+    if not name:
+        email_params = Q(email__icontains=email_addr)
+        email_params |= Q(secondary_email__icontains=email_addr)
+        func = Concat(
+            "first_name", 
+            Value(" "),
+            "last_name",
+            output_field=CharField()
+        )
+        contact = Contact.objects.filter(email_params).annotate(
+            full_name=func
+        )
+        lead = Lead.objects.filter(email_params).annotate(
+            full_name=func
+        )
+        company = Company.objects.filter(email__icontains=email)
+        name = CrmEmail.objects.filter(id=email.id).annotate(
+            contact_name=Subquery(contact.values(
+                "full_name")[:1],
+                output_field=CharField()
+            ),
+            lead_name=Subquery(
+                lead.values("full_name")[:1],
+                output_field=CharField()
+            ),
+            company_name=Subquery(
+                company.values("full_name")[:1],
+                output_field=CharField()
+            )
+        ).annotate(
+            full_name=Coalesce(
+                "contact_name",
+                "lead_name",
+                "company_name"
+            )
+        ).first().full_name
+        if name:
+            address_list.insert(0, f"{name} <{email_addr}>")
+            addresses = ",".join(address_list)
+    return addresses