stripe: Use a common email template for internal billing notices.

This is a prep commit which replaces the 'invoice_overdue'
and 'reminder_to_review_plan' email templates with
'internal_billing_notice'.

This will help us to use the same template as we plan to
send an email to sales when a remote realm with paid plan
attached is locally deleted.

corporate/lib/stripe.py

@@ -4859,9 +4859,10 @@ def invoice_plans_as_needed(event_time: Optional[datetime] = None) -> None:
                     "billing_entity": billing_session.billing_entity_display_name,
                     "end_date": plan.end_date.strftime("%Y-%m-%d"),
                     "support_url": billing_session.support_url(),
+                    "notice_reason": "fixed_price_plan_ends_soon",
                 }
                 send_email(
-                    "zerver/emails/reminder_to_review_plan",
+                    "zerver/emails/internal_billing_notice",
                     to_emails=[BILLING_SUPPORT_EMAIL],
                     from_address=FromAddress.tokenized_no_reply_address(),
                     context=context,
@@ -4881,9 +4882,10 @@ def invoice_plans_as_needed(event_time: Optional[datetime] = None) -> None:
                     context = {
                         "support_url": billing_session.support_url(),
                         "last_audit_log_update": last_audit_log_update_string,
+                        "notice_reason": "invoice_overdue",
                     }
                     send_email(
-                        "zerver/emails/invoice_overdue",
+                        "zerver/emails/internal_billing_notice",
                         to_emails=[BILLING_SUPPORT_EMAIL],
                         from_address=FromAddress.tokenized_no_reply_address(),
                         context=context,

templates/zerver/emails/internal_billing_notice.html

@@ -1,7 +1,12 @@
 {% extends "zerver/emails/email_base_default.html" %}
 
 {% block content %}
+
+{% if notice_reason == "fixed_price_plan_ends_soon" %}
 <p>Reminder to re-evaluate the pricing and configure a new fixed-price plan accordingly.</p>
+{% elif notice_reason == "invoice_overdue" %}
+<b>Last data upload</b>: {{ last_audit_log_update }}
+{% endif %}
 
 <br /><br />
 

templates/zerver/emails/internal_billing_notice.subject.txt

@@ -0,0 +1,5 @@
+{% if notice_reason == "fixed_price_plan_ends_soon" %}
+Fixed-price plan for {{billing_entity}} ends on {{end_date}}
+{% elif notice_reason == "invoice_overdue" %}
+Invoice overdue due to stale data
+{% endif %}

templates/zerver/emails/internal_billing_notice.txt

@@ -0,0 +1,7 @@
+{% if notice_reason == "fixed_price_plan_ends_soon" %}
+Reminder to re-evaluate the pricing and configure a new fixed-price plan accordingly.
+{% elif notice_reason == "invoice_overdue" %}
+Last data upload: {{ last_audit_log_update }}
+{% endif %}
+
+Support URL: {{ support_url }}

templates/zerver/emails/invoice_overdue.html

@@ -1,10 +0,0 @@
-{% extends "zerver/emails/email_base_default.html" %}
-
-{% block content %}
-<b>Support URL</b>: <a href="{{ support_url }}">{{ support_url }}</a>
-
-<br /><br />
-
-<b>Last data upload</b>: {{ last_audit_log_update }}
-
-{% endblock %}

templates/zerver/emails/invoice_overdue.subject.txt

@@ -1 +0,0 @@
-Invoice overdue due to stale data

templates/zerver/emails/invoice_overdue.txt

@@ -1,3 +0,0 @@
-Support URL: {{ support_url }}
-
-Last data upload: {{ last_audit_log_update }}

templates/zerver/emails/reminder_to_review_plan.subject.txt

@@ -1 +0,0 @@
-Fixed-price plan for {{billing_entity}} ends on {{end_date}}

templates/zerver/emails/reminder_to_review_plan.txt

@@ -1,3 +0,0 @@
-Reminder to re-evaluate the pricing and configure a new fixed-price plan accordingly.
-
-Support URL: {{ support_url }}