Allow deleting default letter contact blocks

It’s possible to delete default letter contact blocks because there is a
fallback – having a blank letter contact block. This is different to SMS
senders and reply to addresses.

For this to make sense it also means:
- adding the ‘blank’ letter contact block to the list of letter contact
  blocks
- having a way of setting the default back to being blank

app/main/views/service_settings.py

@@ -755,11 +755,10 @@ def service_edit_letter_contact(service_id, letter_contact_id):
     if request.method == 'GET':
         form.is_default.data = letter_contact_block['is_default']
     if form.validate_on_submit():
-        service_api_client.update_letter_contact(
-            current_service.id,
-            letter_contact_id=letter_contact_id,
+        current_service.edit_letter_contact_block(
+            id=letter_contact_id,
             contact_block=form.letter_contact_block.data.replace('\r', '') or None,
-            is_default=True if letter_contact_block['is_default'] else form.is_default.data
+            is_default=letter_contact_block['is_default'] or form.is_default.data
         )
         return redirect(url_for('.service_letter_contact_details', service_id=service_id))
 
@@ -771,6 +770,13 @@ def service_edit_letter_contact(service_id, letter_contact_id):
         letter_contact_id=letter_contact_block['id'])
 
 
+@main.route("/services/<service_id>/service-settings/letter-contact/make-blank-default")
+@user_has_permissions('manage_service')
+def service_make_blank_default_letter_contact(service_id):
+    current_service.remove_default_letter_contact_block()
+    return redirect(url_for('.service_letter_contact_details', service_id=service_id))
+
+
 @main.route(
     "/services/<service_id>/service-settings/letter-contact/<letter_contact_id>/delete",
     methods=['POST'],

app/models/service.py

@@ -1,5 +1,7 @@
-from flask import abort, current_app
+from flask import Markup, abort, current_app
 from notifications_utils.field import Field
+from notifications_utils.formatters import nl2br
+from notifications_utils.take import Take
 from werkzeug.utils import cached_property
 
 from app.models import JSONModel
@@ -324,11 +326,36 @@ class Service(JSONModel):
     def default_letter_contact_block(self):
         return next(
             (
-                Field(x['contact_block'], html='escape')
-                for x in self.letter_contact_details if x['is_default']
+                letter_contact_block
+                for letter_contact_block in self.letter_contact_details
+                if letter_contact_block['is_default']
             ), None
         )
 
+    @property
+    def default_letter_contact_block_html(self):
+        if self.default_letter_contact_block:
+            return Markup(Take(Field(
+                self.default_letter_contact_block['contact_block'],
+                html='escape',
+            )).then(
+                nl2br
+            ))
+        return ''
+
+    def edit_letter_contact_block(self, id, contact_block, is_default):
+        service_api_client.update_letter_contact(
+            self.id, letter_contact_id=id, contact_block=contact_block, is_default=is_default,
+        )
+
+    def remove_default_letter_contact_block(self):
+        if self.default_letter_contact_block:
+            self.edit_letter_contact_block(
+                self.default_letter_contact_block['id'],
+                self.default_letter_contact_block['contact_block'],
+                is_default=False,
+            )
+
     def get_letter_contact_block(self, id):
         return service_api_client.get_letter_contact(self.id, id)
 

app/navigation.py

@@ -260,6 +260,7 @@ class HeaderNavigation(Navigation):
         'service_email_reply_to',
         'service_letter_contact_details',
         'service_letter_validation_preview',
+        'service_make_blank_default_letter_contact',
         'service_name_change',
         'service_name_change_confirm',
         'service_preview_email_branding',
@@ -390,6 +391,7 @@ class MainNavigation(Navigation):
             'service_edit_sms_sender',
             'service_email_reply_to',
             'service_letter_contact_details',
+            'service_make_blank_default_letter_contact',
             'service_name_change',
             'service_name_change_confirm',
             'service_preview_email_branding',
@@ -787,6 +789,7 @@ class CaseworkNavigation(Navigation):
         'service_email_reply_to',
         'service_letter_contact_details',
         'service_letter_validation_preview',
+        'service_make_blank_default_letter_contact',
         'service_name_change',
         'service_name_change_confirm',
         'service_preview_email_branding',
@@ -1059,6 +1062,7 @@ class OrgNavigation(Navigation):
         'service_email_reply_to',
         'service_letter_contact_details',
         'service_letter_validation_preview',
+        'service_make_blank_default_letter_contact',
         'service_name_change',
         'service_name_change_confirm',
         'service_preview_email_branding',

app/templates/views/service-settings.html

@@ -213,8 +213,14 @@
 
         {% call settings_row(if_has_permission='letter') %}
           {{ text_field('Sender addresses') }}
-          {% call field(status='default' if current_service.default_letter_contact_block == None else '') %}
-            {{ current_service.default_letter_contact_block | string | nl2br | safe if current_service.default_letter_contact_block else 'Not set'}}
+          {% call field(status='' if current_service.count_letter_contact_details else 'default') %}
+            {% if current_service.default_letter_contact_block %}
+              {{ current_service.default_letter_contact_block_html }}
+            {% elif current_service.count_letter_contact_details %}
+              Blank
+            {% else %}
+              Not set
+            {% endif %}
             {% if current_service.count_letter_contact_details > 1 %}
               <div class="hint">
                 {{ '…and %d more' | format(current_service.count_letter_contact_details - 1) }}

app/templates/views/service-settings/letter-contact-details.html

@@ -17,11 +17,18 @@
     ) }}
   </div>
   <div class="user-list">
-    {% if not letter_contact_details %}
-      <div class="user-list-item">
-        <span class="hint">You haven’t added any letter contact details yet</span>
-      </div>
-    {% endif %}
+    <div class="user-list-item">
+      <span class="hint">
+        Blank
+        {% if current_service.default_letter_contact_block %}
+          {% if current_user.has_permissions('manage_service') %}
+            <a class="user-list-edit-link" href="{{ url_for('.service_make_blank_default_letter_contact', service_id =current_service.id) }}">Make default</a>
+          {% endif %}
+        {% else %}
+          (default)
+        {% endif %}
+      </span>
+    </div>
     {% for item in letter_contact_details %}
       <div class="user-list-item">
         <p>

app/templates/views/service-settings/letter-contact/edit.html

@@ -24,20 +24,24 @@
       rows=10,
       highlight_tags=True
     ) }}
+
+
     {% if form.is_default.data %}
       <p class="form-group">
-        This is currently your default address for {{ current_service.name }}
+        This is the default address for {{ current_service.name }}
       </p>
     {% else %}
       <div class="form-group">
         {{ checkbox(form.is_default) }}
       </div>
     {% endif %}
+
     {{ page_footer(
       'Save',
       delete_link=url_for('.service_confirm_delete_letter_contact', service_id=current_service.id, letter_contact_id=letter_contact_id),
       delete_link_text='Delete'
     ) }}
+
   {% endcall %}
 
 {% endblock %}