Allow international addresses in spreadsheets

For services with permission, they can now put international addresses
into their spreadsheets without getting a postcode error.

This also means they can start using address line 7 instead of postcode,
since it doesn’t make sense to put a country in a field called
‘postcode’. But this will be undocumented to start with, because we’re
not giving any real users the permission.

It does now mean that the number of possible placeholders (7 + postcode)
is greater than the number of allowed placeholders (7), so we have to
account for that in the one-off address flow where we’re populating the
placeholders automatically. We’re sticking with 6 + postcode here for
backwards compatibility.

app/main/views/send.py

@@ -18,7 +18,10 @@ from notifications_python_client.errors import HTTPError
 from notifications_utils import LETTER_MAX_PAGE_COUNT, SMS_CHAR_COUNT_LIMIT
 from notifications_utils.columns import Columns
 from notifications_utils.pdf import is_letter_too_long
-from notifications_utils.postal_address import PostalAddress
+from notifications_utils.postal_address import (
+    PostalAddress,
+    address_lines_1_to_6_and_postcode_keys,
+)
 from notifications_utils.recipients import RecipientCSV, first_column_headings
 from notifications_utils.sanitise_text import SanitiseASCII
 from xlrd.biffh import XLRDError
@@ -59,6 +62,11 @@ from app.utils import (
     user_has_permissions,
 )
 
+letter_address_columns = [
+    column.replace('_', ' ')
+    for column in address_lines_1_to_6_and_postcode_keys
+]
+
 
 def get_example_csv_fields(column_headers, use_example_as_example, submitted_fields):
     if use_example_as_example:
@@ -77,7 +85,7 @@ def get_example_csv_rows(template, use_example_as_example=True, submitted_fields
             (submitted_fields or {}).get(
                 key, get_example_letter_address(key) if use_example_as_example else key
             )
-            for key in first_column_headings['letter']
+            for key in letter_address_columns
         ]
     }[template.template_type] + get_example_csv_fields(
         (
@@ -364,7 +372,10 @@ def send_one_off_letter_address(service_id, template_id):
         get_normalised_placeholders_from_session()
     )
 
-    form = LetterAddressForm(address=current_session_address.normalised)
+    form = LetterAddressForm(
+        address=current_session_address.normalised,
+        allow_international_letters=current_service.has_permission('international_letters'),
+    )
 
     if form.validate_on_submit():
         session['placeholders'].update(PostalAddress(form.address.data).as_personalisation)
@@ -376,7 +387,8 @@ def send_one_off_letter_address(service_id, template_id):
         if all_placeholders_in_session(placeholders):
             return get_notification_check_endpoint(service_id, template)
 
-        first_non_address_placeholder_index = len(first_column_headings['letter'])
+        first_non_address_placeholder_index = len(address_lines_1_to_6_and_postcode_keys)
+
         return redirect(url_for(
             'main.send_one_off_step',
             service_id=service_id,
@@ -468,7 +480,7 @@ def send_test_step(service_id, template_id, step_index):
 
     # if we're in a letter, we should show address block rather than "address line #" or "postcode"
     if template.template_type == 'letter':
-        if step_index < len(first_column_headings['letter']):
+        if step_index < len(address_lines_1_to_6_and_postcode_keys):
             return redirect(url_for(
                 '.send_one_off_letter_address',
                 service_id=service_id,
@@ -665,7 +677,8 @@ def _check_messages(service_id, template_id, upload_id, preview_row, letters_as_
             [user.name, user.mobile_number, user.email_address] for user in Users(service_id)
         ) if current_service.trial_mode else None,
         remaining_messages=remaining_messages,
-        international_sms=current_service.has_permission('international_sms'),
+        allow_international_sms=current_service.has_permission('international_sms'),
+        allow_international_letters=current_service.has_permission('international_letters'),
     )
 
     if request.args.get('from_test'):
@@ -845,10 +858,12 @@ def go_to_dashboard_after_tour(service_id, example_template_id):
 
 def fields_to_fill_in(template, prefill_current_user=False):
 
-    recipient_columns = first_column_headings[template.template_type]
+    if 'letter' == template.template_type:
+        return letter_address_columns + list(template.placeholders)
+
+    if not prefill_current_user:
+        return first_column_headings[template.template_type] + list(template.placeholders)
 
-    if 'letter' == template.template_type or not prefill_current_user:
-        return recipient_columns + list(template.placeholders)
     if template.template_type == 'sms':
         session['recipient'] = current_user.mobile_number
         session['placeholders']['phone number'] = current_user.mobile_number
@@ -1126,8 +1141,14 @@ def get_sms_sender_from_session():
 def get_spreadsheet_column_headings_from_template(template):
     column_headings = []
 
+    if template.template_type == 'letter':
+        # We want to avoid showing `address line 7` for now
+        recipient_columns = letter_address_columns
+    else:
+        recipient_columns = first_column_headings[template.template_type]
+
     for column_heading in (
-        first_column_headings[template.template_type] + list(template.placeholders)
+        recipient_columns + list(template.placeholders)
     ):
         if column_heading not in Columns.from_keys(column_headings):
             column_headings.append(column_heading)