Add page to create new letter branding

This has a form with 3 fields - the file upload field, logo name, and an
optional logo domain. Logos need to be uploaded in `.svg` format and we
then convert this to `.png` format and upload both file types to S3 as
well as saving the letter branding details in the database.

app/main/__init__.py

@@ -29,6 +29,7 @@ from app.main.views import (  # noqa
     find_users,
     platform_admin,
     email_branding,
+    letter_branding,
     conversation,
     organisations,
     notifications,

app/main/forms.py

@@ -851,6 +851,21 @@ class ServiceUpdateEmailBranding(StripWhitespaceForm):
             raise ValidationError('This field is required')
 
 
+class SVGFileUpload(StripWhitespaceForm):
+    file = FileField_wtf(
+        'Upload an SVG logo',
+        validators=[
+            FileAllowed(['svg'], 'SVG Images only!'),
+            DataRequired(message="You need to upload a file to submit")
+        ]
+    )
+
+
+class ServiceLetterBrandingDetails(StripWhitespaceForm):
+    name = StringField('Name of brand', validators=[DataRequired()])
+    domain = GovernmentDomainField('Domain')
+
+
 class PDFUploadForm(StripWhitespaceForm):
     file = FileField_wtf(
         'Upload a letter in PDF format to check if it fits in the printable area',

app/main/views/letter_branding.py

@@ -0,0 +1,103 @@
+from flask import (
+    current_app,
+    redirect,
+    render_template,
+    request,
+    session,
+    url_for,
+)
+from flask_login import login_required
+from requests import get as requests_get
+
+from app import letter_branding_client
+from app.main import main
+from app.main.forms import ServiceLetterBrandingDetails, SVGFileUpload
+from app.s3_client.s3_logo_client import (
+    LETTER_TEMP_TAG,
+    delete_letter_temp_file,
+    delete_letter_temp_files_created_by,
+    get_letter_filename_with_no_path_or_extension,
+    letter_filename_for_db,
+    permanent_letter_logo_name,
+    persist_logo,
+    upload_letter_png_logo,
+    upload_letter_temp_logo,
+)
+from app.utils import get_logo_cdn_domain, user_is_platform_admin
+
+
+@main.route("/letter-branding/create", methods=['GET', 'POST'])
+@main.route("/letter-branding/create/<path:logo>", methods=['GET', 'POST'])
+@login_required
+@user_is_platform_admin
+def create_letter_branding(logo=None):
+    file_upload_form = SVGFileUpload()
+    letter_branding_details_form = ServiceLetterBrandingDetails()
+
+    file_upload_form_submitted = file_upload_form.file.data
+    details_form_submitted = request.form.get('operation') == 'branding-details'
+
+    if file_upload_form_submitted and file_upload_form.validate_on_submit():
+        upload_filename = upload_letter_temp_logo(
+            file_upload_form.file.data.filename,
+            file_upload_form.file.data,
+            current_app.config['AWS_REGION'],
+            user_id=session["user_id"]
+        )
+
+        if logo and logo.startswith(LETTER_TEMP_TAG.format(user_id=session['user_id'])):
+            delete_letter_temp_file(logo)
+
+        return redirect(url_for('.create_letter_branding', logo=upload_filename))
+
+    if details_form_submitted and letter_branding_details_form.validate_on_submit():
+        if logo:
+            db_filename = letter_filename_for_db(logo, session['user_id'])
+
+            letter_branding_client.create_letter_branding(
+                filename=db_filename,
+                name=letter_branding_details_form.name.data,
+                domain=letter_branding_details_form.domain.data,
+            )
+
+            png_file = get_png_file_from_svg(logo)
+
+            persist_logo(logo, permanent_letter_logo_name(db_filename, 'svg'))
+
+            upload_letter_png_logo(
+                permanent_letter_logo_name(db_filename, 'png'),
+                png_file,
+                current_app.config['AWS_REGION'],
+            )
+
+            delete_letter_temp_files_created_by(session['user_id'])
+
+            # TODO: redirect to all letter branding page once it exists
+            return redirect(url_for('main.platform_admin'))
+
+        # Show error on upload form if trying to submit with no logo
+        file_upload_form.validate()
+
+    return render_template(
+        'views/letter-branding/manage-letter-branding.html',
+        file_upload_form=file_upload_form,
+        letter_branding_details_form=letter_branding_details_form,
+        cdn_url=get_logo_cdn_domain(),
+        logo=logo
+    )
+
+
+def get_png_file_from_svg(filename):
+    filename_for_template_preview = get_letter_filename_with_no_path_or_extension(filename)
+
+    template_preview_svg_endpoint = '{}/{}.svg.png'.format(
+        current_app.config['TEMPLATE_PREVIEW_API_HOST'],
+        filename_for_template_preview
+    )
+
+    response = requests_get(
+        template_preview_svg_endpoint,
+        headers={'Authorization': 'Token {}'.format(current_app.config['TEMPLATE_PREVIEW_API_KEY'])}
+    )
+
+    return response.content

app/navigation.py

@@ -75,6 +75,7 @@ class HeaderNavigation(Navigation):
         'platform-admin': {
             'add_organisation',
             'create_email_branding',
+            'create_letter_branding',
             'email_branding',
             'find_users_by_email',
             'live_services',
@@ -405,6 +406,7 @@ class MainNavigation(Navigation):
         'conversation_updates',
         'cookies',
         'create_email_branding',
+        'create_letter_branding',
         'data_retention',
         'delete_template_folder',
         'delivery_and_failure',
@@ -583,6 +585,7 @@ class CaseworkNavigation(Navigation):
         'copy_template',
         'create_api_key',
         'create_email_branding',
+        'create_letter_branding',
         'data_retention',
         'delete_service_template',
         'delete_template_folder',
@@ -817,6 +820,7 @@ class OrgNavigation(Navigation):
         'copy_template',
         'create_api_key',
         'create_email_branding',
+        'create_letter_branding',
         'data_retention',
         'delete_service_template',
         'delete_template_folder',

app/s3_client/s3_logo_client.py

@@ -6,6 +6,9 @@ from notifications_utils.s3 import s3upload as utils_s3upload
 
 TEMP_TAG = 'temp-{user_id}_'
 EMAIL_LOGO_LOCATION_STRUCTURE = '{temp}{unique_id}-{filename}'
+LETTER_PREFIX = 'letters/static/images/letter-template/'
+LETTER_TEMP_TAG = LETTER_PREFIX + TEMP_TAG
+LETTER_TEMP_LOGO_LOCATION = 'letters/static/images/letter-template/temp-{user_id}_{unique_id}-{filename}'
 
 
 def get_s3_object(bucket_name, filename):
@@ -33,10 +36,14 @@ def get_s3_objects_filter_by_prefix(prefix):
     return s3.Bucket(bucket_name).objects.filter(Prefix=prefix)
 
 
-def get_temp_truncated_email_filename(filename, user_id):
+def get_temp_truncated_filename(filename, user_id):
     return filename[len(TEMP_TAG.format(user_id=user_id)):]
 
 
+def get_letter_filename_with_no_path_or_extension(filename):
+    return filename[len(LETTER_PREFIX):-4]
+
+
 def upload_email_logo(filename, filedata, region, user_id):
     upload_file_name = EMAIL_LOGO_LOCATION_STRUCTURE.format(
         temp=TEMP_TAG.format(user_id=user_id),
@@ -55,20 +62,74 @@ def upload_email_logo(filename, filedata, region, user_id):
     return upload_file_name
 
 
+def upload_letter_temp_logo(filename, filedata, region, user_id):
+    upload_filename = LETTER_TEMP_LOGO_LOCATION.format(
+        user_id=user_id,
+        unique_id=str(uuid.uuid4()),
+        filename=filename
+    )
+    bucket_name = current_app.config['LOGO_UPLOAD_BUCKET_NAME']
+    utils_s3upload(
+        filedata=filedata,
+        region=region,
+        bucket_name=bucket_name,
+        file_location=upload_filename,
+        content_type='image/svg+xml'
+    )
+
+    return upload_filename
+
+
+def upload_letter_png_logo(filename, filedata, region):
+    bucket_name = current_app.config['LOGO_UPLOAD_BUCKET_NAME']
+    utils_s3upload(
+        filedata=filedata,
+        region=region,
+        bucket_name=bucket_name,
+        file_location=filename,
+        content_type='image/png'
+    )
+
+
 def permanent_email_logo_name(filename, user_id):
     if filename.startswith(TEMP_TAG.format(user_id=user_id)):
-        return get_temp_truncated_email_filename(filename=filename, user_id=user_id)
+        return get_temp_truncated_filename(filename=filename, user_id=user_id)
     else:
         return filename
 
 
+def permanent_letter_logo_name(filename, extension):
+    return LETTER_PREFIX + filename + '.' + extension
+
+
+def letter_filename_for_db(filename, user_id):
+    filename = get_letter_filename_with_no_path_or_extension(filename)
+
+    if filename.startswith(TEMP_TAG.format(user_id=user_id)):
+        filename = get_temp_truncated_filename(filename=filename, user_id=user_id)
+
+    return filename
+
+
 def delete_email_temp_files_created_by(user_id):
     for obj in get_s3_objects_filter_by_prefix(TEMP_TAG.format(user_id=user_id)):
         delete_s3_object(obj.key)
 
 
+def delete_letter_temp_files_created_by(user_id):
+    for obj in get_s3_objects_filter_by_prefix(LETTER_TEMP_TAG.format(user_id=user_id)):
+        delete_s3_object(obj.key)
+
+
 def delete_email_temp_file(filename):
     if not filename.startswith(TEMP_TAG[:5]):
         raise ValueError('Not a temp file: {}'.format(filename))
 
     delete_s3_object(filename)
+
+
+def delete_letter_temp_file(filename):
+    if not filename.startswith(LETTER_TEMP_TAG[:43]):
+        raise ValueError('Not a temp file: {}'.format(filename))
+
+    delete_s3_object(filename)

app/templates/views/letter-branding/manage-letter-branding.html

@@ -0,0 +1,37 @@
+{% extends "views/platform-admin/_base_template.html" %}
+{% from "components/file-upload.html" import file_upload %}
+{% from "components/page-footer.html" import page_footer %}
+{% from "components/textbox.html" import textbox %}
+{% from "components/form.html" import form_wrapper %}
+
+{% block per_page_title %}
+  Create letter branding
+{% endblock %}
+
+{% block platform_admin_content %}
+
+  <h1 class="heading-large">Add letter branding</h1>
+  <div class="grid-row">
+    <div class="column-three-quarters">
+      {% if logo %}
+        <div id="logo-img">
+          <img src="https://{{ cdn_url }}/{{ logo }}"/>
+        </div>
+      {% endif %}
+      {{ file_upload(file_upload_form.file) }}
+      {% call form_wrapper() %}
+        <div class="form-group">
+          <div style='margin-top:15px;'>{{textbox(letter_branding_details_form.name)}}</div>
+          <div style='margin-top:15px;'>{{textbox(letter_branding_details_form.domain)}}</div>
+          {{ page_footer(
+            'Save',
+            button_name='operation',
+            button_value='branding-details',
+            back_link=url_for('main.platform_admin'),
+            back_link_text='Back to letter branding selection',
+          ) }}
+        </div>
+      {% endcall %}
+    </div>
+
+{% endblock %}