Merge pull request #1725 from alphagov/rc_add_get_template_preview

Add get template preview

app/template/rest.py

@@ -1,10 +1,12 @@
+import base64
 from flask import (
     Blueprint,
+    current_app,
     jsonify,
-    request,
+    request)
-    current_app
+from requests import post as requests_post
-)
 
+from app.dao.notifications_dao import get_notification_by_id
 from app.dao.templates_dao import (
     dao_update_template,
     dao_create_template,
@@ -12,8 +14,8 @@ from app.dao.templates_dao import (
     dao_get_template_by_id_and_service_id,
     dao_get_all_templates_for_service,
     dao_get_template_versions,
-    dao_update_template_reply_to
+    dao_update_template_reply_to,
-)
+    dao_get_template_by_id)
 from notifications_utils.template import SMSMessageTemplate
 from app.dao.services_dao import dao_fetch_service_by_id
 from app.models import SMS_TYPE
@@ -179,3 +181,49 @@ def redact_template(template, data):
     if not template.redact_personalisation:
         dao_redact_template(template, data['created_by'])
     return 'null', 200
+
+
+@template_blueprint.route('/preview/<uuid:notification_id>/<file_type>', methods=['GET'])
+def preview_letter_template_by_notification_id(service_id, notification_id, file_type):
+    if file_type not in ('pdf', 'png'):
+        raise InvalidRequest({'content': ["file_type must be pdf or png"]}, status_code=400)
+
+    page = request.args.get('page')
+
+    notification = get_notification_by_id(notification_id)
+
+    template = dao_get_template_by_id(notification.template_id)
+
+    template_for_letter_print = {
+        "id": str(notification.template_id),
+        "subject": template.subject,
+        "content": template.content,
+        "version": str(template.version)
+    }
+
+    service = dao_fetch_service_by_id(service_id)
+
+    data = {
+        'letter_contact_block': notification.reply_to_text,
+        'template': template_for_letter_print,
+        'values': notification.personalisation,
+        'dvla_org_id': service.dvla_organisation_id,
+    }
+
+    resp = requests_post(
+        '{}/preview.{}{}'.format(
+            current_app.config['TEMPLATE_PREVIEW_API_HOST'],
+            file_type,
+            '?page={}'.format(page) if page else ''
+        ),
+        json=data,
+        headers={'Authorization': 'Token {}'.format(current_app.config['TEMPLATE_PREVIEW_API_KEY'])}
+    )
+
+    if resp.status_code != 200:
+        raise InvalidRequest(
+            'Error generating preview for {}'.format(notification_id), status_code=500
+        )
+
+    content = base64.b64encode(resp.content).decode('utf-8')
+    return jsonify({"content": content})

tests/app/celery/test_letters_pdf_tasks.py

@@ -157,7 +157,6 @@ def test_create_letters_pdf_handles_s3_errors(mocker, sample_letter_notification
             'Type': 'Sender'
         }
     }
-
     mock_s3 = mocker.patch('app.letters.utils.s3upload', side_effect=ClientError(error_response, 'operation_name'))
     mock_retry = mocker.patch('app.celery.letters_pdf_tasks.create_letters_pdf.retry')
 

tests/app/celery/test_tasks.py

@@ -1258,7 +1258,6 @@ def test_build_dvla_file_retries_if_s3_err(sample_letter_template, mocker):
             'Type': 'Sender'
         }
     }
-
     mocker.patch('app.celery.tasks.LetterDVLATemplate', return_value='dvla|string')
     mocker.patch('app.celery.tasks.s3upload', side_effect=ClientError(error_response, 'operation_name'))
     retry_mock = mocker.patch('app.celery.tasks.build_dvla_file.retry', side_effect=Retry)

tests/app/template/test_rest.py

@@ -1,3 +1,4 @@
+import base64
 import json
 import random
 import string
@@ -14,9 +15,9 @@ from tests.app.conftest import (
     sample_template as create_sample_template,
     sample_template_without_email_permission,
     sample_template_without_letter_permission,
-    sample_template_without_sms_permission,
+    sample_template_without_sms_permission)
-)
 from tests.app.db import create_service, create_letter_contact, create_template
+from tests.conftest import set_config_values
 
 
 @pytest.mark.parametrize('template_type, subject', [
@@ -794,3 +795,82 @@ def test_update_redact_template_400s_if_no_created_by(admin_request, sample_temp
 
     assert sample_template.redact_personalisation is False
     assert sample_template.template_redacted.updated_at == original_updated_time
+
+
+def test_preview_letter_template_by_id_invalid_file_type(
+        sample_letter_notification,
+        admin_request):
+
+    resp = admin_request.get(
+        'template.preview_letter_template_by_notification_id',
+        service_id=sample_letter_notification.service_id,
+        template_id=sample_letter_notification.template_id,
+        notification_id=sample_letter_notification.id,
+        file_type='doc',
+        _expected_status=400
+    )
+
+    assert ['file_type must be pdf or png'] == resp['message']['content']
+
+
+def test_preview_letter_template_by_id_valid_file_type(
+        notify_api,
+        client,
+        admin_request,
+        sample_letter_notification):
+
+    with set_config_values(notify_api, {
+        'TEMPLATE_PREVIEW_API_HOST': 'http://localhost/notifications-template-preview',
+        'TEMPLATE_PREVIEW_API_KEY': 'test-key'
+    }):
+        import requests_mock
+        with requests_mock.Mocker() as request_mock:
+            content = b'\x00\x01'
+
+            request_mock.post(
+                'http://localhost/notifications-template-preview/preview.pdf',
+                content=content,
+                headers={'X-pdf-page-count': '1'},
+                status_code=200
+            )
+
+            resp = admin_request.get(
+                'template.preview_letter_template_by_notification_id',
+                service_id=sample_letter_notification.service_id,
+                notification_id=sample_letter_notification.id,
+                file_type='pdf'
+            )
+
+            assert base64.b64decode(resp['content']) == content
+
+
+def test_preview_letter_template_by_id_template_preview_500(
+        notify_api,
+        client,
+        admin_request,
+        sample_letter_notification):
+
+    with set_config_values(notify_api, {
+        'TEMPLATE_PREVIEW_API_HOST': 'http://localhost/notifications-template-preview',
+        'TEMPLATE_PREVIEW_API_KEY': 'test-key'
+    }):
+        import requests_mock
+        with requests_mock.Mocker() as request_mock:
+            content = b'\x00\x01'
+
+            request_mock.post(
+                'http://localhost/notifications-template-preview/preview.pdf',
+                content=content,
+                headers={'X-pdf-page-count': '1'},
+                status_code=404
+            )
+
+            resp = admin_request.get(
+                'template.preview_letter_template_by_notification_id',
+                service_id=sample_letter_notification.service_id,
+                notification_id=sample_letter_notification.id,
+                file_type='pdf',
+                _expected_status=500
+            )
+
+            assert resp['message'] == 'Error generating preview for {}'.format(sample_letter_notification.id)