Merge branch 'feature/zlib_url' into 'master'

Shorten the form URL by compressing and b64 encoding it

See merge request cara/cara!147

cara/apps/calculator/__init__.py

@@ -1,10 +1,12 @@
 import datetime
+import base64
 import html
 import json
 import os
 from pathlib import Path
 import traceback
 import uuid
+import zlib
 
 import jinja2
 from tornado.web import Application, RequestHandler, StaticFileHandler
@@ -86,8 +88,6 @@ class ConcentrationModel(BaseRequestHandler):
 
         try:
             form = model_generator.FormData.from_dict(requested_model_config)
-        except (KeyboardInterrupt, SystemExit):
-            raise
         except Exception as err:
             if self.settings.get("debug", False):
                 import traceback
@@ -131,6 +131,18 @@ class CalculatorForm(BaseRequestHandler):
         self.finish(report)
 
 
+class CompressedCalculatorFormInputs(BaseRequestHandler):
+    def get(self, compressed_args: str):
+        # Convert a base64 zlib encoded shortened URL into a non compressed
+        # URL, and redirect.
+        try:
+            args = zlib.decompress(base64.b64decode(compressed_args)).decode()
+        except Exception as err:  # noqa
+            self.set_status(400)
+            return self.finish("Invalid calculator data: it seems incomplete. Was there an error copying & pasting the URL?")
+        self.redirect(f'/calculator?{args}')
+
+
 class ReadmeHandler(BaseRequestHandler):
     def get(self):
         template = self.settings['template_environment'].get_template("userguide.html.j2")
@@ -146,6 +158,7 @@ def make_app(debug=False, prefix='/calculator'):
     calculator_static_dir = Path(__file__).absolute().parent / 'static'
     urls = [
         (r'/?', LandingPage),
+        (r'/_c/(.*)', CompressedCalculatorFormInputs),
         (r'/static/(.*)', StaticFileHandler, {'path': static_dir}),
         (prefix + r'/?', CalculatorForm),
         (prefix + r'/report', ConcentrationModel),

cara/apps/calculator/report_generator.py

@@ -4,6 +4,7 @@ from datetime import datetime
 import io
 from pathlib import Path
 import typing
+import zlib
 
 import qrcode
 import urllib
@@ -70,7 +71,17 @@ def calculate_report_data(model: models.ExposureModel):
 
 def generate_qr_code(prefix, form: FormData):
     form_dict = FormData.to_dict(form)
-    url = prefix + "?" + urllib.parse.urlencode(form_dict)
+
+    # Generate the calculator URL arguments that would be needed to re-create this
+    # form.
+    args = urllib.parse.urlencode(form_dict)
+
+    # Then zlib compress + base64 encode the string. To be inverted by the
+    # /_c/ endpoint.
+    qr_url = prefix + "/_c/" + base64.b64encode(
+        zlib.compress(args.encode())
+    ).decode()
+    url = prefix + "/calculator?" + args
 
     qr = qrcode.QRCode(
         version=1,
@@ -78,13 +89,14 @@ def generate_qr_code(prefix, form: FormData):
         box_size=10,
         border=4,
     )
-    qr.add_data(url)
+    qr.add_data(qr_url)
     qr.make(fit=True)
     img = qr.make_image(fill_color="black", back_color="white").convert('RGB')
 
     return {
         'image': img2base64(_img2bytes(img)),
         'link': url,
+        'qr_url': qr_url,
     }
 
 
@@ -272,7 +284,7 @@ def build_report(base_url: str, model: models.ExposureModel, form: FormData):
     context.update(calculate_report_data(model))
     alternative_scenarios = manufacture_alternative_scenarios(form)
     context['alternative_scenarios'] = comparison_report(alternative_scenarios)
-    context['qr_code'] = generate_qr_code(f'{base_url}/calculator', form)
+    context['qr_code'] = generate_qr_code(base_url, form)
 
     cara_templates = Path(__file__).parent.parent / "templates"
     calculator_templates = Path(__file__).parent / "templates"

cara/tests/apps/calculator/conftest.py

@@ -0,0 +1,13 @@
+import pytest
+
+from cara.apps.calculator import model_generator
+
+
+@pytest.fixture
+def baseline_form_data():
+    return model_generator.baseline_raw_form_data()
+
+
+@pytest.fixture
+def baseline_form(baseline_form_data):
+    return model_generator.FormData.from_dict(baseline_form_data)

cara/tests/apps/calculator/test_model_generator.py

@@ -6,15 +6,6 @@ from cara import models
 from cara import data
 import numpy as np
 
-@pytest.fixture
-def baseline_form_data():
-    return model_generator.baseline_raw_form_data()
-
-
-@pytest.fixture
-def baseline_form(baseline_form_data):
-    return model_generator.FormData.from_dict(baseline_form_data)
-
 
 def test_model_from_dict(baseline_form_data):
     form = model_generator.FormData.from_dict(baseline_form_data)

cara/tests/apps/calculator/test_report_generator.py

@@ -1,19 +1,8 @@
 import pytest
 
-from cara.apps.calculator import model_generator
 from cara.apps.calculator import report_generator
 
 
-@pytest.fixture
-def baseline_form_data():
-    return model_generator.baseline_raw_form_data()
-
-
-@pytest.fixture
-def baseline_form(baseline_form_data):
-    return model_generator.FormData.from_dict(baseline_form_data)
-
-
 def test_generate_report(baseline_form):
     model = baseline_form.build_model()
 
@@ -32,4 +21,4 @@ def test_generate_report(baseline_form):
     ],
 )
 def test_readable_minutes(test_input, expected):
-    assert report_generator.readable_minutes(test_input) == expected
+    assert report_generator.readable_minutes(test_input) == expected

cara/tests/apps/calculator/test_webapp.py

@@ -0,0 +1,54 @@
+import pytest
+
+from cara.apps.calculator import make_app
+from cara.apps.calculator.report_generator import generate_qr_code
+
+
+@pytest.fixture
+def app():
+    return make_app()
+
+
+async def test_homepage(http_server_client):
+    response = await http_server_client.fetch('/')
+    assert response.code == 200
+
+
+async def test_calculator(http_server_client):
+    # Both with and without a trailing slash.
+    response = await http_server_client.fetch('/calculator')
+    assert response.code == 200
+
+    response = await http_server_client.fetch('/calculator/')
+    assert response.code == 200
+
+
+async def test_qrcode_urls(http_server_client, baseline_form):
+    prefix = 'proto://hostname/prefix'
+    qr_data = generate_qr_code(prefix, baseline_form)
+    expected = f'{prefix}/calculator?activity_type=office&air_changes=0.0'
+    assert qr_data['link'].startswith(expected)
+
+    # We should get a 200 for the link.
+    response = await http_server_client.fetch(qr_data['link'].replace(prefix, ''))
+    assert response.code == 200
+
+    # And a 302 for the QR url itself. The redirected URL should be the same as
+    # in the link.
+    assert qr_data['qr_url'].startswith(prefix)
+    response = await http_server_client.fetch(
+        qr_data['qr_url'].replace(prefix, ''),
+        max_redirects=0,
+        raise_error=False,
+    )
+    assert response.code == 302
+    assert response.headers['Location'] == qr_data['link'].replace(prefix, '')
+
+
+async def test_invalid_compressed_url(http_server_client, baseline_form):
+    response = await http_server_client.fetch(
+        '/_c/invalid-data',
+        max_redirects=0,
+        raise_error=False,
+    )
+    assert response.code == 400

setup.py

@@ -71,6 +71,8 @@ setup(
         'all': [req for reqs in REQUIREMENTS.values() for req in reqs],
     },
     package_data={'cara': [
+        'apps/templates/*.j2',
+        'apps/calculator/templates/*.j2',
         'apps/calculator/*',
         'apps/calculator/*/*',
         'apps/calculator/*/*/*'