From 936ea0ea8e8fd50b15715eb0d9ddf8c9b503b0d0 Mon Sep 17 00:00:00 2001
From: Alexis Metaireau <alexis@notmyidea.org>
Date: Wed, 11 May 2022 11:20:15 +0200
Subject: [PATCH] Almet/qrcode (#1000)

Add a QRCode utility to join the project.
---
 ihatemoney/templates/send_invites.html |  9 +++++++++
 ihatemoney/web.py                      | 21 ++++++++++++++++++++-
 setup.cfg                              |  1 +
 3 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/ihatemoney/templates/send_invites.html b/ihatemoney/templates/send_invites.html
index d5112926..7983d61f 100644
--- a/ihatemoney/templates/send_invites.html
+++ b/ihatemoney/templates/send_invites.html
@@ -26,6 +26,15 @@
                 </a>
             </td>
         </tr>
+        <tr>
+            <td>
+                <h3>{{ _('Scan QR code') }}</h3>
+                <p><small>{% trans download_mobile=url_for(".mobile") %}On a mobile device, with <a href="{{ download_mobile }}">a compatible app installed</a>.{% endtrans %}</small></p>
+            </td>
+            <td>
+                {{ qrcode | safe }}
+            </td>
+        </tr>
         <tr>
             <td>
                 <h3>{{ _('Send via Emails') }}</h3>
diff --git a/ihatemoney/web.py b/ihatemoney/web.py
index dd31c152..e682cbd9 100644
--- a/ihatemoney/web.py
+++ b/ihatemoney/web.py
@@ -9,8 +9,10 @@ some shortcuts to make your life better when coding (see `pull_project`
 and `add_project_id` for a quick overview)
 """
 from functools import wraps
+from io import StringIO
 import json
 import os
+from urllib.parse import urlparse, urlunparse
 
 from flask import (
     Blueprint,
@@ -28,6 +30,8 @@ from flask import (
 )
 from flask_babel import gettext as _
 from flask_mail import Message
+import qrcode
+import qrcode.image.svg
 from sqlalchemy_continuum import Operation
 from werkzeug.exceptions import NotFound
 from werkzeug.security import check_password_hash, generate_password_hash
@@ -586,7 +590,22 @@ def invite():
                     "Sorry, there was an error while trying to send the invitation emails."
                 )
                 # Fall-through: we stay on the same page and display the form again
-    return render_template("send_invites.html", form=form)
+
+    # Generate the SVG QRCode.
+    invite_link = url_for(
+        ".join_project",
+        project_id=g.project.id,
+        token=g.project.generate_token(),
+        _external=True,
+    )
+    invite_link = urlunparse(urlparse(invite_link)._replace(scheme="ihatemoney"))
+    qr = qrcode.QRCode(image_factory=qrcode.image.svg.SvgPathImage)
+    qr.add_data(invite_link)
+    qr.make(fit=True)
+    img = qr.make_image(attrib={"class": "qrcode"})
+    qrcode_svg = img.to_string().decode()
+
+    return render_template("send_invites.html", form=form, qrcode=qrcode_svg)
 
 
 @main.route("/<project_id>/")
diff --git a/setup.cfg b/setup.cfg
index 1404bd91..76802e36 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -40,6 +40,7 @@ install_requires =
     Werkzeug>=2,<2.1  # See https://github.com/spiral-project/ihatemoney/pull/1015
     itsdangerous>=2,<3
     Jinja2>=3,<4
+    qrcode>=7,<8
     requests>=2.22,<3
     SQLAlchemy-Continuum>=1.3.12,<2
     SQLAlchemy>=1.3.0,<1.4  # New 1.4 changes API, see #728