From 307de59b86a040efb284c7bad6158874296de8fe Mon Sep 17 00:00:00 2001
From: Edward Oliveira <edwardr@senado.gov.br>
Date: Mon, 20 Sep 2021 22:59:56 -0300
Subject: [PATCH] web sockets (WIP)

---
 requirements/requirements.txt   |  2 ++
 sapl/asgi.py                    | 19 ++++++++++++
 sapl/painel/consumers.py        | 21 ++++++++++++++
 sapl/painel/routing.py          |  6 ++++
 sapl/painel/urls.py             |  5 +++-
 sapl/painel/views.py            |  6 ++++
 sapl/settings.py                | 17 +++++++++++
 sapl/templates/painel/room.html | 51 +++++++++++++++++++++++++++++++++
 8 files changed, 126 insertions(+), 1 deletion(-)
 create mode 100644 sapl/asgi.py
 create mode 100644 sapl/painel/consumers.py
 create mode 100644 sapl/painel/routing.py
 create mode 100644 sapl/templates/painel/room.html

diff --git a/requirements/requirements.txt b/requirements/requirements.txt
index bcfa70e1b..c8a02db81 100644
--- a/requirements/requirements.txt
+++ b/requirements/requirements.txt
@@ -35,3 +35,5 @@ whitenoise==5.1.0
 
 git+https://github.com/interlegis/trml2pdf
 git+https://github.com/interlegis/django-admin-bootstrapped
+channels==3.0.4
+channels-redis==3.3.0
diff --git a/sapl/asgi.py b/sapl/asgi.py
new file mode 100644
index 000000000..63be23a6d
--- /dev/null
+++ b/sapl/asgi.py
@@ -0,0 +1,19 @@
+import os
+
+import django
+from channels.http import AsgiHandler
+from channels.auth import AuthMiddlewareStack
+from channels.routing import ProtocolTypeRouter, URLRouter
+import sapl.painel.routing
+
+os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'sapl.settings')
+django.setup()
+
+application = ProtocolTypeRouter({
+  "http": AsgiHandler(),
+  "websocket": AuthMiddlewareStack(
+        URLRouter(
+            sapl.painel.routing.websocket_urlpatterns
+        )
+  ),
+})
\ No newline at end of file
diff --git a/sapl/painel/consumers.py b/sapl/painel/consumers.py
new file mode 100644
index 000000000..d987f39f2
--- /dev/null
+++ b/sapl/painel/consumers.py
@@ -0,0 +1,21 @@
+import json
+from channels.generic.websocket import WebsocketConsumer
+
+
+class ChatConsumer(WebsocketConsumer):
+    def connect(self):
+        self.accept()
+        print('conectado ao ws')
+
+    def disconnect(self, close_code):
+        print('desconectado ao ws')
+        pass
+
+    def receive(self, text_data):
+        print('receive message')
+        text_data_json = json.loads(text_data)
+        message = text_data_json['message']
+
+        self.send(text_data=json.dumps({
+            'message': message
+        }))
\ No newline at end of file
diff --git a/sapl/painel/routing.py b/sapl/painel/routing.py
new file mode 100644
index 000000000..f5c85077a
--- /dev/null
+++ b/sapl/painel/routing.py
@@ -0,0 +1,6 @@
+from django.urls import re_path
+from . import consumers
+
+websocket_urlpatterns = [
+    re_path(r'ws/painel/(?P<room_name>\w+)/$', consumers.ChatConsumer.as_asgi()),
+]
\ No newline at end of file
diff --git a/sapl/painel/urls.py b/sapl/painel/urls.py
index 0795d0a35..ca7457bcf 100644
--- a/sapl/painel/urls.py
+++ b/sapl/painel/urls.py
@@ -1,9 +1,11 @@
 from django.conf.urls import url
 
+from django.urls import path
+
 from .apps import AppConfig
 from .views import (cronometro_painel, get_dados_painel, painel_mensagem_view,
                     painel_parlamentar_view, painel_view, painel_votacao_view,
-                    switch_painel, verifica_painel, votante_view)
+                    switch_painel, verifica_painel, votante_view, room)
 
 app_name = AppConfig.name
 
@@ -24,4 +26,5 @@ urlpatterns = [
 
     url(r'^voto-individual/$', votante_view,
         name='voto_individual'),
+    path(r'<str:room_name>/', room, name='room'),
 ]
diff --git a/sapl/painel/views.py b/sapl/painel/views.py
index ed390f95b..8288d7ef7 100644
--- a/sapl/painel/views.py
+++ b/sapl/painel/views.py
@@ -643,3 +643,9 @@ def get_dados_painel(request, pk):
 
     # Retorna que não há nenhuma matéria já votada ou aberta
     return response_nenhuma_materia(get_presentes(pk, response, None))
+
+
+def room(request, room_name):
+    return render(request, 'painel/room.html', {
+        'room_name': room_name
+    })
\ No newline at end of file
diff --git a/sapl/settings.py b/sapl/settings.py
index 8ddf5e4d7..9405985cb 100644
--- a/sapl/settings.py
+++ b/sapl/settings.py
@@ -96,6 +96,7 @@ INSTALLED_APPS = (
     'speedinfo',
 
     'webpack_loader',
+    'channels'
 
 ) + SAPL_APPS
 
@@ -126,6 +127,20 @@ HAYSTACK_CONNECTIONS = {
     },
 }
 
+CHANNEL_LAYERS = {
+    'default': {
+        ### Method 1: Via local Redis
+        # 'BACKEND': 'channels_redis.core.RedisChannelLayer',
+        # 'CONFIG': {
+        #      "hosts": [('127.0.0.1', 6379)],
+        # },
+
+        ### Method 3: Via In-memory channel layer
+        ## Using this method.
+        "BACKEND": "channels.layers.InMemoryChannelLayer"
+    }
+}
+
 MIDDLEWARE = [
     'reversion.middleware.RevisionMiddleware',
     'django.contrib.sessions.middleware.SessionMiddleware',
@@ -203,6 +218,8 @@ TEMPLATES = [
 
 
 WSGI_APPLICATION = 'sapl.wsgi.application'
+ASGI_APPLICATION = 'sapl.asgi.application'
+
 
 CELERY_BROKER_URL = 'redis://localhost:6379'
 
diff --git a/sapl/templates/painel/room.html b/sapl/templates/painel/room.html
new file mode 100644
index 000000000..2365f36f1
--- /dev/null
+++ b/sapl/templates/painel/room.html
@@ -0,0 +1,51 @@
+<!-- chat/templates/chat/room.html -->
+<!DOCTYPE html>
+<html>
+<head>
+    <meta charset="utf-8"/>
+    <title>Chat Room</title>
+</head>
+<body>
+    <textarea id="chat-log" cols="100" rows="20"></textarea><br>
+    <input id="chat-message-input" type="text" size="100"><br>
+    <input id="chat-message-submit" type="button" value="Send">
+    {{ room_name|json_script:"room-name" }}
+    <script>
+        const roomName = JSON.parse(document.getElementById('room-name').textContent);
+
+        const chatSocket = new WebSocket(
+            'ws://'
+            + window.location.host
+            + '/ws/painel/'
+            + roomName
+            + '/'
+        );
+
+        chatSocket.onmessage = function(e) {
+            const data = JSON.parse(e.data);
+            document.querySelector('#chat-log').value += (data.message + '\n');
+        };
+
+        chatSocket.onclose = function(e) {
+            console.error('Chat socket closed unexpectedly');
+        };
+
+        document.querySelector('#chat-message-input').focus();
+        document.querySelector('#chat-message-input').onkeyup = function(e) {
+            if (e.keyCode === 13) {  // enter, return
+                document.querySelector('#chat-message-submit').click();
+            }
+        };
+
+        document.querySelector('#chat-message-submit').onclick = function(e) {
+            const messageInputDom = document.querySelector('#chat-message-input');
+            const message = messageInputDom.value;
+            chatSocket.send(JSON.stringify({
+                'message': message
+            }));
+            messageInputDom.value = '';
+        };
+    </script>
+</body>
+</html>
+