From 564e449e3300a976daadc963cbeac5cce5e48e8e Mon Sep 17 00:00:00 2001
From: Martin Asprusten <martin_asprusten@hotmail.com>
Date: Sun, 20 Apr 2025 14:13:29 +0200
Subject: [PATCH] Web exchange seems to work now

---
 WebServer/static/exchange_client.py           | 13 ++--
 WebServer/static/exchange_worker.js           | 61 +++++++++++----
 WebServer/static/style.css                    |  1 +
 WebServer/templates/exchange.html             | 74 +++++++++++++------
 src/SantaExchange/MessageHandler.py           | 14 ++--
 .../MessageTypes/Announcement.py              |  2 +-
 .../MessageTypes/Introduction.py              |  2 +-
 src/SantaExchange/MessageTypes/Ready.py       |  2 +-
 src/SantaExchange/MessageTypes/Shuffle.py     |  2 +-
 src/SantaExchange/SantasBrain.py              | 47 ++++++++----
 src/SantaExchange/UserInterface.py            |  6 +-
 11 files changed, 155 insertions(+), 69 deletions(-)

diff --git a/WebServer/static/exchange_client.py b/WebServer/static/exchange_client.py
index 8f6adbe..2f4ab84 100644
--- a/WebServer/static/exchange_client.py
+++ b/WebServer/static/exchange_client.py
@@ -1,10 +1,11 @@
+from typing import Optional, Callable
+
 from Crypto.PublicKey.ECC import EccKey
 
-from src.SantaExchange.Message import Message
-from src.SantaExchange.MessageHandler import MessageHandler
-from src.SantaExchange.SantasBrain import Brain
-from src.SantaExchange.UserInterface import UserInterface
-
+from SantaExchange.Message import Message
+from SantaExchange.MessageHandler import MessageHandler
+from SantaExchange.SantasBrain import Brain
+from SantaExchange.UserInterface import UserInterface
 
 class ExchangeClient(MessageHandler, UserInterface):
 	def __init__(self, send_message_function, receive_user_function, announce_recipient_function):
@@ -25,4 +26,4 @@ class ExchangeClient(MessageHandler, UserInterface):
 		self.receive_user_function(name)
 
 	def announce_recipient(self, name: str, other_info: str):
-		self.announce_recipient_function(name, other_info)
\ No newline at end of file
+		self.announce_recipient_function(name, other_info)
diff --git a/WebServer/static/exchange_worker.js b/WebServer/static/exchange_worker.js
index 208bc2f..0be023f 100644
--- a/WebServer/static/exchange_worker.js
+++ b/WebServer/static/exchange_worker.js
@@ -1,23 +1,56 @@
 import "./pyodide.js";
 
 async function prepare() {
+    self.postMessage({type: 'status', stage: 'initialize', text: 'Initializing...'});
 	let pyodide = await loadPyodide();
 	await pyodide.loadPackage("pycryptodome");
-	await pyodide.loadPackage("./santaexchange-0.1-py3-none-any.whl")
-	pyodide.runPython(`
-		class Test:
-			def calculate(self):
-				return 15
+	await pyodide.loadPackage("./santaexchange-0.1-py3-none-any.whl");
+	let response = await fetch('./exchange_client.py');
+	pyodide.runPython(await response.text())
 
-		a = Test()
+	function sendMessage(messageString) {
+	    self.postMessage({type: 'message', message: messageString})
+	}
+
+	function receiveUser(username) {
+	    self.postMessage({type: 'new_user', username: username})
+	}
+
+	function announceRecipient(recipient_name, recipient_info) {
+	    self.postMessage({type: 'status', stage: 'finished', text: `Your secret santa receiver is \n${recipient_name}\n${recipient_info}`})
+	}
+
+	function printLogs(record) {
+	    console.log(record);
+	}
+
+	pyodide.globals.set('send_message', sendMessage);
+	pyodide.globals.set('receive_user', receiveUser);
+	pyodide.globals.set('announce_recipient', announceRecipient);
+	pyodide.globals.set('print_logs_function', printLogs);
+
+	pyodide.runPython(`
+        exchange_worker = ExchangeClient(send_message, receive_user, announce_recipient)
 	`);
 
-	console.log('Running python function');
-	console.log(pyodide.globals.get('a').calculate());
-}
-prepare();
+	addEventListener('message', e => {
+        if (e.data.type == 'message') {
+            pyodide.globals.get('exchange_worker').decode_received_message(e.data.message);
+        } else if (e.data.type == 'set_user') {
+            let username = e.data.username;
+            let userinfo = e.data.userinfo;
+            pyodide.globals.get('exchange_worker').set_user_info(username, userinfo);
+            postMessage({type: 'status', stage: 'wait_for_start', text: 'Waiting for other participants'});
+        } else if (e.data.type == 'start') {
+            postMessage({
+                type: 'status',
+                stage: 'exchanging',
+                text: 'Performing exchange when all users have pressed start. This may take a minute or so.'
+            });
+            pyodide.globals.get('exchange_worker').start_exchange(e.data.users);
+        }
+    });
 
-addEventListener('message', e => {
-	self.postMessage('Loading pyodide');
-	self.postMessage('Loaded pyodide');
-});
\ No newline at end of file
+	self.postMessage({type: 'status', stage: 'wait_for_user', text: 'Initialized'})
+}
+prepare();
\ No newline at end of file
diff --git a/WebServer/static/style.css b/WebServer/static/style.css
index bd42c2e..05a4f67 100644
--- a/WebServer/static/style.css
+++ b/WebServer/static/style.css
@@ -35,4 +35,5 @@ input {
 textarea {
 	width: 30vw;
 	height: 20vh;
+	font-size: 20px;
 }
\ No newline at end of file
diff --git a/WebServer/templates/exchange.html b/WebServer/templates/exchange.html
index 9e40e07..c077d19 100644
--- a/WebServer/templates/exchange.html
+++ b/WebServer/templates/exchange.html
@@ -12,38 +12,70 @@
 	<br />
 	<label for="info_for_santa">Info for your santa (e.g. shipping address or similar):</label><br />
 	<textarea id="info_for_santa"></textarea><br />
-	<button id="submit_info_button">Submit your info</button>
+	<button id="submit_info_button" onclick="submitInfo();">Submit your info</button>
 	<br /><br /><br />
-	<p id="statusParagraph"></p>
-	<button>Start with current participants</button>
+	<pre id="statusParagraph"></pre>
+	<button id="start_exchange_button" onclick="submitStart();">Start with current participants</button>
 	<p>Current participants:</p>
-	<div id='participantList'></div>
-	<!--<script type="text/javascript">
+	<ul id='participantList'>
+
+	</ul>
+	<script type="text/javascript">
 		const socket = io();
 		const client_id = Math.floor(Math.random() * 2**64)
-		socket.emit('join', {room: window.location.pathname, 'client_id': client_id})
 
-		socket.on('message', data => {
-			// All messages are broadcast to everyone, so discard messages that were actually sent from ourselves
-			data = JSON.parse(data);
-			if (data['client_id'] != client_id) {
-				console.log(data);
-				console.log(data['message']);
-				window.pass_message_to_python(JSON.stringify(data['message']));
-			}
-		});
-	</script>-->
+		const other_users = []
+
+		let submitButton = document.getElementById('submit_info_button');
+		let startButton = document.getElementById('start_exchange_button');
+
+		submitButton.disabled = true;
+		startButton.disabled = true;
 
-	<script type="text/javascript">
 		const exchangeWorker = new Worker("{{ url_for('static', filename='exchange_worker.js') }}", { type: 'module' });
 
 		exchangeWorker.onmessage = (e) => {
-			console.log('Received message:');
-			console.log(e);
-			document.getElementById('statusParagraph').innerHTML = e.data;
+			if (e.data.type == 'status') {
+				document.getElementById('statusParagraph').innerHTML = e.data.text;
+				if (e.data.stage == 'wait_for_user') {
+					submitButton.disabled = false;
+					startButton.disabled = true;
+				} else if (e.data.stage == 'wait_for_start') {
+					submitButton.disabled = true;
+					startButton.disabled = false;
+				} else {
+					submitButton.disabled = true;
+					startButton.disabled = true;
+				}
+			} else if (e.data.type == 'message') {
+				socket.emit('message', {client_id: client_id, room: window.location.pathname, message: e.data.message});
+			} else if (e.data.type == 'new_user') {
+				let list = document.getElementById('participantList');
+				const childNode = document.createElement("li");
+				childNode.innerHTML = e.data.username;
+				other_users.push(e.data.username);
+				list.appendChild(childNode);
+			}
 		};
 
-		exchangeWorker.postMessage('Nothing');
+		socket.on('message', data => {
+			// All messages are broadcast to everyone, so discard messages that were actually sent from ourselves
+			if (data['client_id'] != client_id) {
+				exchangeWorker.postMessage({type: 'message', message: data['message']})
+			}
+		});
+
+		function submitInfo() {
+			let name = document.getElementById('own_name').value;
+			let info = document.getElementById('info_for_santa').value;
+			exchangeWorker.postMessage({type: 'set_user', username: name, userinfo: info});
+		}
+
+		function submitStart() {
+			exchangeWorker.postMessage({type: 'start', users: other_users});
+		}
+
+		socket.emit('join', {room: window.location.pathname, client_id: client_id})
 	</script>
 </body>
 </html>
\ No newline at end of file
diff --git a/src/SantaExchange/MessageHandler.py b/src/SantaExchange/MessageHandler.py
index 098641f..de5659e 100644
--- a/src/SantaExchange/MessageHandler.py
+++ b/src/SantaExchange/MessageHandler.py
@@ -8,11 +8,11 @@ from json import JSONDecodeError
 from Crypto.PublicKey import ECC
 from Crypto.PublicKey.ECC import EccKey
 
-from src.SantaExchange.Message import Message
-from src.SantaExchange.MessageTypes.Announcement import AnnouncementMessage
-from src.SantaExchange.MessageTypes.Introduction import IntroductionMessage
-from src.SantaExchange.MessageTypes.Ready import ReadyMessage
-from src.SantaExchange.MessageTypes.Shuffle import ShuffleMessage
+from SantaExchange.Message import Message
+from SantaExchange.MessageTypes.Announcement import AnnouncementMessage
+from SantaExchange.MessageTypes.Introduction import IntroductionMessage
+from SantaExchange.MessageTypes.Ready import ReadyMessage
+from SantaExchange.MessageTypes.Shuffle import ShuffleMessage
 
 logger = logging.getLogger(__name__)
 
@@ -21,9 +21,9 @@ class MessageHandler:
 	def __init__(self):
 		self.receivers: list[Callable[[Message], None]] = []
 
+	# Must be implemented by child class
 	def send_message(self, message: Message, signing_key: EccKey):
-		# Must be implemented by child SantaExchange
-		pass
+		raise NotImplementedError
 
 	def add_message_receiver(self, message_receiver: Callable[[Message], None]):
 		self.receivers.append(message_receiver)
diff --git a/src/SantaExchange/MessageTypes/Announcement.py b/src/SantaExchange/MessageTypes/Announcement.py
index 38adda3..4d46cea 100644
--- a/src/SantaExchange/MessageTypes/Announcement.py
+++ b/src/SantaExchange/MessageTypes/Announcement.py
@@ -1,6 +1,6 @@
 import base64
 
-from src.SantaExchange.Message import Message
+from SantaExchange.Message import Message
 
 
 class AnnouncementMessage(Message):
diff --git a/src/SantaExchange/MessageTypes/Introduction.py b/src/SantaExchange/MessageTypes/Introduction.py
index 6faa26a..51a1cca 100644
--- a/src/SantaExchange/MessageTypes/Introduction.py
+++ b/src/SantaExchange/MessageTypes/Introduction.py
@@ -3,7 +3,7 @@ import base64
 from Crypto.PublicKey import ECC
 from Crypto.PublicKey.ECC import EccKey
 
-from src.SantaExchange.Message import Message
+from SantaExchange.Message import Message
 
 
 class IntroductionMessage(Message):
diff --git a/src/SantaExchange/MessageTypes/Ready.py b/src/SantaExchange/MessageTypes/Ready.py
index a8f9eea..f0ace25 100644
--- a/src/SantaExchange/MessageTypes/Ready.py
+++ b/src/SantaExchange/MessageTypes/Ready.py
@@ -3,7 +3,7 @@ import base64
 from Crypto.PublicKey import ECC
 from Crypto.PublicKey.ECC import EccKey
 
-from src.SantaExchange.Message import Message
+from SantaExchange.Message import Message
 
 
 class ReadyMessage(Message):
diff --git a/src/SantaExchange/MessageTypes/Shuffle.py b/src/SantaExchange/MessageTypes/Shuffle.py
index 982c2ea..12815d4 100644
--- a/src/SantaExchange/MessageTypes/Shuffle.py
+++ b/src/SantaExchange/MessageTypes/Shuffle.py
@@ -1,6 +1,6 @@
 import base64
 
-from src.SantaExchange.Message import Message
+from SantaExchange.Message import Message
 
 
 class ShuffleMessage(Message):
diff --git a/src/SantaExchange/SantasBrain.py b/src/SantaExchange/SantasBrain.py
index 08550c6..5d069a6 100644
--- a/src/SantaExchange/SantasBrain.py
+++ b/src/SantaExchange/SantasBrain.py
@@ -14,15 +14,15 @@ from Crypto.Protocol.DH import key_agreement
 from Crypto.PublicKey import ECC
 from Crypto.PublicKey.ECC import EccKey
 
-from src.SantaExchange import Message
-from src.SantaExchange.Crypto.CSPRNG import CSPRNG
-from src.SantaExchange.Crypto.CommutativeCipher import CommutativeCipher
-from src.SantaExchange.MessageHandler import MessageHandler
-from src.SantaExchange.MessageTypes.Announcement import AnnouncementMessage
-from src.SantaExchange.MessageTypes.Introduction import IntroductionMessage
-from src.SantaExchange.MessageTypes.Ready import ReadyMessage
-from src.SantaExchange.MessageTypes.Shuffle import ShuffleMessage
-from src.SantaExchange.UserInterface import UserInterface
+from SantaExchange import Message
+from SantaExchange.Crypto.CSPRNG import CSPRNG
+from SantaExchange.Crypto.CommutativeCipher import CommutativeCipher
+from SantaExchange.MessageHandler import MessageHandler
+from SantaExchange.MessageTypes.Announcement import AnnouncementMessage
+from SantaExchange.MessageTypes.Introduction import IntroductionMessage
+from SantaExchange.MessageTypes.Ready import ReadyMessage
+from SantaExchange.MessageTypes.Shuffle import ShuffleMessage
+from SantaExchange.UserInterface import UserInterface
 
 logger = logging.getLogger(__name__)
 
@@ -129,6 +129,10 @@ class Brain:
 			self.chosen_participants = sorted([name for name, key in confirmed_existing])
 		self.message_handler.send_message(ready_message, self.signing_key)
 
+		# Might as well start building ciphers and preparing immediately. Also, if the first user in the list happens
+		# to be the last person to send the start message, something needs to trigger the santa loop
+		self.santa_loop_and_send()
+
 	def receive_message(self, message: Message):
 		# If this is an introduction message, it needs special handling
 		if isinstance(message, IntroductionMessage):
@@ -149,14 +153,13 @@ class Brain:
 				self.received_messages[name].append(message)
 
 			# Each received message triggers the main function of this class
-			messages_to_send = self.santa_loop()
-			for message in messages_to_send:
-				self.message_handler.send_message(message, self.signing_key)
+			self.santa_loop_and_send()
 
 	def receive_introduction_message(self, message: IntroductionMessage):
 		discovered_new_participant = False
 		name = message.get_name()
 		key = message.get_key()
+		logger.debug(f'Receiving introduction from user {name}')
 
 		with self.thread_lock:
 			if name in self.known_participants and self.known_participants[name][0] != key:
@@ -174,11 +177,21 @@ class Brain:
 		# Send an introduction message, if we are ready for that
 		if (
 				discovered_new_participant
-				and self.introduction_message is not None
-				and self.signing_key is not None
 		):
+			logger.debug(f'Received new user {name}')
 			self.user_interface.receive_user(name)
-			self.message_handler.send_message(self.introduction_message, self.signing_key)
+			if (
+					self.introduction_message is not None
+					and self.signing_key is not None
+			):
+				logger.debug('Sending own introduction message')
+				self.message_handler.send_message(self.introduction_message, self.signing_key)
+
+
+	def santa_loop_and_send(self):
+		messages_to_send = self.santa_loop()
+		for message in messages_to_send:
+			self.message_handler.send_message(message, self.signing_key)
 
 	# Santa's brain will be driven by receiving messages. We'll call this main method each time we receive a message.
 	# This is probably inefficient, but it makes it easier to follow what the code is doing
@@ -203,6 +216,7 @@ class Brain:
 					or self.announcement_build_cipher is None
 					or self.announcement_shuffle_cipher is None
 			):
+				logger.debug('Building ciphers')
 				should_continue = self.build_ciphers()
 				if not should_continue:
 					return messages_to_send
@@ -212,6 +226,7 @@ class Brain:
 
 			# Shuffle cards
 			if not self.sent_card_shuffling:
+				logger.debug('Shuffling vards')
 				shuffle_message = self.build_shuffle_message(all_participants)
 				if shuffle_message is None:
 					return messages_to_send
@@ -220,6 +235,7 @@ class Brain:
 
 			# Decrypt shuffled cards
 			if not self.sent_card_decryption:
+				logger.debug('Decrypting shuffled cards')
 				decrypt_cards_message = self.build_decrypt_cards_message(all_participants)
 				if decrypt_cards_message is None:
 					return messages_to_send
@@ -432,6 +448,7 @@ class Brain:
 		return ShuffleMessage(self.own_name, decrypted_cards, DECRYPT_CARDS_STAGE)
 
 	def decrypt_card_value(self, card: bytes):
+		logger.debug('Decrypting own drawn card')
 		decrypted_card_bytes = self.card_exchange_cipher.decode(card)
 		if decrypted_card_bytes not in self.card_values:
 			logging.critical(f'Received an invalid card after shuffling. Secret santa exchange failed!')
diff --git a/src/SantaExchange/UserInterface.py b/src/SantaExchange/UserInterface.py
index fb24e76..56095bb 100644
--- a/src/SantaExchange/UserInterface.py
+++ b/src/SantaExchange/UserInterface.py
@@ -6,11 +6,13 @@ class UserInterface:
 		self.user_info_listeners: list[Callable[[str, str], None]] = []
 		self.start_listeners: list[Callable[[list[str]], None]] = []
 
+	# Must be implemented by child class
 	def receive_user(self, name: str):
-		pass
+		raise NotImplementedError
 
+	# Must be implemented by child class
 	def announce_recipient(self, name: str, other_info: str):
-		pass
+		raise NotImplementedError
 
 	def set_user_info(self, name: str, info_for_santa: str):
 		for listener in self.user_info_listeners: