Add reaction and message

lib/helpers/api_helper.dart

@@ -1,5 +1,6 @@
 import "dart:convert";
 import "dart:io";
+import "package:markdown/markdown.dart";
 import "package:nexusbot/controllers/login_controller.dart";
 import "package:nexusbot/controllers/settings_controller.dart";
 import "package:nexusbot/models/registration.dart";
@@ -34,30 +35,68 @@ class ApiHelper {
     return json.decode(response.body)["room_id"];
   }
 
+  Future<String> sendMessage(message, {required String room}) async {
+    final settings = ref.read(SettingsController.provider)!;
+    final response = await http.put(
+      settings.homeserver.replace(
+        path:
+            "_matrix/client/v3/rooms/${await getRoomId(room)}/send/m.room.message/${getTxn()}",
+      ),
+      headers: await getHeaders(),
+      body: json.encode({
+        "msgtype": "m.text",
+        "body": message,
+        "format": "org.matrix.custom.html",
+        "formatted_body": markdownToHtml(message),
+      }),
+    );
+
+    if (response.statusCode != 200) {
+      throw Exception("Message send failed for room $room: ${response.body}");
+    }
+
+    return json.decode(response.body)["event_id"];
+  }
+
+  Future<String> react(
+    String reaction, {
+    required String eventId,
+    required String room,
+  }) async {
+    final settings = ref.read(SettingsController.provider)!;
+    final response = await http.put(
+      settings.homeserver.replace(
+        path:
+            "_matrix/client/v3/rooms/${await getRoomId(room)}/send/m.reaction/${getTxn()}",
+      ),
+      headers: await getHeaders(),
+      body: json.encode({
+        "m.relates_to": {
+          "rel_type": "m.annotation",
+          "event_id": eventId,
+          "key": reaction,
+        },
+      }),
+    );
+
+    if (response.statusCode != 200) {
+      throw Exception("Reaction failed for room $room: ${response.body}");
+    }
+
+    return json.decode(response.body)["event_id"];
+  }
+
   Future<Response> register(Request request) async {
     final settings = ref.read(SettingsController.provider)!;
     final registration = Registration.fromJson(
       json.decode(await request.readAsString()),
     );
 
-    final response = await http.post(
-      settings.homeserver.replace(
-        path:
-            "_matrix/client/v3/rooms/${await getRoomId(settings.adminRoom)}/send/m.room.message/${getTxn()}",
-      ),
-      headers: await getHeaders(),
-      body: json.encode({
-        "msgtype": "m.text",
-        "body":
-            "Signup request from ${registration.username}, email is: ${registration.email}.",
-      }),
-    );
+    final event = await sendMessage("""# Registration request
+- Username: `${registration.username}`
+- Email: `${registration.email}`""", room: settings.adminRoom);
 
-    if (response.statusCode != 200) {
-      throw Exception(
-        "Registration failed for ${registration.username}: ${response.body}",
-      );
-    }
+    await react("✅", eventId: event, room: settings.adminRoom);
 
     return Response.found(settings.successUri);
   }