added the data service as an external component (class)

caimira/apps/calculator/data_service.py

@@ -0,0 +1,65 @@
+import dataclasses
+import json
+import logging
+
+from tornado.web import RequestHandler
+from tornado.httpclient import AsyncHTTPClient, HTTPRequest
+
+LOG = logging.getLogger(__name__)
+
+
+@dataclasses.dataclass
+class DataService(RequestHandler):
+    '''
+    Responsible for establishing a connection to a 
+    database through a REST API by handling authentication 
+    and fetching data. It utilizes the Tornado web framework
+    for asynchronous HTTP requests.
+    '''
+    # Credentials used for authentication
+    credentials: dict
+
+    # Host URL for the CAiMIRA Data Service API
+    host: str = 'https://caimira-data-api.app.cern.ch'
+    
+    async def login(self):
+        client_email = self.credentials["data_service_client_email"]
+        client_password = self.credentials['data_service_client_password']
+
+        if (client_email == None or client_password == None):
+            # If the credentials are not defined, an error is thrown.
+            return self.send_error(500)
+            
+        http_client = AsyncHTTPClient()
+        headers = {'Content-type': 'application/json'}
+        json_body = { "email": f"{client_email}", "password": f"{client_password}"}
+
+        try:
+            response = await http_client.fetch(HTTPRequest(
+                url=self.host + '/login',
+                method='POST',
+                headers=headers,
+                body=json.dumps(json_body),
+            ),
+            raise_error=True)
+        except Exception as err:
+            LOG.error("Something went wrong: %s" % err)
+            self.send_error(500)
+
+        return json.loads(response.body)['access_token']
+    
+    async def fetch(self, access_token: str):
+        http_client = AsyncHTTPClient()
+        headers = {'Authorization': f'Bearer {access_token}'}
+
+        try:
+            response = await http_client.fetch(HTTPRequest(
+                url=self.host + '/data',
+                method='GET',
+                headers=headers,
+            ),
+            raise_error=True)
+        except Exception as e:
+            print("Something went wrong: %s" % e)
+
+        return json.loads(response.body)