Initial commit for adding in a fhirrequests wrapper

Author: Nick Bragdon

.gitignore

@@ -148,6 +148,12 @@ dmypy.json
 # Cython debug symbols
 cython_debug/
 
+# VS Code
+.vscode/
+
+# Virtual Env
+bb2_env/
+
 # PyCharm
 #  JetBrains specific template is maintainted in a separate JetBrains.gitignore that can
 #  be found at https://github.com/github/gitignore/blob/main/Global/JetBrains.gitignore

src/constants.py

@@ -0,0 +1,3 @@
+SDK_HEADER = "python"
+SDK_HEADER_KEY = "X-BLUEBUTTON-SDK"
+REFRESH_TOKEN_ENDPOINT = "/o/token/"

src/fhirRequest.py

@@ -0,0 +1,54 @@
+import datetime
+from constants import REFRESH_TOKEN_ENDPOINT, SDK_HEADER, SDK_HEADER_KEY
+import requests
+from requests.adapters import HTTPAdapter, Retry
+
+
+def fhirRequest(bb, config):
+    auth_token = config.auth_token
+    new_auth_token = handle_expired(bb, auth_token, config.refresh_token)
+
+    if new_auth_token is not None:
+        auth_token = new_auth_token
+
+    retry_config = Retry(
+        total=3, backoff_factor=0.2, status_forcelist=[500, 502, 503, 504]
+    )
+    full_url = bb.base_url + "/v" + bb.version + config.url
+    headers = {
+        "Authorization": "Bearer " + auth_token.access_token,
+        [SDK_HEADER_KEY]: SDK_HEADER,
+    }
+    adapter = HTTPAdapter(max_retries=retry_config)
+    sesh = requests.Session()
+    sesh.mount("https://", adapter)
+    sesh.mount("http://", adapter)
+    response = sesh.get(url=full_url, params=config.params, headers=headers)
+
+    return {"auth_token": new_auth_token, "response": response}
+
+
+def handle_expired(bb, auth_token):
+    if datetime.datetime.now() > auth_token.expires_at:
+        return refresh_access_token(bb, auth_token.refresh_token)
+
+    return None
+
+
+def refresh_access_token(bb, refresh_token):
+    full_url = bb.base_url + "/v" + bb.version + REFRESH_TOKEN_ENDPOINT
+
+    params = {
+        "client_id": bb.client_id,
+        "grant_type": "refresh_token",
+        "refresh_token": refresh_token,
+    }
+
+    my_response = requests.post(
+        url=full_url, params=params, auth=(bb.client_id, bb.client_secret)
+    )
+    response_json = my_response.json()
+    response_json["expires_at"] = datetime.datetime.now() + datetime.timedelta(
+        seconds=response_json["expires_in"]
+    )
+    return response_json