✨ New Election context endpoint (#101)

Author: rkorsak

app/api/v1/mediator/election.py

@@ -1,9 +1,15 @@
 from os.path import realpath, join
 from typing import Any
-from electionguard.election import ElectionDescription, ElectionConstants
-from fastapi import APIRouter, HTTPException
-
-
+from electionguard.election import (
+    ElectionDescription,
+    ElectionConstants,
+    make_ciphertext_election_context,
+)
+from electionguard.group import ElementModP
+from electionguard.serializable import read_json_object, write_json_object
+from fastapi import APIRouter, Body
+
+from ..models import ElectionContextRequest
 from ..tags import CONFIGURE_ELECTION
 
 router = APIRouter()
@@ -22,17 +28,22 @@ def get_election_constants() -> Any:
     return constants.to_json_object()
 
 
-@router.get("/description", tags=[CONFIGURE_ELECTION])
-def get_default_election_description() -> Any:
+@router.post("/context", tags=[CONFIGURE_ELECTION])
+def build_election_context(request: ElectionContextRequest = Body(...)) -> Any:
     """
-    Return a default election description
+    Build a CiphertextElectionContext for a given election
     """
-    with open(DESCRIPTION_FILE, READ) as description_file:
-        result = description_file.read()
-        description = ElectionDescription.from_json(result)
-    if not description:
-        raise HTTPException(
-            status_code=500,
-            detail="Default description not found",
-        )
-    return description
+    description: ElectionDescription = ElectionDescription.from_json_object(
+        request.description
+    )
+    elgamal_public_key: ElementModP = read_json_object(
+        request.elgamal_public_key, ElementModP
+    )
+    number_of_guardians = request.number_of_guardians
+    quorum = request.quorum
+
+    context = make_ciphertext_election_context(
+        number_of_guardians, quorum, elgamal_public_key, description.crypto_hash()
+    )
+
+    return write_json_object(context)

app/api/v1/models/election.py

@@ -1,7 +1,19 @@
 from typing import Any
+from .base import Base
 
-__all__ = ["ElectionDescription", "CiphertextElectionContext"]
+__all__ = ["CiphertextElectionContext", "ElectionContextRequest", "ElectionDescription"]
 
 ElectionDescription = Any
 
 CiphertextElectionContext = Any
+
+
+class ElectionContextRequest(Base):
+    """
+    A request to build an Election Context for a given election
+    """
+
+    description: ElectionDescription
+    elgamal_public_key: str
+    number_of_guardians: int
+    quorum: int