✨ Implement Cast and Spoil Ballot (#42)

* ✨ Implement Cast/Spoil Ballot and Default Election Description

- Implement calls to cast/spoil ballots
- Implement calls to get default election description
- Add serialization methods until new electionguard package is pulled in
- Add jsons package
- Add electionguard package

* 🧪 Add postman collection for existing tests

Author: keithrfung

Pipfile

@@ -10,7 +10,9 @@ mypy = "*"
 pylint = "*"
 
 [packages]
+electionguard = "*"
 fastapi = "*"
+jsons = "*"
 uvicorn = "*"
 
 [requires]

Pipfile.lock

@@ -1,6 +1,8 @@
 from fastapi import APIRouter
 
-from app.api.v1.endpoints import ping
+from app.api.v1.endpoints import ballot, ping, election
 
 api_router = APIRouter()
 api_router.include_router(ping.router, prefix="/ping", tags=["ping"])
+api_router.include_router(election.router, prefix="/election", tags=["election"])
+api_router.include_router(ballot.router, prefix="/ballot", tags=["ballot"])

app/api/v1/api.py

@@ -0,0 +1,65 @@
+from electionguard.ballot import CiphertextBallot
+from electionguard.ballot_box import accept_ballot, BallotBoxState
+from electionguard.election import (
+    CiphertextElectionContext,
+    ElectionDescription,
+    InternalElectionDescription,
+)
+from electionguard.ballot_store import BallotStore
+from fastapi import APIRouter, Body, HTTPException
+from pydantic import BaseModel
+from typing import Any
+from app.utils.serialize import write_json, write_json_object
+
+router = APIRouter()
+
+
+class AcceptBallotRequest(BaseModel):
+    ballot: Any
+    description: Any
+    context: Any
+
+
+@router.post("/cast")
+def cast_ballot(request: AcceptBallotRequest = Body(...)) -> Any:
+    """
+    Cast ballot
+    """
+    cast_ballot = handle_ballot(request, BallotBoxState.CAST)
+    if not cast_ballot:
+        raise HTTPException(
+            status_code=500,
+            detail="Ballot failed to be cast",
+        )
+    return write_json_object(cast_ballot)
+
+
+@router.post("/spoil")
+def spoil_ballot(request: AcceptBallotRequest = Body(...)) -> Any:
+    """
+    Spoil ballot
+    """
+    spoiled_ballot = handle_ballot(request, BallotBoxState.SPOILED)
+    if not spoiled_ballot:
+        raise HTTPException(
+            status_code=500,
+            detail="Ballot failed to be spoiled",
+        )
+    return write_json_object(spoiled_ballot)
+
+
+def handle_ballot(request: AcceptBallotRequest, state: BallotBoxState) -> Any:
+    ballot = CiphertextBallot.from_json(write_json(request.ballot))
+    description = ElectionDescription.from_json(write_json(request.description))
+    internal_description = InternalElectionDescription(description)
+    context = CiphertextElectionContext.from_json(write_json(request.context))
+
+    accepted_ballot = accept_ballot(
+        ballot,
+        state,
+        internal_description,
+        context,
+        BallotStore(),
+    )
+
+    return accepted_ballot

app/api/v1/endpoints/ballot.py

@@ -0,0 +1,27 @@
+from electionguard.election import ElectionDescription
+from fastapi import APIRouter, HTTPException
+from os.path import realpath, join
+from typing import Any
+
+
+router = APIRouter()
+
+DATA_FOLDER_PATH = realpath(join(__file__, "../../../../data"))
+DESCRIPTION_FILE = join(DATA_FOLDER_PATH, "election_description.json")
+READ = "r"
+
+
+@router.get("/description")
+def get_default_election_description() -> Any:
+    """
+    Return a default election description
+    """
+    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