def list_election_candidates(election_id): # noqa: E501
"""List candidates
# noqa: E501
:param election_id: Id of the election
:type election_id: int
:rtype: Candidate
"""
try:
election_id = Web3.toChecksumAddress(election_id)
except ValueError:
message = ('Election ID %s is not an Ethereum address' % election_id)
error = Error(code=1, message=message)
return error, 400
contract = current_app.config['FACTORY_CONTRACT']
if not contract.call('electionExist', [election_id]):
message = ("Election with id %s does not exist" % election_id)
error = Error(code=2, message=message)
return error, 404
provider = contract.provider
election_abi = current_app.config['ELECTION_ABI']
contract = Ethereum(provider, election_id, election_abi)
candidates_number = contract.call('numCandidates')
candidates = list()
for index in range(candidates_number):
candidates.append(lookup_candidate(election_id, index))
return candidates
def get_candidate_votes(election_id, candidate_id): # noqa: E501
"""Get votes for a candidate
# noqa: E501
:param election_id: Id of the election
:type election_id: int
:param candidate_id: Id of the candidate
:type candidate_id: int
:rtype: Object
"""
try:
election_id = Web3.toChecksumAddress(election_id)
except ValueError:
message = ('Election ID %s is not an Ethereum address' %
election_id)
error = Error(
code=1,
message=message
)
return error, 400
contract = current_app.config['FACTORY_CONTRACT']
if not contract.call('electionExist', [election_id]):
message = ("Election with id %s does not exist" % election_id)
error = Error(
code=2,
message=message
)
return error, 404
provider = contract.provider
election_abi = current_app.config['ELECTION_ABI']
contract = Ethereum(provider, election_id, election_abi)
candidates_number = contract.call('numCandidates')
if candidate_id < 0 or candidate_id > candidates_number:
message = ("Candidate with id %s does not exist" % candidate_id)
error = Error(
code=2,
message=message
)
return error, 404
candidate = contract.call('candidates', [candidate_id])
votes = {
'votes': candidate[2]
}
return votes
def lookup_candidate(election_id, candidate_id): # noqa: E501
"""Lookup Candidate
# noqa: E501
:param election_id: Id of the election
:type election_id: int
:param candidate_id: Id of the candidate
:type candidate_id: int
:rtype: Candidate
"""
try:
election_id = Web3.toChecksumAddress(election_id)
except ValueError:
message = ('Election ID %s is not an Ethereum address' % election_id)
error = Error(code=1, message=message)
return error, 400
contract = current_app.config['FACTORY_CONTRACT']
if not contract.call('electionExist', [election_id]):
message = ("Election with id %s does not exist" % election_id)
error = Error(code=2, message=message)
return error, 404
provider = contract.provider
election_abi = current_app.config['ELECTION_ABI']
contract = Ethereum(provider, election_id, election_abi)
candidates_number = contract.call('numCandidates')
if candidate_id < 0 or candidate_id > candidates_number:
message = ("Candidate with id %s does not exist" % candidate_id)
error = Error(code=2, message=message)
return error, 404
candidate = contract.call('candidates', [candidate_id])
candidate_repr = Candidate(id=candidate_id,
name=candidate[0],
description=candidate[1],
votes=candidate[2])
return candidate_repr
def create_candidate_vote(election_id, candidate_id): # noqa: E501
"""Vote for a candidate
# noqa: E501
:param election_id: Id of the election
:type election_id: int
:param candidate_id: Id of the candidate
:type candidate_id: int
:rtype: None
"""
try:
election_id = Web3.toChecksumAddress(election_id)
except ValueError:
message = ('Election ID %s is not an Ethereum address' %
election_id)
error = Error(
code=1,
message=message
)
return error, 400
contract = current_app.config['FACTORY_CONTRACT']
if not contract.call('electionExist', [election_id]):
message = ("Election with id %s does not exist" % election_id)
error = Error(
code=2,
message=message
)
return error, 404
provider = contract.provider
election_abi = current_app.config['ELECTION_ABI']
contract = Ethereum(provider, election_id, election_abi)
candidates_number = contract.call('numCandidates')
if candidate_id < 0 or candidate_id > candidates_number:
message = ("Candidate with id %s does not exist" % candidate_id)
error = Error(
code=2,
message=message
)
return error, 404
if connexion.request.is_json:
info = connexion.request.get_json()
has_voted = contract.call('voted', [info['account']])
if has_voted:
error = Error(
code=6,
message='Already voted before'
)
return error, 401
contract.send('vote', info['account'], info['pkey'], [candidate_id])
def create_election(): # noqa: E501
"""
Create an election on the voting systemd
Returns:
:obj:`~democracy_server.models.election.Election`: Created election
representation
"""
if connexion.request.is_json:
election = CreateElection.from_dict(connexion.request.get_json())
factory = current_app.config['FACTORY_CONTRACT']
account = election.account
pkey = election.pkey
name = election.name
description = election.description
candidates = election.candidates
election = factory.call('electionNames', [name])
if len(candidates) < 2:
message = ('At least two candidates are needed to start an election.'
'%s provided' % str(len(candidates)))
error = Error(code=5, message=message)
return error, 400
if election != "0x0000000000000000000000000000000000000000":
message = ('Election with name \'%s\' already exists on the system' %
name)
error = Error(code=3, message=message)
return error, 400
try:
factory.send('createElection', account, pkey, [name, description])
except ValueError as transact_error:
message = str(transact_error)
error = Error(code=100, message=message)
return error, 500
election = factory.call('electionNames', [name])
provider = factory.provider
election_abi = current_app.config['ELECTION_ABI']
contract = Ethereum(provider, election, election_abi)
for candidate in candidates:
contract.send('addCandidate', account, pkey,
[candidate.name, candidate.description])
contract.send('commit', account, pkey)
return show_election_by_id(election), 201
def show_election_by_id(election_id): # noqa: E501
"""Lookup election
# noqa: E501
:param election_id: The id of the election to retrieve
:type election_id: str
:rtype: Election
"""
try:
election_id = Web3.toChecksumAddress(election_id)
except ValueError:
message = ('Election ID %s is not an Ethereum address' % election_id)
error = Error(code=1, message=message)
return error, 400
contract = current_app.config['FACTORY_CONTRACT']
if not contract.call('electionExist', [election_id]):
message = ("Election with id %s does not exist" % election_id)
error = Error(code=2, message=message)
return error, 404
provider = contract.provider
election_abi = current_app.config['ELECTION_ABI']
contract = Ethereum(provider, election_id, election_abi)
candidates_number = contract.call('numCandidates')
candidates = list()
for index in range(candidates_number):
candidate = contract.call('candidates', [index])
name = candidate[0]
description = candidate[1]
votes = candidate[2]
candidates.append(
Candidate(name=name, description=description, votes=votes))
election = Election(id=election_id,
name=contract.call('name'),
description=contract.call('description'),
candidates=candidates)
return election
def main():
logging.basicConfig(level=logging.INFO)
"""
Swagger server entrypoint function. It makes use of argparse library to
build a beatiful command line
"""
python_dir = os.path.dirname(os.path.relpath(__file__))
specification_dir = os.path.join(python_dir, 'swagger')
swagger_file = os.path.abspath(
os.path.join(specification_dir, 'swagger.yaml'))
parser = argparse.ArgumentParser()
parser.add_argument('--factory-abi',
dest='factory',
required=True,
help='Smart contract Factory JSON interface')
parser.add_argument('--election-abi',
dest='election',
required=True,
help='Smart contract Election JSON interface')
parser.add_argument('--address',
required=True,
help='Smart contract address')
parser.add_argument('--infura',
required=True,
help='Infure URL to build the provider')
parser.add_argument('-p',
'--port',
type=int,
default=8080,
help='Port to run the API')
parser.add_argument('--swagger-file',
dest='swagger_file',
default=swagger_file)
parser.add_argument('-d', '--debug', action='store_true', default=False)
args = parser.parse_args()
swagger_file = os.path.abspath(args.swagger_file)
if args.debug:
logging.basicConfig(level=logging.DEBUG)
app = connexion.FlaskApp(__name__,
specification_dir=os.path.dirname(swagger_file),
debug=args.debug)
with open(args.factory, 'r') as _file:
json_repr = json.loads(_file.read())
if isinstance(json_repr, dict) and 'abi' in json_repr:
factory_abi = json_repr['abi']
else:
factory_abi = json_repr
with open(args.election, 'r') as _file:
json_repr = json.loads(_file.read())
if isinstance(json_repr, dict) and 'abi' in json_repr:
election_abi = json_repr['abi']
else:
election_abi = json_repr
provider = Web3.HTTPProvider(args.infura)
factory_contract = Ethereum(provider, args.address, factory_abi)
app.app.json_encoder = encoder.JSONEncoder
app.add_api(os.path.basename(swagger_file),
arguments={'title': 'Ethereum Voting'},
pythonic_params=True)
app.app.config['FACTORY_CONTRACT'] = factory_contract
app.app.config['ELECTION_ABI'] = election_abi
app.run(port=args.port)