config.py

import datetime

import sqlalchemy as sa

from webservices.env import env
from webservices.common.models import db


def get_cycle_start(year):
    """Round year down to the first year of the two-year election cycle. Used
    when filtering original data for election cycle.
    """
    return year if year % 2 == 1 else year - 1


def get_cycle_end(year):
    """Round year up to the last year of the two-year election cycle. Used
    when querying partitioned itemized data for election cycle.
    """
    return year if year % 2 == 0 else year + 1


CURRENT_YEAR = datetime.datetime.now().year

SQL_CONFIG = {
    "START_YEAR": get_cycle_start(1980),
    "START_YEAR_AGGREGATE": get_cycle_start(2008),
    "END_YEAR_ITEMIZED": get_cycle_start(CURRENT_YEAR),
}

REQUIRED_CREDS = (
    "SQLA_CONN",
    "FEC_SLACK_TOKEN",
)

REQUIRED_SERVICES = ("aws-elasticache-redis", "s3", "aws-elasticsearch")

REQUIRED_TABLES = tuple(db.Model.metadata.tables.keys()) + (
    "ofec_pacronyms",
    "ofec_nicknames",
    "ofec_zips_districts",
)


def load_table(name):
    try:
        return sa.Table(name, db.metadata, autoload_with=db.engine)
    except sa.exc.NoSuchTableError:
        return None


def check_keys(keys, getter, formatter):
    missing = [key for key in keys if getter(key) is None]
    if missing:
        print(formatter.format(", ".join(keys)))
    return missing


CHECKS = [
    (REQUIRED_CREDS, env.get_credential, "Missing creds {}"),
    (
        REQUIRED_SERVICES,
        lambda service: env.get_service(label=service),
        "Missing services {}",
    ),
    (REQUIRED_TABLES, load_table, "Missing tables {}"),
]


def check_config():
    results = [check_keys(*check) for check in CHECKS]
    if any(results):
        raise RuntimeError("Invalid configuration: {0}".format(results))