"""Build common script-entry structure."""
import sys
import logging
from typing import Callable
from argparse import Namespace
from logging import StreamHandler

from redis import Redis
from MySQLdb import Connection
from gn_libs.mysqldb import database_connection

from uploader import jobs
from uploader.check_connections import check_db, check_redis

from scripts.redis_logger import setup_redis_logger

def build_main(
        args: Namespace,
        run_fn: Callable[
            [Redis, Connection, str, Namespace, logging.Logger],
            int
        ],
        loggername: str
) -> Callable[[],int]:
    """Build a function to be used as an entry-point for scripts."""
    def main():
        try:
            logging.basicConfig(
                format=(
                    "%(asctime)s - %(levelname)s %(name)s: "
                    "(%(pathname)s: %(lineno)d) %(message)s"),
                level=args.loglevel)
            logger = logging.getLogger(loggername)
            with (Redis.from_url(args.redisuri, decode_responses=True) as rconn,
                  database_connection(args.databaseuri) as dbconn):
                fqjobid = jobs.job_key(args.redisprefix, args.jobid)
                rconn.hset(fqjobid, "status", "started")
                logger.addHandler(setup_redis_logger(
                    rconn,
                    fqjobid,
                    f"{fqjobid}:log-messages",
                    args.redisexpiry))
                logger.addHandler(StreamHandler(stream=sys.stdout))

                check_db(args.databaseuri)
                check_redis(args.redisuri)
                if not args.rqtl2bundle.exists():
                    logger.error("File not found: '%s'.", args.rqtl2bundle)
                    return 2

                returncode = run_fn(rconn, dbconn, fqjobid, args, logger)
                if returncode == 0:
                    rconn.hset(fqjobid, "status", "completed:success")
                    return returncode
                rconn.hset(fqjobid, "status", "completed:error")
                return returncode
        except Exception as _exc:# pylint: disable=[broad-except]
            logger.error("The process failed!", exc_info=True)
            rconn.hset(fqjobid, "status", "completed:error")
            return 4

    return main