"""Handle jobs"""
import os
import shlex
import subprocess
from uuid import uuid4
from datetime import timedelta

from redis import Redis

def error_filename(job_id, error_dir):
    "Compute the path of the file where errors will be dumped."
    return f"{error_dir}/job_{job_id}.error"

def build_file_verification_job(
        redis_conn: Redis, filepath: str, filetype: str, redisurl: str,
        ttl_seconds: int):
    "Build a file verification job"
    job_id = str(uuid4())
    command = [
        "python3", "-m", "scripts.validate_file", filetype, filepath, redisurl,
        job_id
    ]
    the_job = {
        "job_id": job_id, "command": shlex.join(command), "status": "pending",
        "filename": os.path.basename(filepath), "percent": 0,
        "filetype": filetype, "job-type": "file-verification"
    }
    redis_conn.hset(name=the_job["job_id"], mapping=the_job)
    redis_conn.expire(name=the_job["job_id"], time=timedelta(seconds=ttl_seconds))
    return the_job

def launch_job(the_job: dict, redisurl: str, error_dir):
    """Launch a job in the background"""
    if not os.path.exists(error_dir):
        os.mkdir(error_dir)

    job_id = the_job["job_id"]
    with open(error_filename(job_id, error_dir),
              "w",
              encoding="utf-8") as errorfile:
        subprocess.Popen( # pylint: disable=[consider-using-with]
            ["python3", "-m", "scripts.worker", redisurl, job_id],
            stderr=errorfile)

    return the_job

def job(redis_conn, job_id: str):
    "Retrieve the job"
    return redis_conn.hgetall(job_id)