import os
import shlex
import subprocess
from uuid import uuid4

from redis import Redis

def error_filename(job_id, error_dir):
    return f"{error_dir}/job_{job_id}.error"

def launch_job(redis_conn: Redis, filepath, filetype, redisurl, error_dir):
    """Launch a job in the background"""
    job_id = str(uuid4())
    command = [
        "python3", "-m" "scripts.worker", filetype, filepath, redisurl, job_id]
    job = {
        "job_id": job_id, "command": shlex.join(command), "status": "pending",
        "filename": os.path.basename(filepath), "percent": 0
    }
    redis_conn.hset(name=job["job_id"], mapping=job)

    if not os.path.exists(error_dir):
        os.mkdir(error_dir)

    with open(error_filename(job_id, error_dir), "w") as errorfile:
        subprocess.Popen(command, stderr=errorfile)

    return job

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