import os

from django.core.management.base import BaseCommand
from django.conf import settings

try:
    import crontab
except (ImportError, ModuleNotFoundError):
    crontab = None


def find_job(tab, comment):
    for job in tab:
        if job.comment == comment:
            return job
    return None


class Command(BaseCommand):
    """
    Installs a cron tasks.
    """

    help = "Installs a cron tasks."

    def add_arguments(self, parser):
        parser.add_argument("--action", default="")

    def handle(self, *args, **options):
        """Installs Cron

        :param args: None
        :param options: None
        :return: None
        """
        if not os.path.isfile("/usr/bin/crontab"):
            print("WARNING: /usr/bin/crontab not found, skipping crontab config.")
            return

        if not crontab:
            print("WARNING: crontab module is not installed, skipping crontab config.")
            return

        action = options.get("action")
        tab = crontab.CronTab(user=True)
        virtualenv = os.environ.get("VIRTUAL_ENV", None)

        cwd = settings.PROJECT_DIR.replace("/", "_")

        jobs = [
            {
                "name": "{}_janeway_cron_job".format(cwd),
                "time": 30,
                "task": "execute_cron_tasks",
                "type": "mins",
            },
            {
                "name": "{}_janeway_ithenticate_job".format(cwd),
                "time": 30,
                "task": "store_ithenticate_scores",
                "type": "mins",
            },
            {
                "name": "{}_janeway_sitemaps_job".format(cwd),
                "time": 4,
                "task": "generate_sitemaps",
                "type": "hourly",
            },
            {
                "name": "{}_janeway_reader_notifications".format(cwd),
                "time": 23,
                "task": "send_publication_notifications",
                "type": "daily",
            },
            {
                "name": "{}_import_ror_data".format(cwd),
                "day": 3,
                "task": "import_ror_data",
                "type": "monthly",
            },
            {
                "name": "{}_match_ror_ids".format(cwd),
                "day": 4,
                "task": "match_ror_ids",
                "type": "monthly",
            },
        ]

        if settings.ENABLE_ENHANCED_MAILGUN_FEATURES:
            jobs.append(
                {
                    "name": "{}_janeway_mailgun_job".format(cwd),
                    "time": 59,
                    "task": "check_mailgun_stat",
                    "type": "mins",
                }
            )

        if settings.SITE_SEARCH_INDEXING_FREQUENCY:
            task_time, task_type = settings.SITE_SEARCH_INDEXING_FREQUENCY
            jobs.append(
                {
                    "name": "{}_site_search_data".format(cwd),
                    "time": task_time,
                    "task": "generate_site_search_data",
                    "type": task_type,
                }
            )

        for job in jobs:
            current_job = find_job(tab, job["name"])

            if not current_job:
                django_command = "{0}/manage.py {1}".format(
                    settings.BASE_DIR, job["task"]
                )
                if virtualenv:
                    command = "%s/bin/python3 %s" % (virtualenv, django_command)
                else:
                    command = "%s" % (django_command)

                cron_job = tab.new(command, comment=job["name"])

                if job.get("type") == "monthly":
                    cron_job.setall("47 2 {} * *".format(job["day"]))
                elif job.get("type") == "daily":
                    cron_job.setall("0 {} * * *".format(job["time"]))
                elif job.get("type") == "hourly":
                    cron_job.setall("0 */{} * * *".format(job["time"]))
                else:
                    cron_job.minute.every(job["time"])

            else:
                print("{name} cron job already exists.".format(name=job["name"]))

        if action == "test":
            print(tab.render())
        elif action == "quiet":
            pass
        else:
            tab.write()