""" JobRunningMatchedRatioPolicy

  Policy that calculates the efficiency following the formula::

    ( running ) / ( running + matched + received + checking )

  if the denominator is smaller than 10, it does not take any decision.

"""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function

from DIRAC import S_OK
from DIRAC.ResourceStatusSystem.PolicySystem.PolicyBase import PolicyBase

__RCSID__ = "c59810311 (2021-10-01 10:44:25 +0200) Chris Burr <christopher.burr@cern.ch>"


class JobRunningMatchedRatioPolicy(PolicyBase):
    """
    The JobRunningMatchedRatioPolicy class is a policy that checks the efficiency of the
    jobs according to what is on JobDB.

      Evaluates the JobRunningMatchedRatioPolicy results given by the JobCommand.JobCommand
    """

    @staticmethod
    def _evaluate(commandResult):
        """_evaluate

        efficiency < 0.5 :: Banned
        efficiency < 0.9 :: Degraded

        """

        result = {"Status": None, "Reason": None}

        if not commandResult["OK"]:
            result["Status"] = "Error"
            result["Reason"] = commandResult["Message"]
            return S_OK(result)

        commandResult = commandResult["Value"]

        if not commandResult:
            result["Status"] = "Unknown"
            result["Reason"] = "No values to take a decision"
            return S_OK(result)

        commandResult = commandResult[0]

        if not commandResult:
            result["Status"] = "Unknown"
            result["Reason"] = "No values to take a decision"
            return S_OK(result)

        running = commandResult["Running"]
        matched = commandResult["Matched"]
        received = commandResult["Received"]
        checking = commandResult["Checking"]

        total = running + matched + received + checking

        # we want a minimum amount of jobs to take a decision ( at least 10 pilots )
        if total < 10:
            result["Status"] = "Unknown"
            result["Reason"] = "Not enough jobs to take a decision"
            return S_OK(result)

        efficiency = running / total

        if efficiency <= 0.5:
            result["Status"] = "Banned"
        elif efficiency <= 0.9:
            result["Status"] = "Degraded"
        else:
            result["Status"] = "Active"

        result["Reason"] = "Job Running / Matched ratio of %.2f" % efficiency
        return S_OK(result)