import logging

from doit import get_var

from ee.ds import DataSetManager


def configure_logging():
    log_level = get_var("log-level", None)

    if log_level:
        ee_logger = logging.getLogger("ee")
        formatter = logging.Formatter("%(levelname)s: %(message)s")
        ch = logging.StreamHandler()
        ch.setFormatter(formatter)
        ee_logger.addHandler(ch)

        ee_logger.setLevel(log_level)


class DoItConfig(object):
    def __init__(self):
        self._dsm = None  # type: DataSetManager
        self._data_sets = {}

    def configure(self, *, data_set_manager: DataSetManager):
        self._dsm = data_set_manager

    @property
    def dsm(self):
        if not self._dsm:
            raise Exception("The DataSetManager has not been set")
        return self._dsm

    def data_sets_for(self, task):
        try:
            return self._data_sets[task]
        except KeyError:
            raise KeyError("No such task registered in this module: {}".format(task))

    def out_data_set_for(self, task):
        return self.data_sets_for(task)[0]

    def input_data_sets_for(self, task):
        return self.data_sets_for(task)[1]

    def set_data_sets_for(self, task, out_dataset: str, *in_datasets: str):
        self._data_sets[task] = [out_dataset, list(in_datasets)]

    def change_data_sets_for_task(self, task, _callable):
        ds = self._data_sets[task]
        ds[1] = _callable(ds[1])

    def append_in_data_set_for_task(self, task, *data_sets: str):
        ds = self._data_sets[task]
        ds[1] = ds[1] + list(data_sets)