# coding=utf-8
from earthdiagnostics.utils import Utils
import os
from bscearth.utils.log import Log
import six


class CDFTools(object):
    """
    Class to run CDFTools executables

    :param path: path to CDFTOOLS binaries
    :type path: str
    """

    def __init__(self, path=''):
        self.path = path

    # noinspection PyShadowingBuiltins
    def run(self, command, input, output=None, options=None, log_level=Log.INFO, input_option=None):
        """
        Runs one of the CDFTools

        :param command: executable to run
        :type command: str | iterable
        :param input: input file
        :type input: str
        :param output: output file. Not all tools support this parameter
        :type options: str
        :param options: options for the tool.
        :type options: str | list[str] | Tuple[str]
        :param log_level: log level at which the output of the cdftool command will be added
        :type log_level: int
        :param input_option: option to add before input file
        :type input_option: str
        """

        line = [os.path.join(self.path, command)]

        self._check_command_existence(line[0])
        if input_option:
            line.append(input_option)
        self._check_input(command, input, line)
        if options:
            if isinstance(options, six.string_types):
                options = options.split()
            for option in options:
                line.append(str(option))
        if output:
            if input == output:
                raise ValueError('Input and output file can not be the same on CDFTools')
            line.append('-o')
            line.append(output)
        Log.debug('Executing {0}', ' '.join(line))
        shell_output = Utils.execute_shell_command(line, log_level)

        self._check_output_was_created(line, output)
        return shell_output

    @staticmethod
    def _check_output_was_created(line, output):
        if output:
            if not os.path.exists(output):
                raise Exception('Error executing {0}\n Output file not created', ' '.join(line))

    # noinspection PyShadowingBuiltins
    @staticmethod
    def _check_input(command, input, line):
        if input:
            if isinstance(input, six.string_types):
                line.append(input)
                if not os.path.exists(input):
                    raise ValueError('Error executing {0}\n Input file {1} file does not exist', command, input)
            else:
                for element in input:
                    line.append(element)
                    if not os.path.exists(element):
                        raise ValueError('Error executing {0}\n Input file {1} file does not exist', command, element)

    # noinspection PyMethodMayBeStatic
    def is_exe(self, fpath):
        return os.path.isfile(fpath) and os.access(fpath, os.X_OK)

    def _check_command_existence(self, command):
        if self.path:
            if self.is_exe(os.path.join(self.path, command)):
                return
        else:
            for path in os.environ["PATH"].split(os.pathsep):
                path = path.strip('"')
                exe_file = os.path.join(path, command)
                if self.is_exe(exe_file):
                    return
        raise ValueError('Error executing {0}\n Command does not exist in {1}', command, self.path)