import subprocess

import numpy as np
from autosubmit.config.log import Log
from cdo import Cdo
from nco import Nco
import tempfile
import os
import pwd
import shutil


class Utils(object):
    """
    Container class for miscellaneous utility methods
    """

    nco = Nco()
    """An instance of Nco class ready to be used"""
    cdo = Cdo()
    """An instance of Cdo class ready to be used"""

    @staticmethod
    def setminmax(filename, variable_list):
        """
        Sets the valid_max and valid_min values to the current max and min values on the file
        :param filename: path to file
        :type filename: str
        :param variable_list: list of variables in which valid_min and valid_max will be set
        :type variable_list: str | list
        """
        if isinstance(variable_list, basestring):
            variable_list = variable_list.split()

        Log.info('Getting max and min values for {0}', ' '.join(variable_list))

        dataset = Utils.nco.readCdf(filename)
        for variable in variable_list:
            var = dataset.variables[variable]
            values = [np.max(var), np.min(var)]
            Utils.nco.ncatted(input=filename, output=filename,
                              options='-h -a valid_max,{0},m,f,{1}'.format(variable, values[0]))
            Utils.nco.ncatted(input=filename, output=filename,
                              options='-h -a valid_min,{0},m,f,{1}'.format(variable, values[1]))

    @staticmethod
    def rename_variable(filepath, old_name, new_name, must_exist=True, rename_dimension=False):
        """
        Rename multiple variables from a NetCDF file
        :param filepath: path to file
        :type filepath: str
        :param old_name: variable's name to change
        :type old_name: str
        :param new_name: new name
        :type new_name: str
        :param must_exist: if True, the function will raise an exception if the variable name does not exist
        :type must_exist: bool
        :param rename_dimension: if True, also rename dimensions with the same name
        :type rename_dimension: bool
        """
        Utils.rename_variables(filepath, {old_name: new_name}, must_exist, rename_dimension)

    @staticmethod
    def rename_variables(filepath, dic_names, must_exist=True, rename_dimension=False):
        """
        Rename multiple variables from a NetCDF file
        :param filepath: path to file
        :type filepath: str
        :param dic_names: dictionary containing old names as keys and new names as values
        :type dic_names: dict
        :param must_exist: if True, the function will raise an exception if the variable name does not exist
        :type must_exist: bool
        :param rename_dimension: if True, also rename dimensions with the same name
        :type rename_dimension: bool
        """
        handler = Utils.nco.openCdf(filepath)

        for old_name, new_name in dic_names.items():
            if old_name in handler.variables:
                handler.renameVariable(old_name, new_name)
            elif must_exist:
                raise Exception("Variable {0} does not exist in file {1}".format(old_name, filepath))

            if rename_dimension:
                if old_name in handler.dimensions:
                    handler.renameDimension(old_name, new_name)
                elif must_exist:
                    raise Exception("Variable {0} does not exist in file {1}".format(old_name, filepath))

        handler.close()

    @staticmethod
    def move_file(source, destiny):
        """
        Moves a file from source to destiny, creating dirs if necessary

        :param source: path to source
        :type source: str
        :param destiny:  path to destiny
        :type destiny: str
        """
        if not os.path.exists(os.path.dirname(destiny)):
            os.makedirs(os.path.dirname(destiny))
        shutil.move(source, destiny)

    @staticmethod
    def execute_shell_command(command, log_level=Log.DEBUG):
        """
        Executes a sheel command
        :param command: command to execute
        :type command: str|list
        :param log_level: log level to use for command output
        :type log_level: int
        :return: command output
        :rtype: list
        """
        if isinstance(command, basestring):
            command = command.split()
        process = subprocess.Popen(command, stdout=subprocess.PIPE)
        output = list()
        comunicate = process.communicate()
        for line in comunicate:
            if not line:
                continue
            Log.log.log(log_level, line)
            output.append(line)
        if process.returncode != 0:
            raise Exception('Error executing {0}\n Return code: {1}', ' '.join(command), process.returncode)
        return output

    @staticmethod
    def get_cardinal_coordinate(value, latitude):
        """
        Translates a degree value into degrees NSEO

        :param value: value in degress
        :type value: float
        :param latitude: if True, value is latitude, Otherwise value is longitude
        :type latitude: bool
        :return: transformed value
        :rtype: str
        """
        if latitude:
            if value < 0:
                direction = 'S'
            else:
                direction = 'N'
        else:
            if value < 0:
                direction = 'W'
            else:
                direction = 'E'
        return str(abs(value)) + direction


class TempFile(object):
    """
    Class to manage temporal files
    """

    autoclean = True
    """
    If True, new temporary files are added to the list for future cleaning
    """
    files = list()
    """
    List of files to clean automatically
    """
    scratch_folder = os.path.join('/scratch', pwd.getpwuid(os.getuid())[0])
    """
    Scratch folder to create temporary files on it
    """
    prefix = 'temp'
    """
    Prefix for temporary filenames
    """

    @staticmethod
    def get(filename=None, clean=None):
        """
        Gets a new temporal filename, storing it for automated cleaning

        :param filename: if it is not none, the function will use this filename instead of a random one
        :type filename: str
        :param clean: if true, stores filename for cleaning
        :type clean: bool
        :return: path to the temporal file
        :rtype: str
        """
        if clean is None:
            clean = TempFile.autoclean

        if filename:
            path = os.path.join(TempFile.scratch_folder, filename)
        else:
            path = tempfile.mkstemp(dir=TempFile.scratch_folder, prefix=TempFile.prefix, suffix='.nc')[1]

        if clean:
            TempFile.files.append(path)

        return path

    @staticmethod
    def clean():
        """
        Removes all temporary files created with Tempfile until now
        """
        for temp_file in TempFile.files:
            if os.path.exists(temp_file):
                os.remove(temp_file)
        TempFile.files = list()