# coding=utf-8
"""Compute the MOC for oceanic basins"""
import numpy as np
import six
from bscearth.utils.log import Log

import iris
from iris.coords import DimCoord, AuxCoord
from iris.cube import CubeList
import iris.analysis

from earthdiagnostics.constants import Basins
from earthdiagnostics.diagnostic import Diagnostic, DiagnosticBasinListOption
from earthdiagnostics.modelingrealm import ModelingRealms
from earthdiagnostics.utils import Utils, TempFile


class Moc(Diagnostic):
    """
    Compute the MOC for oceanic basins

    :original author: Virginie Guemas <virginie.guemas@bsc.es>
    :contributor: Javier Vegas-Regidor<javier.vegas@bsc.es>

    :created: March 2012
    :last modified: June 2016

    :param data_manager: data management object
    :type data_manager: DataManager
    :param startdate: startdate
    :type startdate: str
    :param member: member number
    :type member: int
    :param chunk: chunk's number
    :type chunk: int
    """

    alias = 'moc'
    "Diagnostic alias for the configuration file"

    vsftmyz = 'vsftmyz'

    def __init__(self, data_manager, startdate, member, chunk, basins):
        Diagnostic.__init__(self, data_manager)
        self.startdate = startdate
        self.member = member
        self.chunk = chunk
        self.basins = basins

    def __str__(self):
        basins = []
        basins.extend(self.basins.keys())
        return 'MOC Startdate: {0.startdate} Member: {0.member} ' \
            'Chunk: {0.chunk} Basins: {1}'.format(self, basins)

    def __hash__(self):
        return hash(str(self))

    def __eq__(self, other):
        if self._different_type(other):
            return False
        return self.startdate == other.startdate and self.member == other.member and self.chunk == other.chunk

    @classmethod
    def generate_jobs(cls, diags, options):
        """
        Create a job for each chunk to compute the diagnostic

        :param diags: Diagnostics manager class
        :type diags: Diags
        :param options: None
        :type options: list[str]
        :return:
        """
        basins = Basins()
        options_available = (
            DiagnosticBasinListOption(
                'basins',
                'glob'
            ),
        )

        options = cls.process_options(options, options_available)
        basins = options['basins']
        if not basins:
            Log.error('Basins not recognized')
            return ()

        try:
            e1v = iris.load_cube('mesh_hgr.nc', 'e1v')
        except iris.exceptions.ConstraintMismatchError:
            e1v = iris.load_cube('mesh_hgr.nc', 'e1v_0')
        try:
            e3v = iris.load_cube('mesh_hgr.nc', 'e3t_0')
        except iris.exceptions.ConstraintMismatchError:
            e3v = iris.load_cube('mesh_hgr.nc', 'e3t_0')
        e1v = iris.util.squeeze(e1v).data
        e3v = iris.util.squeeze(e3v).data
        if len(e3v.shape) == 1:
            e3v = np.expand_dims(e3v.data, 1)
            e3v = np.expand_dims(e3v, 2)
        else:
            e3v = e3v.data
        mesh = - e1v * e3v

        masks = {}
        basins.sort()
        for basin in basins:
            masks[basin.name] = Utils.get_mask(basin) * mesh / 1e6

        job_list = list()
        for startdate, member, chunk in diags.config.experiment.get_chunk_list():
            job_list.append(Moc(diags.data_manager, startdate, member, chunk, masks))
        return job_list

    def request_data(self):
        """Request data required by the diagnostic"""
        self.variable_file = self.request_chunk(ModelingRealms.ocean, 'vo', self.startdate, self.member, self.chunk)

    def declare_data_generated(self):
        """Declare data to be generated by the diagnostic"""
        self.results = self.declare_chunk(ModelingRealms.ocean, Moc.vsftmyz, self.startdate, self.member, self.chunk)

    def compute(self):
        """Run the diagnostic"""
        data = iris.load_cube(self.variable_file.local_file)
        Log.debug(str(data))
        try:
            data.coord('i')
        except iris.exceptions.CoordinateNotFoundError:
            dims = len(data.shape)
            data.add_dim_coord(iris.coords.DimCoord(np.arange(data.shape[dims - 1]), var_name='i'), dims - 1)
        try:
            data.coord('j')
        except iris.exceptions.CoordinateNotFoundError:
            dims = len(data.shape)
            data.add_dim_coord(iris.coords.DimCoord(np.arange(data.shape[dims - 2]), var_name='j'), dims - 2)

        for coord_name in ('model_level_number', 'Vertical V levels', 'lev'):
            if data.coords(coord_name):
                coord = data.coord(coord_name)
                coord.standard_name = 'depth'
                coord.long_name = 'depth'
                break

        moc_results = CubeList()
        for map_slice in data.slices_over('time'):
            # Force data loading
            map_slice.data
            Log.debug(str(map_slice))
            for basin, mask in six.iteritems(self.basins):
                moc = map_slice.collapsed(('i', 'depth'), iris.analysis.SUM, weights=mask)
                moc.add_aux_coord(
                    AuxCoord([basin], var_name='region', standard_name='region')
                )
                moc_results.append(moc)
        results = moc_results.merge_cube()
        temp = TempFile.get()
        results.var_name = Moc.vsftmyz
        results.remove_coord('i')
        results.remove_coord('depth')
        results.remove_coord('longitude')
        results.units = 'Sverdrup'
        iris.save(results, temp)
        self.results.set_local_file(temp)