from box import Box
from earthdiagnostics import Diagnostic, TempFile, Utils, cdftools


class VerticalMean(Diagnostic):
    """
        Choose vertical level in ocean, or vertically average between
        2 or more  ocean levels

        Created in  February 2012      Author : vguemas@ic3.cat
        Modified (more generic, i.e. for any input var) in December 2014
        Author : eleftheria.exarchou@ic3.cat

        # :param input_file: input file name
        # :param output_file: output file name  (=> 2D field  )
        # :param variable: variable name
        # :param lev_min: upper depth of the layer (in level number)
        # :param lev_max: lower depth of the layer (in level number. If same as the upper layer, then the script just
        selects this layer. If its different, a vertical integral (weighted) between upper and lower level is computed
        """

    def __init__(self, data_manager, startdate, member, chunk, variable, box):
        Diagnostic.__init__(self, data_manager)
        self.startdate = startdate
        self.member = member
        self.chunk = chunk
        self.variable = variable
        self.box = box
        self.required_vars = [variable]
        self.generated_vars = [variable + 'vmean']

    @classmethod
    def generate_jobs(cls, diags, options):
        num_options = len(options) - 1
        if num_options < 1:
            raise Exception('You must specify the variable to average vertically')
        if num_options > 3:
            raise Exception('You must specify between one and three parameters for the vertical mean')
        variable = options[1]

        box = Box(True)
        if num_options >= 2:
            box.min_depth = float(options[2])
        if num_options >= 2:
            box.max_depth = float(options[3])

        job_list = list()
        for startdate in diags.startdates:
            for member in diags.members:
                for chunk in range(1, diags.chunks + 1):
                    job_list.append(VerticalMean(diags.data_manager, startdate, member, chunk,
                                                 variable, box))
        return job_list

    def compute(self):
        temp = TempFile.get()
        variable_file = self.data_manager.get_file('ocean', self.variable, self.startdate, self.member, self.chunk)

        handler = Utils.openCdf(variable_file)
        if self.box.min_depth is None:
            lev_min = handler.variables['lev'][0]
        else:
            lev_min = self.box.min_depth

        if self.box.max_depth is None:
            lev_max = handler.variables['lev'][-1]
        else:
            lev_max = self.box.max_depth
        handler.close()

        cdftools.run('cdfvertmean', input=variable_file, output=temp, options=[self.variable, 'T', lev_min, lev_max,
                                                                               '-debug'])
        Utils.setminmax(temp, '{0}_vert_mean'.format(self.variable))
        self.data_manager.send_file(temp, 'ocean', self.variable + 'vmean', self.startdate, self.member, self.chunk,
                                    box=self.box, rename_var='{0}_vert_mean'.format(self.variable))