"""
Class to handle Orso header information that changes gradually during the reduction process.
"""

import platform
import sys
from datetime import datetime

from orsopy import fileio

from . import __version__


class Header:
    """orso compatible output file header content"""

    def __init__(self):
        self.owner                           = None
        self.experiment                      = None
        self.sample                          = None
        self.measurement_instrument_settings = None
        self.measurement_scheme              = None
        self.measurement_data_files          = []
        self.measurement_additional_files    = []

        self.reduction = fileio.Reduction(
            software    = fileio.Software('eos', version=__version__),
            call        = 'placeholder',
            computer    = platform.node(),
            timestamp   = datetime.now(),
            creator     = None,
            corrections = ['histogramming in lambda and alpha_f',
                           'gravity'],
            )
    #-------------------------------------------------------------------------------------------------
    def data_source(self):
        return fileio.DataSource(
            self.owner,
            self.experiment,
            self.sample,
            fileio.Measurement(
                instrument_settings = self.measurement_instrument_settings,
                scheme              = self.measurement_scheme,
                data_files          = self.measurement_data_files,
                additional_files    = self.measurement_additional_files,
                ),
        )
    #-------------------------------------------------------------------------------------------------
    def columns(self):
        cols = [
            fileio.Column('Qz', '1/angstrom', 'normal momentum transfer'),
            fileio.Column('R', '', 'specular reflectivity'),
            fileio.ErrorColumn(error_of='R', error_type='uncertainty', distribution='gaussian', value_is='sigma'),
            fileio.ErrorColumn(error_of='Qz', error_type='resolution', distribution='gaussian', value_is='sigma'),
            ]
        return cols
    #-------------------------------------------------------------------------------------------------
    def orso_header(self, columns=None, extra_columns=[]):
        """
        Generate ORSO header from a copy of this class' data.
        """
        ds = fileio.DataSource.from_dict(self.data_source().to_dict())
        red = fileio.Reduction.from_dict(self.reduction.to_dict())
        if columns is None:
            columns = self.columns()
        return fileio.Orso(ds, red, columns+extra_columns)
    #-------------------------------------------------------------------------------------------------
    def create_call_string(self):
        callString = ' '.join(sys.argv)
        if '-Y' not in callString:
            callString += f' -Y {datetime.now().year}'
        return callString
    #-------------------------------------------------------------------------------------------------