# -*- mode: python; coding: utf-8 -*
# Copyright (c) 2018 Radio Astronomy Software Group
# Licensed under the 2-clause BSD License

"""
Base class for objects with UVParameter attributes.

Subclassed by UVData and Telescope.
"""
from __future__ import absolute_import, division, print_function

import numpy as np
import warnings

from . import parameter as uvp
from . import version as uvversion


def _warning(msg, *a, **kwargs):
    """Improve the printing of user warnings."""
    return str(msg) + '\n'


class UVBase(object):
    """
    Base class for objects with UVParameter attributes.

    This class is intended to be subclassed and its init method should be
    called in the subclass init after all associated UVParameter attributes are
    defined. The init method of this base class creates properties
    (named using UVParameter.name) from all the UVParameter attributes on the subclass.
    AngleParameter and LocationParameter attributes also have extra convenience
    properties defined:\n
        AngleParameter:\n
            UVParameter.name+'_degrees'\n
        LocationParameter:\n
            UVParameter.name+'_lat_lon_alt'\n
            UVParameter.name+'_lat_lon_alt_degrees'
    """

    def __init__(self):
        """Create properties from UVParameter attributes."""

        warnings.formatwarning = _warning

        # set any UVParameter attributes to be properties
        for p in self:
            this_param = getattr(self, p)
            attr_name = this_param.name
            setattr(self.__class__, attr_name, property(self.prop_fget(p),
                                                        self.prop_fset(p)))
            if isinstance(this_param, uvp.AngleParameter):
                setattr(self.__class__, attr_name + '_degrees',
                        property(self.degree_prop_fget(p), self.degree_prop_fset(p)))
            elif isinstance(this_param, uvp.LocationParameter):
                setattr(self.__class__, attr_name + '_lat_lon_alt',
                        property(self.lat_lon_alt_prop_fget(p),
                                 self.lat_lon_alt_prop_fset(p)))
                setattr(self.__class__, attr_name + '_lat_lon_alt_degrees',
                        property(self.lat_lon_alt_degrees_prop_fget(p),
                                 self.lat_lon_alt_degrees_prop_fset(p)))

        # String to add to history of any files written with this version of pyuvdata
        self.pyuvdata_version_str = ('  Read/written with pyuvdata version: '
                                     + uvversion.version + '.')
        if uvversion.git_hash is not '':
            self.pyuvdata_version_str += ('  Git origin: ' + uvversion.git_origin
                                          + '.  Git hash: ' + uvversion.git_hash
                                          + '.  Git branch: ' + uvversion.git_branch
                                          + '.  Git description: ' + uvversion.git_description + '.')

    def prop_fget(self, param_name):
        """Getter method for UVParameter properties."""
        def fget(self):
            this_param = getattr(self, param_name)
            return this_param.value
        return fget

    def prop_fset(self, param_name):
        """Setter method for UVParameter properties."""
        def fset(self, value):
            this_param = getattr(self, param_name)
            this_param.value = value
            setattr(self, param_name, this_param)
        return fset

    def degree_prop_fget(self, param_name):
        """Degree getter method for AngleParameter properties."""
        def fget(self):
            this_param = getattr(self, param_name)
            return this_param.degrees()
        return fget

    def degree_prop_fset(self, param_name):
        """Degree setter method for AngleParameter properties."""
        def fset(self, value):
            this_param = getattr(self, param_name)
            this_param.set_degrees(value)
            setattr(self, param_name, this_param)
        return fset

    def lat_lon_alt_prop_fget(self, param_name):
        """Lat/lon/alt getter method for LocationParameter properties."""
        def fget(self):
            this_param = getattr(self, param_name)
            return this_param.lat_lon_alt()
        return fget

    def lat_lon_alt_prop_fset(self, param_name):
        """Lat/lon/alt setter method for LocationParameter properties."""
        def fset(self, value):
            this_param = getattr(self, param_name)
            this_param.set_lat_lon_alt(value)
            setattr(self, param_name, this_param)
        return fset

    def lat_lon_alt_degrees_prop_fget(self, param_name):
        """Lat/lon/alt degree getter method for LocationParameter properties."""
        def fget(self):
            this_param = getattr(self, param_name)
            return this_param.lat_lon_alt_degrees()
        return fget

    def lat_lon_alt_degrees_prop_fset(self, param_name):
        """Lat/lon/alt degree setter method for LocationParameter properties."""
        def fset(self, value):
            this_param = getattr(self, param_name)
            this_param.set_lat_lon_alt_degrees(value)
            setattr(self, param_name, this_param)
        return fset

    def __iter__(self):
        """Iterator for all UVParameter attributes."""
        attribute_list = [a for a in dir(self) if not a.startswith('__')
                          and not callable(getattr(self, a))]
        param_list = []
        for a in attribute_list:
            attr = getattr(self, a)
            if isinstance(attr, uvp.UVParameter):
                param_list.append(a)
        for a in param_list:
            yield a

    def required(self):
        """Iterator for all required UVParameter attributes."""
        attribute_list = [a for a in dir(self) if not a.startswith('__')
                          and not callable(getattr(self, a))]
        required_list = []
        for a in attribute_list:
            attr = getattr(self, a)
            if isinstance(attr, uvp.UVParameter):
                if attr.required:
                    required_list.append(a)
        for a in required_list:
            yield a

    def extra(self):
        """Iterator for all non-required UVParameter attributes."""
        attribute_list = [a for a in dir(self) if not a.startswith('__')
                          and not callable(getattr(self, a))]
        extra_list = []
        for a in attribute_list:
            attr = getattr(self, a)
            if isinstance(attr, uvp.UVParameter):
                if not attr.required:
                    extra_list.append(a)
        for a in extra_list:
            yield a

    def __eq__(self, other, check_extra=True):
        """
        Equal if classes match and parameters are equal.

        If check_extra is True, include all parameters, otherwise only include
        required parameters.
        """
        if isinstance(other, self.__class__):
            # only check that required parameters are identical
            self_required = []
            other_required = []
            for p in self.required():
                self_required.append(p)
            for p in other.required():
                other_required.append(p)
            if set(self_required) != set(other_required):
                print('Sets of required parameters do not match. Left is {lset},'
                      ' right is {rset}'.format(lset=self_required,
                                                rset=other_required))
                return False

            if check_extra:
                self_extra = []
                other_extra = []
                for p in self.extra():
                    self_extra.append(p)
                for p in other.extra():
                    other_extra.append(p)
                if set(self_extra) != set(other_extra):
                    print('Sets of extra parameters do not match. Left is {lset},'
                          ' right is {rset}'.format(lset=self_extra,
                                                    rset=other_extra))
                    return False

                p_check = self_required + self_extra
            else:
                p_check = self_required

            p_equal = True
            for p in p_check:
                self_param = getattr(self, p)
                other_param = getattr(other, p)
                if self_param != other_param:
                    print('parameter {} does not match. Left is {},'
                          ' right is {}'.format(p, self_param.value, other_param.value))
                    p_equal = False
            return p_equal
        else:
            print('Classes do not match')
            return False

    def __ne__(self, other):
        """Not equal."""
        return not self.__eq__(other)

    def check(self, check_extra=True, run_check_acceptability=True):
        """
        Check that required parameters exist. Check that parameters have
        appropriate shapes and optionally that the values are acceptable.

        Args:
            check_extra: If true, check shapes and values on all parameters,
                otherwise only check required parameters.
            run_check_acceptability: Option to check if values in required parameters
                are acceptable. Default is True.
        """
        if check_extra:
            p_check = [p for p in self.required()] + [p for p in self.extra()]
        else:
            p_check = [p for p in self.required()]

        for p in p_check:
            param = getattr(self, p)
            # Check required parameter exists
            if param.value is None:
                if param.required is True:
                    raise ValueError('Required UVParameter ' + p
                                     + ' has not been set.')
            else:
                # Check parameter shape
                eshape = param.expected_shape(self)
                # default value of eshape is ()

                if eshape == 'str':
                    # Check that it's a string
                    if not isinstance(param.value, str):
                        raise ValueError('UVParameter ' + p + 'expected to be '
                                         'string, but is not')
                else:
                    # Check the shape of the parameter value. Note that np.shape
                    # returns an empty tuple for single numbers. eshape should do the same.
                    if not np.shape(param.value) == eshape:
                        raise ValueError('UVParameter {param} is not expected shape. '
                                         'Parameter shape is {pshape}, expected shape is '
                                         '{eshape}.'.format(param=p, pshape=np.shape(param.value),
                                                            eshape=eshape))
                    if eshape == ():
                        # Single element
                        if not isinstance(param.value, param.expected_type):
                            raise ValueError('UVParameter ' + p + ' is not the appropriate'
                                             ' type. Is: ' + str(type(param.value))
                                             + '. Should be: ' + str(param.expected_type))
                    else:
                        if isinstance(param.value, list):
                            # List needs to be handled differently than array
                            # list values may be different types, so they all need to be checked
                            for item in param.value:
                                if not isinstance(item, param.expected_type):
                                    raise ValueError('UVParameter ' + p + ' is not the'
                                                     ' appropriate type. Is: '
                                                     + str(type(param.value[0])) + '. Should'
                                                     ' be: ' + str(param.expected_type))
                        else:
                            # Array
                            if not isinstance(param.value.item(0), param.expected_type):
                                raise ValueError('UVParameter ' + p + ' is not the appropriate'
                                                 ' type. Is: ' + str(param.value.dtype)
                                                 + '. Should be: ' + str(param.expected_type))

                if run_check_acceptability:
                    accept, message = param.check_acceptability()
                    if not accept:
                        raise ValueError('UVParameter ' + p + ' has unacceptable values. '
                                         + message)

        return True