# -*- coding: utf-8 -*-
"""
Various types used in ObsPy.

:copyright:
    The ObsPy Development Team (devs@obspy.org)
:license:
    GNU Lesser General Public License, Version 3
    (https://www.gnu.org/copyleft/lesser.html)
"""
from collections import OrderedDict

try:
    import __builtin__
    list = __builtin__.list
except ImportError:
    pass


class Enum(object):
    """
    Enumerated type (enum) implementation for Python.

    :type enums: list[str]
    :type replace: dict, optional
    :param replace: Dictionary of keys which are replaced by values.

    .. rubric:: Example

    >>> from obspy.core.util import Enum
    >>> units = Enum(["m", "s", "m/s", "m/(s*s)", "m*s", "other"])

    There are different ways to access the correct enum values:

        >>> print(units.get('m/s'))
        m/s
        >>> print(units['S'])
        s
        >>> print(units.OTHER)
        other
        >>> print(units[3])
        m/(s*s)
        >>> units.xxx  # doctest: +ELLIPSIS
        Traceback (most recent call last):
        ...
        AttributeError: 'xxx'

    Changing enum values will not work:

        >>> units.m = 5  # doctest: +ELLIPSIS
        Traceback (most recent call last):
        ...
        NotImplementedError
        >>> units['m'] = 'xxx'  # doctest: +ELLIPSIS
        Traceback (most recent call last):
        ...
        NotImplementedError

    Calling with a value will either return the mapped enum value or ``None``:

        >>> print(units("M*s"))
        m*s
        >>> units('xxx')
        >>> print(units(5))
        other

    The following enum allows replacing certain entries:

        >>> units2 = Enum(["m", "s", "m/s", "m/(s*s)", "m*s", "other"],
        ...               replace={'meter': 'm'})
        >>> print(units2('m'))
        m
        >>> print(units2('meter'))
        m
    """
    # marker needed for for usage within ABC classes
    __isabstractmethod__ = False

    def __init__(self, enums, replace={}):
        self.__enums = OrderedDict((str(e).lower(), e) for e in enums)
        self.__replace = replace

    def __call__(self, enum):
        try:
            return self.get(enum)
        except Exception:
            return None

    def get(self, key):
        if isinstance(key, int):
            return list(self.__enums.values())[key]
        if key in self._Enum__replace:
            return self._Enum__replace[key.lower()]
        return self.__enums.__getitem__(key.lower())

    def __getattr__(self, name):
        try:
            return self.get(name)
        except KeyError:
            raise AttributeError("'%s'" % (name, ))

    def __setattr__(self, name, value):
        if name == '_Enum__enums':
            self.__dict__[name] = value
            return
        elif name == '_Enum__replace':
            super(Enum, self).__setattr__(name, value)
            return
        raise NotImplementedError

    __getitem__ = get
    __setitem__ = __setattr__

    def __contains__(self, value):
        return value.lower() in self.__enums

    def values(self):
        return list(self.__enums.values())

    def keys(self):
        return list(self.__enums.keys())

    def items(self):
        return list(self.__enums.items())

    def iteritems(self):
        return iter(self.__enums.items())

    def __str__(self):
        """
        >>> enum = Enum(["c", "a", "b"])
        >>> print(enum)
        Enum(["c", "a", "b"])
        >>> enum = Enum(["not existing",
        ...              "not reported",
        ...              "earthquake",
        ...              "controlled explosion",
        ...              "experimental explosion",
        ...              "industrial explosion"])
        >>> print(enum)  # doctest: +NORMALIZE_WHITESPACE
        Enum(["not existing", "not reported", ..., "experimental explosion",
              "industrial explosion"])
        """
        return self.__repr__()

    def __repr__(self):
        """
        >>> enum = Enum(["c", "a", "b"])
        >>> print(repr(enum))
        Enum(["c", "a", "b"])
        >>> enum = Enum(["not existing",
        ...              "not reported",
        ...              "earthquake",
        ...              "controlled explosion",
        ...              "experimental explosion",
        ...              "industrial explosion"])
        >>> print(repr(enum))  # doctest: +NORMALIZE_WHITESPACE
        Enum(["not existing", "not reported", ..., "experimental explosion",
              "industrial explosion"])
        """
        def _repr_list_of_keys(keys):
            return ", ".join('"{}"'.format(_i) for _i in keys)

        keys = list(self.__enums.keys())
        key_repr = _repr_list_of_keys(keys)
        index = int(len(keys))
        while len(key_repr) > 100:
            if index == 0:
                key_repr = "..."
                break
            index -= 1
            key_repr = (_repr_list_of_keys(keys[:index]) + ", ..., " +
                        _repr_list_of_keys(keys[-index:]))
        return "Enum([{}])".format(key_repr)

    def _repr_pretty_(self, p, cycle):
        p.text(str(self))


class CustomComplex(complex):
    """
    Helper class to inherit from and which stores a complex number that is
    extendable.
    """
    def __new__(cls, *args):
        return super(CustomComplex, cls).__new__(cls, *args)

    def __init__(self, *args):
        pass

    def __iadd__(self, other):
        new = self.__class__(complex(self) + other)
        new.__dict__.update(**self.__dict__)
        self = new

    def __imul__(self, other):
        new = self.__class__(complex(self) * other)
        new.__dict__.update(**self.__dict__)
        self = new


class CustomFloat(float):
    """
    Helper class to inherit from and which stores a float number that is
    extendable.
    """
    def __new__(cls, *args):
        return super(CustomFloat, cls).__new__(cls, *args)

    def __init__(self, *args):
        pass

    def __iadd__(self, other):
        new = self.__class__(float(self) + other)
        new.__dict__.update(**self.__dict__)
        self = new

    def __imul__(self, other):
        new = self.__class__(float(self) * other)
        new.__dict__.update(**self.__dict__)
        self = new


class FloatWithUncertainties(CustomFloat):
    """
    Helper class to inherit from and which stores a float with a given valid
    range, upper/lower uncertainties and eventual additional attributes.
    """
    _minimum = float("-inf")
    _maximum = float("inf")

    def __new__(cls, value, **kwargs):
        if not cls._minimum <= float(value) <= cls._maximum:
            msg = "value %s out of bounds (%s, %s)"
            msg = msg % (value, cls._minimum, cls._maximum)
            raise ValueError(msg)
        return super(FloatWithUncertainties, cls).__new__(cls, value)

    def __init__(self, value, lower_uncertainty=None, upper_uncertainty=None,
                 measurement_method=None):
        # set uncertainties, if initialized with similar type
        if isinstance(value, FloatWithUncertainties):
            if lower_uncertainty is None:
                lower_uncertainty = value.lower_uncertainty
            if upper_uncertainty is None:
                upper_uncertainty = value.upper_uncertainty
        # set/override uncertainties, if explicitly specified
        self.lower_uncertainty = lower_uncertainty
        self.upper_uncertainty = upper_uncertainty
        self.measurement_method = measurement_method


class FloatWithUncertaintiesFixedUnit(FloatWithUncertainties):
    """
    Float value that has lower and upper uncertainties and a fixed unit
    associated with it. Helper class to inherit from setting a custom value for
    the fixed unit (set unit in derived class as class attribute).

    :type value: float
    :param value: Actual float value.
    :type lower_uncertainty: float
    :param lower_uncertainty: Lower uncertainty (aka minusError)
    :type upper_uncertainty: float
    :param upper_uncertainty: Upper uncertainty (aka plusError)
    :type unit: str
    :param unit: Unit for physical interpretation of the float value
        (read only).
    :type measurement_method: str
    :param measurement_method: Method used in the measurement.
    """
    _unit = ""

    def __init__(self, value, lower_uncertainty=None, upper_uncertainty=None,
                 measurement_method=None):
        super(FloatWithUncertaintiesFixedUnit, self).__init__(
            value, lower_uncertainty=lower_uncertainty,
            upper_uncertainty=upper_uncertainty,
            measurement_method=measurement_method)

    @property
    def unit(self):
        return self._unit

    @unit.setter
    def unit(self, value):
        msg = "Unit is fixed for this object class."
        raise ValueError(msg)


class FloatWithUncertaintiesAndUnit(FloatWithUncertainties):
    """
    Float value that has lower and upper uncertainties and a unit associated
    with it.

    :type value: float
    :param value: Actual float value.
    :type lower_uncertainty: float
    :param lower_uncertainty: Lower uncertainty (aka minusError)
    :type upper_uncertainty: float
    :param upper_uncertainty: Upper uncertainty (aka plusError)
    :type unit: str
    :param unit: Unit for physical interpretation of the float value.
    :type measurement_method: str
    :param measurement_method: Method used in the measurement.
    """
    def __init__(self, value, lower_uncertainty=None, upper_uncertainty=None,
                 unit=None, measurement_method=None):
        super(FloatWithUncertaintiesAndUnit, self).__init__(
            value, lower_uncertainty=lower_uncertainty,
            upper_uncertainty=upper_uncertainty,
            measurement_method=measurement_method)
        if unit is None and hasattr(value, "unit"):
            unit = value.unit
        self.unit = unit

    @property
    def unit(self):
        return self._unit

    @unit.setter
    def unit(self, value):
        self._unit = value


class _ComplexUncertainty(complex):
    """
    Complex class which can accept a python None as an argument and map it to
    a float value for storage.
    """
    _none = float("-inf")

    @classmethod
    def _encode(cls, arg):
        if arg is None:
            return cls._none
        return arg

    @classmethod
    def _decode(cls, arg):
        if arg == cls._none:
            return None
        return arg

    def __new__(cls, *args):
        cargs = [cls._encode(a) for a in args]
        if len(args) < 1:
            cargs.append(cls._none)
        if len(args) < 2:
            if args[0] is None:
                cargs.append(cls._none)
            else:
                cargs.append(0)
        return super(_ComplexUncertainty, cls).__new__(cls, *cargs)

    @property
    def real(self):
        _real = super(_ComplexUncertainty, self).real
        return self._decode(_real)

    @property
    def imag(self):
        _imag = super(_ComplexUncertainty, self).imag
        return self._decode(_imag)


class ComplexWithUncertainties(CustomComplex):
    """
    Complex class which can store uncertainties.

    Accepts FloatWithUncertainties and returns FloatWithUncertainties from
    property methods.
    """
    _lower_uncertainty = None
    _upper_uncertainty = None

    @staticmethod
    def _attr(obj, attr):
        try:
            return getattr(obj, attr)
        except AttributeError:
            return None

    @staticmethod
    def _uncertainty(value):
        if isinstance(value, tuple) or isinstance(value, list):
            u = _ComplexUncertainty(*value)
        else:
            u = _ComplexUncertainty(value)
        if u.real is None and u.imag is None:
            return None
        return u

    @property
    def lower_uncertainty(self):
        return self._lower_uncertainty

    @lower_uncertainty.setter
    def lower_uncertainty(self, value):
        self._lower_uncertainty = self._uncertainty(value)

    @property
    def upper_uncertainty(self):
        return self._upper_uncertainty

    @upper_uncertainty.setter
    def upper_uncertainty(self, value):
        self._upper_uncertainty = self._uncertainty(value)

    def __new__(cls, *args, **kwargs):
        return super(ComplexWithUncertainties, cls).__new__(cls, *args)

    def __init__(self, *args, **kwargs):
        """
        Complex type with optional keywords:

        :type lower_uncertainty: complex
        :param lower_uncertainty: Lower uncertainty (aka minusError)
        :type upper_uncertainty: complex
        :param upper_uncertainty: Upper uncertainty (aka plusError)
        :type measurement_method_real: str
        :param measurement_method_real: Method used in the measurement of real
            part.
        :type measurement_method_imag: str
        :param measurement_method_imag: Method used in the measurement of
            imaginary part.

        """
        real_upper = None
        imag_upper = None
        real_lower = None
        imag_lower = None
        if len(args) >= 1:
            if isinstance(args[0], self.__class__):
                self.upper_uncertainty = args[0].upper_uncertainty
                self.lower_uncertainty = args[0].lower_uncertainty
            elif isinstance(args[0], FloatWithUncertainties):
                real_upper = args[0].upper_uncertainty
                real_lower = args[0].lower_uncertainty
        if len(args) >= 2 and isinstance(args[1], FloatWithUncertainties):
            imag_upper = args[1].upper_uncertainty
            imag_lower = args[1].lower_uncertainty
        if self.upper_uncertainty is None:
            self.upper_uncertainty = real_upper, imag_upper
        if self.lower_uncertainty is None:
            self.lower_uncertainty = real_lower, imag_lower
        if "lower_uncertainty" in kwargs:
            self.lower_uncertainty = kwargs['lower_uncertainty']
        if "upper_uncertainty" in kwargs:
            self.upper_uncertainty = kwargs['upper_uncertainty']
        self.measurement_method_real = kwargs.get('measurement_method_real')
        self.measurement_method_imag = kwargs.get('measurement_method_imag')

    @property
    def real(self):
        _real = super(ComplexWithUncertainties, self).real
        _lower = self._attr(self.lower_uncertainty, 'real')
        _upper = self._attr(self.upper_uncertainty, 'real')
        return FloatWithUncertainties(
            _real, lower_uncertainty=_lower, upper_uncertainty=_upper,
            measurement_method=self.measurement_method_real)

    @property
    def imag(self):
        _imag = super(ComplexWithUncertainties, self).imag
        _lower = self._attr(self.lower_uncertainty, 'imag')
        _upper = self._attr(self.upper_uncertainty, 'imag')
        return FloatWithUncertainties(
            _imag, lower_uncertainty=_lower, upper_uncertainty=_upper,
            measurement_method=self.measurement_method_imag)


class ObsPyException(Exception):
    pass


class ObsPyReadingError(ObsPyException):
    pass


class ZeroSamplingRate(ObsPyException):
    pass


if __name__ == '__main__':
    import doctest
    doctest.testmod(exclude_empty=True)
