"""
Misc tools for implementing data structures
"""

import sys
import warnings
from datetime import datetime, timedelta
from functools import partial

import numpy as np
import pandas.lib as lib
import pandas.tslib as tslib
from pandas import compat
from pandas.compat import long, zip, iteritems
from pandas.core.config import get_option
from pandas.types.generic import ABCSeries
from pandas.types.common import _NS_DTYPE
from pandas.types.inference import _iterable_not_string
from pandas.types.missing import isnull
from pandas.api import types
from pandas.types import common

# back-compat of public API
# deprecate these functions
m = sys.modules['pandas.core.common']
for t in [t for t in dir(types) if not t.startswith('_')]:

    def outer(t=t):

        def wrapper(*args, **kwargs):
            warnings.warn("pandas.core.common.{t} is deprecated. "
                          "import from the public API: "
                          "pandas.api.types.{t} instead".format(t=t),
                          DeprecationWarning, stacklevel=3)
            return getattr(types, t)(*args, **kwargs)
        return wrapper

    setattr(m, t, outer(t))

# back-compat for non-public functions
# deprecate these functions
for t in ['is_datetime_arraylike',
          'is_datetime_or_timedelta_dtype',
          'is_datetimelike',
          'is_datetimelike_v_numeric',
          'is_datetimelike_v_object',
          'is_datetimetz',
          'is_int_or_datetime_dtype',
          'is_period_arraylike',
          'is_string_like',
          'is_string_like_dtype']:

    def outer(t=t):

        def wrapper(*args, **kwargs):
            warnings.warn("pandas.core.common.{t} is deprecated. "
                          "These are not longer public API functions, "
                          "but can be imported from "
                          "pandas.types.common.{t} instead".format(t=t),
                          DeprecationWarning, stacklevel=3)
            return getattr(common, t)(*args, **kwargs)
        return wrapper

    setattr(m, t, outer(t))


class PandasError(Exception):
    pass


class PerformanceWarning(Warning):
    pass


class SettingWithCopyError(ValueError):
    pass


class SettingWithCopyWarning(Warning):
    pass


class AmbiguousIndexError(PandasError, KeyError):
    pass


class UnsupportedFunctionCall(ValueError):
    pass


class AbstractMethodError(NotImplementedError):
    """Raise this error instead of NotImplementedError for abstract methods
    while keeping compatibility with Python 2 and Python 3.
    """

    def __init__(self, class_instance):
        self.class_instance = class_instance

    def __str__(self):
        return ("This method must be defined in the concrete class of %s" %
                self.class_instance.__class__.__name__)


def flatten(l):
    """Flatten an arbitrarily nested sequence.

    Parameters
    ----------
    l : sequence
        The non string sequence to flatten

    Notes
    -----
    This doesn't consider strings sequences.

    Returns
    -------
    flattened : generator
    """
    for el in l:
        if _iterable_not_string(el):
            for s in flatten(el):
                yield s
        else:
            yield el


def _consensus_name_attr(objs):
    name = objs[0].name
    for obj in objs[1:]:
        if obj.name != name:
            return None
    return name


def _maybe_match_name(a, b):
    a_has = hasattr(a, 'name')
    b_has = hasattr(b, 'name')
    if a_has and b_has:
        if a.name == b.name:
            return a.name
        else:
            return None
    elif a_has:
        return a.name
    elif b_has:
        return b.name
    return None


def _get_info_slice(obj, indexer):
    """Slice the info axis of `obj` with `indexer`."""
    if not hasattr(obj, '_info_axis_number'):
        raise TypeError('object of type %r has no info axis' %
                        type(obj).__name__)
    slices = [slice(None)] * obj.ndim
    slices[obj._info_axis_number] = indexer
    return tuple(slices)


def _maybe_box(indexer, values, obj, key):

    # if we have multiples coming back, box em
    if isinstance(values, np.ndarray):
        return obj[indexer.get_loc(key)]

    # return the value
    return values


def _maybe_box_datetimelike(value):
    # turn a datetime like into a Timestamp/timedelta as needed

    if isinstance(value, (np.datetime64, datetime)):
        value = tslib.Timestamp(value)
    elif isinstance(value, (np.timedelta64, timedelta)):
        value = tslib.Timedelta(value)

    return value


_values_from_object = lib.values_from_object


def is_bool_indexer(key):
    if isinstance(key, (ABCSeries, np.ndarray)):
        if key.dtype == np.object_:
            key = np.asarray(_values_from_object(key))

            if not lib.is_bool_array(key):
                if isnull(key).any():
                    raise ValueError('cannot index with vector containing '
                                     'NA / NaN values')
                return False
            return True
        elif key.dtype == np.bool_:
            return True
    elif isinstance(key, list):
        try:
            arr = np.asarray(key)
            return arr.dtype == np.bool_ and len(arr) == len(key)
        except TypeError:  # pragma: no cover
            return False

    return False


def _default_index(n):
    from pandas.core.index import RangeIndex
    return RangeIndex(0, n, name=None)


def _mut_exclusive(**kwargs):
    item1, item2 = kwargs.items()
    label1, val1 = item1
    label2, val2 = item2
    if val1 is not None and val2 is not None:
        raise TypeError('mutually exclusive arguments: %r and %r' %
                        (label1, label2))
    elif val1 is not None:
        return val1
    else:
        return val2


def _not_none(*args):
    return (arg for arg in args if arg is not None)


def _any_none(*args):
    for arg in args:
        if arg is None:
            return True
    return False


def _all_not_none(*args):
    for arg in args:
        if arg is None:
            return False
    return True


def _count_not_none(*args):
    return sum(x is not None for x in args)


def _try_sort(iterable):
    listed = list(iterable)
    try:
        return sorted(listed)
    except Exception:
        return listed


def iterpairs(seq):
    """
    Parameters
    ----------
    seq : sequence

    Returns
    -------
    iterator returning overlapping pairs of elements

    Examples
    --------
    >>> list(iterpairs([1, 2, 3, 4]))
    [(1, 2), (2, 3), (3, 4)]
    """
    # input may not be sliceable
    seq_it = iter(seq)
    seq_it_next = iter(seq)
    next(seq_it_next)

    return zip(seq_it, seq_it_next)


def split_ranges(mask):
    """ Generates tuples of ranges which cover all True value in mask

    >>> list(split_ranges([1,0,0,1,0]))
    [(0, 1), (3, 4)]
    """
    ranges = [(0, len(mask))]

    for pos, val in enumerate(mask):
        if not val:  # this pos should be ommited, split off the prefix range
            r = ranges.pop()
            if pos > r[0]:  # yield non-zero range
                yield (r[0], pos)
            if pos + 1 < len(mask):  # save the rest for processing
                ranges.append((pos + 1, len(mask)))
    if ranges:
        yield ranges[-1]


def _long_prod(vals):
    result = long(1)
    for x in vals:
        result *= x
    return result


class groupby(dict):
    """
    A simple groupby different from the one in itertools.

    Does not require the sequence elements to be sorted by keys,
    however it is slower.
    """

    def __init__(self, seq, key=lambda x: x):
        for value in seq:
            k = key(value)
            self.setdefault(k, []).append(value)

    try:
        __iter__ = dict.iteritems
    except AttributeError:  # pragma: no cover
        # Python 3
        def __iter__(self):
            return iter(dict.items(self))


def map_indices_py(arr):
    """
    Returns a dictionary with (element, index) pairs for each element in the
    given array/list
    """
    return dict([(x, i) for i, x in enumerate(arr)])


def union(*seqs):
    result = set([])
    for seq in seqs:
        if not isinstance(seq, set):
            seq = set(seq)
        result |= seq
    return type(seqs[0])(list(result))


def difference(a, b):
    return type(a)(list(set(a) - set(b)))


def intersection(*seqs):
    result = set(seqs[0])
    for seq in seqs:
        if not isinstance(seq, set):
            seq = set(seq)
        result &= seq
    return type(seqs[0])(list(result))


def _asarray_tuplesafe(values, dtype=None):
    from pandas.core.index import Index

    if not (isinstance(values, (list, tuple)) or hasattr(values, '__array__')):
        values = list(values)
    elif isinstance(values, Index):
        return values.values

    if isinstance(values, list) and dtype in [np.object_, object]:
        return lib.list_to_object_array(values)

    result = np.asarray(values, dtype=dtype)

    if issubclass(result.dtype.type, compat.string_types):
        result = np.asarray(values, dtype=object)

    if result.ndim == 2:
        if isinstance(values, list):
            return lib.list_to_object_array(values)
        else:
            # Making a 1D array that safely contains tuples is a bit tricky
            # in numpy, leading to the following
            try:
                result = np.empty(len(values), dtype=object)
                result[:] = values
            except ValueError:
                # we have a list-of-list
                result[:] = [tuple(x) for x in values]

    return result


def _index_labels_to_array(labels):
    if isinstance(labels, (compat.string_types, tuple)):
        labels = [labels]

    if not isinstance(labels, (list, np.ndarray)):
        try:
            labels = list(labels)
        except TypeError:  # non-iterable
            labels = [labels]

    labels = _asarray_tuplesafe(labels)

    return labels


def _maybe_make_list(obj):
    if obj is not None and not isinstance(obj, (tuple, list)):
        return [obj]
    return obj


def is_null_slice(obj):
    """ we have a null slice """
    return (isinstance(obj, slice) and obj.start is None and
            obj.stop is None and obj.step is None)


def is_full_slice(obj, l):
    """ we have a full length slice """
    return (isinstance(obj, slice) and obj.start == 0 and obj.stop == l and
            obj.step is None)


def _get_callable_name(obj):
    # typical case has name
    if hasattr(obj, '__name__'):
        return getattr(obj, '__name__')
    # some objects don't; could recurse
    if isinstance(obj, partial):
        return _get_callable_name(obj.func)
    # fall back to class name
    if hasattr(obj, '__call__'):
        return obj.__class__.__name__
    # everything failed (probably because the argument
    # wasn't actually callable); we return None
    # instead of the empty string in this case to allow
    # distinguishing between no name and a name of ''
    return None


def _apply_if_callable(maybe_callable, obj, **kwargs):
    """
    Evaluate possibly callable input using obj and kwargs if it is callable,
    otherwise return as it is
    """
    if callable(maybe_callable):
        return maybe_callable(obj, **kwargs)
    return maybe_callable


def _all_none(*args):
    for arg in args:
        if arg is not None:
            return False
    return True


def _where_compat(mask, arr1, arr2):
    if arr1.dtype == _NS_DTYPE and arr2.dtype == _NS_DTYPE:
        new_vals = np.where(mask, arr1.view('i8'), arr2.view('i8'))
        return new_vals.view(_NS_DTYPE)

    import pandas.tslib as tslib
    if arr1.dtype == _NS_DTYPE:
        arr1 = tslib.ints_to_pydatetime(arr1.view('i8'))
    if arr2.dtype == _NS_DTYPE:
        arr2 = tslib.ints_to_pydatetime(arr2.view('i8'))

    return np.where(mask, arr1, arr2)


def _dict_compat(d):
    """
    Helper function to convert datetimelike-keyed dicts to Timestamp-keyed dict

    Parameters
    ----------
    d: dict like object

    Returns
    -------
    dict

    """
    return dict((_maybe_box_datetimelike(key), value)
                for key, value in iteritems(d))


def sentinel_factory():
    class Sentinel(object):
        pass

    return Sentinel()


# ----------------------------------------------------------------------
# Detect our environment

def in_interactive_session():
    """ check if we're running in an interactive shell

    returns True if running under python/ipython interactive shell
    """

    def check_main():
        import __main__ as main
        return (not hasattr(main, '__file__') or
                get_option('mode.sim_interactive'))

    try:
        return __IPYTHON__ or check_main()  # noqa
    except:
        return check_main()


def in_qtconsole():
    """
    check if we're inside an IPython qtconsole

    DEPRECATED: This is no longer needed, or working, in IPython 3 and above.
    """
    try:
        ip = get_ipython()  # noqa
        front_end = (
            ip.config.get('KernelApp', {}).get('parent_appname', "") or
            ip.config.get('IPKernelApp', {}).get('parent_appname', ""))
        if 'qtconsole' in front_end.lower():
            return True
    except:
        return False
    return False


def in_ipnb():
    """
    check if we're inside an IPython Notebook

    DEPRECATED: This is no longer used in pandas, and won't work in IPython 3
    and above.
    """
    try:
        ip = get_ipython()  # noqa
        front_end = (
            ip.config.get('KernelApp', {}).get('parent_appname', "") or
            ip.config.get('IPKernelApp', {}).get('parent_appname', ""))
        if 'notebook' in front_end.lower():
            return True
    except:
        return False
    return False


def in_ipython_frontend():
    """
    check if we're inside an an IPython zmq frontend
    """
    try:
        ip = get_ipython()  # noqa
        return 'zmq' in str(type(ip)).lower()
    except:
        pass

    return False


def _random_state(state=None):
    """
    Helper function for processing random_state arguments.

    Parameters
    ----------
    state : int, np.random.RandomState, None.
        If receives an int, passes to np.random.RandomState() as seed.
        If receives an np.random.RandomState object, just returns object.
        If receives `None`, returns np.random.
        If receives anything else, raises an informative ValueError.
        Default None.

    Returns
    -------
    np.random.RandomState
    """

    if types.is_integer(state):
        return np.random.RandomState(state)
    elif isinstance(state, np.random.RandomState):
        return state
    elif state is None:
        return np.random
    else:
        raise ValueError("random_state must be an integer, a numpy "
                         "RandomState, or None")
