"""Array printing function

$Id: arrayprint.py,v 1.9 2005/09/13 13:58:44 teoliphant Exp $

"""
from __future__ import division, absolute_import, print_function

__all__ = ["array2string", "array_str", "array_repr", "set_string_function",
           "set_printoptions", "get_printoptions", "printoptions",
           "format_float_positional", "format_float_scientific"]
__docformat__ = 'restructuredtext'

#
# Written by Konrad Hinsen <hinsenk@ere.umontreal.ca>
# last revision: 1996-3-13
# modified by Jim Hugunin 1997-3-3 for repr's and str's (and other details)
# and by Perry Greenfield 2000-4-1 for numarray
# and by Travis Oliphant  2005-8-22 for numpy


# Note: Both scalartypes.c.src and arrayprint.py implement strs for numpy
# scalars but for different purposes. scalartypes.c.src has str/reprs for when
# the scalar is printed on its own, while arrayprint.py has strs for when
# scalars are printed inside an ndarray. Only the latter strs are currently
# user-customizable.

import sys
import functools
import numbers
if sys.version_info[0] >= 3:
    try:
        from _thread import get_ident
    except ImportError:
        from _dummy_thread import get_ident
else:
    try:
        from thread import get_ident
    except ImportError:
        from dummy_thread import get_ident

import numpy as np
from . import numerictypes as _nt
from .umath import absolute, not_equal, isnan, isinf, isfinite, isnat
from . import multiarray
from .multiarray import (array, dragon4_positional, dragon4_scientific,
                         datetime_as_string, datetime_data, ndarray,
                         set_legacy_print_mode)
from .fromnumeric import ravel, any
from .numeric import concatenate, asarray, errstate
from .numerictypes import (longlong, intc, int_, float_, complex_, bool_,
                           flexible)
from .overrides import array_function_dispatch, set_module
import warnings
import contextlib

_format_options = {
    'edgeitems': 3,  # repr N leading and trailing items of each dimension
    'threshold': 1000,  # total items > triggers array summarization
    'floatmode': 'maxprec',
    'precision': 8,  # precision of floating point representations
    'suppress': False,  # suppress printing small floating values in exp format
    'linewidth': 75,
    'nanstr': 'nan',
    'infstr': 'inf',
    'sign': '-',
    'formatter': None,
    'legacy': False}

def _make_options_dict(precision=None, threshold=None, edgeitems=None,
                       linewidth=None, suppress=None, nanstr=None, infstr=None,
                       sign=None, formatter=None, floatmode=None, legacy=None):
    """ make a dictionary out of the non-None arguments, plus sanity checks """

    options = {k: v for k, v in locals().items() if v is not None}

    if suppress is not None:
        options['suppress'] = bool(suppress)

    modes = ['fixed', 'unique', 'maxprec', 'maxprec_equal']
    if floatmode not in modes + [None]:
        raise ValueError("floatmode option must be one of " +
                         ", ".join('"{}"'.format(m) for m in modes))

    if sign not in [None, '-', '+', ' ']:
        raise ValueError("sign option must be one of ' ', '+', or '-'")

    if legacy not in [None, False, '1.13']:
        warnings.warn("legacy printing option can currently only be '1.13' or "
                      "`False`", stacklevel=3)
    if threshold is not None:
        # forbid the bad threshold arg suggested by stack overflow, gh-12351
        if not isinstance(threshold, numbers.Number) or np.isnan(threshold):
            raise ValueError("threshold must be numeric and non-NAN, try "
                             "sys.maxsize for untruncated representation")
    return options


@set_module('numpy')
def set_printoptions(precision=None, threshold=None, edgeitems=None,
                     linewidth=None, suppress=None, nanstr=None, infstr=None,
                     formatter=None, sign=None, floatmode=None, **kwarg):
    """
    Set printing options.

    These options determine the way floating point numbers, arrays and
    other NumPy objects are displayed.

    Parameters
    ----------
    precision : int or None, optional
        Number of digits of precision for floating point output (default 8).
        May be `None` if `floatmode` is not `fixed`, to print as many digits as
        necessary to uniquely specify the value.
    threshold : int, optional
        Total number of array elements which trigger summarization
        rather than full repr (default 1000).
    edgeitems : int, optional
        Number of array items in summary at beginning and end of
        each dimension (default 3).
    linewidth : int, optional
        The number of characters per line for the purpose of inserting
        line breaks (default 75).
    suppress : bool, optional
        If True, always print floating point numbers using fixed point
        notation, in which case numbers equal to zero in the current precision
        will print as zero.  If False, then scientific notation is used when
        absolute value of the smallest number is < 1e-4 or the ratio of the
        maximum absolute value to the minimum is > 1e3. The default is False.
    nanstr : str, optional
        String representation of floating point not-a-number (default nan).
    infstr : str, optional
        String representation of floating point infinity (default inf).
    sign : string, either '-', '+', or ' ', optional
        Controls printing of the sign of floating-point types. If '+', always
        print the sign of positive values. If ' ', always prints a space
        (whitespace character) in the sign position of positive values.  If
        '-', omit the sign character of positive values. (default '-')
    formatter : dict of callables, optional
        If not None, the keys should indicate the type(s) that the respective
        formatting function applies to.  Callables should return a string.
        Types that are not specified (by their corresponding keys) are handled
        by the default formatters.  Individual types for which a formatter
        can be set are:

        - 'bool'
        - 'int'
        - 'timedelta' : a `numpy.timedelta64`
        - 'datetime' : a `numpy.datetime64`
        - 'float'
        - 'longfloat' : 128-bit floats
        - 'complexfloat'
        - 'longcomplexfloat' : composed of two 128-bit floats
        - 'numpystr' : types `numpy.string_` and `numpy.unicode_`
        - 'object' : `np.object_` arrays
        - 'str' : all other strings

        Other keys that can be used to set a group of types at once are:

        - 'all' : sets all types
        - 'int_kind' : sets 'int'
        - 'float_kind' : sets 'float' and 'longfloat'
        - 'complex_kind' : sets 'complexfloat' and 'longcomplexfloat'
        - 'str_kind' : sets 'str' and 'numpystr'
    floatmode : str, optional
        Controls the interpretation of the `precision` option for
        floating-point types. Can take the following values:

        * 'fixed': Always print exactly `precision` fractional digits,
                even if this would print more or fewer digits than
                necessary to specify the value uniquely.
        * 'unique': Print the minimum number of fractional digits necessary
                to represent each value uniquely. Different elements may
                have a different number of digits. The value of the
                `precision` option is ignored.
        * 'maxprec': Print at most `precision` fractional digits, but if
                an element can be uniquely represented with fewer digits
                only print it with that many.
        * 'maxprec_equal': Print at most `precision` fractional digits,
                but if every element in the array can be uniquely
                represented with an equal number of fewer digits, use that
                many digits for all elements.
    legacy : string or `False`, optional
        If set to the string `'1.13'` enables 1.13 legacy printing mode. This
        approximates numpy 1.13 print output by including a space in the sign
        position of floats and different behavior for 0d arrays. If set to
        `False`, disables legacy mode. Unrecognized strings will be ignored
        with a warning for forward compatibility.

        .. versionadded:: 1.14.0

    See Also
    --------
    get_printoptions, set_string_function, array2string

    Notes
    -----
    `formatter` is always reset with a call to `set_printoptions`.

    Examples
    --------
    Floating point precision can be set:

    >>> np.set_printoptions(precision=4)
    >>> print(np.array([1.123456789]))
    [ 1.1235]

    Long arrays can be summarised:

    >>> np.set_printoptions(threshold=5)
    >>> print(np.arange(10))
    [0 1 2 ..., 7 8 9]

    Small results can be suppressed:

    >>> eps = np.finfo(float).eps
    >>> x = np.arange(4.)
    >>> x**2 - (x + eps)**2
    array([ -4.9304e-32,  -4.4409e-16,   0.0000e+00,   0.0000e+00])
    >>> np.set_printoptions(suppress=True)
    >>> x**2 - (x + eps)**2
    array([-0., -0.,  0.,  0.])

    A custom formatter can be used to display array elements as desired:

    >>> np.set_printoptions(formatter={'all':lambda x: 'int: '+str(-x)})
    >>> x = np.arange(3)
    >>> x
    array([int: 0, int: -1, int: -2])
    >>> np.set_printoptions()  # formatter gets reset
    >>> x
    array([0, 1, 2])

    To put back the default options, you can use:

    >>> np.set_printoptions(edgeitems=3,infstr='inf',
    ... linewidth=75, nanstr='nan', precision=8,
    ... suppress=False, threshold=1000, formatter=None)
    """
    legacy = kwarg.pop('legacy', None)
    if kwarg:
        msg = "set_printoptions() got unexpected keyword argument '{}'"
        raise TypeError(msg.format(kwarg.popitem()[0]))

    opt = _make_options_dict(precision, threshold, edgeitems, linewidth,
                             suppress, nanstr, infstr, sign, formatter,
                             floatmode, legacy)
    # formatter is always reset
    opt['formatter'] = formatter
    _format_options.update(opt)

    # set the C variable for legacy mode
    if _format_options['legacy'] == '1.13':
        set_legacy_print_mode(113)
        # reset the sign option in legacy mode to avoid confusion
        _format_options['sign'] = '-'
    elif _format_options['legacy'] is False:
        set_legacy_print_mode(0)


@set_module('numpy')
def get_printoptions():
    """
    Return the current print options.

    Returns
    -------
    print_opts : dict
        Dictionary of current print options with keys

          - precision : int
          - threshold : int
          - edgeitems : int
          - linewidth : int
          - suppress : bool
          - nanstr : str
          - infstr : str
          - formatter : dict of callables
          - sign : str

        For a full description of these options, see `set_printoptions`.

    See Also
    --------
    set_printoptions, set_string_function

    """
    return _format_options.copy()


@set_module('numpy')
@contextlib.contextmanager
def printoptions(*args, **kwargs):
    """Context manager for setting print options.

    Set print options for the scope of the `with` block, and restore the old
    options at the end. See `set_printoptions` for the full description of
    available options.

    Examples
    --------

    >>> with np.printoptions(precision=2):
    ...     print(np.array([2.0])) / 3
    [0.67]

    The `as`-clause of the `with`-statement gives the current print options:

    >>> with np.printoptions(precision=2) as opts:
    ...      assert_equal(opts, np.get_printoptions())

    See Also
    --------
    set_printoptions, get_printoptions

    """
    opts = np.get_printoptions()
    try:
        np.set_printoptions(*args, **kwargs)
        yield np.get_printoptions()
    finally:
        np.set_printoptions(**opts)


def _leading_trailing(a, edgeitems, index=()):
    """
    Keep only the N-D corners (leading and trailing edges) of an array.

    Should be passed a base-class ndarray, since it makes no guarantees about
    preserving subclasses.
    """
    axis = len(index)
    if axis == a.ndim:
        return a[index]

    if a.shape[axis] > 2*edgeitems:
        return concatenate((
            _leading_trailing(a, edgeitems, index + np.index_exp[ :edgeitems]),
            _leading_trailing(a, edgeitems, index + np.index_exp[-edgeitems:])
        ), axis=axis)
    else:
        return _leading_trailing(a, edgeitems, index + np.index_exp[:])


def _object_format(o):
    """ Object arrays containing lists should be printed unambiguously """