import datetime
import six

from decimal import Decimal

from .functional import Promise


def is_protected_type(obj):
    """Determine if the object instance is of a protected type.

    Objects of protected types are preserved as-is when passed to
    force_text(strings_only=True).
    """
    return isinstance(obj, six.integer_types + (type(None), float, Decimal,
                      datetime.datetime, datetime.date, datetime.time))


def force_bytes(s, encoding='utf-8', strings_only=False, errors='strict'):
    """
    Similar to smart_bytes, except that lazy instances are resolved to
    strings, rather than kept as lazy objects.

    If strings_only is True, don't convert (some) non-string-like objects.
    """
    # Handle the common case first for performance reasons.
    if isinstance(s, bytes):
        if encoding == 'utf-8':
            return s
        else:
            return s.decode('utf-8', errors).encode(encoding, errors)
    if strings_only and is_protected_type(s):
        return s
    if isinstance(s, six.memoryview):
        return bytes(s)
    if isinstance(s, Promise):
        return six.text_type(s).encode(encoding, errors)
    if not isinstance(s, six.string_types):
        try:
            if six.PY3:
                return six.text_type(s).encode(encoding)
            else:
                return bytes(s)
        except UnicodeEncodeError:
            if isinstance(s, Exception):
                # An Exception subclass containing non-ASCII data that doesn't
                # know how to print itself properly. We shouldn't raise a
                # further exception.
                return b' '.join([force_bytes(arg, encoding, strings_only,
                                              errors) for arg in s])
            return six.text_type(s).encode(encoding, errors)
    else:
        return s.encode(encoding, errors)

import datetime
import six

from decimal import Decimal

from .functional import Promise


def is_protected_type(obj):
    """Determine if the object instance is of a protected type.

    Objects of protected types are preserved as-is when passed to
    force_text(strings_only=True).
    """
    return isinstance(obj, six.integer_types + (type(None), float, Decimal,
                      datetime.datetime, datetime.date, datetime.time))


def force_bytes(s, encoding='utf-8', strings_only=False, errors='strict'):
    """
    Similar to smart_bytes, except that lazy instances are resolved to
    strings, rather than kept as lazy objects.

    If strings_only is True, don't convert (some) non-string-like objects.
    """
    # Handle the common case first for performance reasons.
    if isinstance(s, bytes):
        if encoding == 'utf-8':
            return s
        else:
            return s.decode('utf-8', errors).encode(encoding, errors)
    if strings_only and is_protected_type(s):
        return s
    if isinstance(s, bytearray, memoryview):
        return bytes(s)
    if isinstance(s, Promise):
        return six.text_type(s).encode(encoding, errors)
    if not isinstance(s, six.string_types):
        try:
            if six.PY3:
                return six.text_type(s).encode(encoding)
            else:
                return bytes(s)
        except UnicodeEncodeError:
            if isinstance(s, Exception):
                # An Exception subclass containing non-ASCII data that doesn't
                # know how to print itself properly. We shouldn't raise a
                # further exception.
                return b' '.join([force_bytes(arg, encoding, strings_only,
                                              errors) for arg in s])
            return six.text_type(s).encode(encoding, errors)
    else:
        return s.encode(encoding, errors)

Fix Python 3 error