# Copyright 2009-2011 10gen, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you
# may not use this file except in compliance with the License.  You
# may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied.  See the License for the specific language governing
# permissions and limitations under the License.


"""Functions and classes common to multiple pymongo modules."""
import warnings

from pymongo import ReadPreference
from pymongo.errors import ConfigurationError


def raise_config_error(key, dummy):
    """Raise ConfigurationError with the given key name."""
    raise ConfigurationError("Unknown option %s" % (key,))


def validate_boolean(option, value):
    """Validates that 'value' is 'true' or 'false'.
    """
    if isinstance(value, bool):
        return value
    elif isinstance(value, basestring):
        if value not in ('true', 'false'):
            raise ConfigurationError("The value of '%s' must be "
                                     "'true' or 'false'" % (option,))
        return value == 'true'
    raise TypeError("Wrong type for %s, value must "
                    "be a boolean or string representation" % (option,))


def validate_integer(option, value):
    """Validates that 'value' is an integer (or basestring representation).
    """
    if isinstance(value, (int, long)):
        return value
    elif isinstance(value, basestring):
        if not value.isdigit():
            raise ConfigurationError("The value of '%s' must be "
                                     "an integer." % (option,))
        return int(value)
    raise TypeError("Wrong type for %s, value must be an "
                    "integer or string representation" % (option,))


def validate_basestring(option, value):
    """Validates that 'value' is an instance of `basestring`.
    """
    if isinstance(value, basestring):
        return value
    raise TypeError("Wrong type for %s, value must be an "
                    "instance of basestring" % (option,))


def validate_int_or_basestring(option, value):
    """Validates that 'value' is an integer or string.
    """
    if isinstance(value, (int, long)):
        return value
    elif isinstance(value, basestring):
        if value.isdigit():
            return int(value)
        return value
    raise TypeError("Wrong type for %s, value must be an "
                    "integer or a string" % (option,))


def validate_timeout_or_none(option, value):
    """Validates a timeout specified in milliseconds returning
    a value in floating point seconds.
    """
    if value is None:
        return value
    try:
        value = float(value)
    except (ValueError, TypeError):
        raise ConfigurationError("%s must be an instance of int, float, "
                                 "or a string representation" % (option,))
    if value <= 0:
        raise ConfigurationError("%s must be a positive integer" % (option,))
    return value / 1000.0


def validate_read_preference(dummy, value):
    """Validate read preference for a ReplicaSetConnection.
    """
    if value not in range(ReadPreference.PRIMARY,
                          ReadPreference.SECONDARY_ONLY + 1):
        raise ConfigurationError("Not a valid read preference")
    return value


# jounal is an alias for j,
# wtimeoutms is an alias for wtimeout
VALIDATORS = {
    'replicaset': validate_basestring,
    'slaveok': validate_boolean,
    'slave_okay': validate_boolean,
    'safe': validate_boolean,
    'w': validate_int_or_basestring,
    'wtimeout': validate_integer,
    'wtimeoutms': validate_integer,
    'fsync': validate_boolean,
    'j': validate_boolean,
    'journal': validate_boolean,
    'connecttimeoutms': validate_timeout_or_none,
    'sockettimeoutms': validate_timeout_or_none,
    'ssl': validate_boolean,
    'read_preference': validate_read_preference,
}


def validate(option, value):
    """Generic validation function.
    """
    lower = option.lower()
    validator = VALIDATORS.get(lower, raise_config_error)
    value = validator(option, value)
    return lower, value


SAFE_OPTIONS = frozenset([
    'w',
    'wtimeout',
    'wtimeoutms',
    'fsync',
    'j',
    'journal'
])


class BaseObject(object):
    """A base class that provides attributes and methods common
    to multiple pymongo classes.

    SHOULD NOT BE USED BY DEVELOPERS EXTERNAL TO 10GEN
    """

    def __init__(self, **options):

        self.__slave_okay = False
        self.__read_pref = ReadPreference.PRIMARY
        self.__safe = False
        self.__safe_opts = {}
        self.__set_options(options)

    def __set_safe_option(self, option, value, check=False):
        """Validates and sets getlasterror options for this
        object (Connection, Database, Collection, etc.)
        """
        if value is None:
            self.__safe_opts.pop(option, None)
        else:
            if check:
                option, value = validate(option, value)
            self.__safe_opts[option] = value
            self.__safe = True

    def __set_options(self, options):
        """Validates and sets all options passed to this object."""
        for option, value in options.iteritems():
            if option in ('slave_okay', 'slaveok'):
                self.__slave_okay = validate_boolean(option, value)
            elif option == 'read_preference':
                self.__read_pref = validate_read_preference(option, value)
            elif option == 'safe':
                self.__safe = validate_boolean(option, value)
            elif option in SAFE_OPTIONS:
                if option == 'journal':
                    self.__set_safe_option('j', value)
                elif option == 'wtimeoutms':
                    self.__set_safe_option('wtimeout', value)
                else:
                    self.__set_safe_option(option, value)

    def __get_slave_okay(self):
        """DEPRECATED. Use `read_preference` instead.

        .. versionchanged:: 2.1
           Deprecated slave_okay.
        .. versionadded:: 2.0
        """
        return self.__slave_okay

    def __set_slave_okay(self, value):
        """Property setter for slave_okay"""
        warnings.warn("slave_okay is deprecated. Please use "
                      "read_preference instead.", DeprecationWarning)
        self.__slave_okay = validate_boolean('slave_okay', value)

    slave_okay = property(__get_slave_okay, __set_slave_okay)

    def __get_read_pref(self):
        """The read preference for this instance.

        See :class:`~pymongo.ReadPreference` for available options.

        .. versionadded:: 2.1
        """
        return self.__read_pref

    def __set_read_pref(self, value):
        """Property setter for read_preference"""
        self.__read_pref = validate_read_preference('read_preference', value)

    read_preference = property(__get_read_pref, __set_read_pref)

    def __get_safe(self):
        """Use getlasterrer with every write operation?

        .. versionadded:: 2.0
        """
        return self.__safe

    def __set_safe(self, value):
        """Property setter for safe"""
        self.__safe = validate_boolean('safe', value)

    safe = property(__get_safe, __set_safe)

    def get_lasterror_options(self):
        """Returns a dict of the getlasterror options set
        on this instance.

        .. versionadded:: 2.0
        """
        return self.__safe_opts.copy()

    def set_lasterror_options(self, **kwargs):
        """Set getlasterror options for this instance.

        Valid options include j=<bool>, w=<int>, wtimeout=<int>,
        and fsync=<bool>. Implies safe=True.

        :Parameters:
            - `**kwargs`: Options should be passed as keyword
                          arguments (e.g. w=2, fsync=True)

        .. versionadded:: 2.0
        """
        for key, value in kwargs.iteritems():
            self.__set_safe_option(key, value, check=True)

    def unset_lasterror_options(self, *options):
        """Unset getlasterror options for this instance.

        If no options are passed unsets all getlasterror options.
        This does not set `safe` to False.

        :Parameters:
            - `*options`: The list of options to unset.

        .. versionadded:: 2.0
        """
        if len(options):
            for option in options:
                self.__safe_opts.pop(option, None)
        else:
            self.__safe_opts = {}