"""
Boto Common Utils
=================

Note: This module depends on the dicts packed by the loader and,
therefore, must be accessed via the loader or from the __utils__ dict.

This module provides common functionality for the boto execution modules.
The expected usage is to call `assign_funcs` from the `__virtual__` function
of the module. This will bring properly initialized partials of  `_get_conn`
and `_cache_id` into the module's namespace.

Example Usage:

    .. code-block:: python

        def __virtual__():
            __utils__['boto.assign_funcs'](__name__, 'vpc')

        def test():
            conn = _get_conn()
            vpc_id = _cache_id('test-vpc')

.. versionadded:: 2015.8.0
"""


import hashlib
import logging
import sys
from functools import partial

import salt.loader.context
import salt.utils.stringutils
import salt.utils.versions
from salt.exceptions import SaltInvocationError
from salt.loader import minion_mods

# pylint: disable=import-error
try:
    # pylint: disable=import-error
    import boto
    import boto.exception

    # pylint: enable=import-error
    logging.getLogger("boto").setLevel(logging.CRITICAL)
    HAS_BOTO = True
except ImportError:
    HAS_BOTO = False
# pylint: enable=import-error


log = logging.getLogger(__name__)

__salt__ = None
__virtualname__ = "boto"
__salt_loader__ = salt.loader.context.LoaderContext()
__context__ = __salt_loader__.named_context("__context__", {})


def __virtual__():
    """
    Only load if boto libraries exist and if boto libraries are greater than
    a given version.
    """
    has_boto_requirements = salt.utils.versions.check_boto_reqs(check_boto3=False)
    if has_boto_requirements is True:
        global __salt__
        if not __salt__:
            __salt__ = minion_mods(__opts__)
        return __virtualname__
    return has_boto_requirements


def _get_profile(service, region, key, keyid, profile):
    if profile:
        if isinstance(profile, str):
            _profile = __salt__["config.option"](profile)
        elif isinstance(profile, dict):
            _profile = profile
        key = _profile.get("key", None)
        keyid = _profile.get("keyid", None)
        region = _profile.get("region", region or None)
    if not region and __salt__["config.option"](service + ".region"):
        region = __salt__["config.option"](service + ".region")

    if not region:
        region = "us-east-1"
    if not key and __salt__["config.option"](service + ".key"):
        key = __salt__["config.option"](service + ".key")
    if not keyid and __salt__["config.option"](service + ".keyid"):
        keyid = __salt__["config.option"](service + ".keyid")

    label = "boto_{}:".format(service)
    if keyid:
        hash_string = region + keyid + key
        hash_string = salt.utils.stringutils.to_bytes(hash_string)
        cxkey = label + hashlib.md5(hash_string).hexdigest()
    else:
        cxkey = label + region

    return (cxkey, region, key, keyid)


def cache_id(
    service,
    name,
    sub_resource=None,
    resource_id=None,
    invalidate=False,
    region=None,
    key=None,
    keyid=None,
    profile=None,
):
    """
    Cache, invalidate, or retrieve an AWS resource id keyed by name.

    .. code-block:: python

        __utils__['boto.cache_id']('ec2', 'myinstance',
                                   'i-a1b2c3',
                                   profile='custom_profile')
    """

    cxkey, _, _, _ = _get_profile(service, region, key, keyid, profile)
    if sub_resource:
        cxkey = "{}:{}:{}:id".format(cxkey, sub_resource, name)
    else:
        cxkey = "{}:{}:id".format(cxkey, name)

    if invalidate:
        if cxkey in __context__:
            del __context__[cxkey]
            return True
        elif resource_id in __context__.values():
            ctx = {k: v for k, v in __context__.items() if v != resource_id}
            __context__.clear()
            __context__.update(ctx)
            return True
        else:
            return False
    if resource_id:
        __context__[cxkey] = resource_id
        return True

    return __context__.get(cxkey)


def cache_id_func(service):
    """
    Returns a partial ``cache_id`` function for the provided service.

    .. code-block:: python

        cache_id = __utils__['boto.cache_id_func']('ec2')
        cache_id('myinstance', 'i-a1b2c3')
        instance_id = cache_id('myinstance')
    """
    return partial(cache_id, service)


def get_connection(
    service, module=None, region=None, key=None, keyid=None, profile=None
):
    """
    Return a boto connection for the service.

    .. code-block:: python

        conn = __utils__['boto.get_connection']('ec2', profile='custom_profile')
    """

    module = str(module or service)
    module, submodule = ("boto." + module).rsplit(".", 1)

    svc_mod = getattr(__import__(module, fromlist=[submodule]), submodule)

    cxkey, region, key, keyid = _get_profile(service, region, key, keyid, profile)
    cxkey = cxkey + ":conn"

    if cxkey in __context__:
        return __context__[cxkey]

    try:
        conn = svc_mod.connect_to_region(
            region, aws_access_key_id=keyid, aws_secret_access_key=key
        )
        if conn is None:
            raise SaltInvocationError('Region "{}" is not valid.'.format(region))
    except boto.exception.NoAuthHandlerFound:
        raise SaltInvocationError(
            "No authentication credentials found when "
            "attempting to make boto {} connection to "
            'region "{}".'.format(service, region)
        )
    __context__[cxkey] = conn
    return conn


def get_connection_func(service, module=None):
    """
    Returns a partial ``get_connection`` function for the provided service.

    .. code-block:: python

        get_conn = __utils__['boto.get_connection_func']('ec2')
        conn = get_conn()
    """
    return partial(get_connection, service, module=module)


def get_error(e):
    # The returns from boto modules vary greatly between modules. We need to
    # assume that none of the data we're looking for exists.
    aws = {}
    if hasattr(e, "status"):
        aws["status"] = e.status
    if hasattr(e, "reason"):
        aws["reason"] = e.reason
    if hasattr(e, "message") and e.message != "":
        aws["message"] = e.message
    if hasattr(e, "error_code") and e.error_code is not None:
        aws["code"] = e.error_code

    if "message" in aws and "reason" in aws:
        message = "{}: {}".format(aws["reason"], aws["message"])
    elif "message" in aws:
        message = aws["message"]
    elif "reason" in aws:
        message = aws["reason"]
    else:
        message = ""
    r = {"message": message}
    if aws:
        r["aws"] = aws
    return r


def exactly_n(l, n=1):
    """
    Tests that exactly N items in an iterable are "truthy" (neither None,
    False, nor 0).
    """
    i = iter(l)
    return all(any(i) for j in range(n)) and not any(i)


def exactly_one(l):
    return exactly_n(l)


def assign_funcs(modname, service, module=None, pack=None):
    """
    Assign _get_conn and _cache_id functions to the named module.

    .. code-block:: python

        __utils__['boto.assign_partials'](__name__, 'ec2')
    """
    if pack:
        global __salt__  # pylint: disable=W0601
        __salt__ = pack
    mod = sys.modules[modname]
    setattr(mod, "_get_conn", get_connection_func(service, module=module))
    setattr(mod, "_cache_id", cache_id_func(service))

    # TODO: Remove this and import salt.utils.data.exactly_one into boto_* modules instead
    # Leaving this way for now so boto modules can be back ported
    setattr(mod, "_exactly_one", exactly_one)


def paged_call(function, *args, **kwargs):
    """
    Retrieve full set of values from a boto API call that may truncate
    its results, yielding each page as it is obtained.
    """
    marker_flag = kwargs.pop("marker_flag", "marker")
    marker_arg = kwargs.pop("marker_flag", "marker")
    while True:
        ret = function(*args, **kwargs)
        marker = ret.get(marker_flag)
        yield ret
        if not marker:
            break
        kwargs[marker_arg] = marker
