__author__ = 'rolandh'

#!/usr/bin/env python
from saml2 import element_to_extension_element
from saml2 import extension_elements_to_elements
from saml2 import SamlBase
from saml2 import md

__author__ = 'rolandh'

"""
Functions used to import metadata from and export it to a pysaml2 format
"""

IMP_SKIP = ["_certs", "e_e_"]
EXP_SKIP = ["__class__"]

# From pysaml2 SAML2 metadata format to Python dictionary
def _eval(val, onts):
    """
    Convert a value to a basic dict format
    :param val: The value
    :param onts: Schemas to be used in the conversion
    :return: The basic dictionary
    """
    if isinstance(val, basestring):
        val = val.strip()
        if not val:
            return None
        else:
            return val
    elif isinstance(val, dict) or isinstance(val, SamlBase):
        return to_dict(val, onts)
    elif isinstance(val, list):
        lv = []
        for v in val:
            if isinstance(v, dict) or isinstance(v, SamlBase):
                lv.append(to_dict(v, onts))
            else:
                lv.append(v)
        return lv
    return val

def to_dict(_dict, onts):
    """
    Convert a pysaml2 SAML2 metadata format into a basic dictionary format
    The export interface.

    :param _dict: The pysaml2 metadata instance
    :param onts: Schemas to use for the conversion
    :return: The converted information
    """
    res = {}
    if isinstance(_dict, SamlBase):
        res["__class__"] = "%s&%s" % (_dict.c_namespace,_dict.c_tag)
        for key in _dict.keyswv():
            if key in IMP_SKIP:
                continue
            val = getattr(_dict, key)
            if key == "extension_elements":
                _eel = extension_elements_to_elements(val, onts)
                _val = [_eval(_v, onts) for _v in _eel]
            else:
                _val = _eval(val, onts)

            if _val:
                res[key] = _val
    else:
        for key, val in _dict.items():
            _val = _eval(val, onts)
            if _val:
                res[key] = _val
    return res


# From Python dictionary to pysaml2 SAML2 metadata format

def _kwa(val, onts):
    """
    Key word argument conversion

    :param val: A dictionary
    :param onts: Schemas to use in the conversion
    :return: A converted dictionary
    """
    return dict([(k,from_dict(v, onts)) for k,v in val.items() if k not in EXP_SKIP])

def from_dict(val, onts):
    """
    Converts a dictionary into a pysaml2 object
    :param val: A dictionary
    :param onts: Schemas to use in the conversion
    :return: The pysaml2 object instance
    """
    if isinstance(val, dict):
        if "__class__" in val:
            ns, typ = val["__class__"].split("&")
            cls = getattr(onts[ns], typ)
            if cls is md.Extensions:
                lv = []
                for key, ditems in val.items():
                    if key in EXP_SKIP:
                        continue
                    for item in ditems:
                        ns, typ = item["__class__"].split("&")
                        cls = getattr(onts[ns], typ)
                        kwargs = _kwa(item, onts)
                        inst = cls(**kwargs)
                        lv.append(element_to_extension_element(inst))
                return lv
            else:
                kwargs = _kwa(val, onts)
                inst = cls(**kwargs)
            return inst
        else:
            res = {}
            for key, v in val.items():
                res[key] = from_dict(v, onts)
            return res
    elif isinstance(val, basestring):
        return val
    elif isinstance(val, list):
        return [from_dict(v, onts) for v in val]
    else:
        return val