# encoding: utf-8
#
#
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this file,
# You can obtain one at http://mozilla.org/MPL/2.0/.
#
# Author: Kyle Lahnakoski (kyle@lahnakoski.com)
#
from __future__ import absolute_import
from __future__ import division
from __future__ import unicode_literals

from collections import Mapping

from mo_dots import zip as dict_zip, get_logger, wrap
from mo_future import text_type, get_function_arguments, get_function_defaults, get_function_name
from mo_logs import Except


def override(func):
    """
    THIS DECORATOR WILL PUT ALL PARAMETERS INTO THE `kwargs` PARAMETER AND
    THEN PUT ALL `kwargs` PARAMETERS INTO THE FUNCTION PARAMETERS. THIS HAS
    THE BENEFIT OF HAVING ALL PARAMETERS IN ONE PLACE (kwargs), PLUS ALL
    PARAMETERS ARE EXPLICIT FOR CLARITY.

    OF COURSE, THIS MEANS PARAMETER ASSIGNMENT MAY NOT BE UNIQUE: VALUES CAN
    COME FROM EXPLICIT CALL PARAMETERS, OR FROM THE kwargs PARAMETER. IN
    THESE CASES, PARAMETER VALUES ARE CHOSEN IN THE FOLLOWING ORDER:
    1) EXPLICT CALL PARAMETERS
    2) PARAMETERS FOUND IN kwargs
    3) DEFAULT VALUES ASSIGNED IN FUNCTION DEFINITION
    """

    func_name = get_function_name(func)
    params = get_function_arguments(func)
    if not get_function_defaults(func):
        defaults = {}
    else:
        defaults = {k: v for k, v in zip(reversed(params), reversed(get_function_defaults(func)))}

    def raise_error(e, packed):
        e = Except.wrap(e)
        if e.message.startswith(func_name) and "takes at least" in e:
            missing = [p for p in params if str(p) not in packed]
            get_logger().error(
                "Problem calling {{func_name}}:  Expecting parameter {{missing}}, given {{given}}",
                func_name=func_name,
                missing=missing,
                given=packed.keys(),
                stack_depth=1
            )
        get_logger().error("Error dispatching call", e)

    if "kwargs" not in params:
        # WE ASSUME WE ARE ONLY ADDING A kwargs PARAMETER TO SOME REGULAR METHOD
        def wo_kwargs(*args, **kwargs):
            settings = kwargs.get("kwargs")
            ordered_params = dict(zip(params, args))
            packed = params_pack(params, ordered_params, kwargs, settings, defaults)
            try:
                return func(**packed)
            except TypeError as e:
                raise_error(e, packed)
        return wo_kwargs

    elif func_name in ("__init__", "__new__"):
        def w_constructor(*args, **kwargs):
            if "kwargs" in kwargs:
                packed = params_pack(params, kwargs, dict_zip(params[1:], args[1:]), kwargs["kwargs"], defaults)
            elif len(args) == 2 and len(kwargs) == 0 and isinstance(args[1], Mapping):
                # ASSUME SECOND UNNAMED PARAM IS kwargs
                packed = params_pack(params, args[1], defaults)
            else:
                # DO NOT INCLUDE self IN kwargs
                packed = params_pack(params, kwargs, dict_zip(params[1:], args[1:]), defaults)
            try:
                return func(args[0], **packed)
            except TypeError as e:
                raise_error(e, packed)
        return w_constructor

    elif params[0] == "self":
        def w_bound_method(*args, **kwargs):
            if len(args) == 2 and len(kwargs) == 0 and isinstance(args[1], Mapping):
                # ASSUME SECOND UNNAMED PARAM IS kwargs
                packed = params_pack(params, args[1], defaults)
            elif "kwargs" in kwargs and isinstance(kwargs["kwargs"], Mapping):
                # PUT args INTO kwargs
                packed = params_pack(params, kwargs, dict_zip(params[1:], args[1:]), kwargs["kwargs"], defaults)
            else:
                packed = params_pack(params, kwargs, dict_zip(params[1:], args[1:]), defaults)
            try:
                return func(args[0], **packed)
            except TypeError as e:
                raise_error(e, packed)
        return w_bound_method

    else:
        def w_kwargs(*args, **kwargs):
            if len(args) == 1 and len(kwargs) == 0 and isinstance(args[0], Mapping):
                # ASSUME SINGLE PARAMETER IS kwargs
                packed = params_pack(params, args[0], defaults)
            elif "kwargs" in kwargs and isinstance(kwargs["kwargs"], Mapping):
                # PUT args INTO kwargs
                packed = params_pack(params, kwargs, dict_zip(params, args), kwargs["kwargs"], defaults)
            else:
                # PULL kwargs OUT INTO PARAMS
                packed = params_pack(params, kwargs, dict_zip(params, args), defaults)
            try:
                return func(**packed)
            except TypeError as e:
                raise_error(e, packed)
        return w_kwargs


def params_pack(params, *args):
    settings = {}
    for a in args:
        if a == None:
            continue
        for k, v in a.items():
            k = text_type(k)
            if k in settings:
                continue
            settings[k] = v
    settings["kwargs"] = settings

    output = wrap({str(k): settings[k] for k in params if k in settings})
    return output
