"""
Copyright (c) 2016 rllab contributors
https://github.com/rll/rllab
"""

import inspect
import sys


class Serializable(object):

    def __init__(self, *args, **kwargs):
        self.__args = args
        self.__kwargs = kwargs

    def quick_init(self, locals_):
        try:
            if object.__getattribute__(self, "_serializable_initialized"):
                return
        except AttributeError:
            pass
        if sys.version_info >= (3, 0):
            spec = inspect.getfullargspec(self.__init__)
            # Exclude the first "self" parameter
            if spec.varkw:
                kwargs = locals_[spec.varkw]
            else:
                kwargs = dict()
        else:
            spec = inspect.getargspec(self.__init__)
            if spec.keywords:
                kwargs = locals_[spec.keywords]
            else:
                kwargs = dict()
        if spec.varargs:
            varargs = locals_[spec.varargs]
        else:
            varargs = tuple()
        in_order_args = [locals_[arg] for arg in spec.args][1:]
        self.__args = tuple(in_order_args) + varargs
        self.__kwargs = kwargs
        setattr(self, "_serializable_initialized", True)

    def __getstate__(self):
        return {"__args": self.__args, "__kwargs": self.__kwargs}

    def __setstate__(self, d):
        out = type(self)(*d["__args"], **d["__kwargs"])
        self.__dict__.update(out.__dict__)

    @classmethod
    def clone(cls, obj, **kwargs):
        assert isinstance(obj, Serializable)
        d = obj.__getstate__()

        # Split the entries in kwargs between positional and keyword arguments
        # and update d['__args'] and d['__kwargs'], respectively.
        if sys.version_info >= (3, 0):
            spec = inspect.getfullargspec(obj.__init__)
        else:
            spec = inspect.getargspec(obj.__init__)
        in_order_args = spec.args[1:]

        d["__args"] = list(d["__args"])
        for kw, val in kwargs.items():
            if kw in in_order_args:
                d["__args"][in_order_args.index(kw)] = val
            else:
                d["__kwargs"][kw] = val

        out = type(obj).__new__(type(obj))
        out.__setstate__(d)
        return out
