# Copyright 2020 Huawei Technologies Co., Ltd
#
# 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.
# ============================================================================

"""Parameter for cell."""
from copy import copy
import numbers
from .._c_expression import ParamInfo
from .._c_expression import MetaTensor as MetaTensor_
from . import dtype as mstype
from .initializer import initializer
from .tensor import Tensor, MetaTensor
from .._checkparam import Validator
from ..parallel._tensor import _get_slice_index
from ..parallel._auto_parallel_context import auto_parallel_context
from ..parallel._ps_context import _is_role_worker, _is_role_pserver, _is_role_sched, _clone_hash_table
from ..parallel._ps_context import _reinsert_hash_table_size
from ..parallel._ps_context import _insert_weight_init_info, _insert_accumu_init_info
from .seed import _get_global_and_op_seed

__all__ = ['Parameter', 'ParameterTuple']

PARAMETER_NAME_DEFAULT = "Parameter"
PARAMETER_NAME_PREFIX_MAX_LEN = 1024


def _is_in_parallel_mode():
    """Get parallel mode."""
    return auto_parallel_context().get_parallel_mode() in ["semi_auto_parallel", "auto_parallel"]

def init_to_value(init):
    """Get value of initializer."""
    if isinstance(init, str):
        if init == 'zeros':
            return 0.0
        if init == 'ones':
            return 1.0
        raise ValueError("init should be one of values in 'zeros', 'ones'.")
    if isinstance(init, numbers.Number):
        return float(init)
    raise ValueError("init should be number or string")


class Parameter(MetaTensor_):
    """
    Parameter types of cell models.

    After initialized `Parameter` is a subtype of `Tensor`.

    In auto_parallel mode of  "semi_auto_parallel" and "auto_parallel", if init `Parameter` by
    an `MetaTensor`, the type of Parameter will be `MetaTensor` not `Tensor`. `MetaTensor_`
    only saves the shape and type info of a tensor with no memory usage. The shape can be changed while
    compiling for auto-parallel. Call `init_data` will return a Tensor Parameter with initialized data.

    Note:
        Each parameter of Cell is represented by Parameter class.
        A Parameter has to belong to a Cell.
        If there is an operator in the network that requires part of the inputs to be Parameter,
        then the Parameters as this part of the inputs are not allowed to be cast.
        It is recommended to use the default value of `name` when initialize a parameter as one attribute of a cell,
        otherwise, the parameter name may be different than expected.

    Args:
        default_input (Union[Tensor, MetaTensor, Number]): Parameter data, to be set initialized.
        name (str): Name of the child parameter. Default: None.
        requires_grad (bool): True if the parameter requires gradient. Default: True.
        layerwise_parallel (bool): A kind of model parallel mode. When layerwise_parallel is true in parallel mode,
            broadcast and gradients communication would not be applied to parameters. Default: False.

    Example:
        >>> from mindspore import Parameter, Tensor
        >>> from mindspore.common import initializer as init
        >>> from mindspore.ops import operations as P
        >>> from mindspore.nn import Cell
        >>> import mindspore
        >>> import numpy as np
        >>> from mindspore import context
        >>>
        >>> class Net(Cell):
        ...     def __init__(self):
        ...         super(Net, self).__init__()
        ...         self.matmul = P.MatMul()
        ...         self.weight = Parameter(Tensor(np.ones((1,2))), name="w", requires_grad=True)
        ...
        ...     def construct(self, x):
        ...         out = self.matmul(self.weight, x)
        ...         return out
        >>> context.set_context(mode=context.GRAPH_MODE, device_target="CPU")
        >>> net = Net()
        >>> x = Tensor(np.ones((2,1)))
        >>> print(net(x))
        [[2.]]
        >>> net.weight.set_data(Tensor(np.zeros((1,2))))
        Parameter (name=w)
        >>> print(net(x))
        [[0.]]
    """
    __base_type__ = {}

    def __new__(cls, default_input, *args, **kwargs):
        input_class, *class_init_args = Parameter._get_parameter_new_args(default_input)
        new_type = Parameter._get_base_class(input_class)
        obj = input_class.__new__(new_type)
        input_class.__init__(obj, *class_init_args)
        # it's better to make the Initializer a kind of metatensor.
        obj.init_mode = None
        obj.is_default_input_meta = False
        if isinstance(default_input, MetaTensor):
            obj.is_default_input_meta = True
        if not isinstance(obj, Tensor):
            obj.init_mode = default_input
        return obj

    def __reduce_ex__(self, _):
        data = self
        if self.init_mode is not None:
            data = self.init_mode
        else:
            # cast to break deep infinit loop while deepcopy
            data = Tensor(self)
        return (
            Parameter, (data, self.name, self.requires_grad, self.layerwise_parallel))

    def __init__(self, default_input, name=None, requires_grad=True, layerwise_parallel=False):
        self._param_info = ParamInfo()
        self.init_in_server = False
        self.cache_enable = False
        self.name = name
        self.requires_grad = requires_grad
        self.layerwise_parallel = layerwise_parallel
        # this flag for tensor copy data.
        self.init_flag = False
        # this flag is for ge variable copy data.
        self._is_init = False
        self._inited_param = None
        self._sliced = False
        self.is_param_ps = False
        self._cast_type = None
        self._unique = False
        self.is_in_parallel = _is_in_parallel_mode()
        if isinstance(default_input, (MetaTensor, Tensor)):
            MetaTensor_.__init__(self, default_input.dtype, default_input.shape)
        elif isinstance(default_input, int):
            MetaTensor_.__init__(self, mstype.int64, ())
        elif isinstance(default_input, float):
            MetaTensor_.__init__(self, mstype.float32, ())

    @staticmethod
    def _get_base_class(input_class):
        input_class_name = f'Parameter{input_class.__name__}'
        if input_class_name in Parameter.__base_type__:
            new_type = Parameter.__base_type__[input_class_name]
        else:
            new_type = type(input_class_name, (Parameter, input_class), {})
            Parameter.__base_type__[input_class_name] = new_type
        return new_type

    @staticmethod
    def _get_parameter_new_args(data):
        """Set `set_data` of current `Parameter`."""
        if isinstance(data, bool):
            raise ValueError('Parameter data can not be `bool`')
        if isinstance(data, MetaTensor):
            if _is_in_parallel_mode() or _is_role_worker() or _is_role_sched():
                # do not init data while in auto parallel.
                return (MetaTensor_, data.dtype, data.shape)
            data = data.to_tensor()
        if isinstance(data, Tensor):
            # make a copy of Tensor to init the parameter
            return (Tensor, data.asnumpy(),)
        if isinstance(data, int):
            return (Tensor, data, mstype.int32)
        if isinstance(data, float):
            return (Tensor, data, mstype.float32)
        return (Tensor, data)

    def __str__(self):
        return f'Parameter (name={self._param_info.name})'

    def __repr__(self):
        return f'Parameter (name={self._param_info.name})'

    def __parameter__(self):
        """For parse check."""

    def set_param_ps(self, init_in_server=False):
        """
        Set whether the trainable parameter is updated by parameter server and whether the
        trainable parameter is initialized on server.

        Note:
            It only works when a running task is in the parameter server mode.

        Args:
            init_in_server (bool): Whether trainable parameter updated by parameter server is
                initialized on server. Default: False.
        """
        if not(_is_role_worker() or _is_role_pserver() or _is_role_sched()):
            raise RuntimeError("Must complete following two steps before calling set_param_ps: \
                               1. set_ps_context(enable_ps=True) \
                               2. export MS_ROLE environment variable.")

        if init_in_server and (not self.name.endswith("embedding_table")):
            raise RuntimeError("Can not initialize parameter '{}' in server, only parameters of "
                               "sparse operator support initialization in server.".format(self.name))
        self.is_param_ps = True
        self.init_in_server = init_in_server
        self._param_info.init_in_server = init_in_server


    @property
    def inited_param(self):
        """
        Get the new parameter after call the init_data.

        Default is a None, If `self` is a Parameter with out data, after call the
        `init_data` the initialized Parameter with data will be recorded here.
        """
        return self._inited_param


    @property
    def name(self):
        """Get the name of the parameter."""
        return self._param_info.name

    @name.setter
    def name(self, name_):
        """
        Define a name for the parameter.

        Args:
            name_ (`str` or `None`): The name of the parameter. When the parameter is None or an empty string,
                the default value `PARAMETER_NAME_DEFAULT` is used.
        """
        if name_ is None:
            name_ = PARAMETER_NAME_DEFAULT
        elif isinstance(name_, str):
            name_ = name_.strip()
            if name_ == '':
                name_ = PARAMETER_NAME_DEFAULT
            if len(name_) > PARAMETER_NAME_PREFIX_MAX_LEN:
                raise ValueError("The length of the '{}' name should be less than {}.".
                                 format(name_, PARAMETER_NAME_PREFIX_MAX_LEN))
        else:
            raise ValueError("The type of the name should be `str` or `None`.")

        if _is_role_worker() and self.cache_enable:
            if len(self.shape) != 2:
                raise RuntimeError("The dims of parameter '{}' must be 2, but got {}."
                                   .format(self.name, len(self.shape)))
            _reinsert_hash_table_size(name_, self._param_info.name, self.shape[0], self.shape[1])

        self._param_info.name = name_

    @property
    def sliced(self):
        """Get slice status of the parameter."""
        return self._sliced

    @sliced.setter
    def sliced(self, sliced_):
        self._sliced = sliced_

    @property
    def unique(self):
        """whether the parameter is already unique or not."""
        return self._unique

    @unique.setter
    def unique(self, unique_):
        self._unique = unique_

    @property
    def is_init(self):
        """
        Get the initialization status of the parameter.

        In GE backend, the Parameter need a "init graph" to sync the data from host to device.
        This flag indicates whether the data as been sync to the device.

        This flag only work in GE, and it will be set to False in other backend.
        """
        return self._is_init

    @is_init.setter
    def is_init(self, is_init_):
        """
        Set init status of the parameter.

        Args:
            is_init_ (bool): The init status of the parameter.
        """
        self._is_init = is_init_

    def clone(self, init='same'):
        """
        Clone the parameter.

        Args:
            init (Union[Tensor, str, MetaTensor, numbers.Number]): Initialize the shape of the parameter.
                Default: 'same'.

        Returns:
            Parameter, a new parameter.
        """
        x = copy(self)
        # pylint: disable=protected-access
        x._param_info = self._param_info.clone()
        x.is_init = False
        x.is_param_ps = self.is_param_ps
        x.init_in_server = self.init_in_server
        x.cache_enable = self.cache_enable
        if init != 'same':
            shape = self.shape
            dtype = self.dtype
            x.set_data(initializer(init, shape=shape, dtype=dtype))
        return x

    @property
    def layerwise_parallel(self):
        return self._param_info.layerwise_parallel

    @layerwise_parallel.setter
    def layerwise_parallel(self, value=True):
        if not isinstance(value, bool):
            raise TypeError("`layerwise_parallel` parameter must be bool type")
        self._param_info.layerwise_parallel = value

    @property
    def requires_grad(self):
        """Return whether the parameter requires gradient."""
        return self._param_info.requires_grad

    @requires_grad.setter
    def requires_grad(self, value=True):
        if not isinstance(value, bool):
            raise TypeError("`requires_grad` parameter must be bool type")
        self._param_info.requires_grad = value

    @property
    def data(self):
        return self

    def _update_tensor_data(self, data):
        "Update the parameter by a Tensor."
        if isinstance(self, Tensor):
            # for Tensor same shape:
            self.init_flag = False
            return self.assign_value(data)
        # create a new tensor
        return Parameter(data, self.name, self.requires_grad)

    def set_data(self, data, slice_shape=False):
        """
        Set `set_data` of current `Parameter`.

        Args:
            data (Union[Tensor, MetaTensor, int, float]): new data.
            slice_shape (bool): If slice the parameter is set to true, the shape is not checked for consistency.
                                Default: False.

        Returns:
            Parameter, the parameter after set data.
        """
        def raise_type_error(incoming):
            raise TypeError(f"Incoming Parameter dtype can not be converted to current dtype implicitly. "
                            f"Current dtype is {self.dtype}, and incoming is {incoming}. "
                            f"Use .set_dtype(xxx) to change the dtype.")

        if not isinstance(data, (MetaTensor_, int, float)):
            raise TypeError(f"Parameter data must be [`MetaTensor`, `int`, `float`] or a kind of `MetaTensor_` "
                            f"(like `Tensor` or `MetaTensor_`). But with type {type(data)}.")
        if isinstance(data, (int, float)):
            if self.dtype in mstype.int_type and isinstance(data, float):
                raise_type_error(mstype.float_)
            data = Tensor(data, self.dtype)
        # both not init.
        is_incoming_tensor = isinstance(data, Tensor)
        is_current_tensor = isinstance(self, Tensor)

        if is_incoming_tensor and not is_current_tensor:
            raise TypeError("Parameter is a `MetaTensor_` and not initializered, `data` for `set_data`"
                            "should be a MetaTensor. If you want to update it by Tensor, call method"
                            "`init_parameters_data` of `Cell` to init and replace all the Parameter of"
                            "network, then call this method.")
        if tuple(self.shape) != tuple(data.shape):
            # If Slice create Parameter shape can be change.
            if not slice_shape:
                raise ValueError(f"Can not change the shape of Parameter which has been initialized."
                                 f" Current shape is {self.shape}, and incoming is {data.shape}.")
        if self.dtype != data.dtype:
            if mstype.implicit_conversion_seq[self.dtype] < mstype.implicit_conversion_seq[data.dtype]:
                raise_type_error(data.dtype)
            else:
                data = Tensor(data, self.dtype)
        if isinstance(data, MetaTensor):
            # The parameter has been initializered, directly update by the data
            if is_current_tensor:
                self._update_tensor_data(data.to_tensor())
            else:
                # also update the related inited parameter data
                if self.inited_param is not None:
                    self.inited_param.set_data(data)
                self.init_mode = data
        elif is_incoming_tensor or is_current_tensor:
            self._update_tensor_data(data)
        else:
            raise ValueError(f"Not support to update the Parameter by {data}")
        self.sliced = slice_shape
        return self

    def init_data(self, layout=None, set_sliced=False):
        """
        Initialize the parameter data.

        Args:
            layout (list[list[int]]): Parameter slice layout [dev_mat, tensor_map, slice_shape].

                - dev_mat (list[int]): Device matrix.
                - tensor_map (list[int]): Tensor map.
                - slice_shape (list[int]): Shape of slice.
            set_sliced (bool): True if the parameter is set sliced after initializing the data.
                Default: False.

        Raises:
            RuntimeError: If it is from Initializer, and parallel mode has changed after the Initializer created.

        Returns:
            Parameter, the `Parameter` after initializing data. If current `Parameter` was already initialized before,
            returns the same initialized `Parameter`.
        """
        if self.is_default_input_meta:
            is_current_in_parallel = _is_in_parallel_mode()
            if self.is_in_parallel != is_current_in_parallel:
                raise RuntimeError("Must set or change parallel mode before any MetaTensor created.")
        if self.init_mode is None:
            return self
        if self.inited_param is not None:
            return self.inited_param
        if _is_role_worker() and self.cache_enable:
            global_seed, op_seed = _get_global_and_op_seed()
            _insert_weight_init_info(self.name, global_seed, op_seed)
        if layout is not None:
            if not isinstance(layout, tuple):
                raise TypeError("The layout should be tuple! layout is {}.".format(layout))
            if len(layout) < 3:
                raise ValueError("The length of layout must be larger than 3! layout is {}.".format(layout))
            slice_index = int(_get_slice_index(layout[0], layout[1]))
            if (self.init_in_server and self.is_param_ps and isinstance(self.init_mode, MetaTensor)):
                if _is_role_worker() or _is_role_sched():
                    data = self.init_mode.to_tensor(0, [1])
                else:
                    data = self.init_mode.to_tensor(slice_index, layout[2], layout[5])
            else:
                data = self.init_mode.to_tensor(slice_index, layout[2], layout[5])
        else:
            if (self.init_in_server and self.is_param_ps and isinstance(self.init_mode, MetaTensor)):
                if _is_role_worker() or _is_role_sched():
                    data = self.init_mode.to_tensor(0, [1])
                else:
                    data = self.init_mode.to_tensor()
            else:
                data = self.init_mode.to_tensor()

        obj = self._update_tensor_data(data)
        if id(obj) != id(self):
            self._inited_param = obj
        obj.init_mode = None
        obj.sliced = set_sliced
        return obj


class ParameterTuple(tuple):
    """
    Class for storing tuple of parameters.

    Note:
        It is used to store the parameters of the network into the parameter tuple collection.
    """
    def __new__(cls, iterable):
        """Create instance object of ParameterTuple."""
        data = tuple(iterable)
        ids = set()
        orders = {}
        for x in data:
            if not isinstance(x, Parameter):
                raise TypeError(f"ParameterTuple input should be `Parameter` collection."
                                f"But got a {type(iterable)}, {iterable}")
            if id(x) not in ids:
                ids.add(id(x))
                if x.name not in orders.keys():
                    orders[x.name] = [0, x]
                else:
                    if isinstance(orders[x.name], list):
                        name = x.name
                        orders[name][1].name = name + "_" + str(0)
                        x.name = x.name + "_" + str(1)
                        orders[name] = 1
                    else:
                        orders[x.name] += 1
                        x.name = x.name + "_" + str(orders[x.name])
        return tuple.__new__(ParameterTuple, tuple(data))

    def clone(self, prefix, init='same'):
        """
        Clone the parameter.

        Args:
            prefix (str): Namespace of parameter.
            init (str): Initialize the shape of the parameter. Default: 'same'.

        Returns:
            Tuple, the new Parameter tuple.
        """
        Validator.check_str_by_regular(prefix)
        new = []
        for x in self:
            x1 = x.clone(init)
            x1.name = prefix + "." + x1.name
            new.append(x1)

            if not x1.cache_enable:
                continue
            if not x1.name.endswith("embedding_table"):
                raise RuntimeError("Can not enable cache for parameter '{}', Only parameters of "
                                   "sparse operator support enable cache.".format(x1.name))

            if _is_role_worker():
                _clone_hash_table(x.name, x1.name)
                _insert_accumu_init_info(x1.name, init_to_value(init))
        return ParameterTuple(new)

    def __parameter_tuple__(self):
        """For parse check."""