# Copyright (c) 2024 PaddlePaddle Authors. All Rights Reserved.
# Copyright 2018 Google AI, Google Brain and the HuggingFace Inc. team.
#
# 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.

import importlib
from collections import OrderedDict

from paddlenlp.transformers.auto.configuration import model_type_to_module_name


def getattribute_from_module(module, attr):
    if attr is None:
        return None
    if isinstance(attr, tuple):
        return tuple(getattribute_from_module(module, a) for a in attr)
    if hasattr(module, attr):
        return getattr(module, attr)
    # Some of the mappings have entries model_type -> object of another model type. In that case we try to grab the
    # object at the top level.
    paddlenlp_module = importlib.import_module("paddlenlp")

    if module != paddlenlp_module:
        try:
            return getattribute_from_module(paddlenlp_module, attr)
        except ValueError:
            raise ValueError(f"Could not find {attr} neither in {module} nor in {paddlenlp_module}!")
    else:
        raise ValueError(f"Could not find {attr} in {paddlenlp_module}!")


class _LazyAutoMapping(OrderedDict):
    """
    " A mapping config to object (model or tokenizer for instance) that will load keys and values when it is accessed.

    Args:
        - config_mapping: The map model type to config class
        - model_mapping: The map model type to model (or tokenizer) class
    """

    def __init__(self, config_mapping, model_mapping):
        self._config_mapping = config_mapping
        self._reverse_config_mapping = {v: k for k, v in config_mapping.items()}
        self._model_mapping = model_mapping
        self._model_mapping._model_mapping = self
        self._extra_content = {}
        self._modules = {}

    def __len__(self):
        common_keys = set(self._config_mapping.keys()).intersection(self._model_mapping.keys())
        return len(common_keys) + len(self._extra_content)

    def __getitem__(self, key):
        if key in self._extra_content:
            return self._extra_content[key]
        model_type = self._reverse_config_mapping[key.__name__]
        if model_type in self._model_mapping:
            model_name = self._model_mapping[model_type]
            return self._load_attr_from_module(model_type, model_name)

        # Maybe there was several model types associated with this config.
        model_types = [k for k, v in self._config_mapping.items() if v == key.__name__]
        for mtype in model_types:
            if mtype in self._model_mapping:
                model_name = self._model_mapping[mtype]
                return self._load_attr_from_module(mtype, model_name)
        raise KeyError(key)

    def _load_attr_from_module(self, model_type, attr):
        module_name = model_type_to_module_name(model_type)
        if module_name not in self._modules:
            if any(["Tokenizer" in name for name in [model_type, attr]]):
                try:
                    self._modules[module_name] = importlib.import_module(
                        f".{module_name}.tokenizer", "paddlenlp.transformers"
                    )
                except ImportError:
                    pass
            if module_name not in self._modules:
                if any(["Config" in name for name in [model_type, attr]]):
                    try:
                        self._modules[module_name] = importlib.import_module(
                            f".{module_name}.configuration", "paddlenlp.transformers"
                        )
                    except ImportError:
                        pass
            if module_name not in self._modules:
                self._modules[module_name] = importlib.import_module(f".{module_name}", "paddlenlp.transformers")
        return getattribute_from_module(self._modules[module_name], attr)

    def keys(self):
        mapping_keys = [
            self._load_attr_from_module(key, name)
            for key, name in self._config_mapping.items()
            if key in self._model_mapping.keys()
        ]
        return mapping_keys + list(self._extra_content.keys())

    def get(self, key, default):
        try:
            return self.__getitem__(key)
        except KeyError:
            return default

    def __bool__(self):
        return bool(self.keys())

    def values(self):
        mapping_values = [
            self._load_attr_from_module(key, name)
            for key, name in self._model_mapping.items()
            if key in self._config_mapping.keys()
        ]
        return mapping_values + list(self._extra_content.values())

    def items(self):
        mapping_items = [
            (
                self._load_attr_from_module(key, self._config_mapping[key]),
                self._load_attr_from_module(key, self._model_mapping[key]),
            )
            for key in self._model_mapping.keys()
            if key in self._config_mapping.keys()
        ]
        return mapping_items + list(self._extra_content.items())

    def __iter__(self):
        return iter(self.keys())

    def __contains__(self, item):
        if item in self._extra_content:
            return True
        if not hasattr(item, "__name__") or item.__name__ not in self._reverse_config_mapping:
            return False
        model_type = self._reverse_config_mapping[item.__name__]
        return model_type in self._model_mapping

    def register(self, key, value, exist_ok=False):
        """
        Register a new model in this mapping.
        """
        if hasattr(key, "__name__") and key.__name__ in self._reverse_config_mapping:
            model_type = self._reverse_config_mapping[key.__name__]
            if model_type in self._model_mapping.keys() and not exist_ok:
                raise ValueError(f"'{key}' is already used by a Transformers model.")

        self._extra_content[key] = value