# Copyright (c) 2025 Bytedance Ltd. and/or its affiliates
# 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.

# Codes adapted from [SeedVR]
# https://github.com/ByteDance-Seed/SeedVR/blob/main/common/config.py

"""
Configuration utility functions
"""

import importlib
from typing import Any, Callable, List, Union
from omegaconf import DictConfig, ListConfig, OmegaConf

OmegaConf.register_new_resolver("eval", eval)


def load_config(path: str, argv: List[str] = None) -> Union[DictConfig, ListConfig]:
    """
    Load a configuration. Will resolve inheritance.
    """
    config = OmegaConf.load(path)
    if argv is not None:
        config_argv = OmegaConf.from_dotlist(argv)
        config = OmegaConf.merge(config, config_argv)
    config = resolve_recursive(config, resolve_inheritance)
    return config


def resolve_recursive(
    config: Any,
    resolver: Callable[[Union[DictConfig, ListConfig]], Union[DictConfig, ListConfig]],
) -> Any:
    config = resolver(config)
    if isinstance(config, DictConfig):
        for k in config.keys():
            v = config.get(k)
            if isinstance(v, (DictConfig, ListConfig)):
                config[k] = resolve_recursive(v, resolver)
    if isinstance(config, ListConfig):
        for i in range(len(config)):
            v = config.get(i)
            if isinstance(v, (DictConfig, ListConfig)):
                config[i] = resolve_recursive(v, resolver)
    return config


def resolve_inheritance(config: Union[DictConfig, ListConfig]) -> Any:
    """
    Recursively resolve inheritance if the config contains:
    __inherit__: path/to/parent.yaml.
    """
    if isinstance(config, DictConfig):
        inherit = config.pop("__inherit__", None)
        if inherit:
            assert isinstance(inherit, str)
            inherit = load_config(inherit)
            if len(config.keys()) > 0:
                config = OmegaConf.merge(inherit, config)
            else:
                config = inherit
    return config


def import_item(path: str, name: str) -> Any:
    """
    Import a python item. Example: import_item("path.to.file", "MyClass") -> MyClass
    """
    return getattr(importlib.import_module(path), name)


def create_object(config: DictConfig) -> Any:
    """
    Create an object from config.
    The config is expected to contains the following:
    __object__:
      path: path.to.module
      name: MyClass
      args: as_config | as_params (default to as_config)
    """
    item = import_item(
        path=config.__object__.path,
        name=config.__object__.name,
    )
    args = config.__object__.get("args", "as_config")
    if args == "as_config":
        return item(config)
    if args == "as_params":
        config = OmegaConf.to_object(config)
        config.pop("__object__")
        return item(**config)
    raise NotImplementedError(f"Unknown args type: {args}")


def create_dataset(path: str, *args, **kwargs) -> Any:
    """
    Create a dataset. Requires the file to contain a "create_dataset" function.
    """
    return import_item(path, "create_dataset")(*args, **kwargs)