# Copyright 2024 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.
"""
the class of WorkerGroup
"""

import logging
import signal
import threading
import time
from typing import Any, Callable, Dict, List

from .decorator import MAGIC_ATTR, Dispatch, get_predefined_dispatch_fn, get_predefined_execute_fn


class ResourcePool:
    """The resource pool with meta info such as world_size."""

    def __init__(self, process_on_nodes=None, max_colocate_count: int = 10, n_gpus_per_node=8) -> None:
        if process_on_nodes is None:
            process_on_nodes = []
        self._store = process_on_nodes
        self.max_colocate_count = max_colocate_count
        self.n_gpus_per_node = n_gpus_per_node  # this is left for future huawei GPU that contains 16 GPUs per node

    def add_node(self, process_count):
        self._store.append(process_count)

    @property
    def world_size(self):
        return sum(self._store)

    def __call__(self) -> Any:
        return self._store

    @property
    def store(self):
        return self._store

    def local_world_size_list(self) -> List[int]:
        nested_local_world_size_list = [[local_world_size for _ in range(local_world_size)] for local_world_size in self._store]
        return [item for row in nested_local_world_size_list for item in row]

    def local_rank_list(self) -> List[int]:
        nested_local_rank_list = [[i for i in range(local_world_size)] for local_world_size in self._store]
        return [item for row in nested_local_rank_list for item in row]


class ClassWithInitArgs:
    """
    This class stores a class constructor and the args/kwargs to construct the class.
    It is used to instantiate the remote class.
    """

    def __init__(self, cls, *args, **kwargs) -> None:
        self.cls = cls
        self.args = args
        self.kwargs = kwargs

        self.fused_worker_used = False

    # def add_arg(self, arg):
    #     self.args += (arg,)

    # def add_kwarg(self, key, value):
    #     self.kwargs[key] = value

    def __call__(self) -> Any:
        return self.cls(*self.args, **self.kwargs)


def check_workers_alive(workers: List, is_alive: Callable, gap_time: float = 1) -> None:
    import time

    while True:
        for worker in workers:
            if not is_alive(worker):
                logging.warning(f"worker {worker} is not alive sending signal to main thread")
                signal.raise_signal(signal.SIGABRT)
        time.sleep(gap_time)


class WorkerGroup:
    """A group of workers"""

    fused_worker_execute_fn_name = "_fuw_execute"

    def __init__(self, resource_pool: ResourcePool, **kwargs) -> None:
        self._is_init_with_detached_workers = resource_pool is None

        self.fused_worker_used = False

        if resource_pool is not None:
            # handle the case when WorkGroup is attached to an existing one
            self._procecss_dispatch_config = resource_pool()
        else:
            self._procecss_dispatch_config = None

        self._workers = []
        self._worker_names = []

        self._master_addr = None
        self._master_port = None

        self._checker_thread: threading.Thread = None

    def _is_worker_alive(self, worker):
        raise NotImplementedError("WorkerGroup._is_worker_alive called, should be implemented in derived class.")

    def _block_until_all_workers_alive(self) -> None:
        while True:
            all_state = [self._is_worker_alive(worker) for worker in self._workers]
            if False in all_state:
                time.sleep(1)
            else:
                break

    def start_worker_aliveness_check(self, every_n_seconds=1) -> None:
        # before starting checking worker aliveness, make sure all workers are already alive
        self._block_until_all_workers_alive()

        self._checker_thread = threading.Thread(target=check_workers_alive, args=(self._workers, self._is_worker_alive, every_n_seconds))
        self._checker_thread.start()

    @property
    def world_size(self):
        return len(self._workers)

    # execute_all_async and execute_rank_zero_async should be implemented by RayWorkerGroup, TorchRPCWorkerGroup,
    # MegatronWorkerGroup, XperfWorkerGroup should skip

    def _bind_worker_method(self, user_defined_cls, func_generator):
        """
        Bind the worker method to the WorkerGroup
        """

        method_names = []
        for method_name in dir(user_defined_cls):
            try:
                method = getattr(user_defined_cls, method_name)
                assert callable(method), f"{method_name} in {user_defined_cls} is not callable"
            except Exception:
                # if it is a property, it will fail because Class doesn't have instance property
                continue

            if hasattr(method, MAGIC_ATTR):
                # this method is decorated by register
                attribute = getattr(method, MAGIC_ATTR)
                assert isinstance(attribute, Dict), f"attribute must be a dictionary. Got {type(attribute)}"
                assert "dispatch_mode" in attribute, "attribute must contain dispatch_mode in its key"

                dispatch_mode = attribute["dispatch_mode"]
                execute_mode = attribute["execute_mode"]
                blocking = attribute["blocking"]

                # get dispatch fn
                if isinstance(dispatch_mode, Dispatch):
                    # get default dispatch fn
                    fn = get_predefined_dispatch_fn(dispatch_mode=dispatch_mode)
                    dispatch_fn = fn["dispatch_fn"]
                    collect_fn = fn["collect_fn"]
                else:
                    assert isinstance(dispatch_mode, dict)
                    assert "dispatch_fn" in dispatch_mode
                    assert "collect_fn" in dispatch_mode
                    dispatch_fn = dispatch_mode["dispatch_fn"]
                    collect_fn = dispatch_mode["collect_fn"]

                # get execute_fn_name
                execute_mode = get_predefined_execute_fn(execute_mode=execute_mode)
                wg_execute_fn_name = execute_mode["execute_fn_name"]

                # get execute_fn from string
                try:
                    execute_fn = getattr(self, wg_execute_fn_name)
                    assert callable(execute_fn), "execute_fn must be callable"
                except Exception:
                    print(f"execute_fn {wg_execute_fn_name} is invalid")
                    raise

                # bind a new method to the RayWorkerGroup
                func = func_generator(
                    self,
                    method_name,
                    dispatch_fn=dispatch_fn,
                    collect_fn=collect_fn,
                    execute_fn=execute_fn,
                    blocking=blocking,
                )

                try:
                    setattr(self, method_name, func)
                    method_names.append(method_name)
                except Exception as e:
                    raise ValueError(f"Fail to set method_name {method_name}") from e

        return method_names
