# 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.

import logging
import time
from typing import Dict, List, Any, Tuple, Optional

import ray
from ray.util import list_named_actors
from ray.util.placement_group import placement_group, PlacementGroup
from ray.util.scheduling_strategies import PlacementGroupSchedulingStrategy, NodeAffinitySchedulingStrategy
from ray.experimental.state.api import get_actor

from verl.single_controller.base import WorkerGroup, ResourcePool, ClassWithInitArgs, Worker

__all__ = ['Worker']


def get_random_string(length: int) -> str:
    import random
    import string
    letters_digits = string.ascii_letters + string.digits
    return ''.join(random.choice(letters_digits) for _ in range(length))


def func_generator(self, method_name, dispatch_fn, collect_fn, execute_fn, blocking):

    def func(*args, **kwargs):
        args, kwargs = dispatch_fn(self, *args, **kwargs)
        output = execute_fn(method_name, *args, **kwargs)
        if blocking:
            output = ray.get(output)
        output = collect_fn(self, output)
        return output

    return func


def sort_placement_group_by_node_ip(pgs: List[PlacementGroup]) -> List[PlacementGroup]:
    """
    Sort the placement groups by node ip, all bundles in a single placement group should be on the same node.

    FSDPCheckpointManager saves sharded model states and optimizer states in local storage, which requires RANK
    to be consistent across nodes when resume from checkpoint.

    With this function, if there's only one resource pool and there's no node change, RANK should be consistent
    across nodes in multiple ray jobs, even if the whole ray cluster is restarted.
    """
    node_ip = {node["NodeID"]: node["NodeManagerAddress"] for node in ray.nodes()}
    pg_ip = {}
    for pg in pgs:
        specs = ray._private.state.state.placement_group_table(pg.id)
        # all bunles should be on the same node
        node_id = specs["bundles_to_node_id"][0]
        pg_ip[pg.id] = node_ip[node_id]
    return sorted(pgs, key=lambda pg: pg_ip[pg.id])


class RayResourcePool(ResourcePool):

    def __init__(self,
                 process_on_nodes: Optional[List[int]] = None,
                 use_gpu: bool = True,
                 name_prefix: str = "",
                 max_colocate_count: int = 10,
                 detached=False) -> None:
        super().__init__(process_on_nodes, max_colocate_count)
        self.use_gpu = use_gpu
        # print(f"in RayProcessDispatchConfiguration: name_prefix = {name_prefix}")
        self.name_prefix = name_prefix
        self.pgs = None
        self.detached = detached

    def get_placement_groups(self, strategy="STRICT_PACK", name=None):
        if self.pgs is not None:
            return self.pgs

        pg_name_prefix = name if name else \
            f"{self.name_prefix}verl_group_{'_'.join([str(count) for count in self._store])}:"
        # print(f"pg_name_prefix = {pg_name_prefix}")
        pg_scheme = [[{
            "CPU": self.max_colocate_count,
            "GPU": 1
        } if self.use_gpu else {
            "CPU": self.max_colocate_count
        } for _ in range(process_count)] for process_count in self._store]

        lifetime = 'detached' if self.detached else None

        pgs = [
            placement_group(bundles=bundles, strategy=strategy, name=pg_name_prefix + str(idx), lifetime=lifetime)
            for idx, bundles in enumerate(pg_scheme)
        ]

        ray.get([pg.ready() for pg in pgs])

        self.pgs = pgs
        return pgs


def extract_pg_from_exist(resource_pools: Dict[str, RayResourcePool], src_role_names: List[str],
                          resource_pool: RayResourcePool) -> List:

    src_pgs = [
        pg for role_name, resource_pool in resource_pools.items() for pg in resource_pool.get_placement_groups()
        if role_name in src_role_names
    ]

    sorted_src_pgs = sorted(src_pgs, key=lambda pg: pg.bundle_count, reverse=True)
    sorted_process_on_nodes = sorted([(val, idx) for idx, val in enumerate(resource_pool.store)], reverse=True)

    unsorted_pgs: List[Tuple[int, PlacementGroup]] = []
    searching_idx = 0
    for request_process, original_idx in sorted_process_on_nodes:
        assert searching_idx < len(sorted_src_pgs), f"no enough nodes for request: searching {searching_idx} th node"
        assert request_process <= sorted_src_pgs[searching_idx].bundle_count, \
            f"requesting {request_process} processes, bundle count cannot satisfy"
        unsorted_pgs.append((original_idx, sorted_src_pgs[searching_idx]))
        searching_idx += 1

    return [pg for _, pg in sorted(unsorted_pgs)]


def merge_resource_pool(rp1: RayResourcePool, rp2: RayResourcePool) -> RayResourcePool:
    assert rp1.use_gpu == rp2.use_gpu, 'Both RayResourcePool must either use_gpu or not'
    assert rp1.max_colocate_count == rp2.max_colocate_count, 'Both RayResourcePool must has the same max_colocate_count'
    assert rp1.n_gpus_per_node == rp2.n_gpus_per_node, 'Both RayResourcePool must has the same n_gpus_per_node'
    assert rp1.detached == rp2.detached, 'Detached ResourcePool cannot be merged with non-detached ResourcePool'

    new_store = rp1.store + rp2.store

    merged = RayResourcePool(new_store, rp1.use_gpu, f"{rp1.name_prefix}_{rp2.name_prefix}")
    merged.pgs = rp1.get_placement_groups() + rp2.get_placement_groups()

    return merged


class RayClassWithInitArgs(ClassWithInitArgs):

    def __init__(self, cls, *args, **kwargs) -> None:
        # self._options = kwargs.pop('options', dict())
        super().__init__(cls, *args, **kwargs)
        self._options = {}
        self._additional_resource = {}

    def set_additional_resource(self, additional_resource):
        self._additional_resource = additional_resource

    def update_options(self, options: Dict):
        self._options.update(options)

    def __call__(self,
                 placement_group,
                 placement_group_bundle_idx,
                 use_gpu: bool = True,
                 num_gpus=1,
                 sharing_with=None) -> Any:
        if sharing_with is not None:
            target_node_id = ray.get(sharing_with.get_node_id.remote())
            cuda_visible_devices = ray.get(sharing_with.get_cuda_visible_devices.remote())
            options = {"scheduling_strategy": NodeAffinitySchedulingStrategy(node_id=target_node_id, soft=False)}
            return self.cls.options(**options).remote(*self.args,
                                                      cuda_visible_devices=cuda_visible_devices,
                                                      **self.kwargs)

        options = {
            "scheduling_strategy":
                PlacementGroupSchedulingStrategy(placement_group=placement_group,
                                                 placement_group_bundle_index=placement_group_bundle_idx)
        }
        options.update(self._options)

        if use_gpu:
            options["num_gpus"] = num_gpus

        if len(self._additional_resource) > 1:
            for k, v in self._additional_resource.items():
                options[k] = v

        # print("cls:", self.cls)
        # print("args: ", self.args)
        # print("kwargs: ", self.kwargs)
        return self.cls.options(**options).remote(*self.args, **self.kwargs)


class RayWorkerGroup(WorkerGroup):

    def __init__(self,
                 resource_pool: RayResourcePool = None,
                 ray_cls_with_init: RayClassWithInitArgs = None,
                 bin_pack: bool = True,
                 name_prefix: str = None,
                 detached=False,
                 worker_names=None,
                 ray_wait_register_center_timeout: int = 300,
                 **kwargs) -> None:
        super().__init__(resource_pool=resource_pool, **kwargs)
        self.ray_cls_with_init = ray_cls_with_init
        self.name_prefix = get_random_string(length=6) if name_prefix is None else name_prefix
        self._ray_wait_register_center_timeout = ray_wait_register_center_timeout

        if worker_names is not None:
            assert self._is_init_with_detached_workers
            self._worker_names = worker_names

        if self._is_init_with_detached_workers:
            self._init_with_detached_workers(worker_names=worker_names)
        else:
            self._init_with_resource_pool(resource_pool=resource_pool,
                                          ray_cls_with_init=ray_cls_with_init,
                                          bin_pack=bin_pack,
                                          detached=detached)

        if ray_cls_with_init is not None:
            self._bind_worker_method(self.ray_cls_with_init.cls, func_generator)

    def _is_worker_alive(self, worker: ray.actor.ActorHandle):
        worker_state_dict = get_actor(worker._actor_id.hex())
        return worker_state_dict.get("state", "undefined") == "ALIVE" if worker_state_dict is not None else False

    def _init_with_detached_workers(self, worker_names):
        workers = [ray.get_actor(name=name) for name in worker_names]
        self._workers = workers
        self._world_size = len(worker_names)

    def _init_with_resource_pool(self, resource_pool, ray_cls_with_init, bin_pack, detached):
        use_gpu = resource_pool.use_gpu

        strategy = "PACK"
        if bin_pack:
            strategy = "STRICT_PACK"
        pgs = resource_pool.get_placement_groups(strategy=strategy)
        world_size = resource_pool.world_size
        self._world_size = world_size
        # cia.add_kwarg("_world_size", world_size)
        num_gpus = 1 / resource_pool.max_colocate_count

        rank = -1
        local_world_size = resource_pool.store[0]
        for pg_idx, pg in enumerate(sort_placement_group_by_node_ip(pgs)):
            assert local_world_size <= pg.bundle_count, \
                f"when generating for {self.name_prefix}, for the "
            for local_rank in range(local_world_size):
                rank += 1

                # we pass in environment variable at option so that Worker can use environment variable to set
                env_vars = {
                    'WORLD_SIZE': str(world_size),
                    'RANK': str(rank),
                    'WG_PREFIX': self.name_prefix,
                    'WG_BACKEND': 'ray',
                    'RAY_LOCAL_WORLD_SIZE': str(local_world_size),
                    'RAY_LOCAL_RANK': str(local_rank),
                }
                if rank != 0:
                    env_vars['MASTER_ADDR'] = self._master_addr
                    env_vars['MASTER_PORT'] = self._master_port

                import re
                cia_name = type(ray_cls_with_init.cls).__name__
                match = re.search(r"ActorClass\(([^)]+)\)", cia_name)  # ray.remote(Obj) -> "ActorClass(Obj)"
                cia_name = match.group(1) if match else cia_name  # "ActorClass(Obj)" -> "Obj"
                name = f"{self.name_prefix}{cia_name}_{pg_idx}:{local_rank}"  # e.g. Worker_2:5

                ray_cls_with_init.update_options({'runtime_env': {'env_vars': env_vars}, 'name': name})

                if detached:
                    ray_cls_with_init.update_options({'lifetime': 'detached'})

                # create a worker
                worker = ray_cls_with_init(placement_group=pg,
                                           placement_group_bundle_idx=local_rank,
                                           use_gpu=use_gpu,
                                           num_gpus=num_gpus)
                self._workers.append(worker)
                self._worker_names.append(name)

                if rank == 0:
                    register_center_actor = None
                    actor_name = f"{self.name_prefix}_register_center"
                    start_time = time.time()

                    while time.time() - start_time < self._ray_wait_register_center_timeout:
                        if actor_name in list_named_actors():
                            register_center_actor = ray.get_actor(actor_name)
                            break

                        elapsed = int(time.time() - start_time)
                        if elapsed % 30 == 0:
                            logging.warning(
                                f"Waiting for register center actor {actor_name} to be ready. "
                                f"Elapsed time: {elapsed} seconds out of {self._ray_wait_register_center_timeout} seconds."
                            )
                        time.sleep(1)

                    if register_center_actor is None:
                        raise TimeoutError(
                            f"Failed to get register_center_actor {actor_name} in {list_named_actors(all_namespaces=True)} "
                            f"for {self._ray_wait_register_center_timeout} seconds. "
                            "Ensure that any lingering Ray resources from previous runs are cleaned up (e.g., by restarting the Ray cluster), "
                            "or adjust the waiting time by modifying the config `trainer.ray_wait_register_center_timeout`."
                        )

                    rank_zero_info = ray.get(register_center_actor.get_rank_zero_info.remote())
                    self._master_addr, self._master_port = rank_zero_info['MASTER_ADDR'], rank_zero_info['MASTER_PORT']
                    # print(f"rank_zero_info: {rank_zero_info}")
                    # print(f"master_addr: {self._master_addr}, master_port: {self._master_port}")

    @property
    def worker_names(self):
        return self._worker_names

    @classmethod
    def from_detached(cls, worker_names=None, ray_cls_with_init=None):
        worker_group = cls(resource_pool=None,
                           ray_cls_with_init=ray_cls_with_init,
                           name_prefix=None,
                           worker_names=worker_names)
        return worker_group

    def spawn(self, prefix_set):
        """
        spawn to a dictionary of worker groups, each with a subset of method with prefix.

        """

        def _rebind_actor_methods(worker_group, actor_name):
            """
            bind the method with actor_prefix to its original name
            """
            prefix: str = actor_name + '_'
            for method_name in dir(worker_group):
                if method_name.startswith(prefix):
                    # only valid when Python >= 3.9
                    original_method_name = method_name.removeprefix(prefix)
                    method = getattr(worker_group, method_name)
                    setattr(worker_group, original_method_name, method)

        new_worker_group_dict = {}
        for prefix in prefix_set:
            new_worker_group = self.from_detached(worker_names=self._worker_names,
                                                  ray_cls_with_init=self.ray_cls_with_init)

            _rebind_actor_methods(new_worker_group, prefix)
            new_worker_group_dict[prefix] = new_worker_group
        return new_worker_group_dict

    def execute_rank_zero_sync(self, method_name: str, *args, **kwargs):
        return ray.get(self.execute_rank_zero_async(method_name, *args, **kwargs))

    def execute_rank_zero_async(self, method_name: str, *args, **kwargs):
        remote_call = getattr(self._workers[0], method_name)
        return remote_call.remote(*args, **kwargs)

    def execute_rank_zero(self, method_name: str, *args, **kwargs):
        return self.execute_rank_zero_async(method_name, *args, **kwargs)

    def execute_all(self, method_name: str, *args, **kwargs):
        return self.execute_all_async(method_name, *args, **kwargs)

    def execute_all_sync(self, method_name: str, *args, **kwargs):
        return ray.get(self.execute_all_async(method_name, *args, **kwargs))

    def execute_all_async(self, method_name: str, *args, **kwargs):
        # Here, we assume that if all arguments in args and kwargs are lists, and their lengths match len(self._workers),
        # we'll distribute each element in these lists to the corresponding worker
        # print(f"execute_all_async: method {method_name}({args}, {kwargs})")
        length = len(self._workers)
        if all(isinstance(arg, list) for arg in args) and all(isinstance(kwarg, list) for kwarg in kwargs.values()):
            if all(len(arg) == length for arg in args) and all(len(kwarg) == length for kwarg in kwargs.values()):
                # print(f"splitting args and kwargs into {length} shards")
                result = []
                for i in range(length):
                    sliced_args = tuple(arg[i] for arg in args)
                    sliced_kwargs = {k: v[i] for k, v in kwargs.items()}
                    remote_call = getattr(self._workers[i], method_name)
                    result.append(remote_call.remote(*sliced_args, **sliced_kwargs))
                return result

        return [getattr(worker, method_name).remote(*args, **kwargs) for worker in self._workers]

    @property
    def master_address(self):
        return self._master_addr

    @property
    def master_port(self):
        return self._master_port

    @property
    def workers(self):
        return self._workers

    @property
    def world_size(self):
        return self._world_size


"""
Utilities that enables creating workers inside the same ray.Actor, 
with code written in separate ray.Actors.
"""

from unittest.mock import patch
from verl.single_controller.base.decorator import MAGIC_ATTR
import os


def _bind_workers_method_to_parent(cls, key, user_defined_cls):
    """
    Binds the methods of each worker to the WorkerDict. 
    Note that we only bind public methods that are decorated by register
    """
    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 as e:
            # if it is a property, it will fail because Class doesn't have instance property
            continue

        if hasattr(method, MAGIC_ATTR):

            def generate_function(name):

                def func(self, *args, **kwargs):
                    # dispatch to the actual worker
                    return getattr(self.worker_dict[key], name)(*args, **kwargs)

                return func

            func = generate_function(method_name)
            # pass MAGIC_ATTR for outer worker group
            setattr(func, MAGIC_ATTR, getattr(method, MAGIC_ATTR))
            try:
                method_name_with_prefix = key + '_' + method_name
                setattr(cls, method_name_with_prefix, func)
                # print(f'Binding {method_name_with_prefix}')
            except Exception as e:
                raise ValueError(f'Fail to set method_name {method_name}')


def _unwrap_ray_remote(cls):
    if hasattr(cls, '__ray_actor_class__'):
        cls = cls.__ray_actor_class__
    return cls


def create_colocated_worker_cls(class_dict: dict[str, RayClassWithInitArgs]):
    """
    This function should return a class instance that delegates the calls to every 
    cls in cls_dict
    """
    cls_dict = {}
    init_args_dict = {}
    worker_cls = None
    for key, cls in class_dict.items():
        if worker_cls == None:
            worker_cls = cls.cls.__ray_actor_class__.__base__
        else:
            assert worker_cls == cls.cls.__ray_actor_class__.__base__, \
                'the worker class should be the same when share the same process'
        cls_dict[key] = cls.cls
        init_args_dict[key] = {'args': cls.args, 'kwargs': cls.kwargs}

    assert cls_dict.keys() == init_args_dict.keys()

    # TODO: create a class with customizable name
    class WorkerDict(worker_cls):

        def __init__(self):
            super().__init__()
            self.worker_dict = {}
            for key, user_defined_cls in cls_dict.items():
                user_defined_cls = _unwrap_ray_remote(user_defined_cls)
                # directly instantiate the class without remote
                # in worker class, e.g. <verl.single_controller.base.worker.Worker> when DISABLE_WORKER_INIT == 1 it will return immediately
                with patch.dict(os.environ, {'DISABLE_WORKER_INIT': '1'}):
                    self.worker_dict[key] = user_defined_cls(*init_args_dict[key].get('args', ()),
                                                             **init_args_dict[key].get('kwargs', {}))

    # now monkey-patch the methods from inner class to WorkerDict
    for key, user_defined_cls in cls_dict.items():
        user_defined_cls = _unwrap_ray_remote(user_defined_cls)
        _bind_workers_method_to_parent(WorkerDict, key, user_defined_cls)

    remote_cls = ray.remote(WorkerDict)
    remote_cls = RayClassWithInitArgs(cls=remote_cls)
    return remote_cls
