# Copyright (c) 2021, NVIDIA CORPORATION.  All rights reserved.
#
# 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, Optional, Union

from nvflare.apis.fl_component import FLComponent
from nvflare.apis.fl_constant import FLContextKey, ServerCommandKey, ServerCommandNames, SiteType
from nvflare.apis.fl_context import FLContext, FLContextManager
from nvflare.apis.shareable import Shareable
from nvflare.apis.workspace import Workspace
from nvflare.fuel.f3.cellnet.core_cell import FQCN
from nvflare.fuel.f3.cellnet.defs import MessageHeaderKey
from nvflare.fuel.f3.cellnet.defs import ReturnCode as CellReturnCode
from nvflare.private.aux_runner import AuxRunner
from nvflare.private.defs import CellChannel, CellMessageHeaderKeys, new_cell_message
from nvflare.private.event import fire_event
from nvflare.private.fed.utils.fed_utils import create_job_processing_context_properties
from nvflare.widgets.fed_event import ClientFedEventRunner
from nvflare.widgets.info_collector import InfoCollector
from nvflare.widgets.widget import Widget, WidgetID

from .client_engine_executor_spec import ClientEngineExecutorSpec, TaskAssignment
from .client_json_config import ClientJsonConfigurator
from .client_runner import ClientRunner
from .fed_client import FederatedClient


class ClientRunInfo(object):
    def __init__(self, job_id):
        """To init the ClientRunInfo.

        Args:
            job_id: job id
        """
        self.job_id = job_id
        self.current_task_name = ""
        self.start_time = None


# TODO: make this configurable
#   this is the number of retries for client side child/job process to get clients from server
#   we might need to think of removing the whole get clients from server logic from child process
GET_CLIENTS_RETRY = 300


class ClientRunManager(ClientEngineExecutorSpec):
    """ClientRunManager provides the ClientEngine APIs implementation running in the child process."""

    def __init__(
        self,
        client_name: str,
        job_id: str,
        workspace: Workspace,
        client: FederatedClient,
        components: Dict[str, FLComponent],
        handlers: Optional[List[FLComponent]] = None,
        conf: ClientJsonConfigurator = None,
    ) -> None:
        """To init the ClientRunManager.

        Args:
            client_name: client name
            job_id: job id
            workspace: workspace
            client: FL client object
            components: available FL components
            handlers: available handlers
            conf: ClientJsonConfigurator object
        """
        super().__init__()

        self.client = client
        self.handlers = handlers
        self.workspace = workspace
        self.components = components
        # self.aux_runner = ClientAuxRunner()
        self.aux_runner = AuxRunner(self)
        self.add_handler(self.aux_runner)
        self.conf = conf
        self.cell = None

        self.all_clients = None

        if not components:
            self.components = {}

        if not handlers:
            self.handlers = []

        # get job meta!
        job_ctx_props = self.create_job_processing_context_properties(workspace, job_id)
        self.fl_ctx_mgr = FLContextManager(
            engine=self, identity_name=client_name, job_id=job_id, public_stickers={}, private_stickers=job_ctx_props
        )

        self.run_info = ClientRunInfo(job_id=job_id)

        self.widgets = {WidgetID.INFO_COLLECTOR: InfoCollector(), WidgetID.FED_EVENT_RUNNER: ClientFedEventRunner()}
        for _, widget in self.widgets.items():
            self.handlers.append(widget)

        self.logger = logging.getLogger(self.__class__.__name__)

    def get_task_assignment(self, fl_ctx: FLContext) -> TaskAssignment:
        pull_success, task_name, return_shareable = self.client.fetch_task(fl_ctx)
        task = None
        if pull_success:
            shareable = self.client.extract_shareable(return_shareable, fl_ctx)
            task_id = shareable.get_header(key=FLContextKey.TASK_ID)
            task = TaskAssignment(name=task_name, task_id=task_id, data=shareable)
        return task

    def new_context(self) -> FLContext:
        return self.fl_ctx_mgr.new_context()

    def send_task_result(self, result: Shareable, fl_ctx: FLContext) -> bool:
        push_result = self.client.push_results(result, fl_ctx)  # push task execution results
        if push_result[0] == CellReturnCode.OK:
            return True
        else:
            return False

    def get_workspace(self) -> Workspace:
        return self.workspace

    def get_run_info(self) -> ClientRunInfo:
        return self.run_info

    def show_errors(self) -> ClientRunInfo:
        return self.run_info

    def reset_errors(self) -> ClientRunInfo:
        return self.run_info

    def dispatch(self, topic: str, request: Shareable, fl_ctx: FLContext) -> Shareable:
        return self.aux_runner.dispatch(topic=topic, request=request, fl_ctx=fl_ctx)

    def get_component(self, component_id: str) -> object:
        return self.components.get(component_id)

    def get_all_components(self) -> dict:
        return self.components

    def validate_targets(self, inputs) -> ([], []):
        valid_inputs = []
        invalid_inputs = []
        for item in inputs:
            if item == FQCN.ROOT_SERVER:
                valid_inputs.append(item)
            else:
                client = self.get_client_from_name(item)
                if client:
                    valid_inputs.append(item)
                else:
                    invalid_inputs.append(item)
        return valid_inputs, invalid_inputs

    def get_client_from_name(self, client_name):
        for _, c in self.all_clients.items():
            if client_name == c.name:
                return c
        return None

    def get_widget(self, widget_id: str) -> Widget:
        return self.widgets.get(widget_id)

    def fire_event(self, event_type: str, fl_ctx: FLContext):
        fire_event(event=event_type, handlers=self.handlers, ctx=fl_ctx)

    def add_handler(self, handler: FLComponent):
        self.handlers.append(handler)

    def build_component(self, config_dict):
        if not self.conf:
            raise RuntimeError("No configurator set up.")
        return self.conf.build_component(config_dict)

    def get_cell(self):
        return self.cell

    def send_aux_request(
        self,
        targets: Union[None, str, List[str]],
        topic: str,
        request: Shareable,
        timeout: float,
        fl_ctx: FLContext,
        optional=False,
        secure=False,
    ) -> dict:
        if not targets:
            targets = [FQCN.ROOT_SERVER]
        else:
            if isinstance(targets, str):
                if targets == SiteType.ALL:
                    targets = [FQCN.ROOT_SERVER]
                    for _, t in self.all_clients.items():
                        if t.name != self.client.client_name:
                            targets.append(t.name)
                else:
                    targets = [targets]
        if targets:
            return self.aux_runner.send_aux_request(
                targets, topic, request, timeout, fl_ctx, optional=optional, secure=secure
            )
        else:
            return {}

    def get_all_clients_from_server(self, fl_ctx, retry=0):
        job_id = fl_ctx.get_prop(FLContextKey.CURRENT_RUN)
        get_clients_message = new_cell_message({CellMessageHeaderKeys.JOB_ID: job_id}, {})
        return_data = self.client.cell.send_request(
            target=FQCN.ROOT_SERVER,
            channel=CellChannel.SERVER_PARENT_LISTENER,
            topic=ServerCommandNames.GET_CLIENTS,
            request=get_clients_message,
            timeout=5.0,
            optional=True,
        )
        return_code = return_data.get_header(MessageHeaderKey.RETURN_CODE)

        if return_code == CellReturnCode.OK:
            if return_data.payload:
                data = return_data.payload
                self.all_clients = data.get(ServerCommandKey.CLIENTS)
            else:
                raise RuntimeError("Empty clients data from server")
        else:
            # retry to handle the server connect has not been established scenario.
            retry += 1
            if retry < GET_CLIENTS_RETRY:
                time.sleep(0.5)
                self.get_all_clients_from_server(fl_ctx, retry)
            else:
                raise RuntimeError("Failed to get the clients from the server.")

    def register_aux_message_handler(self, topic: str, message_handle_func):
        self.aux_runner.register_aux_message_handler(topic, message_handle_func)

    def fire_and_forget_aux_request(
        self, topic: str, request: Shareable, fl_ctx: FLContext, optional=False, secure=False
    ) -> dict:
        return self.send_aux_request(
            targets=None, topic=topic, request=request, timeout=0.0, fl_ctx=fl_ctx, optional=optional, secure=secure
        )

    def abort_app(self, job_id: str, fl_ctx: FLContext):
        runner = fl_ctx.get_prop(key=FLContextKey.RUNNER, default=None)
        if isinstance(runner, ClientRunner):
            runner.abort()

    def create_job_processing_context_properties(self, workspace, job_id):
        return create_job_processing_context_properties(workspace, job_id)
