# Copyright (c) 2021 PaddlePaddle Authors. 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.

from __future__ import print_function

import numpy as np
import os
import sys
import paddle
import paddle.fluid as fluid
import unittest
import paddle.fluid.layers as layers
from test_collective_api_base import TestCollectiveAPIRunnerBase, runtime_main
import pickle
from paddle.fluid.framework import _enable_legacy_dygraph

paddle.enable_static()


class TestCollectiveGlobalGatherAPI(TestCollectiveAPIRunnerBase):

    def __init__(self):
        self.global_ring_id = 0

    def get_model(self, main_prog, startup_program, rank, indata=None):
        with fluid.program_guard(main_prog, startup_program):
            seed = os.getpid()
            np.random.seed(seed)
            in_feat = 2
            n_expert = 2
            world_size = 2
            tot_expert = n_expert * world_size
            local_input_buf = paddle.static.data(name="local_input_buf",
                                                 shape=[-1, in_feat],
                                                 dtype="float32")
            local_expert_count = paddle.static.data(name="local_expert_count",
                                                    shape=[tot_expert],
                                                    dtype="int64")
            global_expert_count = paddle.static.data(name="global_expert_count",
                                                     shape=[tot_expert],
                                                     dtype="int64")

            output = paddle.distributed.utils.global_gather(
                local_input_buf, local_expert_count, global_expert_count)

            return [output]

    def run_trainer(self, args):
        train_prog = fluid.Program()
        startup_prog = fluid.Program()
        endpoints = args["endpoints"].split(",")
        rank = args["trainerid"]
        current_endpoint = args["currentendpoint"]
        nranks = 2
        paddle.distributed.init_parallel_env()
        if args['backend'] == 'nccl':
            device_id = int(os.getenv("FLAGS_selected_gpus", "0"))
            place = fluid.CUDAPlace(
                device_id)  #if args.use_gpu else fluid.CPUPlace()
        elif args['backend'] == 'bkcl':
            device_id = int(os.getenv("FLAGS_selected_xpus", "0"))
            place = fluid.XPUPlace(device_id)
        else:
            place = fluid.CPUPlace()

        in_feat = 2
        n_expert = 2
        world_size = 2
        tot_expert = n_expert * world_size
        paddle.disable_static()

        # Call paddle.distributed.alltoall() under legacy dygraph
        _enable_legacy_dygraph()
        np.random.seed(os.getpid())
        local_expert_count = np.random.randint(1, 4,
                                               size=tot_expert).astype("int64")
        local_expert_count = paddle.to_tensor(local_expert_count)
        global_expert_count = []
        paddle.distributed.alltoall(paddle.split(local_expert_count, 2, axis=0),
                                    global_expert_count)
        global_expert_count = paddle.concat(global_expert_count, axis=0)
        global_expert_count = global_expert_count.numpy()
        local_expert_count = local_expert_count.numpy()
        fwd_expert_count = sum(global_expert_count)
        np.random.seed(os.getpid())
        local_input_buf = np.random.rand(fwd_expert_count,
                                         in_feat).astype("float32")

        paddle.enable_static()
        if args['static_mode']:
            result = self.get_model(train_prog, startup_prog, rank)
            exe = fluid.Executor(place)
            exe.run(startup_prog)
            fetch_list = []
            for elem in result:
                fetch_list.append(elem.name)
            out = exe.run(train_prog,
                          feed={
                              'local_expert_count': local_expert_count,
                              'global_expert_count': global_expert_count,
                              'local_input_buf': local_input_buf
                          },
                          fetch_list=fetch_list)

        sys.stdout.buffer.write(pickle.dumps(out))


if __name__ == "__main__":
    runtime_main(TestCollectiveGlobalGatherAPI, "global_gather")