// Copyright (c) 2023 Huawei Technologies Co., Ltd
// Copyright (c) 2019, Facebook CORPORATION.
// All rights reserved.
//
// Licensed under the BSD 3-Clause License  (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://opensource.org/licenses/BSD-3-Clause
//
// 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.

#include "op_plugin/AclOpsInterface.h"
#include "op_plugin/OpApiInterface.h"
#include "torch_npu/csrc/framework/utils/RandomOpAdapter.h"
#include "op_plugin/utils/op_api_common.h"

namespace op_api {

namespace {

const int64_t RANDOM_DOUBLE_MAX = 1LL << 53;
const int64_t RANDOM_HALF_MAX = 1LL << 11;
const int64_t RANDOM_FLOAT_MAX = 1LL << 24;
const int64_t RANDOM_BFLOAT16_MAX = 1LL << 8;

}  // namespace
std::map<at::ScalarType, int64_t> initialize_dtype_max_value_map()
{
    return {
        {at::kHalf, RANDOM_HALF_MAX + 1},
        {at::kFloat, RANDOM_FLOAT_MAX + 1},
        {at::kDouble, RANDOM_DOUBLE_MAX + 1},
        {at::kInt, std::numeric_limits<int>::max()},
        {at::kShort, std::numeric_limits<int16_t>::max()},
        {at::kChar, std::numeric_limits<int8_t>::max()},
        {at::kByte, std::numeric_limits<uint8_t>::max()},
        {at::kLong, std::numeric_limits<long>::max()},
        {at::kBFloat16, RANDOM_BFLOAT16_MAX + 1},
        {at::kBool, 1}
    };
};

static std::map<at::ScalarType, int64_t> DTYPE_MAX_VALUE_MAP = initialize_dtype_max_value_map();

int64_t get_dtype_max_value(at::ScalarType dtype)
{
    auto iter = DTYPE_MAX_VALUE_MAP.find(dtype);
    TORCH_CHECK(iter != DTYPE_MAX_VALUE_MAP.end(),
                "self scalar_type:", dtype, "is not surpported.", OPS_ERROR(ErrCode::TYPE));
    return iter->second;
}

at::Tensor& random_op_api_(at::Tensor& self, int64_t from, int64_t to, c10::optional<at::Generator> generator)
{
    auto gen = at::get_generator_or_default<at_npu::NPUGeneratorImpl>(generator,
                                                                      at_npu::detail::getDefaultNPUGenerator());
    auto pair = gen->philox_engine_inputs(10);
    EXEC_NPU_CMD(aclnnInplaceRandom, self, from, to, pair.first, pair.second);
    return self;
}

at::Tensor& random_(at::Tensor& self, int64_t from, c10::optional<int64_t> to,
                    c10::optional<at::Generator> generator)
{
    DO_COMPATIBILITY(aclnnInplaceRandom, acl_op::random_(self, from, to, generator));
    int64_t to_ = to.value_or(get_dtype_max_value(self.scalar_type()));
    random_op_api_(self, from, to_, generator);
    return self;
}

at::Tensor& random_(at::Tensor& self, int64_t to, c10::optional<at::Generator> generator)
{
    DO_COMPATIBILITY(aclnnInplaceRandom, acl_op::random_(self, to, generator));
    int64_t from = 0;
    random_op_api_(self, from, to, generator);
    return self;
}

at::Tensor& random_(at::Tensor& self, c10::optional<at::Generator> generator)
{
    DO_COMPATIBILITY(aclnnInplaceRandom, acl_op::random_(self, generator));
    int64_t from = 0;
    int64_t to = get_dtype_max_value(self.scalar_type());
    random_op_api_(self, from, to, generator);
    return self;
}

}