/*******************************************************************************
* Copyright 2019 Intel Corporation
*
* 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.
*******************************************************************************/

#ifndef GPU_GENERIC_REF_SUM_HPP
#define GPU_GENERIC_REF_SUM_HPP

#include <mutex>

#include "common/primitive.hpp"
#include "common/reorder.hpp"
#include "common/reorder_pd.hpp"
#include "common/stream.hpp"

#include "gpu/gpu_engine.hpp"
#include "gpu/gpu_primitive.hpp"
#include "gpu/gpu_resource.hpp"
#include "gpu/gpu_sum_pd.hpp"

namespace dnnl {
namespace impl {
namespace gpu {
namespace generic {

struct ref_sum_t : public gpu::primitive_t {
    using gpu::primitive_t::primitive_t;
    struct pd_t : public gpu_sum_pd_t {
        using gpu_sum_pd_t::gpu_sum_pd_t;

        pd_t(const pd_t &rhs) = default;
        ~pd_t() override = default;

        DECLARE_SUM_PD_T("ref:any", ref_sum_t);

        status_t init(impl::engine_t *engine) {
            VDISPATCH_SUM_SC(
                    gpu_sum_pd_t::init(engine), VERBOSE_BAD_ENGINE_KIND);

            if (has_zero_dim_memory()) return status::success;
            reorder_pds_.resize(n_ + need_output_reorder());
            for (int i = 0; i < n_; ++i) {
                primitive_attr_t r_attr;
                VDISPATCH_SUM_SC(r_attr.scales_.set(DNNL_ARG_SRC, 0),
                        VERBOSE_UNSUPPORTED_ATTR);
                if (i != 0) {
                    VDISPATCH_SUM_SC(r_attr.post_ops_.append_sum(1.0),
                            VERBOSE_UNSUPPORTED_POSTOP);
                }

                VDISPATCH_SUM_SC(
                        reorder_primitive_desc_create(reorder_pds_[i], engine,
                                src_md(i), dst_acc_md(), &r_attr),
                        "reorder_primitive_desc_create()");
            }

            if (need_output_reorder()) {
                VDISPATCH_SUM_SC(reorder_primitive_desc_create(reorder_pds_[n_],
                                         engine, dst_acc_md(), dst_md()),
                        "reorder_primitive_desc_create()");
            }

            scale_md_.ndims = 1;
            scale_md_.dims[0] = 1;
            scale_md_.data_type = data_type::f32;
            VDISPATCH_SUM_SC(memory_desc_init_by_tag(scale_md_, format_tag::x),
                    VERBOSE_UNSUPPORTED_TAG);

            init_scratchpad(engine);
            return status::success;
        }

        std::vector<std::shared_ptr<primitive_desc_t>> reorder_pds_;
        memory_desc_t scale_md_;

    private:
        void init_scratchpad(impl::engine_t *engine) {
            using namespace memory_tracking::names;
            auto scratchpad = scratchpad_registry().registrar();
            auto *gpu_engine = utils::downcast<gpu::engine_t *>(engine);
            if (need_output_reorder()) {
                const memory_desc_wrapper dst_acc_d(dst_acc_md());
                scratchpad.book(key_sum_reduction, dst_acc_d.size(), 1,
                        gpu_engine->get_buffer_alignment());
            }

            for (size_t i = 0; i < reorder_pds_.size(); i++) {
                scratchpad.book(key_nested_multiple + (int)i,
                        reorder_pds_[i]->scratchpad_registry());
            }
        }
    };

    status_t init(impl::engine_t *engine) override {
        const size_t n = pd()->reorder_pds_.size();
        reorders_.resize(n);
        for (size_t i = 0; i < n; ++i) {
            CHECK(create_nested_primitive(
                    reorders_[i], pd()->reorder_pds_[i], engine));
        }
        return status::success;
    }

    status_t init_res_storage(
            impl::engine_t *engine, gpu_resource_t *r) const override {
        // TODO: this is a dirty fix to a real problem that pops up when
        // multiple threads creating this primitive. Execution hangs at unmap().
        static std::mutex mutex;
        std::lock_guard<std::mutex> lock(mutex);

        const int count = pd()->n_inputs();
        const float *s_data = pd()->scales();
        for (int i = 0; i < count; i++) {
            // copy scales on gpu
            const size_t size = sizeof(float);
            std::unique_ptr<memory_storage_t> scales;
            memory_storage_t *scale = nullptr;
            auto s = engine->create_memory_storage(&scale, size);
            if (s != status::success) return s;
            float *mapped_mem_storage = nullptr;
            s = scale->map_data((void **)&mapped_mem_storage, nullptr, size);
            if (s != status::success) return s;
            if (!mapped_mem_storage) return status::out_of_memory;
            mapped_mem_storage[0] = s_data[i];
            s = scale->unmap_data((void *)mapped_mem_storage, nullptr);
            if (s != status::success) return s;
            scales.reset(scale);
            r->add_memory_storage(i, std::move(scales));
        }
        return status::success;
    }
    status_t execute(const exec_ctx_t &ctx) const override {
        using namespace memory_tracking::names;

        if (pd()->has_zero_dim_memory()) return status::success;

        const auto n = pd()->n_inputs();
        exec_args_t r_args;

        std::unique_ptr<memory_t, memory_deleter_t> p_temp_dst_acc;
        if (pd()->need_output_reorder()) {
            auto scratchpad = ctx.get_scratchpad_grantor().get_memory_storage(
                    key_sum_reduction);
            CHECK(safe_ptr_assign(p_temp_dst_acc,
                    new memory_t(ctx.stream()->engine(), pd()->dst_acc_md(),
                            std::move(scratchpad))));
        }

        auto dst = ctx.args().at(DNNL_ARG_DST);
        memory_arg_t dst_acc = {p_temp_dst_acc.get(), false};

        for (int i = 0; i < n; ++i) {
            std::unique_ptr<memory_t, memory_deleter_t> scales_mem;
            CHECK(safe_ptr_assign(scales_mem,
                    new memory_t(ctx.stream()->engine(), &pd()->scale_md_,
                            nullptr)));
            CHECK(scales_mem->set_data_handle(
                    CTX_GPU_RES_STORAGE(i).data_handle()));
            r_args[DNNL_ARG_SRC] = ctx.args().at(DNNL_ARG_MULTIPLE_SRC + i);
            r_args[DNNL_ARG_DST] = pd()->need_output_reorder() ? dst_acc : dst;
            r_args[DNNL_ARG_ATTR_SCALES | DNNL_ARG_SRC]
                    = {scales_mem.get(), true};
            exec_ctx_t r_ctx(ctx, std::move(r_args));

            auto *nested_grantor = create_nested_grantor(
                    ctx.get_scratchpad_grantor(), key_nested_multiple + i,
                    reorders_[i]->pd()->scratchpad_registry());
            r_ctx.set_scratchpad_grantor(nested_grantor);
            CHECK(reorders_[i]->execute(r_ctx));
        }

        if (pd()->need_output_reorder()) {
            dst_acc = {p_temp_dst_acc.get(), true};
            r_args[DNNL_ARG_SRC] = dst_acc;
            r_args[DNNL_ARG_DST] = dst;
            exec_ctx_t r_ctx(ctx, std::move(r_args));

            auto *nested_grantor = create_nested_grantor(
                    ctx.get_scratchpad_grantor(), key_nested_multiple + n,
                    reorders_[n]->pd()->scratchpad_registry());
            r_ctx.set_scratchpad_grantor(nested_grantor);
            CHECK(reorders_[n]->execute(r_ctx));
        }

        return status::success;
    }

private:
    const pd_t *pd() const { return (const pd_t *)primitive_t::pd().get(); }
    std::vector<std::shared_ptr<impl::primitive_t>> reorders_;
};

} // namespace generic
} // namespace gpu
} // namespace impl
} // namespace dnnl

#endif
