/* Copyright (c) 2022 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. */

#ifdef PADDLE_WITH_HETERPS
#include "paddle/fluid/framework/fleet/heter_ps/hashtable.h"
#include "paddle/fluid/framework/fleet/heter_ps/optimizer_conf.h"

namespace paddle {
namespace framework {

#if defined(PADDLE_WITH_XPU_KP)

__device__ void update_lr(OptimizerConfig& optimizer_config, float& w,
                          float& g2sum,
                          float g,  // NOLINT
                          float scale) {
  float local_learning_rate = optimizer_config.learning_rate;
  float local_initial_g2sum = optimizer_config.initial_g2sum;
  float local_min_bound = optimizer_config.min_bound;
  float local_max_bound = optimizer_config.max_bound;

  double add_g2sum = 0;
  double ratio = local_learning_rate *
                 sqrt(local_initial_g2sum / (local_initial_g2sum + g2sum));
  double scaled_grad = g / scale;

  w += scaled_grad * ratio;

  if (w < local_min_bound) w = local_min_bound;
  if (w > local_max_bound) w = local_max_bound;

  add_g2sum += scaled_grad * scaled_grad;

  g2sum += add_g2sum;
}

__device__ void update_mf(OptimizerConfig& optimizer_config, int n, float* w,
                          float& g2sum, const float* g, float scale) {
  float local_mf_learning_rate = optimizer_config.mf_learning_rate;
  float local_mf_initial_g2sum = optimizer_config.mf_initial_g2sum;
  float local_mf_min_bound = optimizer_config.mf_min_bound;
  float local_mf_max_bound = optimizer_config.mf_max_bound;

  double add_g2sum = 0;
  double ratio =
      local_mf_learning_rate *
      sqrt(local_mf_initial_g2sum / (local_mf_initial_g2sum + g2sum));
  for (int i = 0; i < n; ++i) {
    double scaled_grad = g[i] / scale;
    w[i] += scaled_grad * ratio;

    if (w[i] < local_mf_min_bound) w[i] = local_mf_min_bound;
    if (w[i] > local_mf_max_bound) w[i] = local_mf_max_bound;
    add_g2sum += scaled_grad * scaled_grad;
  }

  g2sum += add_g2sum / n;
}

__device__ float xpu_rand_uniform() { return 0.1; }

template <typename ValType, typename GradType>
__device__ void update_value(OptimizerConfig& optimizer_config, ValType& val,
                             const GradType& grad) {  // NOLINT
  val.slot = grad.slot;
  val.show += grad.show;
  val.clk += grad.clk;

  float local_nonclk_coeff = optimizer_config.nonclk_coeff;
  float local_clk_coeff = optimizer_config.clk_coeff;

  float local_mf_create_thresholds = optimizer_config.mf_create_thresholds;
  float local_mf_initial_range = optimizer_config.mf_initial_range;

  val.delta_score +=
      local_nonclk_coeff * (grad.show - grad.clk) + local_clk_coeff * grad.clk;

  update_lr(optimizer_config, val.lr, val.lr_g2sum, grad.lr_g, grad.show);

  if (val.mf_size == 0) {
    if (local_mf_create_thresholds <=
        local_nonclk_coeff * (val.show - val.clk) + local_clk_coeff * val.clk) {
      val.mf_size = MF_DIM + 1;
      val.mf[0] = 0;

      for (int i = 0; i < MF_DIM; ++i) {
        val.mf[i + 1] = (xpu_rand_uniform()) * local_mf_initial_range;
      }
    }
  } else {
    update_mf(optimizer_config, MF_DIM, &val.mf[1], val.mf[0], grad.mf_g,
              grad.show);
  }
}

template <typename KeyType, typename ValType, typename Table>
__global__ void insert_kernel(Table& table, const KeyType* const keys,
                              const ValType* const vals, long long len) {
  int cid = core_id();
  int ncores = core_num();
  if (cid >= ncores) {
    return;
  }
  int thread_id = ncores * cluster_id() + cid;
  int nthreads = ncores * cluster_num();

  const int buf_size = 150;
  __local__ KeyType local_keys[buf_size];
  __local__ ValType local_vals[buf_size];
  int len_per_loop = min(buf_size, roundup_div(len, nthreads));

  for (int i = thread_id * len_per_loop; i < len;
       i += nthreads * len_per_loop) {
    int read_len = min(len_per_loop, len - i);
    GM2LM(keys, local_keys, read_len * sizeof(KeyType));
    GM2LM(vals, local_vals, read_len * sizeof(ValType));
    for (int k = 0; k < read_len; k++) {
      auto status = table.insert(local_keys[k], local_vals[k]);
      assert(status != false && "error: insert fails: table is full");
    }
  }
}

template <typename KeyType, typename ValType, typename Table>
__global__ void search_kernel(Table& table, const KeyType* const keys,
                              ValType* const vals, long long len) {
  int cid = core_id();
  int ncores = core_num();
  if (cid >= ncores) {
    return;
  }
  int thread_id = ncores * cluster_id() + cid;
  int nthreads = ncores * cluster_num();

  const int buf_size = 150;
  __local__ KeyType local_keys[buf_size];
  __local__ ValType local_vals[buf_size];

  int len_per_loop = min(buf_size, roundup_div(len, nthreads));
  for (int i = thread_id * len_per_loop; i < len;
       i += nthreads * len_per_loop) {
    int read_len = min(len_per_loop, len - i);
    GM2LM(keys, local_keys, read_len * sizeof(KeyType));
    for (int k = 0; k < read_len; k++) {
      ValType* val = table.find(local_keys[k]);
      if (val != NULL) {
        local_vals[k] = *val;
      }
    }
    LM2GM(local_vals, vals + i, read_len * sizeof(ValType));
  }
}

template <typename KeyType, typename ValType, typename Table, typename GradType>
__global__ void update_kernel(Table& table, OptimizerConfig& optimizer_config,
                              const KeyType* const keys,
                              const GradType* const grads, long long len) {
  int cid = core_id();
  int ncores = core_num();
  if (cid >= ncores) {
    return;
  }
  int thread_id = ncores * cluster_id() + cid;
  int nthreads = ncores * cluster_num();

  const int buf_size = 250;
  __local__ KeyType local_keys[buf_size];
  __local__ GradType local_grads[buf_size];

  int len_per_loop = min(buf_size, roundup_div(len, nthreads));
  for (int i = thread_id * len_per_loop; i < len;
       i += nthreads * len_per_loop) {
    int read_len = min(len_per_loop, len - i);

    GM2LM(keys, local_keys, read_len * sizeof(KeyType));
    GM2LM(grads, local_grads, read_len * sizeof(GradType));

    for (int k = 0; k < read_len; k++) {
      ValType* val = table.find(local_keys[k]);
      if (val != NULL) {
        update_value(optimizer_config, *val, local_grads[i]);
      }
    }
  }
}

template <typename KeyType, typename ValType>
HashTable<KeyType, ValType>::HashTable(size_t capacity) {
  auto tmp_container = XPUCacheArray<KeyType, ValType>(capacity);
  xpu_malloc(reinterpret_cast<void**>(&container_),
             sizeof(XPUCacheArray<KeyType, ValType>));
  xpu_memcpy((void*)container_, &tmp_container,
             sizeof(XPUCacheArray<KeyType, ValType>), XPU_HOST_TO_DEVICE);
  xpu_malloc(reinterpret_cast<void**>(&device_optimizer_config_),
             sizeof(OptimizerConfig));
  xpu_memcpy((void*)device_optimizer_config_, &host_optimizer_config_,
             sizeof(OptimizerConfig), XPU_HOST_TO_DEVICE);

  rwlock_.reset(new phi::RWLock);
}

template <typename KeyType, typename ValType>
HashTable<KeyType, ValType>::~HashTable() {
  xpu_free((void*)container_);
  xpu_free((void*)device_optimizer_config_);
}

template <typename KeyType, typename ValType>
void HashTable<KeyType, ValType>::show() {
  container_->print();
}

template <typename KeyType, typename ValType>
void HashTable<KeyType, ValType>::set_sparse_sgd(
    const OptimizerConfig& optimizer_config) {
  host_optimizer_config_.set_sparse_sgd(optimizer_config);
  xpu_memcpy((void*)device_optimizer_config_, &host_optimizer_config_,
             sizeof(OptimizerConfig), XPU_HOST_TO_DEVICE);
}

template <typename KeyType, typename ValType>
void HashTable<KeyType, ValType>::set_embedx_sgd(
    const OptimizerConfig& optimizer_config) {
  host_optimizer_config_.set_embedx_sgd(optimizer_config);
  xpu_memcpy((void*)device_optimizer_config_, &host_optimizer_config_,
             sizeof(OptimizerConfig), XPU_HOST_TO_DEVICE);
}

template <typename KeyType, typename ValType>
template <typename StreamType>
void HashTable<KeyType, ValType>::get(const KeyType* d_keys, ValType* d_vals,
                                      size_t len, StreamType stream) {
  if (len == 0) {
    return;
  }
  long long c_len = (long long)len;
  search_kernel<KeyType, ValType,
                XPUCacheArray<KeyType, ValType>><<<4, 64, stream>>>(
      *container_, d_keys, d_vals, c_len);
}

template <typename KeyType, typename ValType>
template <typename StreamType>
void HashTable<KeyType, ValType>::get(const KeyType* d_keys, char* d_vals,
                                      size_t len, StreamType stream) {
  if (len == 0) {
    return;
  }
  // TODO(zhangminxu): to be implemented
}

template <typename KeyType, typename ValType>
template <typename StreamType>
void HashTable<KeyType, ValType>::insert(const KeyType* d_keys,
                                         const ValType* d_vals, size_t len,
                                         StreamType stream) {
  if (len == 0) {
    return;
  }
  long long c_len = (long long)len;
  insert_kernel<KeyType, ValType,
                XPUCacheArray<KeyType, ValType>><<<4, 64, stream>>>(
      *container_, d_keys, d_vals, c_len);
}

template <typename KeyType, typename ValType>
template <typename StreamType>
void HashTable<KeyType, ValType>::dump_to_cpu(int devid, StreamType stream) {
  // TODO(zhangminxu): to be implemented
}

template <typename KeyType, typename ValType>
template <typename GradType, typename StreamType>
void HashTable<KeyType, ValType>::update(const KeyType* d_keys,
                                         const GradType* d_grads, size_t len,
                                         StreamType stream) {
  if (len == 0) {
    return;
  }
  long long c_len = (long long)len;
  update_kernel<KeyType, ValType, XPUCacheArray<KeyType, ValType>,
                GradType><<<4, 64, stream>>>(
      *container_, *device_optimizer_config_, d_keys, d_grads, c_len);
}

template <typename KeyType, typename ValType>
template <typename StreamType>
void HashTable<KeyType, ValType>::update(const KeyType* d_keys,
                                         const char* d_grads, size_t len,
                                         StreamType stream) {
  if (len == 0) {
    return;
  }
  // TODO(zhangminxu): to be implemented
}

template class HashTable<unsigned long, paddle::framework::FeatureValue>;

template void HashTable<unsigned long, paddle::framework::FeatureValue>::get<
    XPUStream>(const unsigned long* d_keys,
               paddle::framework::FeatureValue* d_vals, size_t len,
               XPUStream stream);

// template void
// HashTable<unsigned long, paddle::framework::FeatureValue>::get<XPUStream>(
//    const unsigned long* d_keys, char* d_vals, size_t len, XPUStream stream);

template void HashTable<unsigned long, paddle::framework::FeatureValue>::insert<
    XPUStream>(const unsigned long* d_keys,
               const paddle::framework::FeatureValue* d_vals, size_t len,
               XPUStream stream);

// template void HashTable<unsigned long,
// paddle::framework::FeatureValue>::insert<
//    XPUStream>(const unsigned long* d_keys, size_t len, char* pool,
//               size_t start_index, XPUStream stream);

template void HashTable<unsigned long, paddle::framework::FeatureValue>::
    dump_to_cpu<XPUStream>(int devid, XPUStream stream);

template void HashTable<unsigned long, paddle::framework::FeatureValue>::update<
    paddle::framework::FeaturePushValue, XPUStream>(
    const unsigned long* d_keys,
    const paddle::framework::FeaturePushValue* d_grads, size_t len,
    XPUStream stream);

// template void HashTable<unsigned long,
// paddle::framework::FeatureValue>::update<
//    XPUStream>(const unsigned long* d_keys, const char* d_grads,
//                          size_t len, XPUStream stream);

#endif
}  // end namespace framework
}  // end namespace paddle
#endif