#pragma once

#include <algorithm>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#include "paddle/framework/attr_checker.h"
#include "paddle/framework/op_desc.pb.h"
#include "paddle/framework/op_proto.pb.h"
#include "paddle/framework/operator.h"

namespace paddle {
namespace framework {

// helper class to set attribute type
struct AttrTypeHelper {
  template <typename T>
  static void SetAttrType(AttrProto* attr);

  static Attribute GetAttrValue(const AttrDesc& attr_desc) {
    switch (attr_desc.type()) {
      case paddle::framework::AttrType::INT: {
        return attr_desc.i();
      }
      case paddle::framework::AttrType::FLOAT: {
        return attr_desc.f();
      }
      case paddle::framework::AttrType::STRING: {
        return attr_desc.s();
      }
      case paddle::framework::AttrType::INTS: {
        std::vector<int> val(attr_desc.ints_size());
        for (int i = 0; i < attr_desc.ints_size(); ++i) {
          val[i] = attr_desc.ints(i);
        }
        return val;
      }
      case paddle::framework::AttrType::FLOATS: {
        std::vector<float> val(attr_desc.floats_size());
        for (int i = 0; i < attr_desc.floats_size(); ++i) {
          val[i] = attr_desc.floats(i);
        }
        return val;
      }
      case paddle::framework::AttrType::STRINGS: {
        std::vector<std::string> val(attr_desc.strings_size());
        for (int i = 0; i < attr_desc.strings_size(); ++i) {
          val[i] = attr_desc.strings(i);
        }
        return val;
      }
    }
    PADDLE_ENFORCE(false, "Unknown OpDesc::AttrDesc::type !");
    return boost::blank();
  }
};

// this class not only make proto but also init attribute checkers.
class OpProtoAndCheckerMaker {
 public:
  OpProtoAndCheckerMaker(OpProto* proto, OpAttrChecker* op_checker)
      : proto_(proto), op_checker_(op_checker) {}

  ~OpProtoAndCheckerMaker() { CheckNoDuplicatedAttrs(); }

 protected:
  void AddInput(const std::string& name, const std::string& comment,
                bool multiple = false) {
    auto input = proto_->mutable_inputs()->Add();
    *input->mutable_name() = name;
    *input->mutable_comment() = comment;
    input->set_multiple(multiple);
    if (multiple) {
      SetHasMultipleInput();
    }
  }

  void AddInputs(const std::string& name, const std::string& comment) {
    AddInput(name, comment, true);
  }

  void AddOutput(const std::string& name, const std::string& comment,
                 bool temporary = false, bool multiple = false) {
    auto output = proto_->mutable_outputs()->Add();
    *output->mutable_name() = name;
    *output->mutable_comment() = comment;
    output->set_multiple(multiple);
    if (multiple) {
      SetHasMultipleOutput();
    }
    output->set_temporary(temporary);
    if (temporary) {
      SetHasTemporaryOutput();
    }
  }

  void AddOutputs(const std::string& name, const std::string& comment,
                  bool temporary = false) {
    AddOutput(name, comment, temporary, true);
  }

  template <typename T>
  TypedAttrChecker<T>& AddAttr(const std::string& name,
                               const std::string& comment,
                               bool generated = false) {
    auto attr = proto_->mutable_attrs()->Add();
    *attr->mutable_name() = name;
    *attr->mutable_comment() = comment;
    attr->set_generated(generated);
    AttrTypeHelper::SetAttrType<T>(attr);
    return op_checker_->AddAttrChecker<T>(name);
  }

  void AddComment(const std::string& comment) {
    *(proto_->mutable_comment()) = comment;
  }

 private:
  void SetHasMultiple(const std::string& in_out, bool* flag) {
    if (!*flag) {
      AddAttr<std::vector<int>>(in_out + "_format",
                                "The multiple index of " + in_out +
                                    "\n"
                                    R"DOC(
This attribute is used by Paddle core framework. Paddle's Op support each input
or output could be a list of variable. This attribute is used to show how that
list organized.

e.g.
  input = ["a", "b", "c", "d", "e", "f"]
  input_format = [0, 4, 5, 6]

means
  The number of all input variables this op is six, and they are segmented into
  three inputs.

  The first input is input[0:4], second is input[4:5], third is input[5:6].
)DOC",
                                /*generated*/ true);
      *flag = true;
    }
  }

  void SetHasMultipleInput() { SetHasMultiple("input", &has_multiple_input_); }
  void SetHasMultipleOutput() {
    SetHasMultiple("output", &has_multiple_output_);
  }

  void SetHasTemporaryOutput() {
    if (!has_temporary_output_) {
      AddAttr<std::vector<int>>("temporary_index",
                                R"DOC(The temporary index of output.

Not all output of Paddle Op is used by user. For faster computation, each op
could output some its internal state to other op, other op could take that
output to make compute faster.

Add a mark to which output is temporary is helpful for future optimization.
)DOC",
                                /*generated*/ true)
          .SetDefault(std::vector<int>());
      has_temporary_output_ = true;
    }
  }

  void CheckNoDuplicatedAttrs() {
    std::unordered_set<std::string> names;
    size_t cnt = 0;
    for (auto& attr : proto_->attrs()) {
      names.insert(attr.name());
      ++cnt;
    }
    PADDLE_ENFORCE(names.size() == cnt,
                   "Cannot register two attribute in same name!");
  }

  OpProto* proto_;
  OpAttrChecker* op_checker_;
  bool has_multiple_input_{false};
  bool has_multiple_output_{false};
  bool has_temporary_output_{false};
};

class OpRegistry {
  using OpCreator = std::function<OperatorBase*()>;

 public:
  template <typename OpType, typename ProtoMakerType>
  static void RegisterOp(const std::string& op_type) {
    creators()[op_type] = [] { return new OpType; };
    OpProto& op_proto = protos()[op_type];
    OpAttrChecker& op_checker = op_checkers()[op_type];
    ProtoMakerType(&op_proto, &op_checker);
    *op_proto.mutable_type() = op_type;
    PADDLE_ENFORCE(
        op_proto.IsInitialized(),
        "Fail to initialize %s's OpProto, because %s is not initialized",
        op_type, op_proto.InitializationErrorString());
  }

  static OperatorBase* CreateOp(const OpDesc& op_desc) {
    std::string op_type = op_desc.type();
    OperatorBase* op = creators().at(op_type)();
    op->desc_ = op_desc;
    op->inputs_.reserve((size_t)op_desc.inputs_size());
    std::copy(op_desc.inputs().begin(), op_desc.inputs().end(),
              std::back_inserter(op->inputs_));
    op->outputs_.reserve((size_t)op_desc.outputs_size());
    std::copy(op_desc.outputs().begin(), op_desc.outputs().end(),
              std::back_inserter(op->outputs_));
    for (auto& attr : op_desc.attrs()) {
      op->attrs_[attr.name()] = AttrTypeHelper::GetAttrValue(attr);
    }
    op_checkers().at(op_type).Check(op->attrs_);
    op->Init();
    return op;
  }

 private:
  static std::unordered_map<std::string, OpCreator>& creators() {
    static std::unordered_map<std::string, OpCreator> creators_;
    return creators_;
  }

  static std::unordered_map<std::string, OpProto>& protos() {
    static std::unordered_map<std::string, OpProto> protos_;
    return protos_;
  };

  static std::unordered_map<std::string, OpAttrChecker>& op_checkers() {
    static std::unordered_map<std::string, OpAttrChecker> op_checkers_;
    return op_checkers_;
  };
};

template <typename OpType, typename ProtoMakerType>
class OpRegisterHelper {
 public:
  OpRegisterHelper(const char* op_type) {
    OpRegistry::RegisterOp<OpType, ProtoMakerType>(op_type);
  }
};

#define STATIC_ASSERT_GLOBAL_NAMESPACE(uniq_name, msg)                        \
  struct __test_global_namespace_##uniq_name##__ {};                          \
  static_assert(std::is_same<::__test_global_namespace_##uniq_name##__,       \
                             __test_global_namespace_##uniq_name##__>::value, \
                msg)

#define REGISTER_OP(__op_type, __op_class, __op_maker_class)                 \
  STATIC_ASSERT_GLOBAL_NAMESPACE(__reg_op__##__op_type,                      \
                                 "REGISTER_OP must be in global namespace"); \
  static ::paddle::framework::OpRegisterHelper<__op_class, __op_maker_class> \
      __op_register_##__op_type##__(#__op_type);                             \
  int __op_register_##__op_type##_handle__() { return 0; }

#define REGISTER_OP_KERNEL(type, GPU_OR_CPU, PlaceType, KernelType)       \
  STATIC_ASSERT_GLOBAL_NAMESPACE(                                         \
      __reg_op_kernel_##type##_##GPU_OR_CPU##__,                          \
      "REGISTER_OP_KERNEL must be in global namespace");                  \
  struct __op_kernel_register__##type##__ {                               \
    __op_kernel_register__##type##__() {                                  \
      ::paddle::framework::OperatorWithKernel::OpKernelKey key;           \
      key.place_ = PlaceType();                                           \
      ::paddle::framework::OperatorWithKernel::AllOpKernels()[#type][key] \
          .reset(new KernelType());                                       \
    }                                                                     \
  };                                                                      \
  static __op_kernel_register__##type##__ __reg_kernel_##type##__;        \
  int __op_kernel_register_##type##_handle_##GPU_OR_CPU##__() { return 0; }

#define REGISTER_OP_GPU_KERNEL(type, KernelType) \
  REGISTER_OP_KERNEL(type, GPU, ::paddle::platform::GPUPlace, KernelType)

#define REGISTER_OP_CPU_KERNEL(type, KernelType) \
  REGISTER_OP_KERNEL(type, CPU, ::paddle::platform::CPUPlace, KernelType)

#define USE_OP_WITHOUT_KERNEL(op_type)                      \
  STATIC_ASSERT_GLOBAL_NAMESPACE(                           \
      __use_op_without_kernel_##op_type,                    \
      "USE_OP_WITHOUT_KERNEL must be in global namespace"); \
  extern int __op_register_##op_type##_handle__();          \
  static int __use_op_ptr_##op_type##_without_kernel__      \
      __attribute__((unused)) = __op_register_##op_type##_handle__()

#define USE_OP_KERNEL(op_type, DEVICE_TYPE)                               \
  STATIC_ASSERT_GLOBAL_NAMESPACE(                                         \
      __use_op_kernel_##op_type##_##DEVICE_TYPE##__,                      \
      "USE_OP_KERNEL must be in global namespace");                       \
  extern int __op_kernel_register_##op_type##_handle_##DEVICE_TYPE##__(); \
  static int __use_op_ptr_##op_type##_##DEVICE_TYPE##_kernel__            \
      __attribute__((unused)) =                                           \
          __op_kernel_register_##op_type##_handle_##DEVICE_TYPE##__()

#ifdef PADDLE_ONLY_CPU
#define USE_OP(op_type)           \
  USE_OP_WITHOUT_KERNEL(op_type); \
  USE_OP_KERNEL(op_type, CPU);

#else
#define USE_OP(op_type)           \
  USE_OP_WITHOUT_KERNEL(op_type); \
  USE_OP_KERNEL(op_type, CPU);    \
  USE_OP_KERNEL(op_type, GPU)
#endif

}  // namespace framework
}  // namespace paddle