// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef FLUTTER_FML_TRACE_EVENT_H_
#define FLUTTER_FML_TRACE_EVENT_H_

#include "flutter/fml/build_config.h"

#if defined(OS_FUCHSIA)

// Forward to the system tracing mechanism on Fuchsia.

#include <trace/event.h>

#define TRACE_EVENT0(a, b) TRACE_DURATION(a, b)
#define TRACE_EVENT1(a, b, c, d) TRACE_DURATION(a, b, c, d)
#define TRACE_EVENT2(a, b, c, d, e, f) TRACE_DURATION(a, b, c, d, e, f)
#define TRACE_EVENT_ASYNC_BEGIN0(a, b, c) TRACE_ASYNC_BEGIN(a, b, c)
#define TRACE_EVENT_ASYNC_END0(a, b, c) TRACE_ASYNC_END(a, b, c)
#define TRACE_EVENT_ASYNC_BEGIN1(a, b, c, d, e) TRACE_ASYNC_BEGIN(a, b, c, d, e)
#define TRACE_EVENT_ASYNC_END1(a, b, c, d, e) TRACE_ASYNC_END(a, b, c, d, e)

#endif  // defined(OS_FUCHSIA)

#include <cstddef>
#include <cstdint>
#include <string>
#include <type_traits>
#include <vector>

#include "flutter/fml/macros.h"
#include "third_party/dart/runtime/include/dart_tools_api.h"

#if !defined(OS_FUCHSIA)

#ifndef TRACE_EVENT_HIDE_MACROS

#define __FML__TOKEN_CAT__(x, y) x##y
#define __FML__TOKEN_CAT__2(x, y) __FML__TOKEN_CAT__(x, y)
#define __FML__AUTO_TRACE_END(name)                                  \
  ::fml::tracing::ScopedInstantEnd __FML__TOKEN_CAT__2(__trace_end_, \
                                                       __LINE__)(name);

// This macro has the FML_ prefix so that it does not collide with the macros
// from trace/event.h on Fuchsia.
//
// TODO(chinmaygarde): All macros here should have the FML prefix.
#define FML_TRACE_COUNTER(category_group, name, counter_id, arg1, args...) \
  ::fml::tracing::TraceCounter(category_group, name, counter_id, arg1, ##args);

#define TRACE_EVENT0(category_group, name)           \
  ::fml::tracing::TraceEvent0(category_group, name); \
  __FML__AUTO_TRACE_END(name)

#define TRACE_EVENT1(category_group, name, arg1_name, arg1_val)           \
  ::fml::tracing::TraceEvent1(category_group, name, arg1_name, arg1_val); \
  __FML__AUTO_TRACE_END(name)

#define TRACE_EVENT2(category_group, name, arg1_name, arg1_val, arg2_name, \
                     arg2_val)                                             \
  ::fml::tracing::TraceEvent2(category_group, name, arg1_name, arg1_val,   \
                              arg2_name, arg2_val);                        \
  __FML__AUTO_TRACE_END(name)

#define TRACE_EVENT_ASYNC_BEGIN0(category_group, name, id) \
  ::fml::tracing::TraceEventAsyncBegin0(category_group, name, id);

#define TRACE_EVENT_ASYNC_END0(category_group, name, id) \
  ::fml::tracing::TraceEventAsyncEnd0(category_group, name, id);

#define TRACE_EVENT_ASYNC_BEGIN1(category_group, name, id, arg1_name,        \
                                 arg1_val)                                   \
  ::fml::tracing::TraceEventAsyncBegin1(category_group, name, id, arg1_name, \
                                        arg1_val);

#define TRACE_EVENT_ASYNC_END1(category_group, name, id, arg1_name, arg1_val) \
  ::fml::tracing::TraceEventAsyncEnd1(category_group, name, id, arg1_name,    \
                                      arg1_val);

#define TRACE_EVENT_INSTANT0(category_group, name) \
  ::fml::tracing::TraceEventInstant0(category_group, name);

#define TRACE_FLOW_BEGIN(category, name, id) \
  ::fml::tracing::TraceEventFlowBegin0(category, name, id);

#define TRACE_FLOW_STEP(category, name, id) \
  ::fml::tracing::TraceEventFlowStep0(category, name, id);

#define TRACE_FLOW_END(category, name, id) \
  ::fml::tracing::TraceEventFlowEnd0(category, name, id);

#endif  // TRACE_EVENT_HIDE_MACROS

#endif  // !defined(OS_FUCHSIA)

namespace fml {
namespace tracing {

using TraceArg = const char*;
using TraceIDArg = int64_t;

void TraceTimelineEvent(TraceArg category_group,
                        TraceArg name,
                        TraceIDArg id,
                        Dart_Timeline_Event_Type type,
                        const std::vector<const char*>& names,
                        const std::vector<std::string>& values);

inline std::string TraceToString(const char* string) {
  return std::string{string};
}

inline std::string TraceToString(std::string string) {
  return string;
}

template <typename T, typename = std::enable_if_t<std::is_arithmetic<T>::value>>
std::string TraceToString(T string) {
  return std::to_string(string);
}

inline void SplitArgumentsCollect(std::vector<const char*>& keys,
                                  std::vector<std::string>& values) {}

template <typename Key, typename Value, typename... Args>
void SplitArgumentsCollect(std::vector<const char*>& keys,
                           std::vector<std::string>& values,
                           Key key,
                           Value value,
                           Args... args) {
  keys.emplace_back(key);
  values.emplace_back(TraceToString(value));
  SplitArgumentsCollect(keys, values, args...);
}

inline std::pair<std::vector<const char*>, std::vector<std::string>>
SplitArguments() {
  return {};
}

template <typename Key, typename Value, typename... Args>
std::pair<std::vector<const char*>, std::vector<std::string>>
SplitArguments(Key key, Value value, Args... args) {
  std::vector<const char*> keys;
  std::vector<std::string> values;
  SplitArgumentsCollect(keys, values, key, value, args...);
  return std::make_pair(std::move(keys), std::move(values));
}

template <typename... Args>
void TraceCounter(TraceArg category,
                  TraceArg name,
                  TraceIDArg identifier,
                  Args... args) {
  auto split = SplitArguments(args...);
  TraceTimelineEvent(category, name, identifier, Dart_Timeline_Event_Counter,
                     split.first, split.second);
}

void TraceEvent0(TraceArg category_group, TraceArg name);

void TraceEvent1(TraceArg category_group,
                 TraceArg name,
                 TraceArg arg1_name,
                 TraceArg arg1_val);

void TraceEvent2(TraceArg category_group,
                 TraceArg name,
                 TraceArg arg1_name,
                 TraceArg arg1_val,
                 TraceArg arg2_name,
                 TraceArg arg2_val);

void TraceEventEnd(TraceArg name);

void TraceEventAsyncBegin0(TraceArg category_group,
                           TraceArg name,
                           TraceIDArg id);

void TraceEventAsyncEnd0(TraceArg category_group, TraceArg name, TraceIDArg id);

void TraceEventAsyncBegin1(TraceArg category_group,
                           TraceArg name,
                           TraceIDArg id,
                           TraceArg arg1_name,
                           TraceArg arg1_val);

void TraceEventAsyncEnd1(TraceArg category_group,
                         TraceArg name,
                         TraceIDArg id,
                         TraceArg arg1_name,
                         TraceArg arg1_val);

void TraceEventInstant0(TraceArg category_group, TraceArg name);

void TraceEventFlowBegin0(TraceArg category_group,
                          TraceArg name,
                          TraceIDArg id);

void TraceEventFlowStep0(TraceArg category_group, TraceArg name, TraceIDArg id);

void TraceEventFlowEnd0(TraceArg category_group, TraceArg name, TraceIDArg id);

class ScopedInstantEnd {
 public:
  ScopedInstantEnd(std::string str) : label_(std::move(str)) {}

  ~ScopedInstantEnd() { TraceEventEnd(label_.c_str()); }

 private:
  const std::string label_;

  FML_DISALLOW_COPY_AND_ASSIGN(ScopedInstantEnd);
};

}  // namespace tracing
}  // namespace fml

#endif  // FLUTTER_FML_TRACE_EVENT_H_