#include "node_counters.h"
#include "uv.h"
#include "env.h"
#include "env-inl.h"

#include <string.h>


namespace node {

using v8::FunctionCallbackInfo;
using v8::FunctionTemplate;
using v8::GCCallbackFlags;
using v8::GCEpilogueCallback;
using v8::GCPrologueCallback;
using v8::GCType;
using v8::HandleScope;
using v8::Isolate;
using v8::Local;
using v8::Object;
using v8::String;
using v8::Value;

static uint64_t counter_gc_start_time;
static uint64_t counter_gc_end_time;


void COUNTER_NET_SERVER_CONNECTION(const FunctionCallbackInfo<Value>&) {
  NODE_COUNT_SERVER_CONN_OPEN();
}


void COUNTER_NET_SERVER_CONNECTION_CLOSE(const FunctionCallbackInfo<Value>&) {
  NODE_COUNT_SERVER_CONN_CLOSE();
}


void COUNTER_HTTP_SERVER_REQUEST(const FunctionCallbackInfo<Value>&) {
  NODE_COUNT_HTTP_SERVER_REQUEST();
}


void COUNTER_HTTP_SERVER_RESPONSE(const FunctionCallbackInfo<Value>&) {
  NODE_COUNT_HTTP_SERVER_RESPONSE();
}


void COUNTER_HTTP_CLIENT_REQUEST(const FunctionCallbackInfo<Value>&) {
  NODE_COUNT_HTTP_CLIENT_REQUEST();
}


void COUNTER_HTTP_CLIENT_RESPONSE(const FunctionCallbackInfo<Value>&) {
  NODE_COUNT_HTTP_CLIENT_RESPONSE();
}


static void counter_gc_start(Isolate* isolate,
                             GCType type,
                             GCCallbackFlags flags) {
  counter_gc_start_time = NODE_COUNT_GET_GC_RAWTIME();
}


static void counter_gc_done(Isolate* isolate,
                            GCType type,
                            GCCallbackFlags flags) {
  uint64_t endgc = NODE_COUNT_GET_GC_RAWTIME();
  if (endgc != 0) {
    uint64_t totalperiod = endgc - counter_gc_end_time;
    uint64_t gcperiod = endgc - counter_gc_start_time;

    if (totalperiod > 0) {
      unsigned int percent = static_cast<unsigned int>(
          (gcperiod * 100) / totalperiod);

      NODE_COUNT_GC_PERCENTTIME(percent);
      counter_gc_end_time = endgc;
    }
  }
}


void InitPerfCounters(Environment* env, Local<Object> target) {
  HandleScope scope(env->isolate());

  static struct {
    const char* name;
    void (*func)(const FunctionCallbackInfo<Value>&);
  } tab[] = {
#define NODE_PROBE(name) #name, name
    { NODE_PROBE(COUNTER_NET_SERVER_CONNECTION) },
    { NODE_PROBE(COUNTER_NET_SERVER_CONNECTION_CLOSE) },
    { NODE_PROBE(COUNTER_HTTP_SERVER_REQUEST) },
    { NODE_PROBE(COUNTER_HTTP_SERVER_RESPONSE) },
    { NODE_PROBE(COUNTER_HTTP_CLIENT_REQUEST) },
    { NODE_PROBE(COUNTER_HTTP_CLIENT_RESPONSE) }
#undef NODE_PROBE
  };

  for (int i = 0; i < ARRAY_SIZE(tab); i++) {
    Local<String> key = OneByteString(env->isolate(), tab[i].name);
    Local<Value> val = env->NewFunctionTemplate(tab[i].func)->GetFunction();
    target->Set(key, val);
  }

  // Only Windows performance counters supported
  // To enable other OS, use conditional compilation here
  InitPerfCountersWin32();

  // init times for GC percent calculation and hook callbacks
  counter_gc_start_time = NODE_COUNT_GET_GC_RAWTIME();
  counter_gc_end_time = counter_gc_start_time;

  env->isolate()->AddGCPrologueCallback(counter_gc_start);
  env->isolate()->AddGCEpilogueCallback(counter_gc_done);
}


void TermPerfCounters(Local<Object> target) {
  // Only Windows performance counters supported
  // To enable other OS, use conditional compilation here
  TermPerfCountersWin32();
}

}  // namespace node
