#include "stdafx.hpp"
#include <iostream>
#include <windows.h>
#include <pthread.h>
#include <list>
using namespace std;

pthread_mutex_t mutex;
LuaPlus::LuaState* pState = LuaPlus::LuaState::Create( true );

//-- start Task.h --

struct Task{
  static list<Task*> runningTasks;
  static list<Task*> doneTasks;
  static pthread_mutex_t mutex;
  list<Task*>::iterator iterator;

  virtual ~Task(){}

  bool start(){
    pthread_mutex_lock(&mutex);
    bool hasSpace = runningTasks.size() < 100;
    if(hasSpace){
      runningTasks.push_front(this);
      iterator = runningTasks.begin();
      pthread_t unusedID;
      pthread_create(&unusedID, NULL, Task::threadBody, this);
    }
    pthread_mutex_unlock(&mutex);
    return hasSpace;
  }

  virtual void run() = 0;
  virtual void processResults() = 0;

protected:
  void finish(){
    pthread_mutex_lock(&mutex);
    runningTasks.erase(iterator);
    doneTasks.push_front(this);
    pthread_mutex_unlock(&mutex);
  }

  static void* threadBody(void* instance){
    Task* task = static_cast<Task*>(instance);
    task->run();
    task->finish();
    return NULL;
  }
};
//-- end Task.h --

//-- start Task.cpp --

//Instantiate Task's static attributes
pthread_mutex_t Task::mutex;
list<Task*> Task::runningTasks;
list<Task*> Task::doneTasks;

//-- end Task.cpp --

struct SumTask: public Task{
  int a, b, c;
  void run(){
    Sleep(3000);
    c = a+b;
  }
  void processResults(){
    LuaPlus::LuaFunction<int> CPP_OnMyEvent = pState->GetGlobal("LUA_OnMyEvent");
    CPP_OnMyEvent(a,b,c);
  }
};

//functions called by Lua
bool runSumTask(int a, int b){
  SumTask *task = new SumTask();
  task->a = a; task->b = b;
  bool ok = task->start();
  if(!ok)
    delete task;
  return ok;
}

int gatherResults(){
  pthread_mutex_lock(&Task::mutex);
  int totalResults = Task::doneTasks.size();
  while(Task::doneTasks.size() > 0){
    Task* t = Task::doneTasks.front();
    Task::doneTasks.pop_front();
    t->processResults();
    delete t;
  }
  pthread_mutex_unlock(&Task::mutex);
  return totalResults;
}

int main() {
    pthread_mutex_init(&mutex, NULL); //initialize the mutex
    LuaPlus::LuaObject globals = pState->GetGlobals();

    globals.RegisterDirect("runSumTask", runSumTask);
    globals.RegisterDirect("gatherResults", gatherResults);

    char pPath[ MAX_PATH ];
    GetCurrentDirectory(MAX_PATH,pPath);
    strcat_s(pPath,MAX_PATH,"\\main.lua");
    if( pState->DoFile(pPath) ) { //run our main.lua script which contains the callback function that will run a print
        if( pState->GetTop() == 1 )
            std::cout << "An error occured: " << pState->CheckString(1) << std::endl;
    }

    //clean up
    LuaPlus::LuaState::Destroy( pState );
    pState = nullptr;
    pthread_mutex_destroy(&mutex);
    getchar(); //keep console from closing
    return 0;
}