#include <cassert>
#include <string>
#include <iostream>
#include "luaincl.h"

#include "Script.h"
#include "RestoreStack.h"
#include "This.h"
#include "LuaCallback.h"

// ---------------------------------------------------------------------------

namespace OrxScript
{

#define BEGIN_LUA_CHECK(vm)   lua_State *state = (lua_State *) vm; \
                              if (vm.isOk ()) {
#define END_LUA_CHECK         }


  /**
   * @brief Constructor. Sets up the lua stack and the "this" table
   *
   *
   *
   */

  LuaScript::LuaScript ()
      : methodCount (0) , argumentCount (0), functionName()
  {
    virtualMachine.init();
    lua_State *state = (lua_State *) virtualMachine;

    if (virtualMachine.isOk ())
    {
      // Create a reference to the "this" table. Each reference is unique
      lua_newtable (state);
      thisReference = luaL_ref (state, LUA_REGISTRYINDEX);

      // Save the "this" table to index 0 of the "this" table
      LuaRestoreStack rs (virtualMachine);
      lua_rawgeti (state, LUA_REGISTRYINDEX, thisReference);
      lua_pushlightuserdata (state, (void *) this);
      lua_rawseti (state, -2, 0);
    }

  }


  /**
   * @brief Deconstructor
   *
   */

  LuaScript::~LuaScript (void)
  {
    LuaRestoreStack rs (virtualMachine);

    BEGIN_LUA_CHECK (virtualMachine)
    // Get the reference "this" table
    lua_rawgeti (state, LUA_REGISTRYINDEX, thisReference);

    // Clear index 0
    lua_pushnil (state);
    lua_rawseti (state, -2, 0);
    END_LUA_CHECK

  }



  /**
   * @brief Compiles a given buffer. (reads it into the lua stack)
   * @param pbBuffer buffer to compile
   * @param size_t length of the buffer
   *
   * @return true if it succeeded
   */

  bool LuaScript::compileBuffer (unsigned char *pbBuffer, size_t szLen)
  {
    assert (pbBuffer != NULL && "LuaScript::compileBuffer ->  pbBuffer == NULL");
    assert (szLen != 0 && "LuaScript::compileBuffer -> szLen == 0");
    assert (virtualMachine.isOk () && "VM Not OK");

    // Make sure we have the correct "this" table
    LuaThis luaThis (virtualMachine, thisReference);

    return virtualMachine.runBuffer (pbBuffer, szLen);
  }


  /**
   * @brief Compiles a given file. (reads it into the lua stack)
   * @param strFilename filename
   *
   * @return true if it succeeded
   */

  bool LuaScript::compileFile (const std::string& strFilename)
  {
    //assert (strFilename != NULL && "LuaScript::compileFile -> strFilename == NULL");
    assert (virtualMachine.isOk () && "VM Not OK");

    // Make sure we have the correct "this" table
    LuaThis luaThis (virtualMachine, thisReference);

    return virtualMachine.runFile (strFilename);
  }


  /**
   * @brief Registers a function with Lua, the function will be registered in the "this" table
   * @param strFuncName name of the function by which it goes by in lua
   *
   * @return the pseudoindex of the function
   */

  int LuaScript::registerFunction (const std::string& strFuncName)
  {
    //  assert (strFuncName != NULL && "LuaScript::registerFunction -> strFuncName == NULL");
    assert (virtualMachine.isOk () && "VM Not OK");

    int iMethodIdx = -1;

    LuaRestoreStack rs (virtualMachine);

    BEGIN_LUA_CHECK (virtualMachine)
    iMethodIdx = ++methodCount;

    // Register a function with the lua script. Added it to the "this" table
    lua_rawgeti (state, LUA_REGISTRYINDEX, thisReference);

    // Push the function and parameters
    lua_pushstring (state, strFuncName.c_str());
    lua_pushnumber (state, (lua_Number) iMethodIdx);
    lua_pushcclosure (state, luaCallback, 1);
    lua_settable (state, -3);

    END_LUA_CHECK

    return iMethodIdx;
  }


  /**
   * @brief Selects a script function to run
   * @param  strFuncName name of the function to run
   *
   * @return true on success
   */
  bool LuaScript::selectScriptFunction (const std::string& strFuncName)
  {
    //  assert (strFuncName != NULL && "LuaScript::selectScriptFunction -> strFuncName == NULL");
    assert (virtualMachine.isOk () && "VM Not OK");

    bool fSuccess = true;

    BEGIN_LUA_CHECK (virtualMachine)
    // Look up function name
    lua_rawgeti (state, LUA_REGISTRYINDEX, thisReference);
    lua_pushstring (state, strFuncName.c_str());
    lua_rawget (state, -2);
    lua_remove (state, -2);

    // Put the "this" table back
    lua_rawgeti (state, LUA_REGISTRYINDEX, thisReference);

    // Check that we have a valid function
    if (!lua_isfunction (state, -2))
    {
      fSuccess = false;
      lua_pop (state, 2);
    }
    else
    {
      argumentCount = 0;
      functionName = strFuncName;
    }
    END_LUA_CHECK

    return fSuccess;
  }


  /**
   * @brief Checks to see if a function exists
   * @param  functionName  Function name
   *
   * @return true if the function exists
   */
  bool LuaScript::scriptHasFunction (const std::string& functionName)
  {
    // printf("entered scriptHasFunction\n");

    //  assert (strScriptName != NULL && "LuaScript::scriptHasFunction -> strScriptName == NULL");
    assert (virtualMachine.isOk () && "VM Not OK");

    // printf("assertions passed\n");

    LuaRestoreStack rs (virtualMachine);

    bool fFoundFunc = false;

    BEGIN_LUA_CHECK (virtualMachine)
    lua_rawgeti (state, LUA_REGISTRYINDEX, thisReference);
    lua_pushstring (state, functionName.c_str());
    lua_rawget (state, -2);
    lua_remove (state, -2);

    if (lua_isfunction (state, -1))
    {
      fFoundFunc = true;
    }
    END_LUA_CHECK

    return fFoundFunc;

  }


  /**
   * @brief Adds a parameter to the parameter list
   * @param  string  string to be added as parameter for a function.
   *
   */

  void LuaScript::addParam (const std::string& string)
  {
    assert (virtualMachine.isOk () && "VM Not OK");

    BEGIN_LUA_CHECK (virtualMachine);
    lua_pushstring (state, string.c_str());
    ++argumentCount;
    END_LUA_CHECK;
  }


  /**
   * @brief Adds a parameter to the parameter list
   * @param  iInt  integer to be added as parameter for a function.
   *
   */

  void LuaScript::addParam (int iInt)
  {
    assert (virtualMachine.isOk () && "VM Not OK");

    BEGIN_LUA_CHECK (virtualMachine)
    lua_pushnumber (state, (lua_Number) iInt);
    ++argumentCount;
    END_LUA_CHECK
  }


  /**
   * @brief Adds a parameter to the parameter list
   * @param  fFloat  float to be added as parameter for a function.
   *
   */
  void LuaScript::addParam (float fFloat)
  {
    assert (virtualMachine.isOk () && "VM Not OK");

    BEGIN_LUA_CHECK (virtualMachine)
    lua_pushnumber (state, (lua_Number) fFloat);
    ++argumentCount;
    END_LUA_CHECK
  }


  /**
   * @brief Runs the selected script function
   * @param  nReturns the count of return values
   *
   * @return true on success
   */
  bool LuaScript::run (int nReturns /* = 0 */)
  {
    assert (virtualMachine.isOk () && "VM Not OK");

    // At this point there should be a parameters and a function on the
    // Lua stack. Each function get a "this" parameter as default and is
    // pushed onto the stack when the method is selected

    bool fSuccess = virtualMachine.callFunction (argumentCount + 1, nReturns);

    if (fSuccess == true && nReturns > 0)
    {
      // Check for returns
      handleReturns (virtualMachine, functionName);
      lua_pop ((lua_State *) virtualMachine, nReturns);
    }

    return fSuccess;
  }


  /**
   * @brief This function adds an object to a script so that the object is accessable from within the luascript.
   *
   * @param scriptable the scriptable object to add.
   * @param strObjName the name that the object goes by in the script.
   * @param luaScript  the script to which the scrtiptable is added
   *
   * @return a lua reference to the added object
   *
   *
   *
   */

  int LuaScript::addScriptableToScript(Scriptable* scriptable, const std::string& strObjName)
  {

    lua_State *state = (lua_State *) (this->virtualMachine);

    if(strObjName.compare(std::string("this")) != 0)
    {
      if (virtualMachine.isOk ())
      {
        /*create object table*/
        // Create a reference to the "object" table and set a name for the reference. Each reference is unique

        lua_newtable (state);
        int  objRef = luaL_ref (state, LUA_REGISTRYINDEX);
        lua_rawgeti (state, LUA_REGISTRYINDEX, objRef);
        lua_setglobal (state, strObjName.c_str());


        // Save the "object" table to index 0 of the "object" table
        LuaRestoreStack rs(virtualMachine);
        lua_rawgeti (state, LUA_REGISTRYINDEX, objRef);
        lua_pushlightuserdata (state, scriptable);
        lua_rawseti (state, -2, 0);

        if(! addScriptableToList(scriptable,objRef))
          std::cout<<"scriptable not added"<<std::endl;
        if(!(scriptable->scriptableAdded(this,thisReference,objRef)))
          std::cout<<"scriptableAdded returned false"<<std::endl;

        return objRef;
      }
    }

    return -1;

  }



  /**
   * @brief Add the function to a scriptable in the Script
   * @param strFuncName name of the function by which it goes by in lua
   * @param toScriptable reference to the scriptable the function should be associated with
   * @param methodIndex index of the last function.
   *
   * @return the pseudoindex of the function, -1 on failure
   */

  int LuaScript::addFunctionToScriptable(const std::string& strFuncName, int toScriptable, int lastMethodIndex)
  {
    //  assert (strFuncName != NULL && "LuaScript::registerFunction -> strFuncName == NULL");
    assert (virtualMachine.isOk () && "VM Not OK");


    //get the last method index from the Script
    Scriptable* scriptable = getScriptableByReference(toScriptable);
    int iMethodIdx = -1;

    if(scriptable)
    {
      LuaRestoreStack rs (virtualMachine);

      BEGIN_LUA_CHECK (virtualMachine)
      // Register a function with the lua script. Added it to the "toScrtiptable" table
      lua_rawgeti (state, LUA_REGISTRYINDEX, toScriptable);

      if (lua_istable (state, 1))
      {
        iMethodIdx = ++lastMethodIndex;

        // Push the function and parameters
        lua_pushstring (state, strFuncName.c_str());
        lua_pushnumber (state, (lua_Number) iMethodIdx);
        lua_pushcclosure (state, luaCallback, 1);
        lua_settable (state, -3);
      }
      END_LUA_CHECK

    }
    return iMethodIdx;
  }


  Scriptable* LuaScript::getScriptableByReference(int scrptblRef)
  {

    bool notFound = true;
    std::list<Scrptbl>::iterator it = scriptableList.begin();

    while(notFound && it != scriptableList.end() )
    {
      if((*it).scriptableRef == scrptblRef)
      {
        notFound = false;
        return (*it).scriptable;
      }
      it++;
    }


    if(notFound)
      return NULL;

  }

  int LuaScript::getReferenceByScriptable(Scriptable* scrptbl)
  {
    bool notFound = true;

    std::list<Scrptbl>::iterator it = scriptableList.begin();

    while(notFound && it != scriptableList.end() )
    {
      if((*it).scriptable == scrptbl)
      {
        notFound = false;
        return (*it).scriptableRef;
      }
      it++;
    }
    if(notFound)
      return -1;
  }

  bool LuaScript::addScriptableToList(Scriptable* scrptbl, int scriptableRef)
  {
    if(scrptbl)
    {
      if(getReferenceByScriptable(scrptbl) == -1) // Script isn't there yet
      {
        Scrptbl scriptableTmp;
        scriptableTmp.scriptable = scrptbl;
        scriptableTmp.scriptableRef = scriptableRef;
        scriptableList.push_back(scriptableTmp);
        return true;
      }
    }

    return false;

  }

  bool LuaScript::removeScriptableFromList(Scriptable* toRemove)
  {
    if(toRemove)
    {
      int scrptbl = getReferenceByScriptable(toRemove);

      if(scrptbl != -1)// if the scriptable is on the list
      {
        std::list<Scrptbl>::iterator it = scriptableList.begin();

        while((*it).scriptable != toRemove && it != scriptableList.end() )
        {
          it++;
        }

        if(it != scriptableList.end())
        {
          scriptableList.erase(it);
          return true;
        }
      }
    }
    return false;
  }

  bool LuaScript::removeScriptableFromList(int scriptable)
  {
    return removeScriptableFromList(getScriptableByReference(scriptable));
  }


  char LuaScript::whatIsThis()
  {
    char result = 'l';
    return result;
  }
}