// Skip rarely used Windows API functions
#define WIN32_LEAN_AND_MEAN

// Headers
#include <GMLuaModule.h>

// Module definition
GMOD_MODULE( Init, Shutdown );

// Globals
ILuaInterface* g_Lua;

// Typedefs
typedef unsigned int uint;
typedef unsigned char byte;

// Functions
LUA_FUNCTION( GMAllocate ) {
    // Check argument types
    g_Lua->CheckType( 1, GLua::TYPE_NUMBER );

    // Read size
    uint size = uint( g_Lua->GetInteger( 1 ) );

    // Allocate it
    byte* ptrMem = new byte[ size ];

    // Push the result
    g_Lua->Push( float( int( ptrMem ) ) );

    // We're done
    return 1;
}

LUA_FUNCTION( GMDeallocate ) {
    // Check argument types
    g_Lua->CheckType( 1, GLua::TYPE_NUMBER );

    // Read pointer
    byte* ptrMem = (byte*)g_Lua->GetInteger( 1 );

    // Deallocate
    delete [] ptrMem;

    // We're done
    return 0;
}

LUA_FUNCTION( GMSet ) {
    // Check argument types
    g_Lua->CheckType( 1, GLua::TYPE_NUMBER );
    g_Lua->CheckType( 2, GLua::TYPE_NUMBER );
    g_Lua->CheckType( 3, GLua::TYPE_NUMBER );

    // Read pointer
    byte* ptrMem = (byte*)g_Lua->GetInteger( 1 );

    // Read size and value
    byte val = byte( g_Lua->GetInteger( 2 ) );
    uint size = uint( g_Lua->GetInteger( 3 ) );

    // Set
    memset( ptrMem, val, size );

    // We're done
    return 0;
}

LUA_FUNCTION( GMCopy ) {
    // Check argument types
    g_Lua->CheckType( 1, GLua::TYPE_NUMBER );
    g_Lua->CheckType( 2, GLua::TYPE_NUMBER );
    g_Lua->CheckType( 3, GLua::TYPE_NUMBER );

    // Read pointers
    byte* ptrMemSrc = (byte*)g_Lua->GetInteger( 1 );
    byte* ptrMemDst = (byte*)g_Lua->GetInteger( 2 );

    // Read size
    uint size = uint( g_Lua->GetInteger( 3 ) );

    // Copy
    memcpy( ptrMemDst, ptrMemSrc, size );

    // We're done
    return 0;
}

LUA_FUNCTION( GMSetByte ) {
    // Check argument types
    g_Lua->CheckType( 1, GLua::TYPE_NUMBER );
    g_Lua->CheckType( 2, GLua::TYPE_NUMBER );

    // Read pointer
    byte* ptrMem = (byte*)g_Lua->GetInteger( 1 );

    // Read size and value
    byte val = byte( g_Lua->GetInteger( 2 ) );

    // Set
    memset( ptrMem, val, sizeof( byte ) );

    // We're done
    return 0;
}

LUA_FUNCTION( GMGetByte ) {
    // Check argument types
    g_Lua->CheckType( 1, GLua::TYPE_NUMBER );

    // Read pointer
    byte* ptrMem = (byte*)g_Lua->GetInteger( 1 );

    // Push the result
    g_Lua->Push( float( *ptrMem ) );

    // We're done
    return 1;
}

// Initialization
int Init( lua_State *L )
{
    // Get the lua instance
    g_Lua = Lua();

    // Register module
    g_Lua->NewGlobalTable( "heap" );
    ILuaObject* module = g_Lua->GetGlobal( "heap" );

    // Register functions
    module->SetMember( "Allocate", GMAllocate );
    module->SetMember( "Deallocate", GMDeallocate );
    module->SetMember( "Set", GMSet );
    module->SetMember( "SetByte", GMSetByte );
    module->SetMember( "GetByte", GMGetByte );
    module->SetMember( "Copy", GMCopy );

    // Clean up
    module->UnReference();

    // Why hello there
    g_Lua->Msg( "[HEAP] Module loaded!\n" );

    // Return
    return 0;
}


// Shutdown
int Shutdown( lua_State *L )
{
    // Good bye world
    g_Lua->Msg( "[HEAP] Module unloaded!\n" );

    // Return
    return 0;
}