// Copyright (C) 2012-2015 ChaosForge Ltd
// http://chaosforge.org/
//
// This file is part of Nova libraries. 
// For conditions of distribution and use, see copying.txt file in root folder.

#include "nv/lib/lua.hh"

#if NV_LUA_VERSION == NV_LUA_5C
size_t( *lua_rawlen )        ( lua_State *L, int idx ) = nullptr;
int( *lua_absindex )      ( lua_State *L, int idx ) = nullptr;
void( *lua_getglobal )     ( lua_State *L, const char *var ) = nullptr;
void( *lua_setglobal )     ( lua_State *L, const char *var ) = nullptr;
void( *luaL_requiref )     ( lua_State *L, const char *modname, lua_CFunction openf, int glb ) = nullptr;
void( *luaL_setmetatable ) ( lua_State *L, const char *tname ) = nullptr;
void*  ( *luaL_testudata )    ( lua_State *L, int ud, const char *tname ) = nullptr;
void( *lua_copy )          ( lua_State *L, int fromidx, int toidx ) = nullptr;
int( *lua_compare )       ( lua_State *L, int idx1, int idx2, int op ) = nullptr;
void( *lua_rawgetp )       ( lua_State *L, int idx, const void *p ) = nullptr;
void( *lua_rawsetp )       ( lua_State *L, int idx, const void *p ) = nullptr;
void( *lua_pushglobaltable )( lua_State* L ) = nullptr;
void( *luaL_setfuncs )     ( lua_State *L, const luaL_Reg *l, int nup ) = nullptr;
int( *luaL_getsubtable )  ( lua_State *L, int idx, const char *fname ) = nullptr;

const lua_Number* ( *lua_version ) ( lua_State *L ) = nullptr;

// only loaded in 5.1 mode to implement lua_compare
static int( *lua_equal )        ( lua_State *L, int idx1, int idx2 ) = nullptr;
static int( *lua_lessthan )     ( lua_State *L, int idx1, int idx2 ) = nullptr;
#endif


#if defined( NV_LUA_DYNAMIC )

#include "nv/core/library.hh"

#if NV_LUA_VERSION == NV_LUA_52
#	undef luaL_loadfile
#	undef luaL_loadbuffer
#	undef luaL_prepbuffer
#	undef lua_tonumber
#	undef lua_tointeger
#	undef lua_tounsigned
#	undef lua_call
#	undef lua_pcall
#	undef lua_yield
#endif

#define NV_LUA_FUN( rtype, fname, fparams ) rtype (*fname) fparams = nullptr;
#if NV_LUA_VERSION == NV_LUA_52
#	define NV_LUA_FUN_51( rtype, fname, fparams )
#	define NV_LUA_FUN_52 NV_LUA_FUN
#elif NV_LUA_VERSION == NV_LUA_51
#	define NV_LUA_FUN_51 NV_LUA_FUN
#	define NV_LUA_FUN_52( rtype, fname, fparams ) 
#else
#	define NV_LUA_FUN_51( rtype, fname, fparams )
#	define NV_LUA_FUN_52( rtype, fname, fparams ) 
#endif

#include <nv/lib/detail/lua_functions.inc>

#undef NV_LUA_FUN
#undef NV_LUA_FUN_51
#undef NV_LUA_FUN_52

#if NV_LUA_VERSION == NV_LUA_5C
#	define NV_LUA_COMPAT_FUN( rt, fn, fp,u1,u2,u3,u4,u5 ) rt (*fn) fp = nullptr;
#	include <nv/lib/detail/lua_functions_compat.inc>
#	undef NV_LUA_COMPAT_FUN

#	define NV_LUA_COMPAT_FUN( u1,u2,u3,rt2,fn2,fp2,u4,u5 ) static rt2 (*fn2##_compat) fp2 = nullptr;
#	include <nv/lib/detail/lua_functions_compat.inc>
#	undef NV_LUA_COMPAT_FUN

#	define NV_LUA_COMPAT_FUN( rt, fn, fp, rt2, fn2, fp2,arg,ret ) \
		static rt call_##fn2##_compat fp { ret fn2##_compat arg; } 
#	include <nv/lib/detail/lua_functions_compat.inc>
#	undef NV_LUA_COMPAT_FUN

#endif

#endif

#if NV_LUA_VERSION == NV_LUA_5C
int LUA_UPVALUEINDEX = 0;
int LUA_REGISTRYINDEX = 0;
int LUA_VERSION_NUM = 0;
#	define LUAI_MAXSTACK_52		    1000000
#	define LUAI_FIRSTPSEUDOIDX_52	(-LUAI_MAXSTACK_52 - 1000)
#	define LUA_REGISTRYINDEX_52	    LUAI_FIRSTPSEUDOIDX_52
#	define LUA_GLOBALSINDEX_51      (-10002)
#	define LUA_GLOBALSINDEX_52      2
#	define LUA_REGISTRYINDEX_51     (-10000)

static int lua_absindex_51( lua_State *L, int idx )
{
	return ( idx > 0 ? idx : idx + lua_gettop( L ) + 1 );
};

static void lua_getglobal_51( lua_State *L, const char *var )
{
	lua_getfield( L, LUA_GLOBALSINDEX_51, var );
};

static void lua_setglobal_51( lua_State *L, const char *var )
{
	lua_setfield( L, LUA_GLOBALSINDEX_51, var );
};

static void luaL_requiref_51( lua_State *L, const char *modname, lua_CFunction openf, int glb )
{
	lua_pushcfunction( L, openf );
	lua_pushstring( L, modname );
	lua_call( L, 1, 1 );
	if ( glb != 0 )
	{
		lua_pushvalue( L, LUA_GLOBALSINDEX_51 );
		lua_pushvalue( L, -2 );
		lua_setfield( L, -2, modname );
		lua_pop( L, 1 );
	}
}

static void luaL_setmetatable_51( lua_State *L, const char *tname )
{
	luaL_getmetatable( L, tname );
	lua_setmetatable( L, -2 );
}

static void *luaL_testudata_51( lua_State *L, int ud, const char *tname )
{
	void *p = lua_touserdata( L, ud );
	if ( p != NULL )
	{
		if ( lua_getmetatable( L, ud ) )
		{
			luaL_getmetatable( L, tname );
			if ( !lua_rawequal( L, -1, -2 ) )
				p = NULL;
			lua_pop( L, 2 );
			return p;
		}
	}
	return NULL;
}

static const lua_Number *lua_version_51( lua_State* )
{
	static const lua_Number version = lua_Number( LUA_VERSION_NUM );
	return &version;
}

static void lua_copy_51( lua_State *L, int fromidx, int toidx )
{
	toidx = lua_absindex( L, toidx );
	lua_pushvalue( L, fromidx );
	lua_replace( L, toidx );
}

static int lua_compare_51( lua_State *L, int idx1, int idx2, int op )
{
	switch ( op )
	{
	case LUA_OPEQ: return lua_equal( L, idx1, idx2 );
	case LUA_OPLT: return lua_lessthan( L, idx1, idx2 );
	case LUA_OPLE: return lua_lessthan( L, idx1, idx2 ) || lua_equal( L, idx1, idx2 );
	default:
		return 0;
	}
}

static void lua_rawgetp_51( lua_State *L, int idx, const void *p )
{
	idx = lua_absindex( L, idx );
	void* pp = const_cast<void *>( p ); // EVIL
	lua_pushlightuserdata( L, pp );
	lua_rawget( L, idx );
}

static void lua_rawsetp_51( lua_State *L, int idx, const void *p )
{
	idx = lua_absindex( L, idx );
	void* pp = const_cast<void *>( p ); // EVIL
	lua_pushlightuserdata( L, pp );
	lua_insert( L, -1 );
	lua_rawset( L, idx );
}

static int luaL_getsubtable_51( lua_State *L, int idx, const char *fname )
{
	lua_getfield( L, idx, fname );
	if ( lua_istable( L, -1 ) ) return 1;
	else
	{
		idx = lua_absindex( L, idx );
		lua_pop( L, 1 );
		lua_newtable( L );
		lua_pushvalue( L, -1 );
		lua_setfield( L, idx, fname );
		return 0;
	}
}

static void luaL_setfuncs_51( lua_State *L, const luaL_Reg *l, int nup )
{
	luaL_checkstack( L, nup, "too many upvalues" );
	for ( ; l->name != NULL; l++ )
	{
		for ( int i = 0; i < nup; i++ )
		{
			lua_pushvalue( L, -nup );
		}
		lua_pushcclosure( L, l->func, nup );
		lua_setfield( L, -( nup + 2 ), l->name );
	}
	lua_pop( L, nup );
}

static void lua_pushglobaltable_51( lua_State* L )
{
	lua_pushvalue( L, LUA_GLOBALSINDEX_51 );
}

static void lua_pushglobaltable_52( lua_State* L )
{
	lua_rawgeti( L, LUA_REGISTRYINDEX_52, LUA_GLOBALSINDEX_52 );
}


#endif

#if defined( NV_LUA_DYNAMIC )

bool nv::load_lua_library( const char* path )
{
	static nv::library lua_library;
	if ( lua_library.is_open() ) return true;
#if NV_LUA_VERSION == NV_LUA_5C
	if ( path == nullptr )
	{
		if (!lua_library.try_open( NV_LUA_PATH_JIT ) &&
			!lua_library.try_open( NV_LUA_PATH_52 ) )
		{
			lua_library.open( NV_LUA_PATH_51 );
		}
	}
	else
#else
		lua_library.open( path );
#endif

#	define NV_LUA_FUN( rtype, fname, fparams ) void_assign( fname, lua_library.get(#fname) );
#	if NV_LUA_VERSION == NV_LUA_52
#		define NV_LUA_FUN_51( rtype, fname, fparams )
#		define NV_LUA_FUN_52 NV_LUA_FUN
#	elif NV_LUA_VERSION == NV_LUA_51
#		define NV_LUA_FUN_51 NV_LUA_FUN
#		define NV_LUA_FUN_52( rtype, fname, fparams ) 
#	else
#		define NV_LUA_FUN_51( rtype, fname, fparams )
#		define NV_LUA_FUN_52( rtype, fname, fparams ) 
#	endif

#	include <nv/lib/detail/lua_functions.inc>

#	undef NV_LUA_FUN
#	undef NV_LUA_FUN_51
#	undef NV_LUA_FUN_52

#if NV_LUA_VERSION == NV_LUA_5C
#	define NV_LUA_LOAD( fname ) void_assign( fname, lua_library.get(#fname) );
#	define NV_LUA_LOAD_AS( fname,fname2 ) void_assign( fname, lua_library.get(#fname2) );
	bool version_52 = lua_library.try_get("luaL_checkversion_") != nullptr;
	if (version_52)
	{
#	define NV_LUA_COMPAT_FUN( u1, fn, u2, u3, fn2, u5, u6, u7 ) \
	void_assign( fn2##_compat, lua_library.get(#fn2) ); \
	fn = call_##fn2##_compat; 
#	include <nv/lib/detail/lua_functions_compat.inc>
#	undef NV_LUA_COMPAT_FUN
		NV_LUA_LOAD( lua_rawlen );
		NV_LUA_LOAD( lua_absindex );
		NV_LUA_LOAD( lua_getglobal );
		NV_LUA_LOAD( lua_setglobal );
		NV_LUA_LOAD( luaL_setmetatable );
		NV_LUA_LOAD( luaL_testudata );
		NV_LUA_LOAD( lua_version );
		NV_LUA_LOAD( lua_copy );
		NV_LUA_LOAD( lua_compare );
		NV_LUA_LOAD( lua_rawgetp );
		NV_LUA_LOAD( lua_rawsetp );
		NV_LUA_LOAD( luaL_setfuncs );
		NV_LUA_LOAD( luaL_getsubtable );
		NV_LUA_LOAD( luaL_requiref );

		lua_pushglobaltable = lua_pushglobaltable_52;

		LUA_UPVALUEINDEX  = LUA_REGISTRYINDEX_52;
		LUA_REGISTRYINDEX = LUA_REGISTRYINDEX_52;
		LUA_VERSION_NUM   = 502;
	}
	else
	{
#	define NV_LUA_COMPAT_FUN( u1, fn, u2, u3, u4, u5, u6, u7 ) \
		void_assign(fn, lua_library.get(#fn) );
#	include <nv/lib/detail/lua_functions_compat.inc>
#	undef NV_LUA_COMPAT_FUN
		NV_LUA_LOAD_AS( lua_rawlen, lua_objlen )
		lua_absindex        = lua_absindex_51;
		lua_getglobal       = lua_getglobal_51;
		lua_setglobal       = lua_setglobal_51;
		luaL_setmetatable   = luaL_setmetatable_51;
		luaL_testudata      = luaL_testudata_51;
		lua_version         = lua_version_51;
		lua_copy            = lua_copy_51;
		lua_rawgetp         = lua_rawgetp_51;
		lua_rawsetp         = lua_rawsetp_51;
		lua_pushglobaltable = lua_pushglobaltable_51;
		luaL_setfuncs       = luaL_setfuncs_51;
		luaL_getsubtable    = luaL_getsubtable_51;
		luaL_requiref       = luaL_requiref_51;

		NV_LUA_LOAD( lua_lessthan );
		NV_LUA_LOAD( lua_equal );
		lua_compare       = lua_compare_51;
		LUA_UPVALUEINDEX  = LUA_GLOBALSINDEX_51;
		LUA_REGISTRYINDEX = LUA_REGISTRYINDEX_51;
		LUA_VERSION_NUM   = 501;
	}
#	undef NV_LUA_LOAD
#endif

	return true;
}

#else

bool nv::load_lua_library( const char* path )
{
	lua_rawlen = lua_objlen;
	lua_absindex = lua_absindex_51;
	lua_getglobal = lua_getglobal_51;
	lua_setglobal = lua_setglobal_51;
	luaL_setmetatable = luaL_setmetatable_51;
	luaL_testudata = luaL_testudata_51;
	lua_version = lua_version_51;
	lua_copy = lua_copy_51;
	lua_rawgetp = lua_rawgetp_51;
	lua_rawsetp = lua_rawsetp_51;
	lua_pushglobaltable = lua_pushglobaltable_51;
	luaL_setfuncs = luaL_setfuncs_51;
	luaL_getsubtable = luaL_getsubtable_51;
	luaL_requiref = luaL_requiref_51;

	NV_LUA_LOAD( lua_lessthan );
	NV_LUA_LOAD( lua_equal );
	lua_compare = lua_compare_51;
	LUA_UPVALUEINDEX = LUA_GLOBALSINDEX_51;
	LUA_REGISTRYINDEX = LUA_REGISTRYINDEX_51;
	LUA_VERSION_NUM = 501;
	return true;
}

#endif