#include <stdlib.h>

#include <errno.h>

#include <windows.h>

#include <lua.h>

#include <lualib.h>

#include <lauxlib.h>

#include "_whelk.h"

#define WHELK_KEYHANDLE		"HKEY"

#define whelk_checkkeyptr(L,n)	((HKEY *)luaL_checkudata(L,n,WHELK_KEYHANDLE))

static HKEY whelk_checkkey(lua_State *L,int n)

{

    HKEY *key=whelk_checkkeyptr(L,n);

    if (*key==INVALID_HANDLE_VALUE)

	luaL_error(L,"attempt to use a closed WIN32 registry key");

    return *key;

}

static HKEY *newkey(lua_State *L)

{

    HKEY *key=(HKEY *)lua_newuserdata(L,sizeof(HKEY));

    *key=INVALID_HANDLE_VALUE;

    luaL_getmetatable(L,WHELK_KEYHANDLE);

    lua_setmetatable(L,-2);

    return key;

}

static int get_value(lua_State *L)

{

    DWORD type,nb;

    HRESULT result;

    int retval=1;

    void *data;

    HKEY key=whelk_checkkey(L,1);

    const char *subkey=luaL_checkstring(L,2);

    const char *value=luaL_checkstring(L,3);

    result=whelk_reg_get_value(key,subkey,value,&type,&data,&nb);

    if (result!=ERROR_SUCCESS)

    {

	lua_pushnil(L);

	lua_pushfstring(L,"%s: Failed to get value",value);

	lua_pushinteger(L,result);

	retval=3;

    }

    else

	switch(type)

	{

	    case REG_SZ:

	    case REG_EXPAND_SZ:

		lua_pushstring(L,(char *)data);

		break;

	    case REG_DWORD:

		lua_pushnumber(L,*(DWORD *)data);

		break;

	    default:

		lua_pushnil(L);

		lua_pushfstring(L,"%s: Data is not a string or number",value);

		lua_pushinteger(L,ERROR_INVALID_PARAMETER);

		retval=3;

	}

    free(data);

    return retval;

}

static int set_value(lua_State *L)

{

    DWORD type;

    int nb;

    HRESULT result;

    lua_Number number;

    DWORD d;

    const void *data;

    HKEY key=whelk_checkkey(L,1);

    const char *subkey=luaL_checkstring(L,2);

    const char *value=luaL_checkstring(L,3);

    switch(lua_type(L,4))

    {

	case LUA_TSTRING:

	    data=lua_tostring(L,4);

	    type=REG_SZ;

	    nb=-1;

	    break;

	case LUA_TNUMBER:

	    number=lua_tonumber(L,4);

	    d=(DWORD)number;

	    if ((lua_Number)d!=number)

	    {

		lua_pushnil(L);

		lua_pushfstring(L,"%s: Data is not storable as DWORD",value);

		lua_pushinteger(L,ERROR_INVALID_PARAMETER);

	    }

	    data=&d;

	    type=REG_DWORD;

	    nb=sizeof(d);

	    break;

	case LUA_TNIL:

	    data=NULL;

	    type=REG_NONE;

	    nb=0;

	    break;

	default:

	    lua_pushnil(L);

	    lua_pushfstring(L,"%s: Data is not a string or number",value);

	    lua_pushinteger(L,ERROR_INVALID_PARAMETER);

	    return 3;

    }

    result=whelk_reg_set_value(key,subkey,value,type,data,nb);

    if (result!=ERROR_SUCCESS)

    {

	lua_pushnil(L);

	lua_pushfstring(L,"%s: Failed to set value",value);

	lua_pushinteger(L,result);

	return 3;

    }

    return 1;

}

static int delete_key(lua_State *L)

{

    HRESULT result;

    HKEY key=whelk_checkkey(L,1);

    const char *subkey=luaL_checkstring(L,2);

    result=whelk_reg_delete_key(key,subkey);

    if (result!=ERROR_SUCCESS)

    {

	lua_pushnil(L);

	lua_pushfstring(L,"%s: Failed to delete key",subkey);

	lua_pushinteger(L,result);

	return 3;

    }

    return 1;

}

static int reg_gc(lua_State *L)

{

    HKEY key=*whelk_checkkeyptr(L,1);

    if (key!=INVALID_HANDLE_VALUE)

	(void)whelk_reg_close_key(key);

    return 0;

}

static const luaL_Reg reg_methods[]={

    { "GetValue",get_value },

    { "SetValue",set_value },

    { "DeleteKey",delete_key },

    { "__gc",reg_gc },

    { NULL }

};

static void create_predefined_key(lua_State *L,HKEY key,const char *name)

{

    *newkey(L)=key;

    lua_setfield(L,-3,name);

}

void whelk_open_reg_keys(lua_State *L)

{

    luaL_newmetatable(L,WHELK_KEYHANDLE);

    lua_pushvalue(L,-1);

    lua_setfield(L,-2,"__index");

    luaL_register(L,NULL,reg_methods);

    create_predefined_key(L,HKEY_CLASSES_ROOT,"KEY_CLASSES_ROOT");

    create_predefined_key(L,HKEY_CURRENT_CONFIG,"KEY_CURRENT_CONFIG");

    create_predefined_key(L,HKEY_CURRENT_USER,"KEY_CURRENT_USER");

    create_predefined_key(L,HKEY_LOCAL_MACHINE,"KEY_LOCAL_MACHINE");

    create_predefined_key(L,HKEY_USERS,"KEY_USERS");

}