/* tolua: event functions
** Support code for Lua bindings.
** Written by Waldemar Celes
** TeCGraf/PUC-Rio
** Apr 2003
** $Id: $
*/

/* This code is free software; you can redistribute it and/or modify it.
** The software provided hereunder is on an "as is" basis, and
** the author has no obligation to provide maintenance, support, updates,
** enhancements, or modifications.
*/

#include <stdio.h>

#include "tolua++.h"

/* Store at ubox
    * It stores, creating the corresponding table if needed,
    * the pair key/value in the corresponding ubox table
*/
static void storeatubox (lua_State* L, int lo)
{
#ifdef LUA_VERSION_NUM
    lua_getfenv(L, lo);
    if (lua_rawequal(L, -1, TOLUA_NOPEER)) {
        lua_pop(L, 1);
        lua_newtable(L);
        lua_pushvalue(L, -1);
        lua_setfenv(L, lo);    /* stack: k,v,table  */
    };
    lua_insert(L, -3);
    lua_settable(L, -3); /* on lua 5.1, we trade the "tolua_peers" lookup for a settable call */
    lua_pop(L, 1);
#else
    /* stack: key value (to be stored) */
    lua_pushstring(L,"tolua_peers");
    lua_rawget(L,LUA_REGISTRYINDEX);        /* stack: k v ubox */
    lua_pushvalue(L,lo);
    lua_rawget(L,-2);                       /* stack: k v ubox ubox[u] */
    if (!lua_istable(L,-1))
    {
        lua_pop(L,1);                          /* stack: k v ubox */
        lua_newtable(L);                       /* stack: k v ubox table */
        lua_pushvalue(L,1);
        lua_pushvalue(L,-2);                   /* stack: k v ubox table u table */
        lua_rawset(L,-4);                      /* stack: k v ubox ubox[u]=table */
    }
    lua_insert(L,-4);                       /* put table before k */
    lua_pop(L,1);                           /* pop ubox */
    lua_rawset(L,-3);                       /* store at table */
    lua_pop(L,1);                           /* pop ubox[u] */
#endif
}

/* Module index function
*/
static int module_index_event (lua_State* L)
{
    lua_pushstring(L,".get");
    lua_rawget(L,-3);
    if (lua_istable(L,-1))
    {
        lua_pushvalue(L,2);  /* key */
        lua_rawget(L,-2);
        if (lua_iscfunction(L,-1))
        {
            lua_call(L,0,1);
            return 1;
        }
        else if (lua_istable(L,-1))
            return 1;
    }
    /* call old index meta event */
    if (lua_getmetatable(L,1))
    {
        lua_pushstring(L,"__index");
        lua_rawget(L,-2);
        lua_pushvalue(L,1);
        lua_pushvalue(L,2);
        if (lua_isfunction(L,-1))
        {
            lua_call(L,2,1);
            return 1;
        }
        else if (lua_istable(L,-1))
        {
            lua_gettable(L,-3);
            return 1;
        }
    }
    lua_pushnil(L);
    return 1;
}

/* Module newindex function
*/
static int module_newindex_event (lua_State* L)
{
    lua_pushstring(L,".set");
    lua_rawget(L,-4);
    if (lua_istable(L,-1))
    {
        lua_pushvalue(L,2);  /* key */
        lua_rawget(L,-2);
        if (lua_iscfunction(L,-1))
        {
            lua_pushvalue(L,1); /* only to be compatible with non-static vars */
            lua_pushvalue(L,3); /* value */
            lua_call(L,2,0);
            return 0;
        }
    }
    /* call old newindex meta event */
    if (lua_getmetatable(L,1) && lua_getmetatable(L,-1))
    {
        lua_pushstring(L,"__newindex");
        lua_rawget(L,-2);
        if (lua_isfunction(L,-1))
        {
            lua_pushvalue(L,1);
            lua_pushvalue(L,2);
            lua_pushvalue(L,3);
            lua_call(L,3,0);
        }
    }
    lua_settop(L,3);
    lua_rawset(L,-3);
    return 0;
}

/* Class index function
    * If the object is a userdata (ie, an object), it searches the field in
    * the alternative table stored in the corresponding "ubox" table.
*/
static int class_index_event (lua_State* L)
{
    int t = lua_type(L,1);
    if (t == LUA_TUSERDATA)
    {
        /* Access alternative table */
#ifdef LUA_VERSION_NUM /* new macro on version 5.1 */
        lua_getfenv(L,1);
        if (!lua_rawequal(L, -1, TOLUA_NOPEER)) {
            lua_pushvalue(L, 2); /* key */
            lua_gettable(L, -2); /* on lua 5.1, we trade the "tolua_peers" lookup for a gettable call */
            if (!lua_isnil(L, -1))
                return 1;
        };
#else
        lua_pushstring(L,"tolua_peers");
        lua_rawget(L,LUA_REGISTRYINDEX);        /* stack: obj key ubox */
        lua_pushvalue(L,1);
        lua_rawget(L,-2);                       /* stack: obj key ubox ubox[u] */
        if (lua_istable(L,-1))
        {
            lua_pushvalue(L,2);  /* key */
            lua_rawget(L,-2);                      /* stack: obj key ubox ubox[u] value */
            if (!lua_isnil(L,-1))
                return 1;
        }
#endif
        lua_settop(L,2);                        /* stack: obj key */
        /* Try metatables */
        lua_pushvalue(L,1);                     /* stack: obj key obj */
        while (lua_getmetatable(L,-1))
        {   /* stack: obj key obj mt */
            lua_remove(L,-2);                      /* stack: obj key mt */
            if (lua_isnumber(L,2))                 /* check if key is a numeric value */
            {
                /* try operator[] */
                lua_pushstring(L,".geti");
                lua_rawget(L,-2);                      /* stack: obj key mt func */
                if (lua_isfunction(L,-1))
                {
                    lua_pushvalue(L,1);
                    lua_pushvalue(L,2);
                    lua_call(L,2,1);
                    return 1;
                }
            }
            else
            {
                lua_pushvalue(L,2);                    /* stack: obj key mt key */
                lua_rawget(L,-2);                      /* stack: obj key mt value */
                if (!lua_isnil(L,-1))
                    return 1;
                else
                    lua_pop(L,1);
                /* try C/C++ variable */
                lua_pushstring(L,".get");
                lua_rawget(L,-2);                      /* stack: obj key mt tget */
                if (lua_istable(L,-1))
                {
                    lua_pushvalue(L,2);
                    lua_rawget(L,-2);                      /* stack: obj key mt value */
                    if (lua_iscfunction(L,-1))
                    {
                        lua_pushvalue(L,1);
                        lua_pushvalue(L,2);
                        lua_call(L,2,1);
                        return 1;
                    }
                    else if (lua_istable(L,-1))
                    {
                        /* deal with array: create table to be returned and cache it in ubox */
                        void* u = *((void**)lua_touserdata(L,1));
                        lua_newtable(L);                /* stack: obj key mt value table */
                        lua_pushstring(L,".self");
                        lua_pushlightuserdata(L,u);
                        lua_rawset(L,-3);               /* store usertype in ".self" */
                        lua_insert(L,-2);               /* stack: obj key mt table value */
                        lua_setmetatable(L,-2);         /* set stored value as metatable */
                        lua_pushvalue(L,-1);            /* stack: obj key met table table */
                        lua_pushvalue(L,2);             /* stack: obj key mt table table key */
                        lua_insert(L,-2);               /*  stack: obj key mt table key table */
                        storeatubox(L,1);               /* stack: obj key mt table */
                        return 1;
                    }
                }
            }
            lua_settop(L,3);
        }
        lua_pushnil(L);
        return 1;
    }
    else if (t== LUA_TTABLE)
    {
        module_index_event(L);
        return 1;
    }
    lua_pushnil(L);
    return 1;
}

/* Newindex function
    * It first searches for a C/C++ varaible to be set.
    * Then, it either stores it in the alternative ubox table (in the case it is
    * an object) or in the own table (that represents the class or module).
*/
static int class_newindex_event (lua_State* L)
{
    int t = lua_type(L,1);
    if (t == LUA_TUSERDATA)
    {
        /* Try accessing a C/C++ variable to be set */
        lua_getmetatable(L,1);
        while (lua_istable(L,-1))                /* stack: t k v mt */
        {
            if (lua_isnumber(L,2))                 /* check if key is a numeric value */
            {
                /* try operator[] */
                lua_pushstring(L,".seti");
                lua_rawget(L,-2);                      /* stack: obj key mt func */
                if (lua_isfunction(L,-1))
                {
                    lua_pushvalue(L,1);
                    lua_pushvalue(L,2);
                    lua_pushvalue(L,3);
                    lua_call(L,3,0);
                    return 0;
                }
            }
            else
            {
                lua_pushstring(L,".set");
                lua_rawget(L,-2);                      /* stack: t k v mt tset */
                if (lua_istable(L,-1))
                {
                    lua_pushvalue(L,2);
                    lua_rawget(L,-2);                     /* stack: t k v mt tset func */
                    if (lua_iscfunction(L,-1))
                    {
                        lua_pushvalue(L,1);
                        lua_pushvalue(L,3);
                        lua_call(L,2,0);
                        return 0;
                    }
                    lua_pop(L,1);                          /* stack: t k v mt tset */
                }
                lua_pop(L,1);                           /* stack: t k v mt */
                if (!lua_getmetatable(L,-1))            /* stack: t k v mt mt */
                    lua_pushnil(L);
                lua_remove(L,-2);                       /* stack: t k v mt */
            }
        }
        lua_settop(L,3);                          /* stack: t k v */

        /* then, store as a new field */
        storeatubox(L,1);
    }
    else if (t== LUA_TTABLE)
    {
        module_newindex_event(L);
    }
    return 0;
}

static int class_call_event(lua_State* L) {

    if (lua_istable(L, 1)) {
        lua_pushstring(L, ".call");
        lua_rawget(L, 1);
        if (lua_isfunction(L, -1)) {

            lua_insert(L, 1);
            lua_call(L, lua_gettop(L)-1, 1);

            return 1;
        };
    };
    tolua_error(L,"Attempt to call a non-callable object.",NULL);
    return 0;
};

static int do_operator (lua_State* L, const char* op)
{
    if (lua_isuserdata(L,1))
    {
        /* Try metatables */
        lua_pushvalue(L,1);                     /* stack: op1 op2 */
        while (lua_getmetatable(L,-1))
        {   /* stack: op1 op2 op1 mt */
            lua_remove(L,-2);                      /* stack: op1 op2 mt */
            lua_pushstring(L,op);                  /* stack: op1 op2 mt key */
            lua_rawget(L,-2);                      /* stack: obj key mt func */
            if (lua_isfunction(L,-1))
            {
                lua_pushvalue(L,1);
                lua_pushvalue(L,2);
                lua_call(L,2,1);
                return 1;
            }
            lua_settop(L,3);
        }
    }
    tolua_error(L,"Attempt to perform operation on an invalid operand",NULL);
    return 0;
}

static int class_add_event (lua_State* L)
{
    return do_operator(L,".add");
}

static int class_sub_event (lua_State* L)
{
    return do_operator(L,".sub");
}

static int class_mul_event (lua_State* L)
{
    return do_operator(L,".mul");
}

static int class_div_event (lua_State* L)
{
    return do_operator(L,".div");
}

static int class_lt_event (lua_State* L)
{
    return do_operator(L,".lt");
}

static int class_le_event (lua_State* L)
{
    return do_operator(L,".le");
}

static int class_eq_event (lua_State* L)
{
    /* copying code from do_operator here to return false when no operator is found */
    if (lua_isuserdata(L,1))
    {
        /* Try metatables */
        lua_pushvalue(L,1);                     /* stack: op1 op2 */
        while (lua_getmetatable(L,-1))
        {   /* stack: op1 op2 op1 mt */
            lua_remove(L,-2);                      /* stack: op1 op2 mt */
            lua_pushstring(L,".eq");                  /* stack: op1 op2 mt key */
            lua_rawget(L,-2);                      /* stack: obj key mt func */
            if (lua_isfunction(L,-1))
            {
                lua_pushvalue(L,1);
                lua_pushvalue(L,2);
                lua_call(L,2,1);
                return 1;
            }
            lua_settop(L,3);
        }
    }

    lua_settop(L, 3);
    lua_pushboolean(L, 0);
    return 1;
}

/*
static int class_gc_event (lua_State* L)
{
    void* u = *((void**)lua_touserdata(L,1));
    fprintf(stderr, "collecting: looking at %p\n", u);
    lua_pushstring(L,"tolua_gc");
    lua_rawget(L,LUA_REGISTRYINDEX);
    lua_pushlightuserdata(L,u);
    lua_rawget(L,-2);
    if (lua_isfunction(L,-1))
    {
        lua_pushvalue(L,1);
        lua_call(L,1,0);
         lua_pushlightuserdata(L,u);
        lua_pushnil(L);
        lua_rawset(L,-3);
    }
    lua_pop(L,2);
    return 0;
}
*/
TOLUA_API int class_gc_event (lua_State* L)
{
    void* u = *((void**)lua_touserdata(L,1));
    int top;
    /*fprintf(stderr, "collecting: looking at %p\n", u);*/
    /*
    lua_pushstring(L,"tolua_gc");
    lua_rawget(L,LUA_REGISTRYINDEX);
    */
    lua_pushvalue(L, lua_upvalueindex(1));
    lua_pushlightuserdata(L,u);
    lua_rawget(L,-2);            /* stack: gc umt    */
    lua_getmetatable(L,1);       /* stack: gc umt mt */
    /*fprintf(stderr, "checking type\n");*/
    top = lua_gettop(L);
    if (tolua_fast_isa(L,top,top-1, lua_upvalueindex(2))) /* make sure we collect correct type */
    {
        /*fprintf(stderr, "Found type!\n");*/
        /* get gc function */
        lua_pushliteral(L,".collector");
        lua_rawget(L,-2);           /* stack: gc umt mt collector */
        if (lua_isfunction(L,-1)) {
            /*fprintf(stderr, "Found .collector!\n");*/
        }
        else {
            lua_pop(L,1);
            /*fprintf(stderr, "Using default cleanup\n");*/
            lua_pushcfunction(L,tolua_default_collect);
        }

        lua_pushvalue(L,1);         /* stack: gc umt mt collector u */
        lua_call(L,1,0);

        lua_pushlightuserdata(L,u); /* stack: gc umt mt u */
        lua_pushnil(L);             /* stack: gc umt mt u nil */
        lua_rawset(L,-5);           /* stack: gc umt mt */
    }
    lua_pop(L,3);
    return 0;
}


/* Register module events
    * It expects the metatable on the top of the stack
*/
TOLUA_API void tolua_moduleevents (lua_State* L)
{
    lua_pushstring(L,"__index");
    lua_pushcfunction(L,module_index_event);
    lua_rawset(L,-3);
    lua_pushstring(L,"__newindex");
    lua_pushcfunction(L,module_newindex_event);
    lua_rawset(L,-3);
}

/* Check if the object on the top has a module metatable
*/
TOLUA_API int tolua_ismodulemetatable (lua_State* L)
{
    int r = 0;
    if (lua_getmetatable(L,-1))
    {
        lua_pushstring(L,"__index");
        lua_rawget(L,-2);
        r = (lua_tocfunction(L,-1) == module_index_event);
        lua_pop(L,2);
    }
    return r;
}

/* Register class events
    * It expects the metatable on the top of the stack
*/
TOLUA_API void tolua_classevents (lua_State* L)
{
    lua_pushstring(L,"__index");
    lua_pushcfunction(L,class_index_event);
    lua_rawset(L,-3);
    lua_pushstring(L,"__newindex");
    lua_pushcfunction(L,class_newindex_event);
    lua_rawset(L,-3);

    lua_pushstring(L,"__add");
    lua_pushcfunction(L,class_add_event);
    lua_rawset(L,-3);
    lua_pushstring(L,"__sub");
    lua_pushcfunction(L,class_sub_event);
    lua_rawset(L,-3);
    lua_pushstring(L,"__mul");
    lua_pushcfunction(L,class_mul_event);
    lua_rawset(L,-3);
    lua_pushstring(L,"__div");
    lua_pushcfunction(L,class_div_event);
    lua_rawset(L,-3);

    lua_pushstring(L,"__lt");
    lua_pushcfunction(L,class_lt_event);
    lua_rawset(L,-3);
    lua_pushstring(L,"__le");
    lua_pushcfunction(L,class_le_event);
    lua_rawset(L,-3);
    lua_pushstring(L,"__eq");
    lua_pushcfunction(L,class_eq_event);
    lua_rawset(L,-3);

    lua_pushstring(L,"__call");
    lua_pushcfunction(L,class_call_event);
    lua_rawset(L,-3);

    lua_pushstring(L,"__gc");
    lua_pushstring(L, "tolua_gc_event");
    lua_rawget(L, LUA_REGISTRYINDEX);
    /*lua_pushcfunction(L,class_gc_event);*/
    lua_rawset(L,-3);
}

