#include "lpx-table.hpp"

// Clear the table.  Removes metatable and all key-value pairs.
int lpx_table_clear(lua_State *L) {
    const int tab = lua_gettop(L);
    luaL_checktype(L, tab, LUA_TTABLE);

    // Clear the metatable.
    lua_pushnil(L);
    lua_setmetatable(L, tab);

    // Clear the elements.
    lua_pushnil(L);
    while (lua_next(L, tab) != 0) {
        lua_pop(L, 1); // Pop the old value.
        lua_pushvalue(L, -1); // Clone the key
        lua_pushnil(L); // Push the new value.
        lua_settable(L, tab);
    }

    // Remove the arguments and return nothing.
    lua_remove(L, tab);
    return 0;
}

int lpx_table_coerce(lua_State *L) {
    if (!lua_istable(L, -1)) {
        lua_pop(L, 1);
        lua_newtable(L);
    }
    return 1;
}

static const struct luaL_Reg lpx_table_lib [] = {
    {"clear", lpx_table_clear},
    {"coerce", lpx_table_coerce},
    {NULL, NULL}  /* sentinel */
};

int luaopen_lpx_table (lua_State *L) {
    luaL_openlib(L, "table", lpx_table_lib, 0);
    return 1;
}