/*
Copyright (c) 2013 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.

Author: Leonardo de Moura
*/
#include "util/lua.h"
#include "util/luaref.h"
#include "util/splay_map.h"

namespace lean {
typedef splay_map<luaref, luaref, luaref_lt_proc> lua_splay_map;
DECL_UDATA(lua_splay_map)

static int mk_lua_splay_map(lua_State * L) {
    lua_splay_map r;
    return push_lua_splay_map(L, r);
}

static int lua_splay_map_size(lua_State * L) {
    lua_pushinteger(L, to_lua_splay_map(L, 1).size());
    return 1;
}

static int lua_splay_map_contains(lua_State * L) {
    lua_pushboolean(L, to_lua_splay_map(L, 1).contains(luaref(L, 2)));
    return 1;
}

static int lua_splay_map_empty(lua_State * L) {
    lua_pushboolean(L, to_lua_splay_map(L, 1).empty());
    return 1;
}

static int lua_splay_map_insert(lua_State * L) {
    to_lua_splay_map(L, 1).insert(luaref(L, 2), luaref(L, 3));
    return 0;
}

static int lua_splay_map_erase(lua_State * L) {
    to_lua_splay_map(L, 1).erase(luaref(L, 2));
    return 0;
}

static int lua_splay_map_find(lua_State * L) {
    lua_splay_map & m = to_lua_splay_map(L, 1);
    luaref const * val = m.find(luaref(L, 2));
    if (val) {
        lean_assert(val->get_state() == L);
        val->push();
    } else {
        lua_pushnil(L);
    }
    return 1;
}

static int lua_splay_map_copy(lua_State * L) {
    return push_lua_splay_map(L, to_lua_splay_map(L, 1));
}

static int lua_splay_map_for_each(lua_State * L) {
    // Remark: we take a copy of the map to make sure
    // for_each will not crash if the map is updated while being
    // traversed.
    // The copy operation is very cheap O(1).
    lua_splay_map m(to_lua_splay_map(L, 1)); // map
    luaL_checktype(L, 2, LUA_TFUNCTION); // user-fun
    m.for_each([&](luaref const & k, luaref const & v) {
        lua_pushvalue(L, 2); // push user-fun
        k.push();
        v.push();
        pcall(L, 2, 0, 0);
        });
    return 0;
}

static const struct luaL_Reg lua_splay_map_m[] = {
    {"__gc",            lua_splay_map_gc}, // never throws
    {"__len",           safe_function<lua_splay_map_size> },
    {"contains",        safe_function<lua_splay_map_contains>},
    {"size",            safe_function<lua_splay_map_size>},
    {"empty",           safe_function<lua_splay_map_empty>},
    {"insert",          safe_function<lua_splay_map_insert>},
    {"erase",           safe_function<lua_splay_map_erase>},
    {"find",            safe_function<lua_splay_map_find>},
    {"copy",            safe_function<lua_splay_map_copy>},
    {"for_each",        safe_function<lua_splay_map_for_each>},
    {0, 0}
};

void open_splay_map(lua_State * L) {
    luaL_newmetatable(L, lua_splay_map_mt);
    lua_pushvalue(L, -1);
    lua_setfield(L, -2, "__index");
    setfuncs(L, lua_splay_map_m, 0);

    SET_GLOBAL_FUN(mk_lua_splay_map,          "splay_map");
    SET_GLOBAL_FUN(lua_splay_map_pred,        "is_splay_map");
}
}