#ifndef OSM2PGSQL_LUA_UTILS_HPP

#define OSM2PGSQL_LUA_UTILS_HPP

/**

* SPDX-License-Identifier: GPL-2.0-or-later

*

* This file is part of osm2pgsql (https://osm2pgsql.org/).

*

* Copyright (C) 2006-2026 by the osm2pgsql developer community.

* For a full list of authors see the git log.

*/

// This file contains helper functions for talking to Lua. It is used from

// the flex output backend. All functions start with "luaX_".

#include <lua.hpp>

#include <cassert>

#include <cstdint>

#include <initializer_list>

#include <string_view>

#include <utility>

void luaX_set_context(lua_State *lua_state, void *ptr) noexcept;

void *luaX_get_context(lua_State *lua_state) noexcept;

void luaX_pushstring(lua_State *lua_state, std::string_view str) noexcept;

void luaX_add_table_str(lua_State *lua_state, char const *key,

char const *value) noexcept;

void luaX_add_table_str(lua_State *lua_state, char const *key,

std::string_view value) noexcept;

void luaX_add_table_int(lua_State *lua_state, char const *key,

int64_t value) noexcept;

void luaX_add_table_num(lua_State *lua_state, char const *key,

double value) noexcept;

void luaX_add_table_bool(lua_State *lua_state, char const *key,

bool value) noexcept;

void luaX_add_table_func(lua_State *lua_state, char const *key,

lua_CFunction func) noexcept;

void luaX_set_up_metatable(

lua_State *lua_state, char const *name, char const *luaclass,

std::initializer_list<std::pair<char const *, lua_CFunction>> map);

template <typename COLLECTION, typename FUNC>

void luaX_add_table_array(lua_State *lua_state, char const *key,

COLLECTION const &collection, FUNC const &func)

{

lua_pushstring(lua_state, key);

lua_createtable(lua_state, (int)collection.size(), 0);

int n = 0;

for (auto const &member : collection) {

lua_pushinteger(lua_state, ++n);

func(member);

lua_rawset(lua_state, -3);

}

lua_rawset(lua_state, -3);

}

char const *luaX_get_table_string(lua_State *lua_state, char const *key,

int table_index, char const *error_msg);

char const *luaX_get_table_string(lua_State *lua_state, char const *key,

int table_index, char const *error_msg,

char const *default_value);

uint32_t luaX_get_table_optional_uint32(lua_State *lua_state, char const *key,

int table_index, char const *error_msg,

uint32_t min, uint32_t max,

char const *range);

uint64_t luaX_get_table_optional_uint64(lua_State *lua_state, char const *key,

int table_index, char const *error_msg,

uint64_t min, uint64_t max,

char const *range);

bool luaX_get_table_bool(lua_State *lua_state, char const *key, int table_index,

char const *error_msg, bool default_value);

int luaX_pcall(lua_State *lua_state, int narg, int nres);

/**

* Returns true if the value on top of the stack is an empty Lua table.

*

* \pre Value on top of the Lua stack must be a Lua table.

* \post Stack is unchanged.

*/

bool luaX_is_empty_table(lua_State *lua_state);

/**

* Check that the value on the top of the Lua stack is a simple array.

* This means that all keys must be consecutive integers starting from 1.

*

* \returns True if this is an array (also for Lua tables without any items)

*

* \pre Value on top of the Lua stack must be a Lua table.

* \post Stack is unchanged.

*/

bool luaX_is_array(lua_State *lua_state);

/**

* Call a function for each item in a Lua array table. The item value will

* be on the top of the stack inside that function.

*

* \pre Value on top of the Lua stack must be a Lua array table.

* \pre The function must leave the Lua stack in the same condition it found

* it in.

* \post Stack is unchanged.

*/

template <typename FUNC>

void luaX_for_each(lua_State *lua_state, FUNC const &func)

{

assert(lua_istable(lua_state, -1));

lua_pushnil(lua_state);

while (lua_next(lua_state, -2) != 0) {

#ifndef NDEBUG

int const top = lua_gettop(lua_state);

#endif

func();

assert(top == lua_gettop(lua_state));

lua_pop(lua_state, 1);

}

}

#endif // OSM2PGSQL_LUA_UTILS_HPP