luautil.c

/* luautil.c */

#include <stdlib.h>
#include <stdio.h>

#include <lua.h>
#include <lauxlib.h>
#include <lualib.h>

#include "baize.h"
#include "moon.h"
#include "pile.h"
#include "tableau.h"

#include "luautil.h"

extern lua_State *L;

void OpenLua(struct Baize *const baize)
{
    // nb there isn't a luaL_resetstate() so any globals set in one variant end up in the next
    L = luaL_newstate();
    luaL_openlibs(L);

    MoonRegisterFunctions(L);

    // create a handle to this Baize inside Lua TODO maybe not needed
    lua_pushlightuserdata(L, baize);      lua_setglobal(L, "BAIZE");

    lua_pushinteger(L, FAN_NONE);         lua_setglobal(L, "FAN_NONE");
    lua_pushinteger(L, FAN_DOWN);         lua_setglobal(L, "FAN_DOWN");
    lua_pushinteger(L, FAN_LEFT);         lua_setglobal(L, "FAN_LEFT");
    lua_pushinteger(L, FAN_RIGHT);        lua_setglobal(L, "FAN_RIGHT");
    lua_pushinteger(L, FAN_DOWN3);        lua_setglobal(L, "FAN_DOWN3");
    lua_pushinteger(L, FAN_LEFT3);        lua_setglobal(L, "FAN_LEFT3");
    lua_pushinteger(L, FAN_RIGHT3);       lua_setglobal(L, "FAN_RIGHT3");

    lua_pushinteger(L, MOVE_ANY);         lua_setglobal(L, "MOVE_ANY");
    lua_pushinteger(L, MOVE_ONE);         lua_setglobal(L, "MOVE_ONE");
    lua_pushinteger(L, MOVE_ONE_PLUS);    lua_setglobal(L, "MOVE_ONE_PLUS");
    lua_pushinteger(L, MOVE_ONE_OR_ALL);  lua_setglobal(L, "MOVE_ONE_OR_ALL");

    lua_createtable(L, 0, 0);             lua_setglobal(L, "Cell");
    lua_createtable(L, 0, 0);             lua_setglobal(L, "Discard");
    lua_createtable(L, 0, 0);             lua_setglobal(L, "Foundation");
    lua_createtable(L, 0, 0);             lua_setglobal(L, "Label");
    lua_createtable(L, 0, 0);             lua_setglobal(L, "Reserve");
    lua_createtable(L, 0, 0);             lua_setglobal(L, "Stock");
    lua_createtable(L, 0, 0);             lua_setglobal(L, "Tableau");
    lua_createtable(L, 0, 0);             lua_setglobal(L, "Waste");
}

void CloseLua()
{
    if (L) {
        lua_close(L);
        L = NULL;
    }
}

_Bool LuaUtilGetGlobalBool(const char* var, const _Bool def)
{
    _Bool result = def;
    // fprintf(stderr, "stack %d\n", lua_gettop(L));
    int typ = lua_getglobal(L, var);    // pushes value onto stack
    if ( typ == LUA_TNIL ) {
        // fprintf(stderr, "%s is nil\n", var);
        result = def;
    } else if ( typ != LUA_TBOOLEAN ) {
        fprintf(stderr, "ERROR: %s: %s is not a _Boolean\n", __func__, var);
        result = def;
    } else {
        result = lua_toboolean(L, -1); // does not alter stack
    }
    lua_pop(L, 1); // remove _Boolean from stack
    // fprintf(stderr, "%s=%d\n", var, result);
    // fprintf(stderr, "stack %d\n", lua_gettop(L));
    return result;
}

int LuaUtilGetGlobalInt(const char* var, const int def)
{
    int result = def;
    // fprintf(stderr, "stack %d\n", lua_gettop(L));
    int typ = lua_getglobal(L, var);    // pushes value onto stack
    if ( typ == LUA_TNIL ) {
        // fprintf(stderr, "%s is nil\n", var);
        result = def;
    } else if ( typ != LUA_TNUMBER ) {
        fprintf(stderr, "%s is not a number\n", var);
        result = def;
    } else {
        int isnum;
        result = (int)lua_tointegerx(L, -1, &isnum); // does not alter stack
        if ( !isnum ) {
            fprintf(stderr, "ERROR: %s: %s cannot be converted to an integer\n", __func__, var);
            result = def;
        }
    }
    lua_pop(L, 1); // remove integer from stack
    // fprintf(stderr, "%s=%d\n", var, result);
    // fprintf(stderr, "stack %d\n", lua_gettop(L));
    return result;
}

float LuaUtilGetGlobalFloat(const char* var, const float def)
{
    float result = def;
    // fprintf(stderr, "stack %d\n", lua_gettop(L));
    int typ = lua_getglobal(L, var);    // pushes value onto stack
    if ( typ == LUA_TNIL ) {
        // fprintf(stderr, "%s is nil\n", var);
        result = def;
    } else if ( typ != LUA_TNUMBER ) {
        fprintf(stderr, "%s is not a number\n", var);
        result = def;
    } else {
        int isnum;
        result = (float)lua_tonumberx(L, -1, &isnum); // does not alter stack
        if ( !isnum ) {
            fprintf(stderr, "ERROR: %s: %s cannot be converted to a number\n", __func__, var);
            result = def;
        }
    }
    lua_pop(L, 1); // remove integer from stack
    // fprintf(stderr, "%s=%f\n", var, result);
    // fprintf(stderr, "stack %d\n", lua_gettop(L));
    return result;
}

const char* LuaUtilGetGlobalString(const char* var, const char* def)
{
    const char* result = def;
    // fprintf(stderr, "stack %d\n", lua_gettop(L));
    int typ = lua_getglobal(L, var);    // pushes value onto stack
    if ( typ != LUA_TSTRING ) {
        fprintf(stderr, "%s is not a string\n", var);
        result = def;
    } else {
        result = lua_tostring(L, -1); // does not alter stack
        if ( !result ) {
            fprintf(stderr, "ERROR: %s: %s cannot be converted to a string\n", __func__, var);
            result = def;
        }
    }
    lua_pop(L, 1); // remove integer from stack
    // fprintf(stderr, "%s=%s\n", var, result);
    // fprintf(stderr, "stack %d\n", lua_gettop(L));
    return result;
}

float LuaUtilGetFieldFloat(const char* key, const float def)
{
    // assumes table is on top of stack
    float result = def;
    int isnum;
    int  typ = lua_getfield(L, -1, key);    // pushes onto the stack the value t[k], where t is the value at the given index
    if ( typ == LUA_TNIL ) {
        // fprintf(stderr, "%s is nil\n", key);
        result = def;
    } else if ( typ != LUA_TNUMBER ) {
        fprintf(stderr, "ERROR: %s: %s is not a number\n", __func__, key);
        result = def;
    } else {
        result = (float)lua_tonumberx(L, -1, &isnum);    // returns a lua_Number
        if ( !isnum ) {
            fprintf(stderr, "ERROR: %s: %s cannot be converted to a number\n", __func__, key);
            result = def;
        }
    }
    lua_pop(L, 1);  // remove number
    return result;
}

_Bool LuaUtilSetupTableMethod(const char *table, const char *method)
{
    int typ = lua_getglobal(L, table);
    if (typ != LUA_TTABLE) {
        fprintf(stderr, "INFO: %s: %s is not a table\n", __func__, table);
        lua_pop(L, 1);  // remove table name
        return 0;
    }
    typ = lua_getfield(L, -1, method);
    if (typ != LUA_TFUNCTION) {
        fprintf(stderr, "INFO: %s: %s.%s is not a function\n", __func__, table, method);
        lua_pop(L, 2);  // remove table and method names
        return 0;
    }
    return 1;
}