#include <iostream>
#include <lua.hpp>
#include <stdlib.h>                 /* exit() */
#include "ag.h"
using namespace std;

static void usage();
static void report_errors(lua_State * L, int status);
static void register_libraries(lua_State * L);

int main(int argc, char * argv[])
{
    const char * program = NULL;
    for (int i = 1; i < argc; i++)
    {
        if (argv[i][0] != '-')
        {
            if (program == NULL)
            {
                program = argv[i];
            }
            else
            {
                cerr << "Warning: argument " << argv[i] << " ignored!" << endl;
            }
        }
        else
        {
            cerr << "Warning: Unrecognized option '" << argv[i]+1
                 << "'" << endl;
        }
    }

    if (program == NULL)
    {
        usage();
    }

    lua_State * L = lua_open();

    register_libraries(L);

    int s = luaL_loadfile(L, program);

    if ( s == 0 )
    {
        // execute Lua program
        s = lua_pcall(L, 0, LUA_MULTRET, 0);
    }
    else
    {
        cerr << "Warning: problem loading '" << program << "'" << endl;
        return 1;
    }

    report_errors(L, s);
    lua_close(L);

    return 0;
}

static void report_errors(lua_State * L, int status)
{
    if ( status!=0 )
    {
        cerr << "-- " << lua_tostring(L, -1) << endl;
        lua_pop(L, 1); // remove error message
    }
}

static void usage()
{
    cerr << "Usage: anaglym [options] program.lua[c]" << endl;
    exit(42);
}

static void register_libraries(lua_State * L)
{
    /* Load the Lua string library */
    lua_pushcfunction(L, luaopen_string);
    lua_pcall(L, 0, 0, 0);

    /* Load the Lua math library */
    lua_pushcfunction(L, luaopen_math);
    lua_pcall(L, 0, 0, 0);

    /* Load the Lua table library */
    lua_pushcfunction(L, luaopen_table);
    lua_pcall(L, 0, 0, 0);

    ag::register_functions(L);
}