/*    /lib/events/listen.c
 *    From the Dead Souls Object Library
 *    Handles responses to the listen verb
 *    Created by Descartes of Borg 951008
 *    Version: @(#) listen.c 1.8@(#)
 *    Last modified: 96/12/31
 */

#include <function.h>

static private mixed   Listen  = 0;
static private mapping Listens = ([]);

// abstract methods
string GetShort();
// end abstract methods

varargs string GetListen(string str, object who){
    mixed val;

    if( !str || str == "default" ){
        val = Listen;
    }
    else {
        val = Listens[str];
    }
    if( !val ){
        return 0;
    }
    if( functionp(val) ){
        if( functionp(val) & FP_OWNER_DESTED ){
            return "An error occured in a function pointer.";
        }
        return evaluate(val, who, str);
    }
    else if( arrayp(val) ){
        return val[query_night()];
    }
    else return val;
}

string array GetListens(){
    return keys(Listens);
}

mapping RemoveListen(string item){
    if( !item || item == "default" ){
        Listen = 0;
    }
    else {
        map_delete(Listens, item);
    }
    return Listens;
}

varargs mixed SetListen(mixed array args...){
    if( sizeof(args) == 1 ){
        if( mapp(args[0]) ){
            if( args[0]["default"] ){
                Listen = args[0]["default"];
                map_delete(args[0], "default");
            }
            return (Listens = expand_keys(args[0]));
        }
        else {
            Listen = args[0];
        }
        return args[0];
    }
    else if( sizeof(args) == 2 ){
        if( !args[1] ){
            return SetListen(args[0]);
        }
        else if( arrayp(args[0]) ){
            foreach(string item in args[0]){
                SetListen(item, args[1]);
            }
            return args[1];
        }
        else {
            if( !args[0] || args[0] == "default" ){
                Listen = args[1];
                return Listen;
            }
            else {
                Listens[args[0]] = args[1];
                return Listens[args[0]];
            }
        }
    }
    else {
        error("Wrong number of arguments to SetListen():\n\t"
          "Expected 1 or 2, got " + sizeof(args) + "\n");
    }
}

varargs mixed eventListen(object who, string str){
    str = GetListen(str, who);
    if( !str ){
        who->eventPrint("You hear nothing unusual.");
        return 1;
    }
    environment(who)->eventPrint(who->GetName() + " listens to " + GetShort() +
      ".", who);
    who->eventPrint(str);
    return 1;
}

mixed direct_listen_obj(){
    if( !Listen ){
        return "You hear nothing unusual.";
    }
    else {
        return 1;
    }
}

mixed direct_listen_to_obj(){
    return direct_listen_obj();
}

mixed direct_listen_to_str_word_obj(string str){
    str = remove_article(lower_case(str));
    if( !Listens[str] ){
        return "You hear nothing special.";
    }
    else {
        return 1;
    }
}

mapping GetListenMap(){
    mapping Listens = ([]);
    foreach(object ob in this_object()->GetDummyItems()){
        if( ob->GetListen() ){
            Listens[ob->GetId()] = ob->GetListen();
        }
    }
    if(this_object()->GetListen()) Listens["default"] = this_object()->GetListen();
    return copy(Listens);
}