/*    /lib/magic.c
 *    From Dead Souls LPMud
 *    A module for allowing living beings to cast magic spells.
 *    Created by Descartes of Borg 961027
 *    Version: @(#) magic.c 1.13@(#)
 *    Last modified: 96/11/03
 */

#include <daemons.h>
#include <rounds.h>
#include <magic.h>

private mapping SpellBook = ([]);

// abstract methods
int GetInCombat();
int GetMagicPoints();
string GetName();
int GetParalyzed();
varargs mixed eventPrint(string msg, mixed args...);
int GetSkillLevel(string skill);
int GetStaminaPoints();
void SetAttack(object array e, function f, int type);
// end abstract methods

static varargs void eventCast(object spell, string limb, object array targs);
static void eventTrainSpell(object spell);

mapping GetSpellBook() {
    return copy(SpellBook);
}

void SetSpellBook(mapping book) {
    SpellBook = book;
}

int GetSpellLevel(string spell) {
    return SpellBook[spell];
}

varargs mixed CanCast(object spell) {
    string tmp;

    if( GetParalyzed() ) {
	return "You cannot do anything.";
    }
    if( environment()->GetProperty("no magic") ) {
	return "Supernatural forces prevent your magic.";
    }
    if( !spell ) {
	return "No such spell exists in this reality.";
    }
    if( spell->GetVerb() == "pray" ) {
	tmp = "prayer";
    }
    else {
	tmp = "spell";
    }
    if( !SpellBook[spell->GetSpell()] ) {
	return "You have never heard of that " + tmp + " before.";
    }
    if( GetMagicPoints() < spell->GetRequiredMagic() ) {
	return "You do not have the power required.";
    }
    if( GetStaminaPoints() < spell->GetRequiredStamina() ) {
	return "You are too tired.";
    }
    foreach(string skill in spell->GetSkills()) {
	if( GetSkillLevel(skill) < spell->GetSkillRequired(skill) ) {
	    return "That " + tmp + " is beyond your comprehension.";
	}
    }
    return 1;
}

varargs mixed eventPrepareCast(string verb, mixed array args...) {
    object spell = SPELLS_D->GetSpell(verb = lower_case(verb));
    object array targets, send_to;
    string special, arg;
    mixed tmp;
    int type;

    tmp = spell->eventParse(this_object(), args...);
    if( !arrayp(tmp) ) {
	if( stringp(tmp) ) {
	    eventPrint(tmp);
	}
	else {
	    eventPrint("You are confused.");
	}
	return 1;
    }
    args = tmp;
    targets = spell->GetTargets(this_object(), args...);
    args = filter(args, (: stringp :));
    if( spell->GetAutoHeal() == 0 ) {
	if( !sizeof(args) ) {
	    object array existing = filter(targets, (: $1 :));

	    if( sizeof(existing) != 1 ) {
		error("This spell was poorly constructed.");
	    }
	    arg = existing[0]->GetRandomLimb("torso");
	}
	else {
	    arg = args[0];
	}
    }
    else {
	if( !sizeof(args) ) {
	    arg = 0;
	}
	else {
	    arg = args[0];
	}
    }
    if( spell->GetVerb() == "pray" ) {
	special = "a prayer";
    }
    else {
	special = "an incantation";
    }
    if( targets ) {
	send_to = filter(targets, (: environment($1) == environment() :));
    }
    else {
	send_to = 0;
    }
    send_messages(({ "close", "begin" }),
      "$agent_name $agent_verb $agent_possessive eyes and "
      "$agent_verb uttering " + special + ".", this_object(),
      send_to, environment());
    type = spell->GetSpellType();
    if( GetInCombat() || (type == SPELL_COMBAT) ) {
	if( type == SPELL_COMBAT ) {
	    SetAttack(targets, (: eventCast($(spell), $(arg), $(targets)) :),
	      ROUND_MAGIC);
	}
	else {
	    SetAttack(0, (: eventCast($(spell), $(arg), $(targets)) :),
	      ROUND_MAGIC);
	}
    }
    else {
	eventCast(spell, arg, targets);
    }
    return 1;
}

static varargs void eventCast(object spell, string limb, object array targs) {
    string name = spell->GetSpell();

    if( SpellBook[name] < 100 ) {
	eventTrainSpell(spell);
    }
    if( spell->CanCast(this_object(), SpellBook[name], limb, targs) ) {
	spell->eventCast(this_object(), SpellBook[name], limb, targs);
    }
}

mixed eventLearnSpell(string spell) {
    object magic = SPELLS_D->GetSpell(spell = lower_case(spell));

    foreach(string skill in magic->GetSkills()) {
	if( magic->GetRequiredSkill(skill) > GetSkillLevel(skill) ) {
	    return 0;
	}
    }
    if( !SpellBook[spell] ) {
	SpellBook[spell] = 1;
    }
    return 1;
}

static void eventTrainSpell(object spell) {
    string name = spell->GetSpell();
    int x = SpellBook[name] + 1;

    foreach(string skill in spell->GetSkills() ) {
	if( (5 * GetSkillLevel(skill)) < x ) {
	    return;
	}
    }
    SpellBook[name] = x;
}
