disease.c

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/*
 * static char *rcsid_disease_c =
 *   "$Id: disease.c 11578 2009-02-23 22:02:27Z lalo $";
 */
/*
    CrossFire, A Multiplayer game for X-windows

    Copyright (C) 2006 Mark Wedel & Crossfire Development Team
    Copyright (C) 1992 Frank Tore Johansen

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

    The authors can be reached via e-mail to crossfire-devel@real-time.com
*/

/*
 * For DISEASES:
 * Stat            Property        Definition
 *
 * attacktype      Attack effects  Attacktype of the disease. usu. AT_GODPOWER.
 * other_arch      Creation        object created and dropped when symptom moved.
 * title           Message         When the "disease" "infects" something, it will
 *                                 print "title victim!!!" to the player who owns
 *                                 the "disease".
 * wc+             Infectiousness  How well the plague spreads person-to-person
 * magic+          Range           range of infection
 * Stats*          Disability      What stats are reduced by the disease (str con...)
 * maxhp+          Persistence     How long the disease can last OUTSIDE the host.
 *  * value           TimeLeft        Counter for persistence
 * dam^            Damage          How much damage it does (%?).
 * maxgrace+       Duration        How long before the disease is naturally cured.
 * food            DurCount        Counter for Duration
 *
 * speed           Speed           How often the disease moves.
 * last_sp^        Lethargy        Percentage of max speed--10 = 10% speed.
 *
 * maxsp^          Mana deplete    Saps mana.
 * ac^             Progressiveness How the diseases increases in severity.
 * last_eat*^      Deplete food    saps food if negative
 * last_heal       GrantImmunity   If nonzero, disease does NOT grant immunity
 *                                 when it runs out
 *
 * exp             experience      experience awarded when plague cured
 * hp*^            ReduceRegen     reduces regeneration of disease-bearer
 * sp*^            ReduceSpRegen   reduces spellpoint regeneration
 *
 * name            Name            Name of the plague
 * msg             message         What the plague says when it strikes.
 * race            those affected  species/race the plague strikes (* = everything)
 * level           Plague Level    General description of the plague's deadliness
 * armour          Attenuation     reduction in wc per generation of disease.
 *                                 This builds in a self-limiting factor.
 *
 *
 * Explanations:
 * * means this # should be negative to cause adverse effect.
 * + means that this effect is modulated in spells by ldur
 * ^ means that this effect is modulated in spells by ldam
 *
 * attacktype is the attacktype used by the disease to smite "dam" damage with.
 *
 * wc/127 is the chance of someone in range catching it.
 *
 * magic is the range at which infection may occur.  If negative, the range is
 * NOT level dependent.
 *
 * Stats are stat modifications.  These should typically be negative.
 *
 * maxhp is how long the disease will persist if the host dies and "drops" it,
 *       in "disease moves", i.e., moves of the disease.  If negative, permanent.
 *
 * value is the counter for maxhp, it starts at maxhp and drops...
 *
 * dam     if positive, it is straight damage.  if negative, a %-age.
 *
 * maxgrace  how long in "disease moves" the disease lasts in the host, if negative,
 *           permanent until cured.
 *
 * food    if negative, disease is permanent.  otherwise, decreases at <speed>,
 *         disease goes away at food=0, set to "maxgrace" on infection.
 *
 * speed is the speed of the disease, how fast "disease moves" occur.
 *
 * last_sp is the lethargy imposed on the player by the disease.  A lethargy
 *        of "1" reduces the players speed to 1% of its normal value.
 *
 * maxsp how much mana is sapped per "disease move".  if negative, a %-age is
 *      taken.
 *
 * ac  every "disease move" the severity of the symptoms are increased by
 *     ac/100.  (severity = 1 + (accumlated_progression)/100)
 *
 * last_eat  increases food usage if negative.
 *
 *
 *
 * For SYMPTOMS:
 *
 * Stats            modify stats
 * hp               modify regen
 * value            progression counter (multiplier = value/100)
 * food             modify food use (from last_eat in DISEASE)
 * maxsp            suck mana ( as noted for DISEASE)
 * last_sp          Lethargy
 * msg              What to say
 * speed            speed of movement, from DISEASE
 */

#include <global.h>
#include <object.h>
#include <living.h>
#ifndef __CEXTRACT__
#include <sproto.h>
#endif
#include <spells.h>
#include <sounds.h>
#include <skills.h>
#include <assert.h>

static void remove_symptoms(object *disease);
static object *find_symptom(object *disease);
static void check_infection(object *disease);
static void do_symptoms(object *disease);
static void grant_immunity(object *disease);



/*  IMPLEMENTATION NOTES

Diseases may be contageous.  They are objects which exist in a player's
inventory.  They themselves do nothing, except modify Symptoms, or
spread to other live objects.  Symptoms are what actually damage the player:
these are their own object. */

static int is_susceptible_to_disease(object *victim, object *disease) {
    /* Non living and DMs are immune. */
    if (!QUERY_FLAG(victim, FLAG_ALIVE) || QUERY_FLAG(victim, FLAG_WIZ))
        return 0;

    if (strstr(disease->race, "*") && !QUERY_FLAG(victim, FLAG_UNDEAD))
        return 1;

    if ((disease->race == undead_name) && QUERY_FLAG(victim, FLAG_UNDEAD))
        return 1;

    if ((victim->race && strstr(disease->race, victim->race))
    || strstr(disease->race, victim->name))
        return 1;

    return 0;
}

int move_disease(object *disease) {
    /*  first task is to determine if the disease is inside or outside of someone.
     * If outside, we decrement 'value' until we're gone.
     */

    /* DMs don't infect, and don't suffer either. */
    if (disease->env && QUERY_FLAG(disease->env, FLAG_WIZ))
        return 0;

    if (disease->env == NULL) { /* we're outside of someone */
        if (disease->stats.maxhp > 0)
            disease->value--;
        if (disease->value == 0) {
            remove_ob(disease);
            free_object(disease);
            return 1;
        }
    } else {
        /* if we're inside a person, have the disease run its course */
        /* negative foods denote "perpetual" diseases. */
        if (disease->stats.food > 0) {
            disease->stats.food--;
            if (disease->stats.food == 0) {
                remove_symptoms(disease);  /* remove the symptoms of this disease */
                grant_immunity(disease);
                remove_ob(disease);
                free_object(disease);
                return 1;
            }
        }
    }
    /*  check to see if we infect others */
    check_infection(disease);

    /* impose or modify the symptoms of the disease */
    if (disease->env && is_susceptible_to_disease(disease->env, disease))
        do_symptoms(disease);

    return 0;
}

static void remove_symptoms(object *disease) {
    object *symptom, *victim = NULL;

    assert(disease != NULL);

    while ((symptom = find_symptom(disease)) != NULL) {
        if (!victim)
            victim = symptom->env;
        remove_ob(symptom);
        free_object(symptom);
    }
    if (victim)
        fix_object(victim);
}

static object *find_symptom(object *disease) {
    object *walk;

    assert(disease->env != NULL);

    /* check the inventory for symptoms */
    for (walk = disease->env->inv; walk; walk = walk->below)
        if (!strcmp(walk->name, disease->name) && walk->type == SYMPTOM)
            return walk;
    return NULL;
}

static void check_infection(object *disease) {
    int x, y, range, mflags;
    mapstruct *map, *map2;
    object *tmp;
    sint16 i, j, i2, j2;

    range = abs(disease->magic);
    if (disease->env) {
        x = disease->env->x;
        y = disease->env->y;
        map = disease->env->map;
    } else {
        x = disease->x;
        y = disease->y;
        map = disease->map;
    }

    if (map == NULL)
        return;
    for (i = x-range; i <= x+range; i++) {
        for (j = y-range; j <= y+range; j++) {
            mflags = get_map_flags(map, &map2, i, j, &i2, &j2);
            if (!(mflags&P_OUT_OF_MAP) && (mflags&P_IS_ALIVE)) {
                for (tmp = GET_MAP_OB(map2, i2, j2); tmp; tmp = tmp->above) {
                    infect_object(tmp, disease, 0);
                }
            }
        }
    }
    return;
}

int infect_object(object *victim, object *disease, int force) {
    object *tmp;
    object *new_disease;

    /* don't infect inanimate objects */
    if (!QUERY_FLAG(victim, FLAG_MONSTER) && !(victim->type == PLAYER))
        return 0;

    /* check and see if victim can catch disease:  diseases
     *  are specific
     */
    if (!is_susceptible_to_disease(victim, disease))
        return 0;

    /* If disease is on battleground, only infect other victims on battleground.
       Not checking results in spectators being infected, which could lead to PK. */
    if ((disease->map && op_on_battleground(disease, NULL, NULL, NULL))
    || (disease->env && op_on_battleground(disease->env, NULL, NULL, NULL)))
        if (!op_on_battleground(victim, NULL, NULL, NULL))
            return 0;

    /* roll the dice on infection before doing the inventory check!  */
    if (!force && (random_roll(0, 126, victim, PREFER_HIGH) >= disease->stats.wc))
        return 0;

    /* do an immunity check */
    if (victim->head)
        tmp = victim->head->inv;
    else
        tmp = victim->inv;

    /* There used to (IMO) be a flaw in the below - it used to be the case
     * that if level check was done for both immunity and disease. This could
     * result in a person with multiple afflictions of the same disease
     * (eg, level 1 cold, level 2 cold, level 3 cold, etc), as long as
     * they were cast in that same order.  Instead, change it so that
     * if you diseased, you can't get diseased more.
     */

    for (/* tmp initialized in if, above */; tmp; tmp = tmp->below) {
        if (tmp->type == SIGN && !strcmp(tmp->name, disease->name) && tmp->level >= disease->level)
            return 0;  /*Immune! */
        else if (tmp->type == DISEASE && !strcmp(tmp->name, disease->name))
            return 0; /* already diseased */
    }

    /*  If we've gotten this far, go ahead and infect the victim.  */
    new_disease = get_object();
    copy_object(disease, new_disease);
    new_disease->stats.food = disease->stats.maxgrace;
    new_disease->value = disease->stats.maxhp;
    new_disease->stats.wc -= disease->last_grace;  /* self-limiting factor */

    /* Unfortunately, set_owner does the wrong thing to the skills pointers
     *  resulting in exp going into the owners *current *chosen skill.
     */

    if (get_owner(disease)) {
        set_owner(new_disease, disease->owner);

        /* Only need to update skill if different */
        if (new_disease->skill != disease->skill) {
            if (new_disease->skill)
                free_string(new_disease->skill);
            if (disease->skill)
                new_disease->skill = add_refcount(disease->skill);
        }
    } else { /* for diseases which are passed by hitting, set owner and praying skill*/
        if (disease->env && disease->env->type == PLAYER) {
            object *player = disease->env;

            set_owner(new_disease, player);
            /* the skill pointer for these diseases should already be set up -
             * hardcoding in 'praying' is not the right approach.
             */
        }
    }

    insert_ob_in_ob(new_disease, victim);
    /* This appears to be a horrible case of overloading 'NO_PASS'
     * for meaning in the diseases.
     */
    new_disease->move_block = 0;
    if (new_disease->owner && new_disease->owner->type == PLAYER) {
        char buf[128];

        /* if the disease has a title, it has a special infection message
         * This messages is printed in the form MESSAGE victim
         */
        if (new_disease->title)
            snprintf(buf, sizeof(buf), "%s %s!!", disease->title, victim->name);
        else
            snprintf(buf, sizeof(buf), "You infect %s with your disease, %s!", victim->name, new_disease->name);

        if (victim->type == PLAYER)
            draw_ext_info(NDI_UNIQUE|NDI_RED, 0, new_disease->owner, MSG_TYPE_ATTACK, MSG_TYPE_ATTACK_DID_HIT,
                          buf, buf);
        else
            draw_ext_info(0, 4, new_disease->owner, MSG_TYPE_ATTACK, MSG_TYPE_ATTACK_DID_HIT,
                          buf, buf);
    }
    if (victim->type == PLAYER)
        draw_ext_info(NDI_UNIQUE|NDI_RED, 0, victim, MSG_TYPE_ATTRIBUTE, MSG_TYPE_ATTRIBUTE_BAD_EFFECT_START,
                      "You suddenly feel ill.", NULL);

    return 1;
}

static void do_symptoms(object *disease) {
    object *symptom;
    object *victim;
    object *tmp;
    victim = disease->env;

    /* This is a quick hack - for whatever reason, disease->env will point
     * back to disease, causing endless loops.  Why this happens really needs
     * to be found, but this should at least prevent the infinite loops.
     */

    if (victim == NULL || victim == disease)
        return;/* no-one to inflict symptoms on */

    /* DMs don't suffer from diseases. */
    if (QUERY_FLAG(victim, FLAG_WIZ))
        return;

    symptom = find_symptom(disease);
    if (symptom == NULL) {
        /* no symptom?  need to generate one! */
        object *new_symptom;

        /* first check and see if the carrier of the disease is immune.  If so, no symptoms!  */
        if (!is_susceptible_to_disease(victim, disease))
            return;

        /* check for an actual immunity */
        /* do an immunity check */
        if (victim->head)
            tmp = victim->head->inv;
        else
            tmp = victim->inv;

        for (/* tmp initialized in if, above */; tmp; tmp = tmp->below) {
            if (tmp->type == SIGN) /* possibly an immunity, or diseased*/
                if (!strcmp(tmp->name, disease->name) && tmp->level >= disease->level)
                    return;  /*Immune! */
        }

        new_symptom = create_archetype(ARCH_SYMPTOM);

        /* Something special done with dam.  We want diseases to be more
         * random in what they'll kill, so we'll make the damage they
         * do random, note, this has a weird effect with progressive diseases.
         */
        if (disease->stats.dam != 0) {
            int dam = disease->stats.dam;

            /* reduce the damage, on average, 50%, and making things random. */

            dam = random_roll(1, FABS(dam), victim, PREFER_LOW);
            if (disease->stats.dam < 0)
                dam = -dam;
            new_symptom->stats.dam = dam;
        }

        new_symptom->stats.maxsp = disease->stats.maxsp;
        new_symptom->stats.food = new_symptom->stats.maxgrace;

        FREE_AND_COPY(new_symptom->name, disease->name);
        FREE_AND_COPY(new_symptom->name_pl, disease->name);
        new_symptom->level = disease->level;
        new_symptom->speed = disease->speed;
        new_symptom->value = 0;
        new_symptom->stats.Str = disease->stats.Str;
        new_symptom->stats.Dex = disease->stats.Dex;
        new_symptom->stats.Con = disease->stats.Con;
        new_symptom->stats.Wis = disease->stats.Wis;
        new_symptom->stats.Int = disease->stats.Int;
        new_symptom->stats.Pow = disease->stats.Pow;
        new_symptom->stats.Cha = disease->stats.Cha;
        new_symptom->stats.sp  = disease->stats.sp;
        new_symptom->stats.food = disease->last_eat;
        new_symptom->stats.maxsp = disease->stats.maxsp;
        new_symptom->last_sp = disease->last_sp;
        new_symptom->stats.exp = 0;
        new_symptom->stats.hp = disease->stats.hp;
        new_symptom->msg = add_string(disease->msg);
        new_symptom->attacktype = disease->attacktype;
        new_symptom->other_arch = disease->other_arch;

        set_owner(new_symptom, disease->owner);
        if (new_symptom->skill != disease->skill) {
            if (new_symptom->skill)
                free_string(new_symptom->skill);
            if (disease->skill)
                new_symptom->skill = add_refcount(disease->skill);
        }
        new_symptom->move_block = 0;
        insert_ob_in_ob(new_symptom, victim);
        return;
    }

    /* now deal with progressing diseases:  we increase the debility
     * caused by the symptoms.
     */

    if (disease->stats.ac != 0) {
        float scale;

        symptom->value += disease->stats.ac;
        scale = 1.0+symptom->value/100.0;
        /* now rescale all the debilities */
        symptom->stats.Str = (int)(scale*disease->stats.Str);
        symptom->stats.Dex = (int)(scale*disease->stats.Dex);
        symptom->stats.Con = (int)(scale*disease->stats.Con);
        symptom->stats.Wis = (int)(scale*disease->stats.Wis);
        symptom->stats.Int = (int)(scale*disease->stats.Int);
        symptom->stats.Pow = (int)(scale*disease->stats.Pow);
        symptom->stats.Cha = (int)(scale*disease->stats.Cha);
        symptom->stats.dam = (int)(scale*disease->stats.dam);
        symptom->stats.sp = (int)(scale*disease->stats.sp);
        symptom->stats.food = (int)(scale*disease->last_eat);
        symptom->stats.maxsp = (int)(scale*disease->stats.maxsp);
        symptom->last_sp = (int)(scale*disease->last_sp);
        symptom->stats.exp = 0;
        symptom->stats.hp = (int)(scale*disease->stats.hp);
        symptom->msg = add_string(disease->msg);
        symptom->attacktype = disease->attacktype;
        symptom->other_arch = disease->other_arch;
    }
    SET_FLAG(symptom, FLAG_APPLIED);
    fix_object(victim);
}

static void grant_immunity(object *disease) {
    object *immunity;
    object *walk;

    /* Don't give immunity to this disease if last_heal is set. */
    if (disease->last_heal)
        return;

    assert(disease->env != NULL);

    /*  first, search for an immunity of the same name */
    for (walk = disease->env->inv; walk; walk = walk->below) {
        if (walk->type == SIGN && !strcmp(disease->name, walk->name)) {
            walk->level = disease->level;
            return; /* just update the existing immunity. */
        }
    }
    immunity = create_archetype("immunity");
    immunity->name = add_string(disease->name);
    immunity->level = disease->level;
    immunity->move_block = 0;
    insert_ob_in_ob(immunity, disease->env);
    return;
}

void move_symptom(object *symptom) {
    object *victim = symptom->env;
    object *new_ob;
    int sp_reduce;
    tag_t tag = symptom->count;

    if (victim == NULL || victim->map == NULL) { /* outside a monster/player, die immediately */
        remove_ob(symptom);
        free_object(symptom);
        return;
    }

    if (symptom->stats.dam > 0)
        hit_player(victim, symptom->stats.dam, symptom, symptom->attacktype, 1);
    else
        hit_player(victim, MAX(1, -victim->stats.maxhp*symptom->stats.dam/100.0), symptom, symptom->attacktype, 1);

    /* In most cases, if the victim has been freed, the logic that
     * does that will also free the symptom, so check for that.
     */
    if (QUERY_FLAG(victim, FLAG_FREED)) {
        if (!was_destroyed(symptom, tag)) {
            remove_ob(symptom);
            free_object(symptom);
        }
        return;
    }

    if (symptom->stats.maxsp > 0)
        sp_reduce = symptom->stats.maxsp;
    else
        sp_reduce = MAX(1, victim->stats.maxsp*symptom->stats.maxsp/100.0);
    victim->stats.sp = MAX(0, victim->stats.sp-sp_reduce);

    /* create the symptom "other arch" object and drop it here
     * under every part of the monster
     * The victim may well have died.
     */

    if (symptom->other_arch) {
        object *tmp;

        tmp = victim;
        if (tmp->head != NULL)
            tmp = tmp->head;
        for (/*tmp initialized above */; tmp != NULL; tmp = tmp->more) {
            char name[MAX_BUF];

            new_ob = arch_to_object(symptom->other_arch);
            snprintf(name, sizeof(name), "%s's %s", victim->name, new_ob->name);
            FREE_AND_COPY(new_ob->name, name);
            if (new_ob->name_pl != NULL) {
                snprintf(name, sizeof(name), "%s's %s", victim->name, new_ob->name_pl);
                FREE_AND_COPY(new_ob->name_pl, name);
            }
            new_ob->x = tmp->x;
            new_ob->y = tmp->y;
            new_ob->map = victim->map;
            insert_ob_in_map(new_ob, victim->map, victim, 0);
        }
    }
    if (!symptom->msg) {
        LOG(llevError, "BUG: move_symptom(): symptom %d (%s) without message!\n", symptom->count, symptom->name);
        return;
    }
    draw_ext_info(NDI_UNIQUE|NDI_RED, 0, victim, MSG_TYPE_ATTRIBUTE, MSG_TYPE_ATTRIBUTE_BAD_EFFECT_START,
                  symptom->msg, symptom->msg);
    return;
}

void check_physically_infect(object *victim, object *hitter) {
    object *walk;

    /* search for diseases, give every disease a chance to infect */
    for (walk = hitter->inv; walk != NULL; walk = walk->below)
        if (walk->type == DISEASE)
            infect_object(victim, walk, 0);
}

int cure_disease(object *sufferer, object *caster) {
    object *disease, *next;
    int casting_level;
    int cure = 0;

    if (caster)
        casting_level = caster->level;
    else
        casting_level = 1000;  /* if null caster, CURE all.  */

    for (disease = sufferer->inv; disease; disease = next) {
        next = disease->below;

        if (disease->type == DISEASE && !QUERY_FLAG(disease, FLAG_STARTEQUIP)) {
             /* attempt to cure this disease. God-given diseases are given by the god, so don't remove them */
            /* If caster lvel is higher than disease level, cure chance
             * is automatic.  If lower, then the chance is basically
             * 1 in level_diff - if there is a 5 level difference, chance
             * is 1 in 5.
             */
            if ((casting_level >= disease->level)
            || (!(random_roll(0, (disease->level-casting_level-1), caster, PREFER_LOW)))) {
                remove_symptoms(disease);
                remove_ob(disease);
                cure = 1;
                if (caster)
                    change_exp(caster, disease->stats.exp, caster->chosen_skill ? caster->chosen_skill->skill : NULL, 0);
                free_object(disease);
            }
        }
    }
    if (cure) {
        /* Only draw these messages once */
        if (caster)
            draw_ext_info_format(NDI_UNIQUE, 0, caster, MSG_TYPE_SPELL, MSG_TYPE_SPELL_HEAL,
                                 "You cure a disease!", NULL);

        draw_ext_info(NDI_UNIQUE, 0, sufferer, MSG_TYPE_ATTRIBUTE, MSG_TYPE_ATTRIBUTE_BAD_EFFECT_END,
                      "You no longer feel diseased.", NULL);
    }
    return cure;
}