path: root/src/map/magic-stmt.cpp

#include "magic-interpreter.hpp"
#include "magic-expr.hpp"
#include "magic-expr-eval.hpp"
#include "magic-interpreter-aux.hpp"

#define INVISIBLE_NPC 127       /* used for local spell effects */

//#define DEBUG

#ifdef DEBUG
static void print_val (val_t * v)
{
    switch (v->ty)
    {
        case TY_UNDEF:
            fprintf (stderr, "UNDEF");
            break;
        case TY_INT:
            fprintf (stderr, "%d", v->v.v_int);
            break;
        case TY_DIR:
            fprintf (stderr, "dir%d", v->v.v_int);
            break;
        case TY_STRING:
            fprintf (stderr, "`%s'", v->v.v_string);
            break;
        default:
            fprintf (stderr, "ty%d", v->ty);
            break;
    }
}

static void dump_env (env_t * env)
{
    int  i;
    for (i = 0; i < env->base_env->vars_nr; i++)
    {
        val_t *v = &env->vars[i];
        val_t *bv = &env->base_env->vars[i];

        fprintf (stderr, "%02x %30s ", i, env->base_env->var_name[i]);
        print_val (v);
        fprintf (stderr, "\t(");
        print_val (bv);
        fprintf (stderr, ")\n");
    }
}
#endif

static void clear_activation_record (cont_activation_record_t * ar)
{
    switch (ar->ty)
    {
        case CONT_STACK_FOREACH:
            free (ar->c.c_foreach.entities);
            break;
        case CONT_STACK_PROC:
            free (ar->c.c_proc.old_actuals);
            break;
    }
}

static void
invocation_timer_callback (timer_id UNUSED, tick_t UNUSED, custom_id_t id, custom_data_t data)
{
    invocation_t *invocation = (invocation_t *) map_id2bl (id);

    if (invocation)
    {
        invocation->timer = 0;
        spell_execute (invocation);
    }
}

static void clear_stack (invocation_t * invocation)
{
    int  i;

    for (i = 0; i < invocation->stack_size; i++)
        clear_activation_record (&invocation->stack[i]);

    invocation->stack_size = 0;
}

void spell_free_invocation (invocation_t * invocation)
{
    if (invocation->status_change_refs)
    {
        free (invocation->status_change_refs);
        /* The following cleanup shouldn't be necessary, but I've added it to help tracking a certain bug */
        invocation->status_change_refs = NULL;
        invocation->status_change_refs_nr = 0;
    }

    if (invocation->flags & INVOCATION_FLAG_BOUND)
    {
        entity_t *e = map_id2bl (invocation->subject);
        if (e && e->type == BL_PC)
            spell_unbind ((character_t *) e, invocation);
    }

    clear_stack (invocation);

    if (invocation->timer)
        delete_timer (invocation->timer, invocation_timer_callback);

    magic_free_env (invocation->env);

    map_delblock (&invocation->bl);
    map_delobject (invocation->bl.id, BL_SPELL);    // also frees the object
//        free(invocation);
}

static void
char_set_weapon_icon (character_t * subject, int count, int icon, int look)
{
    const int old_icon = subject->attack_spell_icon_override;

    subject->attack_spell_icon_override = icon;
    subject->attack_spell_look_override = look;

    if (old_icon && old_icon != icon)
        clif_status_change (&subject->bl, old_icon, 0);

    clif_fixpcpos (subject);
    if (count)
    {
        clif_changelook (&subject->bl, LOOK_WEAPON, look);
        if (icon)
            clif_status_change (&subject->bl, icon, 1);
    }
    else
    {
        /* Set it to `normal' */
        clif_changelook (&subject->bl, LOOK_WEAPON, subject->status.weapon);
    }
}

static void char_set_attack_info (character_t * subject, int speed, int range)
{
    subject->attack_spell_delay = speed;
    subject->attack_spell_range = range;

    if (speed == 0)
    {
        pc_calcstatus (subject, 1);
        clif_updatestatus (subject, SP_ASPD);
        clif_updatestatus (subject, SP_ATTACKRANGE);
    }
    else
    {
        subject->aspd = speed;
        clif_updatestatus (subject, SP_ASPD);
        clif_updatestatus (subject, SP_ATTACKRANGE);
    }
}

void magic_stop_completely (character_t * c)
{
    int  i;
    // Zap all status change references to spells
    for (i = 0; i < MAX_STATUSCHANGE; i++)
        c->sc_data[i].spell_invocation = 0;

    while (c->active_spells)
        spell_free_invocation (c->active_spells);

    if (c->attack_spell_override)
    {
        invocation_t *attack_spell =
            (invocation_t *) map_id2bl (c->attack_spell_override);
        if (attack_spell)
            spell_free_invocation (attack_spell);
        c->attack_spell_override = 0;
        char_set_weapon_icon (c, 0, 0, 0);
        char_set_attack_info (c, 0, 0);
    }
}

/* Spell execution has finished normally or we have been notified by a finished skill timer */
static void try_to_finish_invocation (invocation_t * invocation)
{
    if (invocation->status_change_refs_nr == 0 && !invocation->current_effect)
    {
        if (invocation->end_effect)
        {
            clear_stack (invocation);
            invocation->current_effect = invocation->end_effect;
            invocation->end_effect = NULL;
            spell_execute (invocation);
        }
        else
            spell_free_invocation (invocation);
    }
}

static int trigger_spell (int subject, int spell)
{
    invocation_t *invocation = (invocation_t *) map_id2bl (spell);

    if (!invocation)
        return 0;

    invocation = spell_clone_effect (invocation);

    spell_bind ((character_t *) map_id2bl (subject), invocation);
    magic_clear_var (&invocation->env->vars[VAR_CASTER]);
    invocation->env->vars[VAR_CASTER].ty = TY_ENTITY;
    invocation->env->vars[VAR_CASTER].v.v_int = subject;

    return invocation->bl.id;
}

static void entity_warp (entity_t * target, int destm, int destx, int desty);

static void char_update (character_t * character)
{
    entity_warp ((entity_t *) character, character->bl.m, character->bl.x,
                 character->bl.y);
}

static void timer_callback_effect (timer_id UNUSED, tick_t UNUSED, custom_id_t id, custom_data_t data)
{
    entity_t *target = map_id2bl (id);
    if (target)
        clif_misceffect (target, data);
}

static void entity_effect (entity_t * entity, int effect_nr, int delay)
{
    add_timer (gettick () + delay,
               &timer_callback_effect, entity->id, effect_nr);
}

void magic_unshroud (character_t * other_char)
{
    other_char->state.shroud_active = 0;
    // Now warp the caster out of and back into here to refresh everyone's display
    char_update (other_char);
    clif_displaymessage (other_char->fd, "Your shroud has been dispelled!");
//        entity_effect(&other_char->bl, MAGIC_EFFECT_REVEAL);
}

static void
timer_callback_effect_npc_delete (timer_id UNUSED, tick_t odelay,
                                  custom_id_t npc_id, custom_data_t UNUSED)
{
    struct npc_data *effect_npc = (struct npc_data *) map_id2bl (npc_id);
    npc_free (effect_npc);
}

static struct npc_data *local_spell_effect (int m, int x, int y, int effect,
                                            int tdelay)
{
    int  delay = 30000;         /* 1 minute should be enough for all interesting spell effects, I hope */
    struct npc_data *effect_npc = npc_spawn_text (m, x, y,
                                                  INVISIBLE_NPC, "", "?");
    int  effect_npc_id = effect_npc->bl.id;

    entity_effect (&effect_npc->bl, effect, tdelay);
    add_timer (gettick () + delay,
               timer_callback_effect_npc_delete, effect_npc_id, 0);

    return effect_npc;
}

static int op_sfx (env_t * env, int args_nr, val_t * args)
{
    int  delay = ARGINT (2);

    if (TY (0) == TY_ENTITY)
    {
        entity_effect (ARGENTITY (0), ARGINT (1), delay);
    }
    else if (TY (0) == TY_LOCATION)
    {
        local_spell_effect (ARGLOCATION (0).m,
                            ARGLOCATION (0).x,
                            ARGLOCATION (0).y, ARGINT (1), delay);
    }
    else
        return 1;

    return 0;
}

static int op_instaheal (env_t * env, int args_nr, val_t * args)
{
    entity_t *caster = (VAR (VAR_CASTER).ty == TY_ENTITY)
        ? map_id2bl (VAR (VAR_CASTER).v.v_int) : NULL;
    entity_t *subject = ARGENTITY (0);
    if (!caster)
        caster = subject;

    if (caster->type == BL_PC && subject->type == BL_PC)
    {
        character_t *caster_pc = (character_t *) caster;
        character_t *subject_pc = (character_t *) subject;
        MAP_LOG_PC (caster_pc, "SPELLHEAL-INSTA PC%d FOR %d",
                    subject_pc->status.char_id, ARGINT (1));
    }

    battle_heal (caster, subject, ARGINT (1), ARGINT (2), 0);
    return 0;
}

static int op_itemheal (env_t * env, int args_nr, val_t * args)
{
    entity_t *subject = ARGENTITY (0);
    if (subject->type == BL_PC)
    {
        pc_itemheal ((struct map_session_data *) subject,
                     ARGINT (1), ARGINT (2));
    }
    else
        return op_instaheal (env, args_nr, args);

    return 0;
}

#define SHROUD_HIDE_NAME_TALKING_FLAG	(1 << 0)
#define SHROUD_DISAPPEAR_ON_PICKUP_FLAG	(1 << 1)
#define SHROUD_DISAPPEAR_ON_TALK_FLAG	(1 << 2)

#define ARGCHAR(n) (ARGENTITY(n)->type == BL_PC) ? (character_t *)(ARGENTITY(n)) : NULL

static int op_shroud (env_t * env, int args_nr, val_t * args)
{
    character_t *subject = ARGCHAR (0);
    int  arg = ARGINT (1);

    if (!subject)
        return 0;

    subject->state.shroud_active = 1;
    subject->state.shroud_hides_name_talking =
        (arg & SHROUD_HIDE_NAME_TALKING_FLAG) != 0;
    subject->state.shroud_disappears_on_pickup =
        (arg & SHROUD_DISAPPEAR_ON_PICKUP_FLAG) != 0;
    subject->state.shroud_disappears_on_talk =
        (arg & SHROUD_DISAPPEAR_ON_TALK_FLAG) != 0;
    return 0;
}

static int op_reveal (env_t * env, int args_nr, val_t * args)
{
    character_t *subject = ARGCHAR (0);

    if (subject && subject->state.shroud_active)
        magic_unshroud (subject);

    return 0;
}

static int op_message (env_t * env, int args_nr, val_t * args)
{
    character_t *subject = ARGCHAR (0);

    if (subject)
        clif_displaymessage (subject->fd, ARGSTR (1));

    return 0;
}

static void
timer_callback_kill_npc (timer_id UNUSED, tick_t odelay, custom_id_t npc_id,
                         custom_data_t data)
{
    struct npc_data *npc = (struct npc_data *) map_id2bl (npc_id);
    if (npc)
        npc_free (npc);
}

static int op_messenger_npc (env_t * env, int args_nr, val_t * args)
{
    struct npc_data *npc;
    location_t *loc = &ARGLOCATION (0);

    npc = npc_spawn_text (loc->m, loc->x, loc->y,
                          ARGINT (1), ARGSTR (2), ARGSTR (3));

    add_timer (gettick () + ARGINT (4),
               &timer_callback_kill_npc, npc->bl.id, 0);

    return 0;
}

static void entity_warp (entity_t * target, int destm, int destx, int desty)
{
    if (target->type == BL_PC || target->type == BL_MOB)
    {

        switch (target->type)
        {
            case BL_PC:
            {
                character_t *character = (character_t *) target;
                char *map_name;
                clif_clearchar_area (&character->bl, 3);
                map_delblock (&character->bl);
                character->bl.x = destx;
                character->bl.y = desty;
                character->bl.m = destm;

                pc_touch_all_relevant_npcs (character);

                // Note that touching NPCs may have triggered warping and thereby updated x and y:
                map_name = map[character->bl.m].name;

                // Warp part #1: update relevant data, interrupt trading etc.:
                pc_setpos (character, map_name, character->bl.x, character->bl.y, 0);
                // Warp part #2: now notify the client
                clif_changemap (character, map_name,
                                character->bl.x, character->bl.y);
                break;
            }
            case BL_MOB:
                target->x = destx;
                target->y = desty;
                target->m = destm;
                clif_fixmobpos ((struct mob_data *) target);
                break;
        }
    }
}

static int op_move (env_t * env, int args_nr, val_t * args)
{
    entity_t *subject = ARGENTITY (0);
    int  dir = ARGDIR (1);

    int  newx = subject->x + heading_x[dir];
    int  newy = subject->y + heading_y[dir];

    if (!map_is_solid (subject->m, newx, newy))
        entity_warp (subject, subject->m, newx, newy);

    return 0;
}

static int op_warp (env_t * env, int args_nr, val_t * args)
{
    entity_t *subject = ARGENTITY (0);
    location_t *loc = &ARGLOCATION (1);

    entity_warp (subject, loc->m, loc->x, loc->y);

    return 0;
}

static int op_banish (env_t * env, int args_nr, val_t * args)
{
    entity_t *subject = ARGENTITY (0);

    if (subject->type == BL_MOB)
    {
        struct mob_data *mob = (struct mob_data *) subject;

        if (mob->mode & MOB_MODE_SUMMONED)
            mob_catch_delete (mob, 3);
    }

    return 0;
}

static void
record_status_change (invocation_t * invocation, int bl_id, int sc_id)
{
    int  index = invocation->status_change_refs_nr++;
    status_change_ref_t *cr;

    RECREATE (invocation->status_change_refs, status_change_ref_t, invocation->status_change_refs_nr);

    cr = &invocation->status_change_refs[index];

    cr->sc_type = sc_id;
    cr->bl_id = bl_id;
}

static int op_status_change (env_t * env, int args_nr, val_t * args)
{
    entity_t *subject = ARGENTITY (0);
    int  invocation_id = VAR (VAR_INVOCATION).ty == TY_INVOCATION
        ? VAR (VAR_INVOCATION).v.v_int : 0;
    invocation_t *invocation = (invocation_t *) map_id2bl (invocation_id);

    skill_status_effect (subject, ARGINT (1), ARGINT (2), ARGINT (3),
                         ARGINT (4), ARGINT (5), ARGINT (6), 0,
                         invocation_id);

    if (invocation && subject->type == BL_PC)
        record_status_change (invocation, subject->id, ARGINT (1));

    return 0;
}

static int op_stop_status_change (env_t * env, int args_nr, val_t * args)
{
    entity_t *subject = ARGENTITY (0);

    skill_status_change_end (subject, ARGINT (1), -1);

    return 0;
}

static int op_override_attack (env_t * env, int args_nr, val_t * args)
{
    entity_t *psubject = ARGENTITY (0);
    int  charges = ARGINT (1);
    int  attack_delay = ARGINT (2);
    int  attack_range = ARGINT (3);
    int  icon = ARGINT (4);
    int  look = ARGINT (5);
    int  stopattack = ARGINT (6);
    character_t *subject;

    if (psubject->type != BL_PC)
        return 0;

    subject = (character_t *) psubject;

    if (subject->attack_spell_override)
    {
        invocation_t *old_invocation =
            (invocation_t *) map_id2bl (subject->attack_spell_override);
        if (old_invocation)
            spell_free_invocation (old_invocation);
    }

    subject->attack_spell_override =
        trigger_spell (subject->bl.id, VAR (VAR_INVOCATION).v.v_int);
    subject->attack_spell_charges = charges;

    if (subject->attack_spell_override)
    {
        invocation_t *attack_spell =
            (invocation_t *) map_id2bl (subject->attack_spell_override);
        if (attack_spell && stopattack)
            attack_spell->flags |= INVOCATION_FLAG_STOPATTACK;

        char_set_weapon_icon (subject, charges, icon, look);
        char_set_attack_info (subject, attack_delay, attack_range);
    }

    return 0;
}

static int op_create_item (env_t * env, int args_nr, val_t * args)
{
    struct item item;
    entity_t *entity = ARGENTITY (0);
    character_t *subject;
    int  stackable;
    int  count = ARGINT (2);
    if (count <= 0)
        return 0;

    if (entity->type == BL_PC)
        subject = (character_t *) entity;
    else
        return 0;

    GET_ARG_ITEM (1, item, stackable);

    if (!stackable)
        while (count--)
            pc_additem (subject, &item, 1);
    else
        pc_additem (subject, &item, count);

    return 0;
}

#define AGGRAVATION_MODE_ATTACKS_CASTER(n) 	((n) == 0 || (n) == 2)
#define AGGRAVATION_MODE_MAKES_AGGRESSIVE(n)	((n) > 0)

static int op_aggravate (env_t * env, int args_nr, val_t * args)
{
    entity_t *victim = ARGENTITY (2);
    int  mode = ARGINT (1);
    entity_t *target = ARGENTITY (0);
    struct mob_data *other;

    if (target->type == BL_MOB)
        other = (struct mob_data *) target;
    else
        return 0;

    mob_target (other, victim, battle_get_range (victim));

    if (AGGRAVATION_MODE_MAKES_AGGRESSIVE (mode))
        other->mode = 0x85 | (other->mode & MOB_SENSIBLE_MASK); /* war */

    if (AGGRAVATION_MODE_ATTACKS_CASTER (mode))
    {
        other->target_id = victim->id;
        other->attacked_id = victim->id;
    }

    return 0;
}

#define MONSTER_ATTITUDE_HOSTILE	0
#define MONSTER_ATTITUDE_FRIENDLY	1
#define MONSTER_ATTITUDE_SERVANT	2
#define MONSTER_ATTITUDE_FROZEN		3

static int op_spawn (env_t * env, int args_nr, val_t * args)
{
    area_t *area = ARGAREA (0);
    entity_t *owner_e = ARGENTITY (1);
    int  monster_id = ARGINT (2);
    int  monster_attitude = ARGINT (3);
    int  monster_count = ARGINT (4);
    int  monster_lifetime = ARGINT (5);
    int  i;

    character_t *owner = (monster_attitude == MONSTER_ATTITUDE_SERVANT
                          && owner_e->type ==
                          BL_PC) ? (character_t *) owner_e : NULL;

    for (i = 0; i < monster_count; i++)
    {
        location_t loc;
        magic_random_location (&loc, area);

        int  mob_id;
        struct mob_data *mob;

        mob_id = mob_once_spawn (owner, map[loc.m].name, loc.x, loc.y, "--ja--",    // Is that needed?
                                 monster_id, 1, "");

        mob = (struct mob_data *) map_id2bl (mob_id);

        if (mob)
        {
            mob->mode = mob_db[monster_id].mode;

            switch (monster_attitude)
            {

                case MONSTER_ATTITUDE_SERVANT:
                    mob->state.special_mob_ai = 1;
                    mob->mode |= 0x04;
                    break;

                case MONSTER_ATTITUDE_FRIENDLY:
                    mob->mode = 0x80 | (mob->mode & 1);
                    break;

                case MONSTER_ATTITUDE_HOSTILE:
                    mob->mode = 0x84 | (mob->mode & 1);
                    if (owner)
                    {
                        mob->target_id = owner->bl.id;
                        mob->attacked_id = owner->bl.id;
                    }
                    break;

                case MONSTER_ATTITUDE_FROZEN:
                    mob->mode = 0;
                    break;
            }

            mob->mode |=
                MOB_MODE_SUMMONED | MOB_MODE_TURNS_AGAINST_BAD_MASTER;

            mob->deletetimer = add_timer (gettick () + monster_lifetime,
                                          mob_timer_delete, mob_id, 0);

            if (owner)
            {
                mob->master_id = owner->bl.id;
                mob->master_dist = 6;
            }
        }
    }

    return 0;
}

static
const char *get_invocation_name (env_t * env)
{
    invocation_t *invocation;

    if (VAR (VAR_INVOCATION).ty != TY_INVOCATION)
        return "?";
    invocation = (invocation_t *) map_id2bl (VAR (VAR_INVOCATION).v.v_int);

    if (invocation)
        return invocation->spell->name;
    else
        return "??";
}

static int op_injure (env_t * env, int args_nr, val_t * args)
{
    entity_t *caster = ARGENTITY (0);
    entity_t *target = ARGENTITY (1);
    int  damage_caused = ARGINT (2);
    int  mp_damage = ARGINT (3);
    int  target_hp = battle_get_hp (target);
    int  mdef = battle_get_mdef (target);

    if (target->type == BL_PC && !map[target->m].flag.pvp && !((character_t *) target)->special_state.killable && (caster->type != BL_PC || !((character_t *) caster)->special_state.killer))
        return 0;               /* Cannot damage other players outside of pvp */

    if (target != caster)
    {
        /* Not protected against own spells */
        damage_caused = (damage_caused * (100 - mdef)) / 100;
        mp_damage = (mp_damage * (100 - mdef)) / 100;
    }

    damage_caused = (damage_caused > target_hp) ? target_hp : damage_caused;

    if (damage_caused < 0)
        damage_caused = 0;

    // display damage first, because dealing damage may deallocate the target.
    clif_damage (caster, target, gettick (), 0, 0, damage_caused, 0, 0, 0);

    if (caster->type == BL_PC)
    {
        character_t *caster_pc = (character_t *) caster;
        if (target->type == BL_MOB)
        {
            struct mob_data *mob = (struct mob_data *) target;

            MAP_LOG_PC (caster_pc, "SPELLDMG MOB%d %d FOR %d BY %s",
                        mob->bl.id, mob->mob_class, damage_caused,
                        get_invocation_name (env));
        }
    }
    battle_damage (caster, target, damage_caused, mp_damage);

    return 0;
}

static int op_emote (env_t * env, int args_nr, val_t * args)
{
    entity_t *victim = ARGENTITY (0);
    int  emotion = ARGINT (1);
    clif_emotion (victim, emotion);

    return 0;
}

static int op_set_script_variable (env_t * env, int args_nr, val_t * args)
{
    character_t *c = (ETY (0) == BL_PC) ? ARGPC (0) : NULL;

    if (!c)
        return 1;

    pc_setglobalreg (c, ARGSTR (1), ARGINT (2));

    return 0;
}

static int op_set_hair_colour (env_t * env, int args_nr, val_t * args)
{
    character_t *c = (ETY (0) == BL_PC) ? ARGPC (0) : NULL;

    if (!c)
        return 1;

    pc_changelook (c, LOOK_HAIR_COLOR, ARGINT (1));

    return 0;
}

static int op_set_hair_style (env_t * env, int args_nr, val_t * args)
{
    character_t *c = (ETY (0) == BL_PC) ? ARGPC (0) : NULL;

    if (!c)
        return 1;

    pc_changelook (c, LOOK_HAIR, ARGINT (1));

    return 0;
}

static int op_drop_item_for (env_t * env, int args_nr, val_t * args)
{
    struct item item;
    int  stackable;
    location_t *loc = &ARGLOCATION (0);
    int  count = ARGINT (2);
    int  time = ARGINT (3);
    character_t *c = ((args_nr > 4) && (ETY (4) == BL_PC)) ? ARGPC (4) : NULL;
    int  delay = (args_nr > 5) ? ARGINT (5) : 0;
    int  delaytime[3] = { delay, delay, delay };
    character_t *owners[3] = { c, NULL, NULL };

    GET_ARG_ITEM (1, item, stackable);

    if (stackable)
        map_addflooritem_any (&item, count, loc->m, loc->x, loc->y,
                              owners, delaytime, time, 0);
    else
        while (count-- > 0)
            map_addflooritem_any (&item, 1, loc->m, loc->x, loc->y,
                                  owners, delaytime, time, 0);

    return 0;
}

static int op_gain_exp (env_t * env, int args_nr, val_t * args)
{
    character_t *c = (ETY (0) == BL_PC) ? ARGPC (0) : NULL;

    if (!c)
        return 1;

    pc_gainexp_reason (c, ARGINT (1), ARGINT (2), ARGINT (3));
    return 0;
}

static op_t operations[] = {
    {"sfx", ".ii", op_sfx},
    {"instaheal", "eii", op_instaheal},
    {"itemheal", "eii", op_itemheal},
    {"shroud", "ei", op_shroud},
    {"unshroud", "e", op_reveal},
    {"message", "es", op_message},
    {"messenger_npc", "lissi", op_messenger_npc},
    {"move", "ed", op_move},
    {"warp", "el", op_warp},
    {"banish", "e", op_banish},
    {"status_change", "eiiiiii", op_status_change},
    {"stop_status_change", "ei", op_stop_status_change},
    {"override_attack", "eiiiiii", op_override_attack},
    {"create_item", "e.i", op_create_item},
    {"aggravate", "eie", op_aggravate},
    {"spawn", "aeiiii", op_spawn},
    {"injure", "eeii", op_injure},
    {"emote", "ei", op_emote},
    {"set_script_variable", "esi", op_set_script_variable},
    {"set_hair_colour", "ei", op_set_hair_colour},
    {"set_hair_style", "ei", op_set_hair_style},
    {"drop_item", "l.ii", op_drop_item_for},
    {"drop_item_for", "l.iiei", op_drop_item_for},
    {"gain_experience", "eiii", op_gain_exp},
    {NULL, NULL, NULL}
};

static int operations_sorted = 0;
static int operation_count;

static
int compare_operations (const void *lhs, const void *rhs)
{
    return strcmp (((op_t *) lhs)->name, ((op_t *) rhs)->name);
}

op_t *magic_get_op (char *name, int *index)
{
    op_t key;

    if (!operations_sorted)
    {
        op_t *opc = operations;

        while (opc->name)
            ++opc;

        operation_count = opc - operations;

        qsort (operations, operation_count, sizeof (op_t),
               compare_operations);
        operations_sorted = 1;
    }

    key.name = name;
    op_t *op = (op_t *)bsearch (&key, operations, operation_count, sizeof (op_t),
                        compare_operations);

    if (op && index)
        *index = op - operations;

    return op;
}

void
spell_effect_report_termination (int invocation_id, int bl_id, int sc_id,
                                 int supplanted)
{
    int  i;
    int  index = -1;
    invocation_t *invocation = (invocation_t *) map_id2bl (invocation_id);

    if (!invocation || invocation->bl.type != BL_SPELL)
        return;

    for (i = 0; i < invocation->status_change_refs_nr; i++)
    {
        status_change_ref_t *cr = &invocation->status_change_refs[i];
        if (cr->sc_type == sc_id && cr->bl_id == bl_id)
        {
            index = i;
            break;
        }
    }

    if (index == -1)
    {
        entity_t *entity = map_id2bl (bl_id);
        if (entity->type == BL_PC)
            fprintf (stderr,
                     "[magic] INTERNAL ERROR: spell-effect-report-termination:  tried to terminate on unexpected bl %d, sc %d\n",
                     bl_id, sc_id);
        return;
    }

    if (index == invocation->status_change_refs_nr - 1)
        invocation->status_change_refs_nr--;
    else                        /* Copy last change ref to the one we are deleting */
        invocation->status_change_refs[index] =
            invocation->
            status_change_refs[--invocation->status_change_refs_nr];

    try_to_finish_invocation (invocation);
}

static effect_t *return_to_stack (invocation_t * invocation)
{
    if (!invocation->stack_size)
        return NULL;
    else
    {
        cont_activation_record_t *ar =
            invocation->stack + (invocation->stack_size - 1);
        switch (ar->ty)
        {

            case CONT_STACK_PROC:
            {
                effect_t *ret = ar->return_location;
                int  i;

                for (i = 0; i < ar->c.c_proc.args_nr; i++)
                {
                    val_t *var =
                        &invocation->env->vars[ar->c.c_proc.formals[i]];
                    magic_clear_var (var);
                    *var = ar->c.c_proc.old_actuals[i];
                }

                clear_activation_record (ar);
                --invocation->stack_size;

                return ret;
            }

            case CONT_STACK_FOREACH:
            {
                int  entity_id;
                val_t *var = &invocation->env->vars[ar->c.c_foreach.id];

                do
                {
                    if (ar->c.c_foreach.index >= ar->c.c_foreach.entities_nr)
                    {
                        effect_t *ret = ar->return_location;
                        clear_activation_record (ar);
                        --invocation->stack_size;
                        return ret;
                    }

                    entity_id =
                        ar->c.c_foreach.entities[ar->c.c_foreach.index++];
                }
                while (!entity_id || !map_id2bl (entity_id));

                magic_clear_var (var);
                var->ty = ar->c.c_foreach.ty;
                var->v.v_int = entity_id;

                return ar->c.c_foreach.body;
            }

            case CONT_STACK_FOR:
                if (ar->c.c_for.current > ar->c.c_for.stop)
                {
                    effect_t *ret = ar->return_location;
                    clear_activation_record (ar);
                    --invocation->stack_size;
                    return ret;
                }

                magic_clear_var (&invocation->env->vars[ar->c.c_for.id]);
                invocation->env->vars[ar->c.c_for.id].ty = TY_INT;
                invocation->env->vars[ar->c.c_for.id].v.v_int =
                    ar->c.c_for.current++;

                return ar->c.c_for.body;

            default:
                fprintf (stderr,
                         "[magic] INTERNAL ERROR: While executing spell `%s':  stack corruption\n",
                         invocation->spell->name);
                return NULL;
        }
    }
}

static cont_activation_record_t *add_stack_entry (invocation_t * invocation,
                                                  int ty,
                                                  effect_t * return_location)
{
    cont_activation_record_t *ar =
        invocation->stack + invocation->stack_size++;
    if (invocation->stack_size >= MAX_STACK_SIZE)
    {
        fprintf (stderr,
                 "[magic] Execution stack size exceeded in spell `%s'; truncating effect\n",
                 invocation->spell->name);
        invocation->stack_size--;
        return NULL;
    }

    ar->ty = ty;
    ar->return_location = return_location;
    return ar;
}

static
void find_entities_in_area_c (entity_t * target, va_list va)
{
    int *entities_allocd_p = va_arg (va, int *);
    int *entities_nr_p = va_arg (va, int *);
    int **entities_p = va_arg (va, int **);
    int  filter = va_arg (va, int);

/* The following macro adds an entity to the result list: */
#define ADD_ENTITY(e)                                                   \
        if (*entities_nr_p == *entities_allocd_p) {                     \
                /* Need more space */                                   \
                (*entities_allocd_p) += 32;                             \
                RECREATE (*entities_p, int, *entities_allocd_p); \
        }                                                               \
        (*entities_p)[(*entities_nr_p)++] = e;

    switch (target->type)
    {

        case BL_PC:
            if (filter == FOREACH_FILTER_PC
                || filter == FOREACH_FILTER_ENTITY
                || (filter == FOREACH_FILTER_TARGET
                    && map[target->m].flag.pvp))
                break;
            else if (filter == FOREACH_FILTER_SPELL)
            {                   /* Check all spells bound to the caster */
                invocation_t *invoc = ((character_t *) target)->active_spells;
                /* Add all spells locked onto thie PC */

                while (invoc)
                {
                    ADD_ENTITY (invoc->bl.id);
                    invoc = invoc->next_invocation;
                }
            }
            return;

        case BL_MOB:
            if (filter == FOREACH_FILTER_MOB
                || filter == FOREACH_FILTER_ENTITY
                || filter == FOREACH_FILTER_TARGET)
                break;
            else
                return;

        case BL_SPELL:
            if (filter == FOREACH_FILTER_SPELL)
            {
                invocation_t *invocation = (invocation_t *) target;

                /* Check whether the spell is `bound'-- if so, we'll consider it iff we see the caster (case BL_PC). */
                if (invocation->flags & INVOCATION_FLAG_BOUND)
                    return;
                else
                    break;      /* Add the spell */
            }
            else
                return;

        case BL_NPC:
            if (filter == FOREACH_FILTER_NPC)
                break;
            else
                return;

        default:
            return;
    }

    ADD_ENTITY (target->id);
#undef ADD_ENTITY
}

static void
find_entities_in_area (area_t * area, int *entities_allocd_p,
                       int *entities_nr_p, int **entities_p, int filter)
{
    switch (area->ty)
    {
        case AREA_UNION:
            find_entities_in_area (area->a.a_union[0], entities_allocd_p,
                                   entities_nr_p, entities_p, filter);
            find_entities_in_area (area->a.a_union[1], entities_allocd_p,
                                   entities_nr_p, entities_p, filter);
            break;

        default:
        {
            int  m, x, y, width, height;
            magic_area_rect (&m, &x, &y, &width, &height, area);
            map_foreachinarea (find_entities_in_area_c,
                               m, x, y, x + width, y + height,
                               0 /* filter elsewhere */ ,
                               entities_allocd_p, entities_nr_p, entities_p,
                               filter);
        }
    }
}

static effect_t *run_foreach (invocation_t * invocation, effect_t * foreach,
                              effect_t * return_location)
{
    val_t area;
    int  filter = foreach->e.e_foreach.filter;
    int  id = foreach->e.e_foreach.id;
    effect_t *body = foreach->e.e_foreach.body;

    magic_eval (invocation->env, &area, foreach->e.e_foreach.area);

    if (area.ty != TY_AREA)
    {
        magic_clear_var (&area);
        fprintf (stderr,
                 "[magic] Error in spell `%s':  FOREACH loop over non-area\n",
                 invocation->spell->name);
        return return_location;
    }
    else
    {
        cont_activation_record_t *ar =
            add_stack_entry (invocation, CONT_STACK_FOREACH, return_location);
        int  entities_allocd = 64;
        int *entities_collect;
        int *entities;
        int *shuffle_board;
        int  entities_nr = 0;
        int  i;

        if (!ar)
            return return_location;

        CREATE (entities_collect, int, entities_allocd);

        find_entities_in_area (area.v.v_area, &entities_allocd, &entities_nr,
                               &entities_collect, filter);

        /* Now shuffle */
        CREATE (shuffle_board, int, entities_nr);
        CREATE (entities, int, entities_nr);
        for (i = 0; i < entities_nr; i++)
            shuffle_board[i] = i;

        for (i = entities_nr - 1; i >= 0; i--)
        {
            int  random_index = rand () % (i + 1);
            entities[i] = entities_collect[shuffle_board[random_index]];
            shuffle_board[random_index] = shuffle_board[i]; // thus, we are guaranteed only to use unused indices
        }

        free (entities_collect);
        free (shuffle_board);
        /* Done shuffling */

        ar->c.c_foreach.id = id;
        ar->c.c_foreach.body = body;
        ar->c.c_foreach.index = 0;
        ar->c.c_foreach.entities_nr = entities_nr;
        ar->c.c_foreach.entities = entities;
        ar->c.c_foreach.ty =
            (filter == FOREACH_FILTER_SPELL) ? TY_INVOCATION : TY_ENTITY;

        magic_clear_var (&area);

        return return_to_stack (invocation);
    }
}

static effect_t *run_for (invocation_t * invocation, effect_t * for_,
                          effect_t * return_location)
{
    cont_activation_record_t *ar;
    int  id = for_->e.e_for.id;
    val_t start;
    val_t stop;

    magic_eval (invocation->env, &start, for_->e.e_for.start);
    magic_eval (invocation->env, &stop, for_->e.e_for.stop);

    if (start.ty != TY_INT || stop.ty != TY_INT)
    {
        magic_clear_var (&start);
        magic_clear_var (&stop);
        fprintf (stderr,
                 "[magic] Error in spell `%s':  FOR loop start or stop point is not an integer\n",
                 invocation->spell->name);
        return return_location;
    }

    ar = add_stack_entry (invocation, CONT_STACK_FOR, return_location);

    if (!ar)
        return return_location;

    ar->c.c_for.id = id;
    ar->c.c_for.current = start.v.v_int;
    ar->c.c_for.stop = stop.v.v_int;
    ar->c.c_for.body = for_->e.e_for.body;

    return return_to_stack (invocation);
}

static effect_t *run_call (invocation_t * invocation,
                           effect_t * return_location)
{
    effect_t *current = invocation->current_effect;
    cont_activation_record_t *ar;
    int  args_nr = current->e.e_call.args_nr;
    int *formals = current->e.e_call.formals;
    val_t *old_actuals;
    CREATE (old_actuals, val_t, args_nr);
    int  i;

    ar = add_stack_entry (invocation, CONT_STACK_PROC, return_location);
    ar->c.c_proc.args_nr = args_nr;
    ar->c.c_proc.formals = formals;
    ar->c.c_proc.old_actuals = old_actuals;
    for (i = 0; i < args_nr; i++)
    {
        val_t *env_val = &invocation->env->vars[formals[i]];
        val_t result;
        magic_copy_var (&old_actuals[i], env_val);
        magic_eval (invocation->env, &result, current->e.e_call.actuals[i]);
        *env_val = result;
    }

    return current->e.e_call.body;
}

#ifdef DEBUG
static void print_cfg (int i, effect_t * e)
{
    int  j;
    for (j = 0; j < i; j++)
        printf ("    ");

    printf ("%p: ", e);

    if (!e)
    {
        puts (" -- end --");
        return;
    }

    switch (e->ty)
    {
        case EFFECT_SKIP:
            puts ("SKIP");
            break;
        case EFFECT_END:
            puts ("END");
            break;
        case EFFECT_ABORT:
            puts ("ABORT");
            break;
        case EFFECT_ASSIGN:
            puts ("ASSIGN");
            break;
        case EFFECT_FOREACH:
            puts ("FOREACH");
            print_cfg (i + 1, e->e.e_foreach.body);
            break;
        case EFFECT_FOR:
            puts ("FOR");
            print_cfg (i + 1, e->e.e_for.body);
            break;
        case EFFECT_IF:
            puts ("IF");
            for (j = 0; j < i; j++)
                printf ("    ");
            puts ("THEN");
            print_cfg (i + 1, e->e.e_if.true_branch);
            for (j = 0; j < i; j++)
                printf ("    ");
            puts ("ELSE");
            print_cfg (i + 1, e->e.e_if.false_branch);
            break;
        case EFFECT_SLEEP:
            puts ("SLEEP");
            break;
        case EFFECT_SCRIPT:
            puts ("SCRIPT");
            break;
        case EFFECT_BREAK:
            puts ("BREAK");
            break;
        case EFFECT_OP:
            puts ("OP");
            break;
    }
    print_cfg (i, e->next);
}
#endif

/**
 * Execute a spell invocation until we abort, finish, or hit the next `sleep'.
 *
 * Use spell_execute() to automate handling of timers
 *
 * Returns: 0 if finished (all memory is freed implicitly)
 *          >1 if we hit `sleep'; the result is the number of ticks we should sleep for.
 *          -1 if we paused to wait for a user action (via script interaction)
 */
static int spell_run (invocation_t * invocation, int allow_delete)
{
    const int invocation_id = invocation->bl.id;
#define REFRESH_INVOCATION invocation = (invocation_t *) map_id2bl(invocation_id); if (!invocation) return 0;

#ifdef DEBUG
    fprintf (stderr, "Resuming execution:  invocation of `%s'\n",
             invocation->spell->name);
    print_cfg (1, invocation->current_effect);
#endif
    while (invocation->current_effect)
    {
        effect_t *e = invocation->current_effect;
        effect_t *next = e->next;
        int  i;

#ifdef DEBUG
        fprintf (stderr, "Next step of type %d\n", e->ty);
        dump_env (invocation->env);
#endif

        switch (e->ty)
        {
            case EFFECT_SKIP:
                break;

            case EFFECT_ABORT:
                invocation->flags |= INVOCATION_FLAG_ABORTED;
                invocation->end_effect = NULL;
            case EFFECT_END:
                clear_stack (invocation);
                next = NULL;
                break;

            case EFFECT_ASSIGN:
                magic_eval (invocation->env,
                            &invocation->env->vars[e->e.e_assign.id],
                            e->e.e_assign.expr);
                break;

            case EFFECT_FOREACH:
                next = run_foreach (invocation, e, next);
                break;

            case EFFECT_FOR:
                next = run_for (invocation, e, next);
                break;

            case EFFECT_IF:
                if (magic_eval_int (invocation->env, e->e.e_if.cond))
                    next = e->e.e_if.true_branch;
                else
                    next = e->e.e_if.false_branch;
                break;

            case EFFECT_SLEEP:
            {
                int  sleeptime =
                    magic_eval_int (invocation->env, e->e.e_sleep);
                invocation->current_effect = next;
                if (sleeptime > 0)
                    return sleeptime;
                break;
            }

            case EFFECT_SCRIPT:
            {
                character_t *caster =
                    (character_t *) map_id2bl (invocation->caster);
                if (caster)
                {
                    env_t *env = invocation->env;
                    argrec_t arg[] = { {"@target",
                                        VAR (VAR_TARGET).ty ==
                                        TY_ENTITY ? 0 : VAR (VAR_TARGET).
                                        v.v_int}
                    ,
                    {"@caster", invocation->caster}
                    ,
                    {"@caster_name$", caster ? caster->status.name : ""}
                    };
                    int  message_recipient =
                        VAR (VAR_SCRIPTTARGET).ty ==
                        TY_ENTITY ? VAR (VAR_SCRIPTTARGET).
                        v.v_int : invocation->caster;
                    character_t *recipient =
                        (character_t *) map_id2bl (message_recipient);

                    if (recipient->npc_id
                        && recipient->npc_id != invocation->bl.id)
                        break;  /* Don't send multiple message boxes at once */

                    if (!invocation->script_pos)    // first time running this script?
                        clif_spawn_fake_npc_for_player (recipient,
                                                        invocation->bl.id);
                    // We have to do this or otherwise the client won't think that it's
                    // dealing with an NPC

                    int  newpos = run_script_l (e->e.e_script,
                                                invocation->script_pos,
                                                message_recipient,
                                                invocation->bl.id,
                                                3, arg);
                    /* Returns the new script position, or -1 once the script is finished */
                    if (newpos != -1)
                    {
                        /* Must set up for continuation */
                        recipient->npc_id = invocation->bl.id;
                        recipient->npc_pos = invocation->script_pos = newpos;
                        return -1;  /* Signal `wait for script' */
                    }
                    else
                        invocation->script_pos = 0;
                    clif_clearchar_id (invocation->bl.id, 1, caster->fd);
                }
                REFRESH_INVOCATION; // Script may have killed the caster
                break;
            }

            case EFFECT_BREAK:
                next = return_to_stack (invocation);
                break;

            case EFFECT_OP:
            {
                op_t *op = &operations[e->e.e_op.id];
                val_t args[MAX_ARGS];

                for (i = 0; i < e->e.e_op.args_nr; i++)
                    magic_eval (invocation->env, &args[i], e->e.e_op.args[i]);

                if (!magic_signature_check ("effect", op->name, op->signature,
                                            e->e.e_op.args_nr, args,
                                            e->e.e_op.line_nr,
                                            e->e.e_op.column))
                    op->op (invocation->env, e->e.e_op.args_nr, args);

                for (i = 0; i < e->e.e_op.args_nr; i++)
                    magic_clear_var (&args[i]);

                REFRESH_INVOCATION; // Effect may have killed the caster
                break;
            }

            case EFFECT_CALL:
                next = run_call (invocation, next);
                break;

            default:
                fprintf (stderr,
                         "[magic] INTERNAL ERROR: Unknown effect %d\n",
                         e->ty);
        }

        if (!next)
            next = return_to_stack (invocation);

        invocation->current_effect = next;
    }

    if (allow_delete)
        try_to_finish_invocation (invocation);
    return 0;
#undef REFRESH_INVOCATION
}

static
void spell_execute_d (invocation_t * invocation, int allow_deletion)
{
    int  delta;

    spell_update_location (invocation);
    delta = spell_run (invocation, allow_deletion);

    if (delta > 0)
    {
        if (invocation->timer)
        {
            fprintf (stderr,
                     "[magic] FATAL ERROR: Trying to add multiple timers to the same spell! Already had timer: %d\n",
                     invocation->timer);
            /* *((int *)0x0) = 0; */
        }
        invocation->timer = add_timer (gettick () + delta,
                                       &invocation_timer_callback,
                                       invocation->bl.id, 0);
    }

    /* If 0, the script cleaned itself.  If -1 (wait-for-script), we must wait for the user. */
}

void spell_execute (invocation_t * invocation)
{
    spell_execute_d (invocation, 1);
}

void spell_execute_script (invocation_t * invocation)
{
    if (invocation->script_pos)
        spell_execute_d (invocation, 1);
    /* Otherwise the script-within-the-spell has been terminated by some other means.
     * In practice this happens when the script doesn't wait for user input: the client
     * may still notify the server that it's done.  Without the above check, we'd be
     * running the same spell twice! */
}

int spell_attack (int caster_id, int target_id)
{
    character_t *caster = (character_t *) map_id2bl (caster_id);
    invocation_t *invocation;
    int  stop_attack = 0;

    if (!caster)
        return 0;

    invocation = (invocation_t *) map_id2bl (caster->attack_spell_override);

    if (invocation && invocation->flags & INVOCATION_FLAG_STOPATTACK)
        stop_attack = 1;

    if (invocation && caster->attack_spell_charges > 0)
    {
        magic_clear_var (&invocation->env->vars[VAR_TARGET]);
        invocation->env->vars[VAR_TARGET].ty = TY_ENTITY;
        invocation->env->vars[VAR_TARGET].v.v_int = target_id;

        invocation->current_effect = invocation->trigger_effect;
        invocation->flags &= ~INVOCATION_FLAG_ABORTED;
        spell_execute_d (invocation,
                         0 /* don't delete the invocation if done */ );

        // If the caster died, we need to refresh here:
        invocation =
            (invocation_t *) map_id2bl (caster->attack_spell_override);

        if (invocation && !(invocation->flags & INVOCATION_FLAG_ABORTED))   // If we didn't abort:
            caster->attack_spell_charges--;
    }

    if (invocation && caster->attack_spell_override != invocation->bl.id)
    {
        /* Attack spell changed / was refreshed */
        // spell_free_invocation(invocation); // [Fate] This would be a double free.
    }
    else if (!invocation || caster->attack_spell_charges <= 0)
    {
        caster->attack_spell_override = 0;
        char_set_weapon_icon (caster, 0, 0, 0);
        char_set_attack_info (caster, 0, 0);

        if (stop_attack)
            pc_stopattack (caster);

        if (invocation)
            spell_free_invocation (invocation);
    }

    return 1;
}