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

#include "magic-expr.hpp"
//    magic-expr.cpp - Pure functions for the old magic backend.
//
//    Copyright © 2004-2011 The Mana World Development Team
//    Copyright © 2011-2014 Ben Longbons <b.r.longbons@gmail.com>
//
//    This file is part of The Mana World (Athena server)
//
//    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 3 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, see <http://www.gnu.org/licenses/>.

#include <cassert>

#include <algorithm>

#include "../strings/mstring.hpp"
#include "../strings/astring.hpp"
#include "../strings/zstring.hpp"
#include "../strings/vstring.hpp"
#include "../strings/literal.hpp"

#include "../generic/dumb_ptr.hpp"
#include "../generic/random.hpp"

#include "../io/cxxstdio.hpp"
#include "../io/cxxstdio_enums.hpp"

#include "battle.hpp"
#include "itemdb.hpp"
#include "magic-expr-eval.hpp"
#include "magic-interpreter.hpp"
#include "magic-interpreter-base.hpp"
#include "npc.hpp"
#include "pc.hpp"

#include "../poison.hpp"


namespace tmwa
{
template<class T>
bool CHECK_TYPE(T *v, TYPE t)
{
    return v->ty == t;
}

static
void free_area(dumb_ptr<area_t> area)
{
    if (!area)
        return;

    switch (area->ty)
    {
        case AREA::UNION:
            free_area(area->a.a_union[0]);
            free_area(area->a.a_union[1]);
            break;
        default:
            break;
    }

    area.delete_();
}

static
dumb_ptr<area_t> dup_area(dumb_ptr<area_t> area)
{
    dumb_ptr<area_t> retval = dumb_ptr<area_t>::make();
    *retval = *area;

    switch (area->ty)
    {
        case AREA::UNION:
            retval->a.a_union[0] = dup_area(retval->a.a_union[0]);
            retval->a.a_union[1] = dup_area(retval->a.a_union[1]);
            break;
        default:
            break;
    }

    return retval;
}

void magic_copy_var(val_t *dest, val_t *src)
{
    *dest = *src;

    switch (dest->ty)
    {
        case TYPE::STRING:
            dest->v.v_string = dest->v.v_string.dup();
            break;
        case TYPE::AREA:
            dest->v.v_area = dup_area(dest->v.v_area);
            break;
        default:
            break;
    }

}

void magic_clear_var(val_t *v)
{
    switch (v->ty)
    {
        case TYPE::STRING:
            v->v.v_string.delete_();
            break;
        case TYPE::AREA:
            free_area(v->v.v_area);
            break;
        default:
            break;
    }
}

static
AString show_entity(dumb_ptr<block_list> entity)
{
    switch (entity->bl_type)
    {
        case BL::PC:
            return entity->is_player()->status_key.name.to__actual();
        case BL::NPC:
            return entity->is_npc()->name;
        case BL::MOB:
            return entity->is_mob()->name;
        case BL::ITEM:
            assert (0 && "There is no way this code did what it was supposed to do!"_s);
            /* Sorry about this one... */
            // WTF? item_data is a Item, not a struct item_data
            // return ((struct item_data *) (&entity->is_item()->item_data))->name;
            abort();
        case BL::SPELL:
            return "%invocation(ERROR:this-should-not-be-an-entity)"_s;
        default:
            return "%unknown-entity"_s;
    }
}

static
void stringify(val_t *v, int within_op)
{
    static earray<LString, DIR, DIR::COUNT> dirs //=
    {{
        "south"_s, "south-west"_s,
        "west"_s, "north-west"_s,
        "north"_s, "north-east"_s,
        "east"_s, "south-east"_s,
    }};
    AString buf;

    switch (v->ty)
    {
        case TYPE::UNDEF:
            buf = "UNDEF"_s;
            break;

        case TYPE::INT:
            buf = STRPRINTF("%i"_fmt, v->v.v_int);
            break;

        case TYPE::STRING:
            return;

        case TYPE::DIR:
            buf = dirs[v->v.v_dir];
            break;

        case TYPE::ENTITY:
            buf = show_entity(v->v.v_entity);
            break;

        case TYPE::LOCATION:
            buf = STRPRINTF("<\"%s\", %d, %d>"_fmt,
                    v->v.v_location.m->name_,
                    v->v.v_location.x,
                    v->v.v_location.y);
            break;

        case TYPE::AREA:
            buf = "%area"_s;
            free_area(v->v.v_area);
            break;

        case TYPE::SPELL:
            buf = v->v.v_spell->name;
            break;

        case TYPE::INVOCATION:
        {
            dumb_ptr<invocation> invocation_ = within_op
                ? v->v.v_invocation
                : map_id2bl(wrap<BlockId>(static_cast<uint32_t>(v->v.v_int)))->is_spell();
            buf = invocation_->spell->name;
        }
            break;

        default:
            FPRINTF(stderr, "[magic] INTERNAL ERROR: Cannot stringify %d\n"_fmt,
                    v->ty);
            return;
    }

    v->v.v_string = dumb_string::copys(buf);
    v->ty = TYPE::STRING;
}

static
void intify(val_t *v)
{
    if (v->ty == TYPE::INT)
        return;

    magic_clear_var(v);
    v->ty = TYPE::INT;
    v->v.v_int = 1;
}

static
dumb_ptr<area_t> area_new(AREA ty)
{
    auto retval = dumb_ptr<area_t>::make();
    retval->ty = ty;
    return retval;
}

static
dumb_ptr<area_t> area_union(dumb_ptr<area_t> area, dumb_ptr<area_t> other_area)
{
    dumb_ptr<area_t> retval = area_new(AREA::UNION);
    retval->a.a_union[0] = area;
    retval->a.a_union[1] = other_area;
    retval->size = area->size + other_area->size;   /* Assume no overlap */
    return retval;
}

/**
 * Turns location into area, leaves other types untouched
 */
static
void make_area(val_t *v)
{
    if (v->ty == TYPE::LOCATION)
    {
        auto a = dumb_ptr<area_t>::make();
        v->ty = TYPE::AREA;
        a->ty = AREA::LOCATION;
        a->a.a_loc = v->v.v_location;
        v->v.v_area = a;
    }
}

static
void make_location(val_t *v)
{
    if (v->ty == TYPE::AREA && v->v.v_area->ty == AREA::LOCATION)
    {
        location_t location = v->v.v_area->a.a_loc;
        free_area(v->v.v_area);
        v->ty = TYPE::LOCATION;
        v->v.v_location = location;
    }
}

static
void make_spell(val_t *v)
{
    if (v->ty == TYPE::INVOCATION)
    {
        dumb_ptr<invocation> invoc = v->v.v_invocation;
        //invoc = (dumb_ptr<invocation>) map_id2bl(v->v.v_int);
        if (!invoc)
            v->ty = TYPE::FAIL;
        else
        {
            v->ty = TYPE::SPELL;
            v->v.v_spell = invoc->spell;
        }
    }
}

static
int fun_add(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    if (ARG_TYPE(0) == TYPE::INT && ARG_TYPE(1) == TYPE::INT)
    {
        /* Integer addition */
        RESULTINT = ARGINT(0) + ARGINT(1);
        result->ty = TYPE::INT;
    }
    else if (ARG_MAY_BE_AREA(0) && ARG_MAY_BE_AREA(1))
    {
        /* Area union */
        make_area(&args[0]);
        make_area(&args[1]);
        RESULTAREA = area_union(ARGAREA(0), ARGAREA(1));
        ARGAREA(0) = nullptr;
        ARGAREA(1) = nullptr;
        result->ty = TYPE::AREA;
    }
    else
    {
        /* Anything else -> string concatenation */
        stringify(&args[0], 1);
        stringify(&args[1], 1);
        /* Yes, we could speed this up. */
        // ugh
        MString m;
        m += ARGSTR(0);
        m += ARGSTR(1);
        RESULTSTR = dumb_string::copys(AString(m));
        result->ty = TYPE::STRING;
    }
    return 0;
}

static
int fun_sub(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = ARGINT(0) - ARGINT(1);
    return 0;
}

static
int fun_mul(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = ARGINT(0) * ARGINT(1);
    return 0;
}

static
int fun_div(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    if (!ARGINT(1))
        return 1;               /* division by zero */
    RESULTINT = ARGINT(0) / ARGINT(1);
    return 0;
}

static
int fun_mod(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    if (!ARGINT(1))
        return 1;               /* division by zero */
    RESULTINT = ARGINT(0) % ARGINT(1);
    return 0;
}

static
int fun_or(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = ARGINT(0) || ARGINT(1);
    return 0;
}

static
int fun_and(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = ARGINT(0) && ARGINT(1);
    return 0;
}

static
int fun_not(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = !ARGINT(0);
    return 0;
}

static
int fun_neg(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = ~ARGINT(0);
    return 0;
}

static
int fun_gte(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    if (ARG_TYPE(0) == TYPE::STRING || ARG_TYPE(1) == TYPE::STRING)
    {
        stringify(&args[0], 1);
        stringify(&args[1], 1);
        RESULTINT = ARGSTR(0) >= ARGSTR(1);
    }
    else
    {
        intify(&args[0]);
        intify(&args[1]);
        RESULTINT = ARGINT(0) >= ARGINT(1);
    }
    return 0;
}

static
int fun_lt(dumb_ptr<env_t> env, val_t *result, Slice<val_t> args)
{
    fun_gte(env, result, args);
    RESULTINT = !RESULTINT;
    return 0;
}

static
int fun_gt(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    if (ARG_TYPE(0) == TYPE::STRING || ARG_TYPE(1) == TYPE::STRING)
    {
        stringify(&args[0], 1);
        stringify(&args[1], 1);
        RESULTINT = ARGSTR(0) > ARGSTR(1);
    }
    else
    {
        intify(&args[0]);
        intify(&args[1]);
        RESULTINT = ARGINT(0) > ARGINT(1);
    }
    return 0;
}

static
int fun_lte(dumb_ptr<env_t> env, val_t *result, Slice<val_t> args)
{
    fun_gt(env, result, args);
    RESULTINT = !RESULTINT;
    return 0;
}

static
int fun_eq(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    if (ARG_TYPE(0) == TYPE::STRING || ARG_TYPE(1) == TYPE::STRING)
    {
        stringify(&args[0], 1);
        stringify(&args[1], 1);
        RESULTINT = ARGSTR(0) == ARGSTR(1);
    }
    else if (ARG_TYPE(0) == TYPE::DIR && ARG_TYPE(1) == TYPE::DIR)
        RESULTINT = ARGDIR(0) == ARGDIR(1);
    else if (ARG_TYPE(0) == TYPE::ENTITY && ARG_TYPE(1) == TYPE::ENTITY)
        RESULTINT = ARGENTITY(0) == ARGENTITY(1);
    else if (ARG_TYPE(0) == TYPE::LOCATION && ARG_TYPE(1) == TYPE::LOCATION)
        RESULTINT = (ARGLOCATION(0).x == ARGLOCATION(1).x
                     && ARGLOCATION(0).y == ARGLOCATION(1).y
                     && ARGLOCATION(0).m == ARGLOCATION(1).m);
    else if (ARG_TYPE(0) == TYPE::AREA && ARG_TYPE(1) == TYPE::AREA)
        RESULTINT = ARGAREA(0) == ARGAREA(1); /* Probably not that great an idea... */
    else if (ARG_TYPE(0) == TYPE::SPELL && ARG_TYPE(1) == TYPE::SPELL)
        RESULTINT = ARGSPELL(0) == ARGSPELL(1);
    else if (ARG_TYPE(0) == TYPE::INVOCATION && ARG_TYPE(1) == TYPE::INVOCATION)
        RESULTINT = ARGINVOCATION(0) == ARGINVOCATION(1);
    else
    {
        intify(&args[0]);
        intify(&args[1]);
        RESULTINT = ARGINT(0) == ARGINT(1);
    }
    return 0;
}

static
int fun_ne(dumb_ptr<env_t> env, val_t *result, Slice<val_t> args)
{
    fun_eq(env, result, args);
    RESULTINT = !RESULTINT;
    return 0;
}

static
int fun_bitand(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = ARGINT(0) & ARGINT(1);
    return 0;
}

static
int fun_bitor(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = ARGINT(0) | ARGINT(1);
    return 0;
}

static
int fun_bitxor(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = ARGINT(0) ^ ARGINT(1);
    return 0;
}

static
int fun_bitshl(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = ARGINT(0) << ARGINT(1);
    return 0;
}

static
int fun_bitshr(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = ARGINT(0) >> ARGINT(1);
    return 0;
}

static
int fun_max(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = std::max(ARGINT(0), ARGINT(1));
    return 0;
}

static
int fun_min(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = std::min(ARGINT(0), ARGINT(1));
    return 0;
}

static
int fun_if_then_else(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    if (ARGINT(0))
        magic_copy_var(result, &args[1]);
    else
        magic_copy_var(result, &args[2]);
    return 0;
}

void magic_area_rect(map_local **m, int *x, int *y, int *width, int *height,
        area_t& area_)
{
    area_t *area = &area_; // diff hack
    switch (area->ty)
    {
        case AREA::UNION:
            break;

        case AREA::LOCATION:
            *m = area->a.a_loc.m;
            *x = area->a.a_loc.x;
            *y = area->a.a_loc.y;
            *width = 1;
            *height = 1;
            break;

        case AREA::RECT:
            *m = area->a.a_rect.loc.m;
            *x = area->a.a_rect.loc.x;
            *y = area->a.a_rect.loc.y;
            *width = area->a.a_rect.width;
            *height = area->a.a_rect.height;
            break;

        case AREA::BAR:
        {
            int tx = area->a.a_bar.loc.x;
            int ty = area->a.a_bar.loc.y;
            int twidth = area->a.a_bar.width;
            int tdepth = area->a.a_bar.width;
            *m = area->a.a_bar.loc.m;

            switch (area->a.a_bar.dir)
            {
                case DIR::S:
                    *x = tx - twidth;
                    *y = ty;
                    *width = twidth * 2 + 1;
                    *height = tdepth;
                    break;

                case DIR::W:
                    *x = tx - tdepth;
                    *y = ty - twidth;
                    *width = tdepth;
                    *height = twidth * 2 + 1;
                    break;

                case DIR::N:
                    *x = tx - twidth;
                    *y = ty - tdepth;
                    *width = twidth * 2 + 1;
                    *height = tdepth;
                    break;

                case DIR::E:
                    *x = tx;
                    *y = ty - twidth;
                    *width = tdepth;
                    *height = twidth * 2 + 1;
                    break;

                default:
                    FPRINTF(stderr,
                            "Error: Trying to compute area of NE/SE/NW/SW-facing bar"_fmt);
                    *x = tx;
                    *y = ty;
                    *width = *height = 1;
            }
            break;
        }
    }
}

int magic_location_in_area(map_local *m, int x, int y, dumb_ptr<area_t> area)
{
    switch (area->ty)
    {
        case AREA::UNION:
            return magic_location_in_area(m, x, y, area->a.a_union[0])
                || magic_location_in_area(m, x, y, area->a.a_union[1]);
        case AREA::LOCATION:
        case AREA::RECT:
        case AREA::BAR:
        {
            map_local *am;
            int ax, ay, awidth, aheight;
            magic_area_rect(&am, &ax, &ay, &awidth, &aheight, *area);
            return (am == m
                    && (x >= ax) && (y >= ay)
                    && (x < ax + awidth) && (y < ay + aheight));
        }
        default:
            FPRINTF(stderr, "INTERNAL ERROR: Invalid area\n"_fmt);
            return 0;
    }
}

static
int fun_is_in(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = magic_location_in_area(ARGLOCATION(0).m,
                                        ARGLOCATION(0).x,
                                        ARGLOCATION(0).y, ARGAREA(1));
    return 0;
}

static
int fun_skill(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    if (ENTITY_TYPE(0) != BL::PC
        // don't convert to enum until after the range check
        || ARGINT(1) < 0
        || ARGINT(1) >= static_cast<uint16_t>(MAX_SKILL))
    {
        RESULTINT = 0;
    }
    else
    {
        SkillID id = static_cast<SkillID>(ARGINT(1));
        RESULTINT = ARGPC(0)->status.skill[id].lv;
    }
    return 0;
}

static
int fun_his_shroud(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = (ENTITY_TYPE(0) == BL::PC && ARGPC(0)->state.shroud_active);
    return 0;
}

#define BATTLE_GETTER(name)                                             \
static                                                                  \
int fun_get_##name(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)   \
{                                                                       \
    RESULTINT = battle_get_##name(ARGENTITY(0));                        \
    return 0;                                                           \
}

BATTLE_GETTER(str)
BATTLE_GETTER(agi)
BATTLE_GETTER(vit)
BATTLE_GETTER(dex)
BATTLE_GETTER(luk)
BATTLE_GETTER(int)
BATTLE_GETTER(lv)
BATTLE_GETTER(hp)
BATTLE_GETTER(mdef)
BATTLE_GETTER(def)
BATTLE_GETTER(max_hp)
static
int fun_get_dir(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTDIR = battle_get_dir(ARGENTITY(0));
    return 0;
}

#define MMO_GETTER(name)                                                \
static                                                                  \
int fun_get_##name(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)   \
{                                                                       \
    if (ENTITY_TYPE(0) == BL::PC)                                       \
        RESULTINT = ARGPC(0)->status.name;                              \
    else                                                                \
        RESULTINT = 0;                                                  \
    return 0;                                                           \
}

MMO_GETTER(sp)
MMO_GETTER(max_sp)

static
int fun_name_of(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    if (ARG_TYPE(0) == TYPE::ENTITY)
    {
        RESULTSTR = dumb_string::copys(show_entity(ARGENTITY(0)));
        return 0;
    }
    else if (ARG_TYPE(0) == TYPE::SPELL)
    {
        RESULTSTR = dumb_string::copys(ARGSPELL(0)->name);
        return 0;
    }
    else if (ARG_TYPE(0) == TYPE::INVOCATION)
    {
        RESULTSTR = dumb_string::copys(ARGINVOCATION(0)->spell->name);
        return 0;
    }
    return 1;
}

/* [Freeyorp] I'm putting this one in as name_of seems to have issues with summoned or spawned mobs. */
static
int fun_mob_id(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    if (ENTITY_TYPE(0) != BL::MOB)
        return 1;
    RESULTINT = unwrap<Species>(ARGMOB(0)->mob_class);
    return 0;
}

inline
void COPY_LOCATION(block_list& dest, location_t& src)
{
    dest.bl_x = src.x;
    dest.bl_y = src.y;
    dest.bl_m = src.m;
}

inline
void COPY_LOCATION(location_t& dest, block_list& src)
{
    dest.x = src.bl_x;
    dest.y = src.bl_y;
    dest.m = src.bl_m;
}

static
int fun_location(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    COPY_LOCATION(RESULTLOCATION, *(ARGENTITY(0)));
    return 0;
}

static
int fun_random(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    int delta = ARGINT(0);
    if (delta < 0)
        delta = -delta;
    if (delta == 0)
    {
        RESULTINT = 0;
        return 0;
    }
    RESULTINT = random_::to(delta);

    if (ARGINT(0) < 0)
        RESULTINT = -RESULTINT;
    return 0;
}

static
int fun_random_dir(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    if (ARGINT(0))
        RESULTDIR = random_::choice({DIR::S, DIR::SW, DIR::W, DIR::NW, DIR::N, DIR::NE, DIR::E, DIR::SE});
    else
        RESULTDIR = random_::choice({DIR::S, DIR::W, DIR::N, DIR::E});
    return 0;
}

static
int fun_hash_entity(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = unwrap<BlockId>(ARGENTITY(0)->bl_id);
    return 0;
}

// ret -1: not a string, ret 1: no such item, ret 0: OK
int magic_find_item(Slice<val_t> args, int index, Item *item_, int *stackable)
{
    struct item_data *item_data;
    int must_add_sequentially;

    if (ARG_TYPE(index) == TYPE::INT)
        item_data = itemdb_exists(wrap<ItemNameId>(static_cast<uint16_t>(ARGINT(index))));
    else if (ARG_TYPE(index) == TYPE::STRING)
        item_data = itemdb_searchname(ARGSTR(index));
    else
        return -1;

    if (!item_data)
        return 1;

    // Very elegant.
    must_add_sequentially = (
            item_data->type == ItemType::WEAPON
            || item_data->type == ItemType::ARMOR
            || item_data->type == ItemType::_7
            || item_data->type == ItemType::_8);

    if (stackable)
        *stackable = !must_add_sequentially;

    *item_ = Item();
    item_->nameid = item_data->nameid;

    return 0;
}

static
int fun_count_item(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    dumb_ptr<map_session_data> chr = (ENTITY_TYPE(0) == BL::PC) ? ARGPC(0) : nullptr;
    int stackable;
    Item item;

    GET_ARG_ITEM(1, item, stackable);

    if (!chr)
        return 1;

    RESULTINT = pc_count_all_items(chr, item.nameid);
    return 0;
}

static
int fun_is_equipped(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    dumb_ptr<map_session_data> chr = (ENTITY_TYPE(0) == BL::PC) ? ARGPC(0) : nullptr;
    int stackable;
    Item item;
    bool retval = false;

    GET_ARG_ITEM(1, item, stackable);

    if (!chr)
        return 1;

    for (EQUIP i : EQUIPs)
    {
        IOff0 idx = chr->equip_index_maybe[i];
        if (idx.ok() && chr->status.inventory[idx].nameid == item.nameid)
        {
            retval = true;
            break;
        }
    }

    RESULTINT = retval;
    return 0;
}

static
int fun_is_married(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = (ENTITY_TYPE(0) == BL::PC && ARGPC(0)->status.partner_id);
    return 0;
}

static
int fun_is_dead(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = (ENTITY_TYPE(0) == BL::PC && pc_isdead(ARGPC(0)));
    return 0;
}

static
int fun_is_pc(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = (ENTITY_TYPE(0) == BL::PC);
    return 0;
}

static
int fun_partner(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    if (ENTITY_TYPE(0) == BL::PC && ARGPC(0)->status.partner_id)
    {
        RESULTENTITY =
            map_nick2sd(map_charid2nick(ARGPC(0)->status.partner_id));
        return 0;
    }
    else
        return 1;
}

static
int fun_awayfrom(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    location_t *loc = &ARGLOCATION(0);
    int dx = dirx[ARGDIR(1)];
    int dy = diry[ARGDIR(1)];
    int distance = ARGINT(2);
    while (distance--
        && !bool(read_gatp(loc->m, loc->x + dx, loc->y + dy)
            & MapCell::UNWALKABLE))
    {
        loc->x += dx;
        loc->y += dy;
    }

    RESULTLOCATION = *loc;
    return 0;
}

static
int fun_failed(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = ARG_TYPE(0) == TYPE::FAIL;
    return 0;
}

static
int fun_npc(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    NpcName name = stringish<NpcName>(ARGSTR(0));
    RESULTENTITY = npc_name2id(name);
    return RESULTENTITY == nullptr;
}

static
int fun_pc(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    CharName name = stringish<CharName>(ARGSTR(0));
    RESULTENTITY = map_nick2sd(name);
    return RESULTENTITY == nullptr;
}

static
int fun_distance(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    if (ARGLOCATION(0).m != ARGLOCATION(1).m)
        RESULTINT = 0x7fffffff;
    else
        RESULTINT = std::max(abs(ARGLOCATION(0).x - ARGLOCATION(1).x),
                         abs(ARGLOCATION(0).y - ARGLOCATION(1).y));
    return 0;
}

static
int fun_rdistance(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    if (ARGLOCATION(0).m != ARGLOCATION(1).m)
        RESULTINT = 0x7fffffff;
    else
    {
        int dx = ARGLOCATION(0).x - ARGLOCATION(1).x;
        int dy = ARGLOCATION(0).y - ARGLOCATION(1).y;
        RESULTINT = static_cast<int>(sqrt((dx * dx) + (dy * dy)));
    }
    return 0;
}

static
int fun_anchor(dumb_ptr<env_t> env, val_t *result, Slice<val_t> args)
{
    dumb_ptr<teleport_anchor_t> anchor = magic_find_anchor(ARGSTR(0));

    if (!anchor)
        return 1;

    magic_eval(env, result, anchor->location);

    make_area(result);
    if (result->ty != TYPE::AREA)
    {
        magic_clear_var(result);
        return 1;
    }

    return 0;
}

static
int fun_line_of_sight(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    block_list e1, e2;

    COPY_LOCATION(e1, ARGLOCATION(0));
    COPY_LOCATION(e2, ARGLOCATION(1));

    RESULTINT = battle_check_range(dumb_ptr<block_list>(&e1), dumb_ptr<block_list>(&e2), 0);

    return 0;
}

void magic_random_location(location_t *dest, dumb_ptr<area_t> area)
{
    switch (area->ty)
    {
        case AREA::UNION:
        {
            if (random_::chance({area->a.a_union[0]->size, area->size}))
                magic_random_location(dest, area->a.a_union[0]);
            else
                magic_random_location(dest, area->a.a_union[1]);
            break;
        }

        case AREA::LOCATION:
        case AREA::RECT:
        case AREA::BAR:
        {
            map_local *m;
            int x, y, w, h;
            magic_area_rect(&m, &x, &y, &w, &h, *area);

            if (w <= 1)
                w = 1;

            if (h <= 1)
                h = 1;

            // This is not exactly the same as the old logic,
            // but it's better.
            auto pair = map_randfreecell(m, x, y, w, h);

            dest->m = m;
            dest->x = pair.first;
            dest->y = pair.second;
            break;
        }

        default:
            FPRINTF(stderr, "Unknown area type %d\n"_fmt,
                    area->ty);
    }
}

static
int fun_pick_location(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    magic_random_location(&result->v.v_location, ARGAREA(0));
    return 0;
}

static
int fun_read_script_int(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    dumb_ptr<block_list> subject_p = ARGENTITY(0);
    VarName var_name = stringish<VarName>(ARGSTR(1));
    int array_index = 0;

    if (subject_p->bl_type != BL::PC)
        return 1;

    RESULTINT = get_script_var_i(subject_p->is_player(), var_name, array_index);
    return 0;
}

static
int fun_read_script_str(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    dumb_ptr<block_list> subject_p = ARGENTITY(0);
    VarName var_name = stringish<VarName>(ARGSTR(1));
    int array_index = 0;

    if (subject_p->bl_type != BL::PC)
        return 1;

    RESULTSTR = dumb_string::copys(get_script_var_s(subject_p->is_player(), var_name, array_index));
    return 0;
}

static
int fun_rbox(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    location_t loc = ARGLOCATION(0);
    int radius = ARGINT(1);

    RESULTAREA = area_new(AREA::RECT);
    RESULTAREA->a.a_rect.loc.m = loc.m;
    RESULTAREA->a.a_rect.loc.x = loc.x - radius;
    RESULTAREA->a.a_rect.loc.y = loc.y - radius;
    RESULTAREA->a.a_rect.width = radius * 2 + 1;
    RESULTAREA->a.a_rect.height = radius * 2 + 1;

    return 0;
}

static
int fun_running_status_update(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    if (ENTITY_TYPE(0) != BL::PC && ENTITY_TYPE(0) != BL::MOB)
        return 1;

    StatusChange sc = static_cast<StatusChange>(ARGINT(1));
    RESULTINT = bool(battle_get_sc_data(ARGENTITY(0))[sc].timer);
    return 0;
}

static
int fun_status_option(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = (bool((ARGPC(0))->status.option & static_cast<Option>(ARGINT(1))));
    return 0;
}

static
int fun_element(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = static_cast<int>(battle_get_element(ARGENTITY(0)).element);
    return 0;
}

static
int fun_element_level(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = battle_get_element(ARGENTITY(0)).level;
    return 0;
}

static
int fun_is_exterior(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
#warning "Evil assumptions!"
    RESULTINT = ARGLOCATION(0).m->name_[4] == '1';
    return 0;
}

static
int fun_contains_string(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = nullptr != strstr(ARGSTR(0).c_str(), ARGSTR(1).c_str());
    return 0;
}

static
int fun_strstr(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    const char *offset = strstr(ARGSTR(0).c_str(), ARGSTR(1).c_str());
    RESULTINT = offset - ARGSTR(0).c_str();
    return offset == nullptr;
}

static
int fun_strlen(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = strlen(ARGSTR(0).c_str());
    return 0;
}

static
int fun_substr(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    const char *src = ARGSTR(0).c_str();
    const int slen = strlen(src);
    int offset = ARGINT(1);
    int len = ARGINT(2);

    if (len < 0)
        len = 0;
    if (offset < 0)
        offset = 0;

    if (offset > slen)
        offset = slen;

    if (offset + len > slen)
        len = slen - offset;

    const char *begin = src + offset;
    const char *end = begin + len;
    RESULTSTR = dumb_string::copy(begin, end);

    return 0;
}

static
int fun_sqrt(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    RESULTINT = static_cast<int>(sqrt(ARGINT(0)));
    return 0;
}

static
int fun_map_level(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
#warning "Evil assumptions!"
    RESULTINT = ARGLOCATION(0).m->name_[4] - '0';
    return 0;
}

static
int fun_map_nr(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
#warning "Evil assumptions!"
    MapName mapname = ARGLOCATION(0).m->name_;

    RESULTINT = ((mapname[0] - '0') * 100)
        + ((mapname[1] - '0') * 10) + ((mapname[2] - '0'));
    return 0;
}

static
int fun_dir_towards(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    int dx;
    int dy;

    if (ARGLOCATION(0).m != ARGLOCATION(1).m)
        return 1;

    dx = ARGLOCATION(1).x - ARGLOCATION(0).x;
    dy = ARGLOCATION(1).y - ARGLOCATION(0).y;

    if (ARGINT(1))
    {
        /* 8-direction mode */
        if (abs(dx) > abs(dy) * 2)
        {                       /* east or west */
            if (dx < 0)
                RESULTINT = 2 /* west */ ;
            else
                RESULTINT = 6 /* east */ ;
        }
        else if (abs(dy) > abs(dx) * 2)
        {                       /* north or south */
            if (dy > 0)
                RESULTINT = 0 /* south */ ;
            else
                RESULTINT = 4 /* north */ ;
        }
        else if (dx < 0)
        {                       /* north-west or south-west */
            if (dy < 0)
                RESULTINT = 3 /* north-west */ ;
            else
                RESULTINT = 1 /* south-west */ ;
        }
        else
        {                       /* north-east or south-east */
            if (dy < 0)
                RESULTINT = 5 /* north-east */ ;
            else
                RESULTINT = 7 /* south-east */ ;
        }
    }
    else
    {
        /* 4-direction mode */
        if (abs(dx) > abs(dy))
        {                       /* east or west */
            if (dx < 0)
                RESULTINT = 2 /* west */ ;
            else
                RESULTINT = 6 /* east */ ;
        }
        else
        {                       /* north or south */
            if (dy > 0)
                RESULTINT = 0 /* south */ ;
            else
                RESULTINT = 4 /* north */ ;
        }
    }

    return 0;
}

static
int fun_extract_healer_xp(dumb_ptr<env_t>, val_t *result, Slice<val_t> args)
{
    dumb_ptr<map_session_data> sd = (ENTITY_TYPE(0) == BL::PC) ? ARGPC(0) : nullptr;

    if (!sd)
        RESULTINT = 0;
    else
        RESULTINT = pc_extract_healer_exp(sd, ARGINT(1));
    return 0;
}

#define MAGIC_FUNCTION(name, args, ret, impl) {name, {name, args, ret, impl}}
#define MAGIC_FUNCTION1(name, args, ret) MAGIC_FUNCTION(#name##_s, args, ret, fun_##name)
static // should be LString, but no heterogenous lookup yet
std::map<ZString, fun_t> functions =
{
    MAGIC_FUNCTION("+"_s, ".."_s, '.', fun_add),
    MAGIC_FUNCTION("-"_s, "ii"_s, 'i', fun_sub),
    MAGIC_FUNCTION("*"_s, "ii"_s, 'i', fun_mul),
    MAGIC_FUNCTION("/"_s, "ii"_s, 'i', fun_div),
    MAGIC_FUNCTION("%"_s, "ii"_s, 'i', fun_mod),
    MAGIC_FUNCTION("||"_s, "ii"_s, 'i', fun_or),
    MAGIC_FUNCTION("&&"_s, "ii"_s, 'i', fun_and),
    MAGIC_FUNCTION("<"_s, ".."_s, 'i', fun_lt),
    MAGIC_FUNCTION(">"_s, ".."_s, 'i', fun_gt),
    MAGIC_FUNCTION("<="_s, ".."_s, 'i', fun_lte),
    MAGIC_FUNCTION(">="_s, ".."_s, 'i', fun_gte),
    MAGIC_FUNCTION("=="_s, ".."_s, 'i', fun_eq),
    MAGIC_FUNCTION("!="_s, ".."_s, 'i', fun_ne),
    MAGIC_FUNCTION("|"_s, ".."_s, 'i', fun_bitor),
    MAGIC_FUNCTION("&"_s, "ii"_s, 'i', fun_bitand),
    MAGIC_FUNCTION("^"_s, "ii"_s, 'i', fun_bitxor),
    MAGIC_FUNCTION("<<"_s, "ii"_s, 'i', fun_bitshl),
    MAGIC_FUNCTION(">>"_s, "ii"_s, 'i', fun_bitshr),
    MAGIC_FUNCTION1(not, "i"_s, 'i'),
    MAGIC_FUNCTION1(neg, "i"_s, 'i'),
    MAGIC_FUNCTION1(max, "ii"_s, 'i'),
    MAGIC_FUNCTION1(min, "ii"_s, 'i'),
    MAGIC_FUNCTION1(is_in, "la"_s, 'i'),
    MAGIC_FUNCTION1(if_then_else, "i__"_s, '_'),
    MAGIC_FUNCTION1(skill, "ei"_s, 'i'),
    MAGIC_FUNCTION("str"_s, "e"_s, 'i', fun_get_str),
    MAGIC_FUNCTION("agi"_s, "e"_s, 'i', fun_get_agi),
    MAGIC_FUNCTION("vit"_s, "e"_s, 'i', fun_get_vit),
    MAGIC_FUNCTION("dex"_s, "e"_s, 'i', fun_get_dex),
    MAGIC_FUNCTION("luk"_s, "e"_s, 'i', fun_get_luk),
    MAGIC_FUNCTION("int"_s, "e"_s, 'i', fun_get_int),
    MAGIC_FUNCTION("level"_s, "e"_s, 'i', fun_get_lv),
    MAGIC_FUNCTION("mdef"_s, "e"_s, 'i', fun_get_mdef),
    MAGIC_FUNCTION("def"_s, "e"_s, 'i', fun_get_def),
    MAGIC_FUNCTION("hp"_s, "e"_s, 'i', fun_get_hp),
    MAGIC_FUNCTION("max_hp"_s, "e"_s, 'i', fun_get_max_hp),
    MAGIC_FUNCTION("sp"_s, "e"_s, 'i', fun_get_sp),
    MAGIC_FUNCTION("max_sp"_s, "e"_s, 'i', fun_get_max_sp),
    MAGIC_FUNCTION("dir"_s, "e"_s, 'd', fun_get_dir),
    MAGIC_FUNCTION1(name_of, "."_s, 's'),
    MAGIC_FUNCTION1(mob_id, "e"_s, 'i'),
    MAGIC_FUNCTION1(location, "e"_s, 'l'),
    MAGIC_FUNCTION1(random, "i"_s, 'i'),
    MAGIC_FUNCTION1(random_dir, "i"_s, 'd'),
    MAGIC_FUNCTION1(hash_entity, "e"_s, 'i'),
    MAGIC_FUNCTION1(is_married, "e"_s, 'i'),
    MAGIC_FUNCTION1(partner, "e"_s, 'e'),
    MAGIC_FUNCTION1(awayfrom, "ldi"_s, 'l'),
    MAGIC_FUNCTION1(failed, "_"_s, 'i'),
    MAGIC_FUNCTION1(pc, "s"_s, 'e'),
    MAGIC_FUNCTION1(npc, "s"_s, 'e'),
    MAGIC_FUNCTION1(distance, "ll"_s, 'i'),
    MAGIC_FUNCTION1(rdistance, "ll"_s, 'i'),
    MAGIC_FUNCTION1(anchor, "s"_s, 'a'),
    MAGIC_FUNCTION("random_location"_s, "a"_s, 'l', fun_pick_location),
    MAGIC_FUNCTION("script_int"_s, "es"_s, 'i', fun_read_script_int),
    MAGIC_FUNCTION("script_str"_s, "es"_s, 's', fun_read_script_str),
    MAGIC_FUNCTION1(rbox, "li"_s, 'a'),
    MAGIC_FUNCTION1(count_item, "e."_s, 'i'),
    MAGIC_FUNCTION1(line_of_sight, "ll"_s, 'i'),
    MAGIC_FUNCTION1(running_status_update, "ei"_s, 'i'),
    MAGIC_FUNCTION1(status_option, "ei"_s, 'i'),
    MAGIC_FUNCTION1(element, "e"_s, 'i'),
    MAGIC_FUNCTION1(element_level, "e"_s, 'i'),
    MAGIC_FUNCTION1(his_shroud, "e"_s, 'i'),
    MAGIC_FUNCTION1(is_equipped, "e."_s, 'i'),
    MAGIC_FUNCTION1(is_exterior, "l"_s, 'i'),
    MAGIC_FUNCTION1(contains_string, "ss"_s, 'i'),
    MAGIC_FUNCTION1(strstr, "ss"_s, 'i'),
    MAGIC_FUNCTION1(strlen, "s"_s, 'i'),
    MAGIC_FUNCTION1(substr, "sii"_s, 's'),
    MAGIC_FUNCTION1(sqrt, "i"_s, 'i'),
    MAGIC_FUNCTION1(map_level, "l"_s, 'i'),
    MAGIC_FUNCTION1(map_nr, "l"_s, 'i'),
    MAGIC_FUNCTION1(dir_towards, "lli"_s, 'd'),
    MAGIC_FUNCTION1(is_dead, "e"_s, 'i'),
    MAGIC_FUNCTION1(is_pc, "e"_s, 'i'),
    MAGIC_FUNCTION("extract_healer_experience"_s, "ei"_s, 'i', fun_extract_healer_xp),
};

fun_t *magic_get_fun(ZString name)
{
    auto it = functions.find(name);
    if (it == functions.end())
        return nullptr;
    return &it->second;
}

// 1 on failure
static
int eval_location(dumb_ptr<env_t> env, location_t *dest, e_location_t *expr)
{
    val_t m, x, y;
    magic_eval(env, &m, expr->m);
    magic_eval(env, &x, expr->x);
    magic_eval(env, &y, expr->y);

    if (CHECK_TYPE(&m, TYPE::STRING)
        && CHECK_TYPE(&x, TYPE::INT) && CHECK_TYPE(&y, TYPE::INT))
    {
        MapName name = VString<15>(ZString(m.v.v_string));
        map_local *map_id = map_mapname2mapid(name);
        magic_clear_var(&m);
        if (!map_id)
            return 1;
        dest->m = map_id;
        dest->x = x.v.v_int;
        dest->y = y.v.v_int;
        return 0;
    }
    else
    {
        magic_clear_var(&m);
        magic_clear_var(&x);
        magic_clear_var(&y);
        return 1;
    }
}

static
dumb_ptr<area_t> eval_area(dumb_ptr<env_t> env, e_area_t& expr_)
{
    e_area_t *expr = &expr_; // temporary hack to reduce diff
    auto area = dumb_ptr<area_t>::make();
    area->ty = expr->ty;

    switch (expr->ty)
    {
        case AREA::LOCATION:
            area->size = 1;
            if (eval_location(env, &area->a.a_loc, &expr->a.a_loc))
            {
                area.delete_();
                return nullptr;
            }
            else
                return area;

        case AREA::UNION:
        {
            int i, fail = 0;
            for (i = 0; i < 2; i++)
            {
                area->a.a_union[i] = eval_area(env, *expr->a.a_union[i]);
                if (!area->a.a_union[i])
                    fail = 1;
            }

            if (fail)
            {
                for (i = 0; i < 2; i++)
                {
                    if (area->a.a_union[i])
                        free_area(area->a.a_union[i]);
                }
                area.delete_();
                return nullptr;
            }
            area->size = area->a.a_union[0]->size + area->a.a_union[1]->size;
            return area;
        }

        case AREA::RECT:
        {
            val_t width, height;
            magic_eval(env, &width, expr->a.a_rect.width);
            magic_eval(env, &height, expr->a.a_rect.height);

            area->a.a_rect.width = width.v.v_int;
            area->a.a_rect.height = height.v.v_int;

            if (CHECK_TYPE(&width, TYPE::INT)
                && CHECK_TYPE(&height, TYPE::INT)
                && !eval_location(env, &(area->a.a_rect.loc),
                                   &expr->a.a_rect.loc))
            {
                area->size = area->a.a_rect.width * area->a.a_rect.height;
                magic_clear_var(&width);
                magic_clear_var(&height);
                return area;
            }
            else
            {
                area.delete_();
                magic_clear_var(&width);
                magic_clear_var(&height);
                return nullptr;
            }
        }

        case AREA::BAR:
        {
            val_t width, depth, dir;
            magic_eval(env, &width, expr->a.a_bar.width);
            magic_eval(env, &depth, expr->a.a_bar.depth);
            magic_eval(env, &dir, expr->a.a_bar.dir);

            area->a.a_bar.width = width.v.v_int;
            area->a.a_bar.depth = depth.v.v_int;
            area->a.a_bar.dir = dir.v.v_dir;

            if (CHECK_TYPE(&width, TYPE::INT)
                && CHECK_TYPE(&depth, TYPE::INT)
                && CHECK_TYPE(&dir, TYPE::DIR)
                && !eval_location(env, &area->a.a_bar.loc,
                                   &expr->a.a_bar.loc))
            {
                area->size =
                    (area->a.a_bar.width * 2 + 1) * area->a.a_bar.depth;
                magic_clear_var(&width);
                magic_clear_var(&depth);
                magic_clear_var(&dir);
                return area;
            }
            else
            {
                area.delete_();
                magic_clear_var(&width);
                magic_clear_var(&depth);
                magic_clear_var(&dir);
                return nullptr;
            }
        }

        default:
            FPRINTF(stderr, "INTERNAL ERROR: Unknown area type %d\n"_fmt,
                    area->ty);
            area.delete_();
            return nullptr;
    }
}

static
TYPE type_key(char ty_key)
{
    switch (ty_key)
    {
        case 'i':
            return TYPE::INT;
        case 'd':
            return TYPE::DIR;
        case 's':
            return TYPE::STRING;
        case 'e':
            return TYPE::ENTITY;
        case 'l':
            return TYPE::LOCATION;
        case 'a':
            return TYPE::AREA;
        case 'S':
            return TYPE::SPELL;
        case 'I':
            return TYPE::INVOCATION;
        default:
            return TYPE::NEGATIVE_1;
    }
}

int magic_signature_check(ZString opname, ZString funname, ZString signature,
        Slice<val_t> args, int line, int column)
{
    int i;
    for (i = 0; i < args.size(); i++)
    {
        val_t *arg = &args[i];
        char ty_key = signature[i];
        TYPE ty = arg->ty;
        TYPE desired_ty = type_key(ty_key);

        if (ty == TYPE::ENTITY)
        {
            /* Dereference entities in preparation for calling function */
            arg->v.v_entity = map_id2bl(wrap<BlockId>(static_cast<uint32_t>(arg->v.v_int)));
            if (!arg->v.v_entity)
                ty = arg->ty = TYPE::FAIL;
        }
        else if (ty == TYPE::INVOCATION)
        {
            arg->v.v_invocation = map_id2bl(wrap<BlockId>(static_cast<uint32_t>(arg->v.v_int)))->is_spell();
            if (!arg->v.v_entity)
                ty = arg->ty = TYPE::FAIL;
        }

        if (!ty_key)
        {
            FPRINTF(stderr,
                    "[magic-eval]:  L%d:%d: Too many arguments (%zu) to %s `%s'\n"_fmt,
                    line, column, args.size(), opname, funname);
            return 1;
        }

        if (ty == TYPE::FAIL && ty_key != '_')
            return 1;           /* Fail `in a sane way':  This is a perfectly permissible error */

        if (ty == desired_ty || desired_ty == TYPE::NEGATIVE_1)
            continue;

        if (ty == TYPE::UNDEF)
        {
            FPRINTF(stderr,
                    "[magic-eval]:  L%d:%d: Argument #%d to %s `%s' undefined\n"_fmt,
                    line, column, i + 1, opname, funname);
            return 1;
        }

        /* If we are here, we have a type mismatch but no failure _yet_.  Try to coerce. */
        switch (desired_ty)
        {
            case TYPE::INT:
                intify(arg);
                break;          /* 100% success rate */
            case TYPE::STRING:
                stringify(arg, 1);
                break;          /* 100% success rate */
            case TYPE::AREA:
                make_area(arg);
                break;          /* Only works for locations */
            case TYPE::LOCATION:
                make_location(arg);
                break;          /* Only works for some areas */
            case TYPE::SPELL:
                make_spell(arg);
                break;          /* Only works for still-active invocatoins */
            default:
                break;          /* We'll fail right below */
        }

        ty = arg->ty;
        if (ty != desired_ty)
        {                       /* Coercion failed? */
            if (ty != TYPE::FAIL)
                FPRINTF(stderr,
                        "[magic-eval]:  L%d:%d: Argument #%d to %s `%s' of incorrect type (%d)\n"_fmt,
                        line, column, i + 1, opname, funname,
                        ty);
            return 1;
        }
    }

    return 0;
}

void magic_eval(dumb_ptr<env_t> env, val_t *dest, dumb_ptr<expr_t> expr)
{
    switch (expr->ty)
    {
        case EXPR::VAL:
            magic_copy_var(dest, &expr->e.e_val);
            break;

        case EXPR::LOCATION:
            if (eval_location(env, &dest->v.v_location, &expr->e.e_location))
                dest->ty = TYPE::FAIL;
            else
                dest->ty = TYPE::LOCATION;
            break;

        case EXPR::AREA:
            if ((dest->v.v_area = eval_area(env, expr->e.e_area)))
                dest->ty = TYPE::AREA;
            else
                dest->ty = TYPE::FAIL;
            break;

        case EXPR::FUNAPP:
        {
            val_t arguments[MAX_ARGS];
            int args_nr = expr->e.e_funapp.args_nr;
            int i;
            fun_t *f = expr->e.e_funapp.funp;

            for (i = 0; i < args_nr; ++i)
                magic_eval(env, &arguments[i], expr->e.e_funapp.args[i]);
            if (magic_signature_check("function"_s, f->name, f->signature, Slice<val_t>(arguments, args_nr),
                        expr->e.e_funapp.line_nr, expr->e.e_funapp.column)
                    || f->fun(env, dest, Slice<val_t>(arguments, args_nr)))
                dest->ty = TYPE::FAIL;
            else
            {
                TYPE dest_ty = type_key(f->ret_ty);
                if (dest_ty != TYPE::NEGATIVE_1)
                    dest->ty = dest_ty;

                /* translate entity back into persistent int */
                if (dest->ty == TYPE::ENTITY)
                {
                    if (dest->v.v_entity)
                        dest->v.v_int = static_cast<int32_t>(unwrap<BlockId>(dest->v.v_entity->bl_id));
                    else
                        dest->ty = TYPE::FAIL;
                }
            }

            for (i = 0; i < args_nr; ++i)
                magic_clear_var(&arguments[i]);
            break;
        }

        case EXPR::ID:
        {
            val_t v = env->VAR(expr->e.e_id);
            magic_copy_var(dest, &v);
            break;
        }

        case EXPR::SPELLFIELD:
        {
            val_t v;
            int id = expr->e.e_field.id;
            magic_eval(env, &v, expr->e.e_field.expr);

            if (v.ty == TYPE::INVOCATION)
            {
                dumb_ptr<invocation> t = map_id2bl(wrap<BlockId>(static_cast<uint32_t>(v.v.v_int)))->is_spell();

                if (!t)
                    dest->ty = TYPE::UNDEF;
                else
                {
                    val_t val = t->env->VAR(id);
                    magic_copy_var(dest, &val);
                }
            }
            else
            {
                FPRINTF(stderr,
                        "[magic] Attempt to access field %s on non-spell\n"_fmt,
                        env->base_env->varv[id].name);
                dest->ty = TYPE::FAIL;
            }
            break;
        }

        default:
            FPRINTF(stderr,
                    "[magic] INTERNAL ERROR: Unknown expression type %d\n"_fmt,
                    expr->ty);
            break;
    }
}

int magic_eval_int(dumb_ptr<env_t> env, dumb_ptr<expr_t> expr)
{
    val_t result;
    magic_eval(env, &result, expr);

    if (result.ty == TYPE::FAIL || result.ty == TYPE::UNDEF)
        return 0;

    intify(&result);

    return result.v.v_int;
}

AString magic_eval_str(dumb_ptr<env_t> env, dumb_ptr<expr_t> expr)
{
    val_t result;
    magic_eval(env, &result, expr);

    if (result.ty == TYPE::FAIL || result.ty == TYPE::UNDEF)
        return "?"_s;

    stringify(&result, 0);

    return result.v.v_string.str();
}

dumb_ptr<expr_t> magic_new_expr(EXPR ty)
{
    auto expr = dumb_ptr<expr_t>::make();
    expr->ty = ty;
    return expr;
}
} // namespace tmwa