/* NetHack 3.6	spell.c	$NHDT-Date: 1447653429 2015/11/16 05:57:09 $  $NHDT-Branch: master $:$NHDT-Revision: 1.72 $ */
/*      Copyright (c) M. Stephenson 1988                          */
/* NetHack may be freely redistributed.  See license for details. */

/* JNetHack Copyright */
/* (c) Issei Numata, Naoki Hamada, Shigehiro Miyashita, 1994-2000  */
/* For 3.4-, Copyright (c) SHIRAKATA Kentaro, 2002-2016            */
/* JNetHack may be freely redistributed.  See license for details. */

#include "hack.h"

/* spellmenu arguments; 0 thru n-1 used as spl_book[] index when swapping */
#define SPELLMENU_CAST (-2)
#define SPELLMENU_VIEW (-1)
#define SPELLMENU_SORT (MAXSPELL) /* special menu entry */

/* spell retention period, in turns; at 10% of this value, player becomes
   eligible to reread the spellbook and regain 100% retention (the threshold
   used to be 1000 turns, which was 10% of the original 10000 turn retention
   period but didn't get adjusted when that period got doubled to 20000) */
#define KEEN 20000
/* x: need to add 1 when used for reading a spellbook rather than for hero
   initialization; spell memory is decremented at the end of each turn,
   including the turn on which the spellbook is read; without the extra
   increment, the hero used to get cheated out of 1 turn of retention */
#define incrnknow(spell, x) (spl_book[spell].sp_know = KEEN + (x))

#define spellev(spell) spl_book[spell].sp_lev
#define spellname(spell) OBJ_NAME(objects[spellid(spell)])
#define spellet(spell) \
    ((char) ((spell < 26) ? ('a' + spell) : ('A' + spell - 26)))

STATIC_DCL int FDECL(spell_let_to_idx, (CHAR_P));
STATIC_DCL boolean FDECL(cursed_book, (struct obj * bp));
STATIC_DCL boolean FDECL(confused_book, (struct obj *));
STATIC_DCL void FDECL(deadbook, (struct obj *));
STATIC_PTR int NDECL(learn);
STATIC_DCL boolean NDECL(rejectcasting);
STATIC_DCL boolean FDECL(getspell, (int *));
STATIC_PTR int FDECL(CFDECLSPEC spell_cmp, (const genericptr,
                                            const genericptr));
STATIC_DCL void NDECL(sortspells);
STATIC_DCL boolean NDECL(spellsortmenu);
STATIC_DCL boolean FDECL(dospellmenu, (const char *, int, int *));
STATIC_DCL int FDECL(percent_success, (int));
STATIC_DCL char *FDECL(spellretention, (int, char *));
STATIC_DCL int NDECL(throwspell);
STATIC_DCL void NDECL(cast_protection);
STATIC_DCL void FDECL(spell_backfire, (int));
STATIC_DCL const char *FDECL(spelltypemnemonic, (int));

/* The roles[] table lists the role-specific values for tuning
 * percent_success().
 *
 * Reasoning:
 *   spelbase, spelheal:
 *      Arc are aware of magic through historical research
 *      Bar abhor magic (Conan finds it "interferes with his animal instincts")
 *      Cav are ignorant to magic
 *      Hea are very aware of healing magic through medical research
 *      Kni are moderately aware of healing from Paladin training
 *      Mon use magic to attack and defend in lieu of weapons and armor
 *      Pri are very aware of healing magic through theological research
 *      Ran avoid magic, preferring to fight unseen and unheard
 *      Rog are moderately aware of magic through trickery
 *      Sam have limited magical awareness, preferring meditation to conjuring
 *      Tou are aware of magic from all the great films they have seen
 *      Val have limited magical awareness, preferring fighting
 *      Wiz are trained mages
 *
 *      The arms penalty is lessened for trained fighters Bar, Kni, Ran,
 *      Sam, Val -- the penalty is its metal interference, not encumbrance.
 *      The `spelspec' is a single spell which is fundamentally easier
 *      for that role to cast.
 *
 *  spelspec, spelsbon:
 *      Arc map masters (SPE_MAGIC_MAPPING)
 *      Bar fugue/berserker (SPE_HASTE_SELF)
 *      Cav born to dig (SPE_DIG)
 *      Hea to heal (SPE_CURE_SICKNESS)
 *      Kni to turn back evil (SPE_TURN_UNDEAD)
 *      Mon to preserve their abilities (SPE_RESTORE_ABILITY)
 *      Pri to bless (SPE_REMOVE_CURSE)
 *      Ran to hide (SPE_INVISIBILITY)
 *      Rog to find loot (SPE_DETECT_TREASURE)
 *      Sam to be At One (SPE_CLAIRVOYANCE)
 *      Tou to smile (SPE_CHARM_MONSTER)
 *      Val control the cold (SPE_CONE_OF_COLD)
 *      Wiz all really, but SPE_MAGIC_MISSILE is their party trick
 *
 *      See percent_success() below for more comments.
 *
 *  uarmbon, uarmsbon, uarmhbon, uarmgbon, uarmfbon:
 *      Fighters find body armour & shield a little less limiting.
 *      Headgear, Gauntlets and Footwear are not role-specific (but
 *      still have an effect, except helm of brilliance, which is designed
 *      to permit magic-use).
 */

#define uarmhbon 4 /* Metal helmets interfere with the mind */
#define uarmgbon 6 /* Casting channels through the hands */
#define uarmfbon 2 /* All metal interferes to some degree */

/* since the spellbook itself doesn't blow up, don't say just "explodes" */
#if 0 /*JP*/
static const char explodes[] = "radiates explosive energy";
#endif

/* convert a letter into a number in the range 0..51, or -1 if not a letter */
STATIC_OVL int
spell_let_to_idx(ilet)
char ilet;
{
    int indx;

    indx = ilet - 'a';
    if (indx >= 0 && indx < 26)
        return indx;
    indx = ilet - 'A';
    if (indx >= 0 && indx < 26)
        return indx + 26;
    return -1;
}

/* TRUE: book should be destroyed by caller */
STATIC_OVL boolean
cursed_book(bp)
struct obj *bp;
{
    int lev = objects[bp->otyp].oc_level;
    int dmg = 0;

    switch (rn2(lev)) {
    case 0:
/*JP
        You_feel("a wrenching sensation.");
*/
        You("ねじられたような感覚を感じた．");
        tele(); /* teleport him */
        break;
    case 1:
/*JP
        You_feel("threatened.");
*/
        You("おどされているような気がした．");
        aggravate();
        break;
    case 2:
        make_blinded(Blinded + rn1(100, 250), TRUE);
        break;
    case 3:
        take_gold();
        break;
    case 4:
/*JP
        pline("These runes were just too much to comprehend.");
*/
        pline("このルーン文字を理解するのは困難だ．");
        make_confused(HConfusion + rn1(7, 16), FALSE);
        break;
    case 5:
/*JP
        pline_The("book was coated with contact poison!");
*/
        pline("この本は接触型の毒で覆われている！");
        if (uarmg) {
#if 0 /*JP*/
            erode_obj(uarmg, "gloves", ERODE_CORRODE, EF_GREASE | EF_VERBOSE);
#else
            erode_obj(uarmg, "小手", ERODE_CORRODE, EF_GREASE | EF_VERBOSE);
#endif
            break;
        }
        /* temp disable in_use; death should not destroy the book */
        bp->in_use = FALSE;
        losestr(Poison_resistance ? rn1(2, 1) : rn1(4, 3));
#if 0 /*JP*/
        losehp(rnd(Poison_resistance ? 6 : 10), "contact-poisoned spellbook",
               KILLED_BY_AN);
#else
        losehp(rnd(Poison_resistance ? 6 : 10), "接触毒の魔法書で",
               KILLED_BY_AN);
#endif
        bp->in_use = TRUE;
        break;
    case 6:
        if (Antimagic) {
            shieldeff(u.ux, u.uy);
/*JP
            pline_The("book %s, but you are unharmed!", explodes);
*/
            pline("本は強力なエネルギーを放出した，しかしあなたは傷つかない！");
        } else {
/*JP
            pline("As you read the book, it %s in your %s!", explodes,
*/
            pline("本は強力なエネルギーをあなたの%sに放出した！",
                  body_part(FACE));
            dmg = 2 * rnd(10) + 5;
/*JP
            losehp(Maybe_Half_Phys(dmg), "exploding rune", KILLED_BY_AN);
*/
            losehp(Maybe_Half_Phys(dmg), "強力なルーン文字のエネルギーで", KILLED_BY_AN);
        }
        return TRUE;
    default:
        rndcurse();
        break;
    }
    return FALSE;
}

/* study while confused: returns TRUE if the book is destroyed */
STATIC_OVL boolean
confused_book(spellbook)
struct obj *spellbook;
{
    boolean gone = FALSE;

    if (!rn2(3) && spellbook->otyp != SPE_BOOK_OF_THE_DEAD) {
        spellbook->in_use = TRUE; /* in case called from learn */
        pline(
/*JP
         "Being confused you have difficulties in controlling your actions.");
*/
         "混乱しているので，そういうことをするのは難しい．");
        display_nhwindow(WIN_MESSAGE, FALSE);
/*JP
        You("accidentally tear the spellbook to pieces.");
*/
        You("うっかり，魔法書を引きさいてしまった．");
        if (!objects[spellbook->otyp].oc_name_known
            && !objects[spellbook->otyp].oc_uname)
            docall(spellbook);
        useup(spellbook);
        gone = TRUE;
    } else {
#if 0 /*JP*/
        You("find yourself reading the %s line over and over again.",
            spellbook == context.spbook.book ? "next" : "first");
#else
        You("%sの行を何度も繰り返して読んでいたことに気付いた．",
            spellbook == context.spbook.book ? "次" : "最初");
#endif
    }
    return gone;
}

/* special effects for The Book of the Dead */
STATIC_OVL void
deadbook(book2)
struct obj *book2;
{
    struct monst *mtmp, *mtmp2;
    coord mm;

/*JP
    You("turn the pages of the Book of the Dead...");
*/
    You("死者の書のページをめくった．．．");
    makeknown(SPE_BOOK_OF_THE_DEAD);
    /* KMH -- Need ->known to avoid "_a_ Book of the Dead" */
    book2->known = 1;
    if (invocation_pos(u.ux, u.uy) && !On_stairs(u.ux, u.uy)) {
        register struct obj *otmp;
        register boolean arti1_primed = FALSE, arti2_primed = FALSE,
                         arti_cursed = FALSE;

        if (book2->cursed) {
/*JP
            pline_The("runes appear scrambled.  You can't read them!");
*/
            pline("ルーン文字はごちゃまぜになっており，読むことができなかった！");
            return;
        }

        if (!u.uhave.bell || !u.uhave.menorah) {
/*JP
            pline("A chill runs down your %s.", body_part(SPINE));
*/
            Your("%sに寒けが走った．", body_part(SPINE));
            if (!u.uhave.bell)
/*JP
                You_hear("a faint chime...");
*/
                You_hear("かすかなベルの音を聞いた．．．");
            if (!u.uhave.menorah)
/*JP
                pline("Vlad's doppelganger is amused.");
*/
                pline("ヴラドの生霊は笑った．");
            return;
        }

        for (otmp = invent; otmp; otmp = otmp->nobj) {
            if (otmp->otyp == CANDELABRUM_OF_INVOCATION && otmp->spe == 7
                && otmp->lamplit) {
                if (!otmp->cursed)
                    arti1_primed = TRUE;
                else
                    arti_cursed = TRUE;
            }
            if (otmp->otyp == BELL_OF_OPENING
                && (moves - otmp->age) < 5L) { /* you rang it recently */
                if (!otmp->cursed)
                    arti2_primed = TRUE;
                else
                    arti_cursed = TRUE;
            }
        }

        if (arti_cursed) {
/*JP
            pline_The("invocation fails!");
*/
            pline("特殊能力は発揮されなかった！");
/*JP
            pline("At least one of your artifacts is cursed...");
*/
            pline("少なくとも聖器のひとつが呪われている．．．");
        } else if (arti1_primed && arti2_primed) {
            unsigned soon =
                (unsigned) d(2, 6); /* time til next intervene() */

            /* successful invocation */
            mkinvokearea();
            u.uevent.invoked = 1;
            /* in case you haven't killed the Wizard yet, behave as if
               you just did */
            u.uevent.udemigod = 1; /* wizdead() */
            if (!u.udg_cnt || u.udg_cnt > soon)
                u.udg_cnt = soon;
        } else { /* at least one artifact not prepared properly */
/*JP
            You("have a feeling that %s is amiss...", something);
*/
            You("何かが間違っているような気がした．．．");
            goto raise_dead;
        }
        return;
    }

    /* when not an invocation situation */
    if (book2->cursed) {
    raise_dead:

/*JP
        You("raised the dead!");
*/
        You("死者を蘇らせた！");
        /* first maybe place a dangerous adversary */
        if (!rn2(3) && ((mtmp = makemon(&mons[PM_MASTER_LICH], u.ux, u.uy,
                                        NO_MINVENT)) != 0
                        || (mtmp = makemon(&mons[PM_NALFESHNEE], u.ux, u.uy,
                                           NO_MINVENT)) != 0)) {
            mtmp->mpeaceful = 0;
            set_malign(mtmp);
        }
        /* next handle the affect on things you're carrying */
        (void) unturn_dead(&youmonst);
        /* last place some monsters around you */
        mm.x = u.ux;
        mm.y = u.uy;
        mkundead(&mm, TRUE, NO_MINVENT);
    } else if (book2->blessed) {
        for (mtmp = fmon; mtmp; mtmp = mtmp2) {
            mtmp2 = mtmp->nmon; /* tamedog() changes chain */
            if (DEADMONSTER(mtmp))
                continue;

            if ((is_undead(mtmp->data) || is_vampshifter(mtmp))
                && cansee(mtmp->mx, mtmp->my)) {
                mtmp->mpeaceful = TRUE;
                if (sgn(mtmp->data->maligntyp) == sgn(u.ualign.type)
                    && distu(mtmp->mx, mtmp->my) < 4)
                    if (mtmp->mtame) {
                        if (mtmp->mtame < 20)
                            mtmp->mtame++;
                    } else
                        (void) tamedog(mtmp, (struct obj *) 0);
                else
                    monflee(mtmp, 0, FALSE, TRUE);
            }
        }
    } else {
        switch (rn2(3)) {
        case 0:
/*JP
            Your("ancestors are annoyed with you!");
*/
            Your("先祖はあなたが嫌いなようだ！");
            break;
        case 1:
/*JP
            pline_The("headstones in the cemetery begin to move!");
*/
            pline("墓地の墓石が動きはじめた！");
            break;
        default:
/*JP
            pline("Oh my!  Your name appears in the book!");
*/
            pline("なんてこったい！あなたの名前が本に書いてある！");
        }
    }
    return;
}

STATIC_PTR int
learn(VOID_ARGS)
{
    int i;
    short booktype;
    char splname[BUFSZ];
    boolean costly = TRUE;
    struct obj *book = context.spbook.book;

    /* JDS: lenses give 50% faster reading; 33% smaller read time */
    if (context.spbook.delay && ublindf && ublindf->otyp == LENSES && rn2(2))
        context.spbook.delay++;
    if (Confusion) { /* became confused while learning */
        (void) confused_book(book);
        context.spbook.book = 0; /* no longer studying */
        context.spbook.o_id = 0;
        nomul(context.spbook.delay); /* remaining delay is uninterrupted */
        multi_reason = "reading a book";
        nomovemsg = 0;
        context.spbook.delay = 0;
        return 0;
    }
    if (context
            .spbook.delay) { /* not if (context.spbook.delay++), so at end
                                delay == 0 */
        context.spbook.delay++;
        return 1; /* still busy */
    }
    exercise(A_WIS, TRUE); /* you're studying. */
    booktype = book->otyp;
    if (booktype == SPE_BOOK_OF_THE_DEAD) {
        deadbook(book);
        return 0;
    }

#if 0 /*JP*/
    Sprintf(splname,
            objects[booktype].oc_name_known ? "\"%s\"" : "the \"%s\" spell",
            OBJ_NAME(objects[booktype]));
#else
    Sprintf(splname,
            objects[booktype].oc_name_known ? "\"%s\"" : "\"%s\"",
            OBJ_NAME(objects[booktype]));
#endif
    for (i = 0; i < MAXSPELL; i++)
        if (spellid(i) == booktype || spellid(i) == NO_SPELL)
            break;

    if (i == MAXSPELL) {
        impossible("Too many spells memorized!");
    } else if (spellid(i) == booktype) {
        /* normal book can be read and re-read a total of 4 times */
        if (book->spestudied > MAX_SPELL_STUDY) {
/*JP
            pline("This spellbook is too faint to be read any more.");
*/
            pline("この魔法書の文字は薄すぎてこれ以上読めない．");
            book->otyp = booktype = SPE_BLANK_PAPER;
            /* reset spestudied as if polymorph had taken place */
            book->spestudied = rn2(book->spestudied);
        } else if (spellknow(i) > KEEN / 10) {
/*JP
            You("know %s quite well already.", splname);
*/
            You("すでに%sを熟知している．", splname);
            costly = FALSE;
        } else { /* spellknow(i) <= KEEN/10 */
#if 0 /*JP*/
            Your("knowledge of %s is %s.", splname,
                 spellknow(i) ? "keener" : "restored");
#else
            Your("%sに対する知識は%sされた．", splname,
                 spellknow(i) ? "さらに研ぎすま" : "復元");
#endif
            incrnknow(i, 1);
            book->spestudied++;
            exercise(A_WIS, TRUE); /* extra study */
        }
        /* make book become known even when spell is already
           known, in case amnesia made you forget the book */
        makeknown((int) booktype);
    } else { /* (spellid(i) == NO_SPELL) */
        /* for a normal book, spestudied will be zero, but for
           a polymorphed one, spestudied will be non-zero and
           one less reading is available than when re-learning */
        if (book->spestudied >= MAX_SPELL_STUDY) {
            /* pre-used due to being the product of polymorph */
/*JP
            pline("This spellbook is too faint to read even once.");
*/
            pline("この魔法書の文字は薄すぎてこれ以上読めない．");
            book->otyp = booktype = SPE_BLANK_PAPER;
            /* reset spestudied as if polymorph had taken place */
            book->spestudied = rn2(book->spestudied);
        } else {
            spl_book[i].sp_id = booktype;
            spl_book[i].sp_lev = objects[booktype].oc_level;
            incrnknow(i, 1);
            book->spestudied++;
/*JP
            You(i > 0 ? "add %s to your repertoire." : "learn %s.", splname);
*/
            You(i > 0 ? "%sをレパートリーに加えた．" : "%sを習得した．", splname);
        }
        makeknown((int) booktype);
    }

    if (book->cursed) { /* maybe a demon cursed it */
        if (cursed_book(book)) {
            useup(book);
            context.spbook.book = 0;
            context.spbook.o_id = 0;
            return 0;
        }
    }
    if (costly)
        check_unpaid(book);
    context.spbook.book = 0;
    context.spbook.o_id = 0;
    return 0;
}

int
study_book(spellbook)
register struct obj *spellbook;
{
    int booktype = spellbook->otyp;
    boolean confused = (Confusion != 0);
    boolean too_hard = FALSE;

    /* attempting to read dull book may make hero fall asleep */
    if (!confused && booktype != SPE_BLANK_PAPER
/*JP
        && !strcmp(OBJ_DESCR(objects[booktype]), "dull")) {
*/
        && !strcmp(OBJ_DESCR(objects[booktype]), "鉛色の魔法書")) {
        const char *eyes;
        int dullbook = rnd(25) - ACURR(A_WIS);

        /* adjust chance if hero stayed awake, got interrupted, retries */
        if (context.spbook.delay && spellbook == context.spbook.book)
            dullbook -= rnd(objects[booktype].oc_level);

        if (dullbook > 0) {
            eyes = body_part(EYE);
            if (eyecount(youmonst.data) > 1)
                eyes = makeplural(eyes);
/*JP
            pline("This book is so dull that you can't keep your %s open.",
*/
            pline("この本は退屈すぎて%sを開けていられない．",
                  eyes);
            dullbook += rnd(2 * objects[booktype].oc_level);
            fall_asleep(-dullbook, TRUE);
            return 1;
        }
    }

    if (context.spbook.delay && !confused && spellbook == context.spbook.book
        /* handle the sequence: start reading, get interrupted, have
           context.spbook.book become erased somehow, resume reading it */
        && booktype != SPE_BLANK_PAPER) {
#if 0 /*JP*/
        You("continue your efforts to %s.",
            (booktype == SPE_NOVEL) ? "read the novel" : "memorize the spell");
#else
        You("%sを再開した．",
            (booktype == SPE_NOVEL) ? "読書" : "魔法の学習");
#endif
    } else {
        /* KMH -- Simplified this code */
        if (booktype == SPE_BLANK_PAPER) {
/*JP
            pline("This spellbook is all blank.");
*/
            pline("この魔法書は真っ白だ．");
            makeknown(booktype);
            return 1;
        }

        /* 3.6.0 tribute */
        if (booktype == SPE_NOVEL) {
            /* Obtain current Terry Pratchett book title */
            const char *tribtitle = noveltitle(&spellbook->novelidx);

            if (read_tribute("books", tribtitle, 0, (char *) 0, 0,
                             spellbook->o_id)) {
                u.uconduct.literate++;
                check_unpaid(spellbook);
                if (!u.uevent.read_tribute) {
                    /* give bonus of 20 xp and 4*20+0 pts */
                    more_experienced(20, 0);
                    newexplevel();
                    u.uevent.read_tribute = 1; /* only once */
                }
            }
            return 1;
        }

        switch (objects[booktype].oc_level) {
        case 1:
        case 2:
            context.spbook.delay = -objects[booktype].oc_delay;
            break;
        case 3:
        case 4:
            context.spbook.delay = -(objects[booktype].oc_level - 1)
                                   * objects[booktype].oc_delay;
            break;
        case 5:
        case 6:
            context.spbook.delay =
                -objects[booktype].oc_level * objects[booktype].oc_delay;
            break;
        case 7:
            context.spbook.delay = -8 * objects[booktype].oc_delay;
            break;
        default:
            impossible("Unknown spellbook level %d, book %d;",
                       objects[booktype].oc_level, booktype);
            return 0;
        }

        /* Books are often wiser than their readers (Rus.) */
        spellbook->in_use = TRUE;
        if (!spellbook->blessed && spellbook->otyp != SPE_BOOK_OF_THE_DEAD) {
            if (spellbook->cursed) {
                too_hard = TRUE;
            } else {
                /* uncursed - chance to fail */
                int read_ability =
                    ACURR(A_INT) + 4 + u.ulevel / 2
                    - 2 * objects[booktype].oc_level
                    + ((ublindf && ublindf->otyp == LENSES) ? 2 : 0);
                /* only wizards know if a spell is too difficult */
                if (Role_if(PM_WIZARD) && read_ability < 20 && !confused) {
                    char qbuf[QBUFSZ];
                    Sprintf(qbuf,
#if 0 /*JP*/
                     "This spellbook is %sdifficult to comprehend. Continue?",
                            (read_ability < 12 ? "very " : ""));
#else
                     "この魔法書を理解するのは%s困難だ．続けますか？",
                            (read_ability < 12 ? "とても" : ""));
#endif
                    if (yn(qbuf) != 'y') {
                        spellbook->in_use = FALSE;
                        return 1;
                    }
                }
                /* its up to random luck now */
                if (rnd(20) > read_ability) {
                    too_hard = TRUE;
                }
            }
        }

        if (too_hard) {
            boolean gone = cursed_book(spellbook);

            nomul(context.spbook.delay); /* study time */
            multi_reason = "reading a book";
            nomovemsg = 0;
            context.spbook.delay = 0;
            if (gone || !rn2(3)) {
                if (!gone)
/*JP
                    pline_The("spellbook crumbles to dust!");
*/
                    pline("魔法書は塵となった！");
                if (!objects[spellbook->otyp].oc_name_known
                    && !objects[spellbook->otyp].oc_uname)
                    docall(spellbook);
                useup(spellbook);
            } else
                spellbook->in_use = FALSE;
            return 1;
        } else if (confused) {
            if (!confused_book(spellbook)) {
                spellbook->in_use = FALSE;
            }
            nomul(context.spbook.delay);
            multi_reason = "reading a book";
            nomovemsg = 0;
            context.spbook.delay = 0;
            return 1;
        }
        spellbook->in_use = FALSE;

#if 0 /*JP*/
        You("begin to %s the runes.",
            spellbook->otyp == SPE_BOOK_OF_THE_DEAD ? "recite" : "memorize");
#else
        You("ルーン文字を%sしはじめた．",
            spellbook->otyp == SPE_BOOK_OF_THE_DEAD ? "暗唱" : "記憶");
#endif
    }

    context.spbook.book = spellbook;
    if (context.spbook.book)
        context.spbook.o_id = context.spbook.book->o_id;
/*JP
    set_occupation(learn, "studying", 0);
*/
    set_occupation(learn, "学ぶ", 0);
    return 1;
}

/* a spellbook has been destroyed or the character has changed levels;
   the stored address for the current book is no longer valid */
void
book_disappears(obj)
struct obj *obj;
{
    if (obj == context.spbook.book) {
        context.spbook.book = (struct obj *) 0;
        context.spbook.o_id = 0;
    }
}

/* renaming an object usually results in it having a different address;
   so the sequence start reading, get interrupted, name the book, resume
   reading would read the "new" book from scratch */
void
book_substitution(old_obj, new_obj)
struct obj *old_obj, *new_obj;
{
    if (old_obj == context.spbook.book) {
        context.spbook.book = new_obj;
        if (context.spbook.book)
            context.spbook.o_id = context.spbook.book->o_id;
    }
}

/* called from moveloop() */
void
age_spells()
{
    int i;
    /*
     * The time relative to the hero (a pass through move
     * loop) causes all spell knowledge to be decremented.
     * The hero's speed, rest status, conscious status etc.
     * does not alter the loss of memory.
     */
    for (i = 0; i < MAXSPELL && spellid(i) != NO_SPELL; i++)
        if (spellknow(i))
            decrnknow(i);
    return;
}

/* return True if spellcasting is inhibited;
   only covers a small subset of reasons why casting won't work */
STATIC_OVL boolean
rejectcasting()
{
    /* rejections which take place before selecting a particular spell */
    if (Stunned) {
/*JP
        You("are too impaired to cast a spell.");
*/
        You("魔法を唱えられない．");
        return TRUE;
    } else if (!freehand()) {
        /* Note: !freehand() occurs when weapon and shield (or two-handed
         * weapon) are welded to hands, so "arms" probably doesn't need
         * to be makeplural(bodypart(ARM)).
         *
         * But why isn't lack of free arms (for gesturing) an issue when
         * poly'd hero has no limbs?
         */
/*JP
        Your("arms are not free to cast!");
*/
        pline("魔法を唱えようにも腕の自由が効かない！");
        return TRUE;
    }
    return FALSE;
}

/*
 * Return TRUE if a spell was picked, with the spell index in the return
 * parameter.  Otherwise return FALSE.
 */
STATIC_OVL boolean
getspell(spell_no)
int *spell_no;
{
    int nspells, idx;
    char ilet, lets[BUFSZ], qbuf[QBUFSZ];

    if (spellid(0) == NO_SPELL) {
/*JP
        You("don't know any spells right now.");
*/
        You("今のところ何の魔法も知らない．");
        return FALSE;
    }
    if (rejectcasting())
        return FALSE; /* no spell chosen */

    if (flags.menu_style == MENU_TRADITIONAL) {
        /* we know there is at least 1 known spell */
        for (nspells = 1; nspells < MAXSPELL && spellid(nspells) != NO_SPELL;
             nspells++)
            continue;

        if (nspells == 1)
            Strcpy(lets, "a");
        else if (nspells < 27)
            Sprintf(lets, "a-%c", 'a' + nspells - 1);
        else if (nspells == 27)
            Sprintf(lets, "a-zA");
        /* this assumes that there are at most 52 spells... */
        else
            Sprintf(lets, "a-zA-%c", 'A' + nspells - 27);

        for (;;) {
/*JP
            Sprintf(qbuf, "Cast which spell? [%s *?]", lets);
*/
            Sprintf(qbuf, "どの魔法を唱える？[%s ?]", lets);
            ilet = yn_function(qbuf, (char *) 0, '\0');
            if (ilet == '*' || ilet == '?')
                break; /* use menu mode */
            if (index(quitchars, ilet))
                return FALSE;

            idx = spell_let_to_idx(ilet);
            if (idx < 0 || idx >= nspells) {
/*JP
                You("don't know that spell.");
*/
                You("そんな魔法は知らない．");
                continue; /* ask again */
            }
            *spell_no = idx;
            return TRUE;
        }
    }
/*JP
    return dospellmenu("Choose which spell to cast", SPELLMENU_CAST,
*/
    return dospellmenu("どの魔法を唱える？", SPELLMENU_CAST,
                       spell_no);
}

/* the 'Z' command -- cast a spell */
int
docast()
{
    int spell_no;

    if (getspell(&spell_no))
        return spelleffects(spell_no, FALSE);
    return 0;
}

STATIC_OVL const char *
spelltypemnemonic(skill)
int skill;
{
    switch (skill) {
    case P_ATTACK_SPELL:
/*JP
        return "attack";
*/
        return "攻撃";
    case P_HEALING_SPELL:
/*JP
        return "healing";
*/
        return "治癒";
    case P_DIVINATION_SPELL:
/*JP
        return "divination";
*/
        return "予知";
    case P_ENCHANTMENT_SPELL:
/*JP
        return "enchantment";
*/
        return "補助";
    case P_CLERIC_SPELL:
/*JP
        return "clerical";
*/
        return "僧侶";
    case P_ESCAPE_SPELL:
/*JP
        return "escape";
*/
        return "脱出";
    case P_MATTER_SPELL:
/*JP
        return "matter";
*/
        return "物質";
    default:
        impossible("Unknown spell skill, %d;", skill);
        return "";
    }
}

int
spell_skilltype(booktype)
int booktype;
{
    return objects[booktype].oc_skill;
}

STATIC_OVL void
cast_protection()
{
    int l = u.ulevel, loglev = 0,
        gain, natac = u.uac + u.uspellprot;
    /* note: u.uspellprot is subtracted when find_ac() factors it into u.uac,
       so adding here factors it back out
       (versions prior to 3.6 had this backwards) */

    /* loglev=log2(u.ulevel)+1 (1..5) */
    while (l) {
        loglev++;
        l /= 2;
    }

    /* The more u.uspellprot you already have, the less you get,
     * and the better your natural ac, the less you get.
     *
     *  LEVEL AC    SPELLPROT from successive SPE_PROTECTION casts
     *      1     10    0,  1,  2,  3,  4
     *      1      0    0,  1,  2,  3
     *      1    -10    0,  1,  2
     *      2-3   10    0,  2,  4,  5,  6,  7,  8
     *      2-3    0    0,  2,  4,  5,  6
     *      2-3  -10    0,  2,  3,  4
     *      4-7   10    0,  3,  6,  8,  9, 10, 11, 12
     *      4-7    0    0,  3,  5,  7,  8,  9
     *      4-7  -10    0,  3,  5,  6
     *      7-15 -10    0,  3,  5,  6
     *      8-15  10    0,  4,  7, 10, 12, 13, 14, 15, 16
     *      8-15   0    0,  4,  7,  9, 10, 11, 12
     *      8-15 -10    0,  4,  6,  7,  8
     *     16-30  10    0,  5,  9, 12, 14, 16, 17, 18, 19, 20
     *     16-30   0    0,  5,  9, 11, 13, 14, 15
     *     16-30 -10    0,  5,  8,  9, 10
     */
    natac = (10 - natac) / 10; /* convert to positive and scale down */
    gain = loglev - (int) u.uspellprot / (4 - min(3, natac));

    if (gain > 0) {
        if (!Blind) {
            int rmtyp;
            const char *hgolden = hcolor(NH_GOLDEN), *atmosphere;

            if (u.uspellprot) {
/*JP
                pline_The("%s haze around you becomes more dense.", hgolden);
*/
                pline("あなたのまわりの%s霞が濃くなった．", hgolden);
            } else {
                rmtyp = levl[u.ux][u.uy].typ;
                atmosphere = u.uswallow
                                ? ((u.ustuck->data == &mons[PM_FOG_CLOUD])
/*JP
                                   ? "mist"
*/
                                   ? "霧"
                                   : is_whirly(u.ustuck->data)
/*JP
                                      ? "maelstrom"
*/
                                      ? "渦"
                                      : is_animal(u.ustuck->data)
/*JP
                                         ? "maw"
*/
                                         ? "胃"
/*JP
                                         : "ooze")
*/
                                         : "ねばねば")
                                : (u.uinwater
/*JP
                                   ? "water"
*/
                                   ? "水"
                                   : (rmtyp == CLOUD)
/*JP
                                      ? "cloud"
*/
                                      ? "雲"
                                      : IS_TREE(rmtyp)
/*JP
                                         ? "vegitation"
*/
                                         ? "木"
                                         : IS_STWALL(rmtyp)
/*JP
                                            ? "stone"
*/
                                            ? "石"
/*JP
                                            : "air");
*/
                                            : "空気");
#if 0 /*JP*/
                pline_The("%s around you begins to shimmer with %s haze.",
                          atmosphere, an(hgolden));
#else
                pline("あなたのまわりの%sが%s霧でキラキラと光りはじめた．",
                          atmosphere, hgolden);
#endif
            }
        }
        u.uspellprot += gain;
        u.uspmtime = (P_SKILL(spell_skilltype(SPE_PROTECTION)) == P_EXPERT)
                        ? 20 : 10;
        if (!u.usptime)
            u.usptime = u.uspmtime;
        find_ac();
    } else {
/*JP
        Your("skin feels warm for a moment.");
*/
        Your("肌は一瞬ポカポカした．");
    }
}

/* attempting to cast a forgotten spell will cause disorientation */
STATIC_OVL void
spell_backfire(spell)
int spell;
{
    long duration = (long) ((spellev(spell) + 1) * 3), /* 6..24 */
         old_stun = (HStun & TIMEOUT), old_conf = (HConfusion & TIMEOUT);

    /* Prior to 3.4.1, only effect was confusion; it still predominates.
     *
     * 3.6.0: this used to override pre-existing confusion duration
     * (cases 0..8) and pre-existing stun duration (cases 4..9);
     * increase them instead.   (Hero can no longer cast spells while
     * Stunned, so the potential increment to stun duration here is
     * just hypothetical.)
     */
    switch (rn2(10)) {
    case 0:
    case 1:
    case 2:
    case 3:
        make_confused(old_conf + duration, FALSE); /* 40% */
        break;
    case 4:
    case 5:
    case 6:
        make_confused(old_conf + 2L * duration / 3L, FALSE); /* 30% */
        make_stunned(old_stun + duration / 3L, FALSE);
        break;
    case 7:
    case 8:
        make_stunned(old_conf + 2L * duration / 3L, FALSE); /* 20% */
        make_confused(old_stun + duration / 3L, FALSE);
        break;
    case 9:
        make_stunned(old_stun + duration, FALSE); /* 10% */
        break;
    }
    return;
}

int
spelleffects(spell, atme)
int spell;
boolean atme;
{
    int energy, damage, chance, n, intell;
    int skill, role_skill;
    boolean confused = (Confusion != 0);
    boolean physical_damage = FALSE;
    struct obj *pseudo;
    coord cc;

    /*
     * Reject attempting to cast while stunned or with no free hands.
     * Already done in getspell() to stop casting before choosing
     * which spell, but duplicated here for cases where spelleffects()
     * gets called directly for ^T without intrinsic teleport capability
     * or #turn for non-priest/non-knight.
     * (There's no duplication of messages; when the rejection takes
     * place in getspell(), we don't get called.)
     */
    if (rejectcasting()) {
        return 0; /* no time elapses */
    }

    /*
     * Spell casting no longer affects knowledge of the spell. A
     * decrement of spell knowledge is done every turn.
     */
    if (spellknow(spell) <= 0) {
/*JP
        Your("knowledge of this spell is twisted.");
*/
        Your("この魔法に関する知識はよじれた．");
/*JP
        pline("It invokes nightmarish images in your mind...");
*/
        pline("それは悪夢を心に浮ばせた．．．");
        spell_backfire(spell);
        return 1;
    } else if (spellknow(spell) <= KEEN / 200) { /* 100 turns left */
/*JP
        You("strain to recall the spell.");
*/
        You("魔法を思いだすのに苦労した．");
    } else if (spellknow(spell) <= KEEN / 40) { /* 500 turns left */
/*JP
        You("have difficulty remembering the spell.");
*/
        You("呪文を思い出すのが難しくなってきた．");
    } else if (spellknow(spell) <= KEEN / 20) { /* 1000 turns left */
/*JP
        Your("knowledge of this spell is growing faint.");
*/
        Your("この魔法に関する知識がおぼろげになってきた．");
    } else if (spellknow(spell) <= KEEN / 10) { /* 2000 turns left */
/*JP
        Your("recall of this spell is gradually fading.");
*/
        Your("この魔法に関する知識が徐々に薄れてきた．");
    }
    energy = (spellev(spell) * 5); /* 5 <= energy <= 35 */

    if (u.uhunger <= 10 && spellid(spell) != SPE_DETECT_FOOD) {
/*JP
        You("are too hungry to cast that spell.");
*/
        pline("腹が減りすぎて魔法を唱えられない．");
        return 0;
    } else if (ACURR(A_STR) < 4 && spellid(spell) != SPE_RESTORE_ABILITY) {
/*JP
        You("lack the strength to cast spells.");
*/
        pline("強さが少なすぎて魔法を唱えられない．");
        return 0;
    } else if (check_capacity(
/*JP
                "Your concentration falters while carrying so much stuff.")) {
*/
                "たくさんものを持ちすぎて集中できない．")){
        return 1;
    }

    if (u.uhave.amulet) {
/*JP
        You_feel("the amulet draining your energy away.");
*/
        pline("魔除けがあなたのエネルギーを吸いとっているような気がした．");
        energy += rnd(2 * energy);
    }
    if (energy > u.uen) {
/*JP
        You("don't have enough energy to cast that spell.");
*/
        pline("魔法を唱えるだけの十分なエネルギーがない．");
        return 0;
    } else {
        if (spellid(spell) != SPE_DETECT_FOOD) {
            int hungr = energy * 2;

            /* If hero is a wizard, their current intelligence
             * (bonuses + temporary + current)
             * affects hunger reduction in casting a spell.
             * 1. int = 17-18 no reduction
             * 2. int = 16    1/4 hungr
             * 3. int = 15    1/2 hungr
             * 4. int = 1-14  normal reduction
             * The reason for this is:
             * a) Intelligence affects the amount of exertion
             * in thinking.
             * b) Wizards have spent their life at magic and
             * understand quite well how to cast spells.
             */
            intell = acurr(A_INT);
            if (!Role_if(PM_WIZARD))
                intell = 10;
            switch (intell) {
            case 25:
            case 24:
            case 23:
            case 22:
            case 21:
            case 20:
            case 19:
            case 18:
            case 17:
                hungr = 0;
                break;
            case 16:
                hungr /= 4;
                break;
            case 15:
                hungr /= 2;
                break;
            }
            /* don't put player (quite) into fainting from
             * casting a spell, particularly since they might
             * not even be hungry at the beginning; however,
             * this is low enough that they must eat before
             * casting anything else except detect food
             */
            if (hungr > u.uhunger - 3)
                hungr = u.uhunger - 3;
            morehungry(hungr);
        }
    }

    chance = percent_success(spell);
    if (confused || (rnd(100) > chance)) {
/*JP
        You("fail to cast the spell correctly.");
*/
        You("魔法を正しく唱えることができなかった．");
        u.uen -= energy / 2;
        context.botl = 1;
        return 1;
    }

    u.uen -= energy;
    context.botl = 1;
    exercise(A_WIS, TRUE);
    /* pseudo is a temporary "false" object containing the spell stats */
    pseudo = mksobj(spellid(spell), FALSE, FALSE);
    pseudo->blessed = pseudo->cursed = 0;
    pseudo->quan = 20L; /* do not let useup get it */
    /*
     * Find the skill the hero has in a spell type category.
     * See spell_skilltype for categories.
     */
    skill = spell_skilltype(pseudo->otyp);
    role_skill = P_SKILL(skill);

    switch (pseudo->otyp) {
    /*
     * At first spells act as expected.  As the hero increases in skill
     * with the appropriate spell type, some spells increase in their
     * effects, e.g. more damage, further distance, and so on, without
     * additional cost to the spellcaster.
     */
    case SPE_FIREBALL:
    case SPE_CONE_OF_COLD:
        if (role_skill >= P_SKILLED) {
            if (throwspell()) {
                cc.x = u.dx;
                cc.y = u.dy;
                n = rnd(8) + 1;
                while (n--) {
                    if (!u.dx && !u.dy && !u.dz) {
                        if ((damage = zapyourself(pseudo, TRUE)) != 0) {
                            char buf[BUFSZ];
#if 0 /*JP*/
                            Sprintf(buf, "zapped %sself with a spell",
                                    uhim());
                            losehp(damage, buf, NO_KILLER_PREFIX);
#else
                            Strcpy(buf, "自分自身の魔法を浴びて");
                            losehp(damage, buf, KILLED_BY);
#endif
                        }
                    } else {
                        explode(u.dx, u.dy,
                                pseudo->otyp - SPE_MAGIC_MISSILE + 10,
                                spell_damage_bonus(u.ulevel / 2 + 1), 0,
                                (pseudo->otyp == SPE_CONE_OF_COLD)
                                   ? EXPL_FROSTY
                                   : EXPL_FIERY);
                    }
                    u.dx = cc.x + rnd(3) - 2;
                    u.dy = cc.y + rnd(3) - 2;
                    if (!isok(u.dx, u.dy) || !cansee(u.dx, u.dy)
                        || IS_STWALL(levl[u.dx][u.dy].typ) || u.uswallow) {
                        /* Spell is reflected back to center */
                        u.dx = cc.x;
                        u.dy = cc.y;
                    }
                }
            }
            break;
        } /* else fall through... */

    /* these spells are all duplicates of wand effects */
    case SPE_FORCE_BOLT:
        physical_damage = TRUE;
    /* fall through */
    case SPE_SLEEP:
    case SPE_MAGIC_MISSILE:
    case SPE_KNOCK:
    case SPE_SLOW_MONSTER:
    case SPE_WIZARD_LOCK:
    case SPE_DIG:
    case SPE_TURN_UNDEAD:
    case SPE_POLYMORPH:
    case SPE_TELEPORT_AWAY:
    case SPE_CANCELLATION:
    case SPE_FINGER_OF_DEATH:
    case SPE_LIGHT:
    case SPE_DETECT_UNSEEN:
    case SPE_HEALING:
    case SPE_EXTRA_HEALING:
    case SPE_DRAIN_LIFE:
    case SPE_STONE_TO_FLESH:
        if (!(objects[pseudo->otyp].oc_dir == NODIR)) {
            if (atme) {
                u.dx = u.dy = u.dz = 0;
            } else if (!getdir((char *) 0)) {
                /* getdir cancelled, re-use previous direction */
                /*
                 * FIXME:  reusing previous direction only makes sense
                 * if there is an actual previous direction.  When there
                 * isn't one, the spell gets cast at self which is rarely
                 * what the player intended.  Unfortunately, the way
                 * spelleffects() is organized means that aborting with
                 * "nevermind" is not an option.
                 */
/*JP
                pline_The("magical energy is released!");
*/
                pline("魔法のエネルギーが解放された！");
            }
            if (!u.dx && !u.dy && !u.dz) {
                if ((damage = zapyourself(pseudo, TRUE)) != 0) {
                    char buf[BUFSZ];

/*JP
                    Sprintf(buf, "zapped %sself with a spell", uhim());
*/
                    Strcpy(buf, "自分自身の魔法を浴びて");
                    if (physical_damage)
                        damage = Maybe_Half_Phys(damage);
#if 0 /*JP*/
                    losehp(damage, buf, NO_KILLER_PREFIX);
#else
                    losehp(damage, buf, KILLED_BY);
#endif
                }
            } else
                weffects(pseudo);
        } else
            weffects(pseudo);
        update_inventory(); /* spell may modify inventory */
        break;

    /* these are all duplicates of scroll effects */
    case SPE_REMOVE_CURSE:
    case SPE_CONFUSE_MONSTER:
    case SPE_DETECT_FOOD:
    case SPE_CAUSE_FEAR:
    case SPE_IDENTIFY:
        /* high skill yields effect equivalent to blessed scroll */
        if (role_skill >= P_SKILLED)
            pseudo->blessed = 1;
    /* fall through */
    case SPE_CHARM_MONSTER:
    case SPE_MAGIC_MAPPING:
    case SPE_CREATE_MONSTER:
        (void) seffects(pseudo);
        break;

    /* these are all duplicates of potion effects */
    case SPE_HASTE_SELF:
    case SPE_DETECT_TREASURE:
    case SPE_DETECT_MONSTERS:
    case SPE_LEVITATION:
    case SPE_RESTORE_ABILITY:
        /* high skill yields effect equivalent to blessed potion */
        if (role_skill >= P_SKILLED)
            pseudo->blessed = 1;
    /* fall through */
    case SPE_INVISIBILITY:
        (void) peffects(pseudo);
        break;

    case SPE_CURE_BLINDNESS:
        healup(0, 0, FALSE, TRUE);
        break;
    case SPE_CURE_SICKNESS:
        if (Sick)
/*JP
            You("are no longer ill.");
*/
            Your("病気は直った．");
        if (Slimed)
/*JP
            make_slimed(0L, "The slime disappears!");
*/
            make_slimed(0L, "スライムは消えた！");
        healup(0, 0, TRUE, FALSE);
        break;
    case SPE_CREATE_FAMILIAR:
        (void) make_familiar((struct obj *) 0, u.ux, u.uy, FALSE);
        break;
    case SPE_CLAIRVOYANCE:
        if (!BClairvoyant)
            do_vicinity_map();
        /* at present, only one thing blocks clairvoyance */
        else if (uarmh && uarmh->otyp == CORNUTHAUM)
/*JP
            You("sense a pointy hat on top of your %s.", body_part(HEAD));
*/
            You("とがった帽子を%sの上に発見した．", body_part(HEAD));
        break;
    case SPE_PROTECTION:
        cast_protection();
        break;
    case SPE_JUMPING:
        if (!jump(max(role_skill, 1)))
            pline1(nothing_happens);
        break;
    default:
        impossible("Unknown spell %d attempted.", spell);
        obfree(pseudo, (struct obj *) 0);
        return 0;
    }

    /* gain skill for successful cast */
    use_skill(skill, spellev(spell));

    obfree(pseudo, (struct obj *) 0); /* now, get rid of it */
    return 1;
}

/* Choose location where spell takes effect. */
STATIC_OVL int
throwspell()
{
    coord cc;
    struct monst *mtmp;

    if (u.uinwater) {
/*JP
        pline("You're joking! In this weather?");
*/
        pline("水中で何をしようっていうんだい？");
        return 0;
    } else if (Is_waterlevel(&u.uz)) {
/*JP
        You("had better wait for the sun to come out.");
*/
        You("太陽が現れるまで待ったほうがよいだろう．");
        return 0;
    }

/*JP
    pline("Where do you want to cast the spell?");
*/
    pline("どこに向かって魔法を唱える？");
    cc.x = u.ux;
    cc.y = u.uy;
/*JP
    if (getpos(&cc, TRUE, "the desired position") < 0)
*/
    if (getpos(&cc, TRUE, "望みの場所") < 0)
        return 0; /* user pressed ESC */
    /* The number of moves from hero to where the spell drops.*/
    if (distmin(u.ux, u.uy, cc.x, cc.y) > 10) {
/*JP
        pline_The("spell dissipates over the distance!");
*/
        pline("遠すぎる！");
        return 0;
    } else if (u.uswallow) {
/*JP
        pline_The("spell is cut short!");
*/
        pline("だめだ！近すぎる！");
        exercise(A_WIS, FALSE); /* What were you THINKING! */
        u.dx = 0;
        u.dy = 0;
        return 1;
    } else if ((!cansee(cc.x, cc.y)
                && (!(mtmp = m_at(cc.x, cc.y)) || !canspotmon(mtmp)))
               || IS_STWALL(levl[cc.x][cc.y].typ)) {
/*JP
        Your("mind fails to lock onto that location!");
*/
        You("そこに向かって集中したが失敗した！");
        return 0;
    }

    u.dx = cc.x;
    u.dy = cc.y;
    return 1;
}

/* forget a random selection of known spells due to amnesia;
   they used to be lost entirely, as if never learned, but now we
   just set the memory retention to zero so that they can't be cast */
void
losespells()
{
    int n, nzap, i;

    /* in case reading has been interrupted earlier, discard context */
    context.spbook.book = 0;
    context.spbook.o_id = 0;
    /* count the number of known spells */
    for (n = 0; n < MAXSPELL; ++n)
        if (spellid(n) == NO_SPELL)
            break;

    /* lose anywhere from zero to all known spells;
       if confused, use the worse of two die rolls */
    nzap = rn2(n + 1);
    if (Confusion) {
        i = rn2(n + 1);
        if (i > nzap)
            nzap = i;
    }
    /* good Luck might ameliorate spell loss */
    if (nzap > 1 && !rnl(7))
        nzap = rnd(nzap);

    /*
     * Forget 'nzap' out of 'n' known spells by setting their memory
     * retention to zero.  Every spell has the same probability to be
     * forgotten, even if its retention is already zero.
     *
     * Perhaps we should forget the corresponding book too?
     *
     * (3.4.3 removed spells entirely from the list, but always did
     * so from its end, so the 'nzap' most recently learned spells
     * were the ones lost by default.  Player had sort control over
     * the list, so could move the most useful spells to front and
     * only lose them if 'nzap' turned out to be a large value.
     *
     * Discarding from the end of the list had the virtue of making
     * casting letters for lost spells become invalid and retaining
     * the original letter for the ones which weren't lost, so there
     * was no risk to the player of accidentally casting the wrong
     * spell when using a letter that was in use prior to amnesia.
     * That wouldn't be the case if we implemented spell loss spread
     * throughout the list of known spells; every spell located past
     * the first lost spell would end up with new letter assigned.)
     */
    for (i = 0; nzap > 0; ++i) {
        /* when nzap is small relative to the number of spells left,
           the chance to lose spell [i] is small; as the number of
           remaining candidates shrinks, the chance per candidate
           gets bigger; overall, exactly nzap entries are affected */
        if (rn2(n - i) < nzap) {
            /* lose access to spell [i] */
            spellknow(i) = 0;
#if 0
            /* also forget its book */
            forget_single_object(spellid(i));
#endif
            /* and abuse wisdom */
            exercise(A_WIS, FALSE);
            /* there's now one less spell slated to be forgotten */
            --nzap;
        }
    }
}

/*
 * Allow player to sort the list of known spells.  Manually swapping
 * pairs of them becomes very tedious once the list reaches two pages.
 *
 * Possible extensions:
 *      provide means for player to control ordering of skill classes;
 *      provide means to supply value N such that first N entries stick
 *      while rest of list is being sorted;
 *      make chosen sort order be persistent such that when new spells
 *      are learned, they get inserted into sorted order rather than be
 *      appended to the end of the list?
 */
static const char *spl_sortchoices[] = {
/*JP
    "by casting letter",
*/
    "選択する文字順",
#define SORTBY_LETTER 0
/*JP
    "alphabetically",
*/
    "文字コード順",
#define SORTBY_ALPHA 1
/*JP
    "by level, low to high",
*/
    "レベル昇順",
#define SORTBY_LVL_LO 2
/*JP
    "by level, high to low",
*/
    "レベル降順",
#define SORTBY_LVL_HI 3
/*JP
    "by skill group, alphabetized within each group",
*/
    "スキルグループ毎に文字コード順",
#define SORTBY_SKL_AL 4
/*JP
    "by skill group, low to high level within group",
*/
    "スキルグループ毎にレベル昇順",
#define SORTBY_SKL_LO 5
/*JP
    "by skill group, high to low level within group",
*/
    "スキルグループ毎にレベル降順",
#define SORTBY_SKL_HI 6
/*JP
    "maintain current ordering",
*/
    "現在の順序を維持",
#define SORTBY_CURRENT 7
    /* a menu choice rather than a sort choice */
/*JP
    "reassign casting letters to retain current order",
*/
    "現在の順序を変えずに選択する文字を再割り当て",
#define SORTRETAINORDER 8
};
static int spl_sortmode = 0;   /* index into spl_sortchoices[] */
static int *spl_orderindx = 0; /* array of spl_book[] indices */

/* qsort callback routine */
STATIC_PTR int CFDECLSPEC
spell_cmp(vptr1, vptr2)
const genericptr vptr1;
const genericptr vptr2;
{
    /*
     * gather up all of the possible parameters except spell name
     * in advance, even though some might not be needed:
     *  indx. = spl_orderindx[] index into spl_book[];
     *  otyp. = spl_book[] index into objects[];
     *  levl. = spell level;
     *  skil. = skill group aka spell class.
     */
    int indx1 = *(int *) vptr1, indx2 = *(int *) vptr2,
        otyp1 = spl_book[indx1].sp_id, otyp2 = spl_book[indx2].sp_id,
        levl1 = objects[otyp1].oc_level, levl2 = objects[otyp2].oc_level,
        skil1 = objects[otyp1].oc_skill, skil2 = objects[otyp2].oc_skill;

    switch (spl_sortmode) {
    case SORTBY_LETTER:
        return indx1 - indx2;
    case SORTBY_ALPHA:
        break;
    case SORTBY_LVL_LO:
        if (levl1 != levl2)
            return levl1 - levl2;
        break;
    case SORTBY_LVL_HI:
        if (levl1 != levl2)
            return levl2 - levl1;
        break;
    case SORTBY_SKL_AL:
        if (skil1 != skil2)
            return skil1 - skil2;
        break;
    case SORTBY_SKL_LO:
        if (skil1 != skil2)
            return skil1 - skil2;
        if (levl1 != levl2)
            return levl1 - levl2;
        break;
    case SORTBY_SKL_HI:
        if (skil1 != skil2)
            return skil1 - skil2;
        if (levl1 != levl2)
            return levl2 - levl1;
        break;
    case SORTBY_CURRENT:
    default:
        return (vptr1 < vptr2) ? -1
                               : (vptr1 > vptr2); /* keep current order */
    }
    /* tie-breaker for most sorts--alphabetical by spell name */
    return strcmpi(OBJ_NAME(objects[otyp1]), OBJ_NAME(objects[otyp2]));
}

/* sort the index used for display order of the "view known spells"
   list (sortmode == SORTBY_xxx), or sort the spellbook itself to make
   the current display order stick (sortmode == SORTRETAINORDER) */
STATIC_OVL void
sortspells()
{
    int i;
#if defined(SYSV) || defined(DGUX)
    unsigned n;
#else
    int n;
#endif

    if (spl_sortmode == SORTBY_CURRENT)
        return;
    for (n = 0; n < MAXSPELL && spellid(n) != NO_SPELL; ++n)
        continue;
    if (n < 2)
        return; /* not enough entries to need sorting */

    if (!spl_orderindx) {
        /* we haven't done any sorting yet; list is in casting order */
        if (spl_sortmode == SORTBY_LETTER /* default */
            || spl_sortmode == SORTRETAINORDER)
            return;
        /* allocate enough for full spellbook rather than just N spells */
        spl_orderindx = (int *) alloc(MAXSPELL * sizeof(int));
        for (i = 0; i < MAXSPELL; i++)
            spl_orderindx[i] = i;
    }

    if (spl_sortmode == SORTRETAINORDER) {
        struct spell tmp_book[MAXSPELL];

        /* sort spl_book[] rather than spl_orderindx[];
           this also updates the index to reflect the new ordering (we
           could just free it since that ordering becomes the default) */
        for (i = 0; i < MAXSPELL; i++)
            tmp_book[i] = spl_book[spl_orderindx[i]];
        for (i = 0; i < MAXSPELL; i++)
            spl_book[i] = tmp_book[i], spl_orderindx[i] = i;
        spl_sortmode = SORTBY_LETTER; /* reset */
        return;
    }

    /* usual case, sort the index rather than the spells themselves */
    qsort((genericptr_t) spl_orderindx, n, sizeof *spl_orderindx, spell_cmp);
    return;
}

/* called if the [sort spells] entry in the view spells menu gets chosen */
STATIC_OVL boolean
spellsortmenu()
{
    winid tmpwin;
    menu_item *selected;
    anything any;
    char let;
    int i, n, choice;

    tmpwin = create_nhwindow(NHW_MENU);
    start_menu(tmpwin);
    any = zeroany; /* zero out all bits */

    for (i = 0; i < SIZE(spl_sortchoices); i++) {
        if (i == SORTRETAINORDER) {
            let = 'z'; /* assumes fewer than 26 sort choices... */
            /* separate final choice from others with a blank line */
            any.a_int = 0;
            add_menu(tmpwin, NO_GLYPH, &any, 0, 0, ATR_NONE, "",
                     MENU_UNSELECTED);
        } else {
            let = 'a' + i;
        }
        any.a_int = i + 1;
        add_menu(tmpwin, NO_GLYPH, &any, let, 0, ATR_NONE, spl_sortchoices[i],
                 (i == spl_sortmode) ? MENU_SELECTED : MENU_UNSELECTED);
    }
    end_menu(tmpwin, "View known spells list sorted");

    n = select_menu(tmpwin, PICK_ONE, &selected);
    destroy_nhwindow(tmpwin);
    if (n > 0) {
        choice = selected[0].item.a_int - 1;
        /* skip preselected entry if we have more than one item chosen */
        if (n > 1 && choice == spl_sortmode)
            choice = selected[1].item.a_int - 1;
        free((genericptr_t) selected);
        spl_sortmode = choice;
        return TRUE;
    }
    return FALSE;
}

/* the '+' command -- view known spells */
int
dovspell()
{
    char qbuf[QBUFSZ];
    int splnum, othnum;
    struct spell spl_tmp;

    if (spellid(0) == NO_SPELL) {
/*JP
        You("don't know any spells right now.");
*/
        You("魔法を知らない．");
    } else {
/*JP
        while (dospellmenu("Currently known spells",
*/
        while (dospellmenu("現在知っている魔法一覧",
                           SPELLMENU_VIEW, &splnum)) {
            if (splnum == SPELLMENU_SORT) {
                if (spellsortmenu())
                    sortspells();
            } else {
/*JP
                Sprintf(qbuf, "Reordering spells; swap '%c' with",
*/
                Sprintf(qbuf, "'%c'と並び変える魔法は？",
                        spellet(splnum));
                if (!dospellmenu(qbuf, splnum, &othnum))
                    break;

                spl_tmp = spl_book[splnum];
                spl_book[splnum] = spl_book[othnum];
                spl_book[othnum] = spl_tmp;
            }
        }
    }
    if (spl_orderindx) {
        free((genericptr_t) spl_orderindx);
        spl_orderindx = 0;
    }
    spl_sortmode = SORTBY_LETTER; /* 0 */
    return 0;
}

STATIC_OVL boolean
dospellmenu(prompt, splaction, spell_no)
const char *prompt;
int splaction; /* SPELLMENU_CAST, SPELLMENU_VIEW, or spl_book[] index */
int *spell_no;
{
    winid tmpwin;
    int i, n, how, splnum;
    char buf[BUFSZ], retentionbuf[24];
    const char *fmt;
    menu_item *selected;
    anything any;

    tmpwin = create_nhwindow(NHW_MENU);
    start_menu(tmpwin);
    any = zeroany; /* zero out all bits */

    /*
     * The correct spacing of the columns when not using
     * tab separation depends on the following:
     * (1) that the font is monospaced, and
     * (2) that selection letters are pre-pended to the
     * given string and are of the form "a - ".
     */
    if (!iflags.menu_tab_sep) {
#if 0 /*JP*/
        Sprintf(buf, "%-20s     Level %-12s Fail Retention", "    Name",
                "Category");
#else
        Sprintf(buf, "%-20s     Level  %-12s 成功率", "    Name", "分類");
#endif
        fmt = "%-20s  %2d   %-12s %3d%% %9s";
    } else {
/*JP
        Sprintf(buf, "Name\tLevel\tCategory\tFail\tRetention");
*/
        Sprintf(buf, "名前\tレベル\t分類\t成功率");
        fmt = "%s\t%-d\t%s\t%-d%%\t%s";
    }
    add_menu(tmpwin, NO_GLYPH, &any, 0, 0, iflags.menu_headings, buf,
             MENU_UNSELECTED);
    for (i = 0; i < MAXSPELL && spellid(i) != NO_SPELL; i++) {
        splnum = !spl_orderindx ? i : spl_orderindx[i];
        Sprintf(buf, fmt, spellname(splnum), spellev(splnum),
                spelltypemnemonic(spell_skilltype(spellid(splnum))),
                100 - percent_success(splnum),
                spellretention(splnum, retentionbuf));

        any.a_int = splnum + 1; /* must be non-zero */
        add_menu(tmpwin, NO_GLYPH, &any, spellet(splnum), 0, ATR_NONE, buf,
                 (splnum == splaction) ? MENU_SELECTED : MENU_UNSELECTED);
    }
    how = PICK_ONE;
    if (splaction == SPELLMENU_VIEW) {
        if (spellid(1) == NO_SPELL) {
            /* only one spell => nothing to swap with */
            how = PICK_NONE;
        } else {
            /* more than 1 spell, add an extra menu entry */
            any.a_int = SPELLMENU_SORT + 1;
            add_menu(tmpwin, NO_GLYPH, &any, '+', 0, ATR_NONE,
                     "[sort spells]", MENU_UNSELECTED);
        }
    }
    end_menu(tmpwin, prompt);

    n = select_menu(tmpwin, how, &selected);
    destroy_nhwindow(tmpwin);
    if (n > 0) {
        *spell_no = selected[0].item.a_int - 1;
        /* menu selection for `PICK_ONE' does not
           de-select any preselected entry */
        if (n > 1 && *spell_no == splaction)
            *spell_no = selected[1].item.a_int - 1;
        free((genericptr_t) selected);
        /* default selection of preselected spell means that
           user chose not to swap it with anything */
        if (*spell_no == splaction)
            return FALSE;
        return TRUE;
    } else if (splaction >= 0) {
        /* explicit de-selection of preselected spell means that
           user is still swapping but not for the current spell */
        *spell_no = splaction;
        return TRUE;
    }
    return FALSE;
}

STATIC_OVL int
percent_success(spell)
int spell;
{
    /* Intrinsic and learned ability are combined to calculate
     * the probability of player's success at cast a given spell.
     */
    int chance, splcaster, special, statused;
    int difficulty;
    int skill;

    /* Calculate intrinsic ability (splcaster) */

    splcaster = urole.spelbase;
    special = urole.spelheal;
    statused = ACURR(urole.spelstat);

    if (uarm && is_metallic(uarm))
        splcaster += (uarmc && uarmc->otyp == ROBE) ? urole.spelarmr / 2
                                                    : urole.spelarmr;
    else if (uarmc && uarmc->otyp == ROBE)
        splcaster -= urole.spelarmr;
    if (uarms)
        splcaster += urole.spelshld;

    if (uarmh && is_metallic(uarmh) && uarmh->otyp != HELM_OF_BRILLIANCE)
        splcaster += uarmhbon;
    if (uarmg && is_metallic(uarmg))
        splcaster += uarmgbon;
    if (uarmf && is_metallic(uarmf))
        splcaster += uarmfbon;

    if (spellid(spell) == urole.spelspec)
        splcaster += urole.spelsbon;

    /* `healing spell' bonus */
    if (spellid(spell) == SPE_HEALING || spellid(spell) == SPE_EXTRA_HEALING
        || spellid(spell) == SPE_CURE_BLINDNESS
        || spellid(spell) == SPE_CURE_SICKNESS
        || spellid(spell) == SPE_RESTORE_ABILITY
        || spellid(spell) == SPE_REMOVE_CURSE)
        splcaster += special;

    if (splcaster > 20)
        splcaster = 20;

    /* Calculate learned ability */

    /* Players basic likelihood of being able to cast any spell
     * is based of their `magic' statistic. (Int or Wis)
     */
    chance = 11 * statused / 2;

    /*
     * High level spells are harder.  Easier for higher level casters.
     * The difficulty is based on the hero's level and their skill level
     * in that spell type.
     */
    skill = P_SKILL(spell_skilltype(spellid(spell)));
    skill = max(skill, P_UNSKILLED) - 1; /* unskilled => 0 */
    difficulty =
        (spellev(spell) - 1) * 4 - ((skill * 6) + (u.ulevel / 3) + 1);

    if (difficulty > 0) {
        /* Player is too low level or unskilled. */
        chance -= isqrt(900 * difficulty + 2000);
    } else {
        /* Player is above level.  Learning continues, but the
         * law of diminishing returns sets in quickly for
         * low-level spells.  That is, a player quickly gains
         * no advantage for raising level.
         */
        int learning = 15 * -difficulty / spellev(spell);
        chance += learning > 20 ? 20 : learning;
    }

    /* Clamp the chance: >18 stat and advanced learning only help
     * to a limit, while chances below "hopeless" only raise the
     * specter of overflowing 16-bit ints (and permit wearing a
     * shield to raise the chances :-).
     */
    if (chance < 0)
        chance = 0;
    if (chance > 120)
        chance = 120;

    /* Wearing anything but a light shield makes it very awkward
     * to cast a spell.  The penalty is not quite so bad for the
     * player's role-specific spell.
     */
    if (uarms && weight(uarms) > (int) objects[SMALL_SHIELD].oc_weight) {
        if (spellid(spell) == urole.spelspec) {
            chance /= 2;
        } else {
            chance /= 4;
        }
    }

    /* Finally, chance (based on player intell/wisdom and level) is
     * combined with ability (based on player intrinsics and
     * encumbrances).  No matter how intelligent/wise and advanced
     * a player is, intrinsics and encumbrance can prevent casting;
     * and no matter how able, learning is always required.
     */
    chance = chance * (20 - splcaster) / 15 - splcaster;

    /* Clamp to percentile */
    if (chance > 100)
        chance = 100;
    if (chance < 0)
        chance = 0;

    return chance;
}

STATIC_OVL char *
spellretention(idx, outbuf)
int idx;
char *outbuf;
{
    long turnsleft, percent, accuracy;
    int skill;

    skill = P_SKILL(spell_skilltype(spellid(idx)));
    skill = max(skill, P_UNSKILLED); /* restricted same as unskilled */
    turnsleft = spellknow(idx);
    *outbuf = '\0'; /* lint suppression */

    if (turnsleft < 1L) {
        /* spell has expired; hero can't successfully cast it anymore */
        Strcpy(outbuf, "(gone)");
    } else if (turnsleft >= (long) KEEN) {
        /* full retention, first turn or immediately after reading book */
        Strcpy(outbuf, "100%");
    } else {
        /*
         * Retention is displayed as a range of percentages of
         * amount of time left until memory of the spell expires;
         * the precision of the range depends upon hero's skill
         * in this spell.
         *    expert:  2% intervals; 1-2,   3-4,  ...,   99-100;
         *   skilled:  5% intervals; 1-5,   6-10, ...,   95-100;
         *     basic: 10% intervals; 1-10, 11-20, ...,   91-100;
         * unskilled: 25% intervals; 1-25, 26-50, 51-75, 76-100.
         *
         * At the low end of each range, a value of N% really means
         * (N-1)%+1 through N%; so 1% is "greater than 0, at most 200".
         * KEEN is a multiple of 100; KEEN/100 loses no precision.
         */
        percent = (turnsleft - 1L) / ((long) KEEN / 100L) + 1L;
        accuracy =
            (skill == P_EXPERT) ? 2L : (skill == P_SKILLED)
                                           ? 5L
                                           : (skill == P_BASIC) ? 10L : 25L;
        /* round up to the high end of this range */
        percent = accuracy * ((percent - 1L) / accuracy + 1L);
        Sprintf(outbuf, "%ld%%-%ld%%", percent - accuracy + 1L, percent);
    }
    return outbuf;
}

/* Learn a spell during creation of the initial inventory */
void
initialspell(obj)
struct obj *obj;
{
    int i, otyp = obj->otyp;

    for (i = 0; i < MAXSPELL; i++)
        if (spellid(i) == NO_SPELL || spellid(i) == otyp)
            break;

    if (i == MAXSPELL) {
        impossible("Too many spells memorized!");
    } else if (spellid(i) != NO_SPELL) {
        /* initial inventory shouldn't contain duplicate spellbooks */
        impossible("Spell %s already known.", OBJ_NAME(objects[otyp]));
    } else {
        spl_book[i].sp_id = otyp;
        spl_book[i].sp_lev = objects[otyp].oc_level;
        incrnknow(i, 0);
    }
    return;
}

/*spell.c*/
