/*      $OpenBSD: fish.c,v 1.23 2016/03/07 12:07:56 mestre Exp $        */
/*      $NetBSD: fish.c,v 1.3 1995/03/23 08:28:18 cgd Exp $     */

/*-
 * Copyright (c) 1990, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Muffy Barkocy.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/wait.h>

#include <err.h>
#include <fcntl.h>
#include <paths.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "pathnames.h"

#define RANKS           13
#define HANDSIZE        7
#define CARDS           4
#define TOTCARDS        RANKS * CARDS

#define USER            1
#define COMPUTER        0
#define OTHER(a)        (1 - (a))

const char *const cards[] = {
        "A", "2", "3", "4", "5", "6", "7",
        "8", "9", "10", "J", "Q", "K", NULL,
};
#define PRC(card)       (void)printf(" %s", cards[card])

int promode;
int curcard;
int asked[RANKS], comphand[RANKS], deck[TOTCARDS];
int userasked[RANKS], userhand[RANKS];

void    chkwinner(int, const int *);
int     compmove(void);
int     countbooks(const int *);
int     countcards(const int *);
int     drawcard(int, int *);
int     getans(const char *);
int     gofish(int, int, int *);
void    goodmove(int, int, int *, int *);
void    init(void);
void    instructions(void);
int     nrandom(int);
void    printhand(const int *);
void    printplayer(int);
int     promove(void);
__dead void     usage(void);
int     usermove(void);

int
main(int argc, char *argv[])
{
        int ch, move;

        if (pledge("stdio rpath proc exec", NULL) == -1)
                err(1, "pledge");

        while ((ch = getopt(argc, argv, "ph")) != -1)
                switch(ch) {
                case 'p':
                        promode = 1;
                        break;
                case 'h':
                default:
                        usage();
                }

        instructions();

        if (pledge("stdio", NULL) == -1)
                err(1, "pledge");

        init();

        if (nrandom(2) == 1) {
                printplayer(COMPUTER);
                (void)printf("get to start.\n");
                goto istart;
        }
        printplayer(USER);
        (void)printf("get to start.\n");
        
        for (;;) {
                move = usermove();
                if (!comphand[move]) {
                        if (gofish(move, USER, userhand))
                                continue;
                } else {
                        goodmove(USER, move, userhand, comphand);
                        continue;
                }

istart:         for (;;) {
                        move = compmove();
                        if (!userhand[move]) {
                                if (!gofish(move, COMPUTER, comphand))
                                        break;
                        } else
                                goodmove(COMPUTER, move, comphand, userhand);
                }
        }
}

int
usermove(void)
{
        int n;
        const char *const *p;
        char buf[256];

        (void)printf("\nYour hand is:");
        printhand(userhand);

        for (;;) {
                (void)printf("You ask me for: ");
                (void)fflush(stdout);
                if (fgets(buf, sizeof(buf), stdin) == NULL)
                        exit(0);
                if (buf[0] == '\0')
                        continue;
                if (buf[0] == '\n') {
                        (void)printf("%d cards in my hand, %d in the pool.\n",
                            countcards(comphand), curcard);
                        (void)printf("My books:");
                        (void)countbooks(comphand);
                        continue;
                }
                buf[strlen(buf) - 1] = '\0';
                if (!strcasecmp(buf, "p") && !promode) {
                        promode = 1;
                        (void)printf("Entering pro mode.\n");
                        continue;
                }
                if (!strcasecmp(buf, "quit"))
                        exit(0);
                for (p = cards; *p; ++p)
                        if (!strcasecmp(*p, buf))
                                break;
                if (!*p) {
                        (void)printf("I don't understand!\n");
                        continue;
                }
                n = p - cards;
                if (userhand[n]) {
                        userasked[n] = 1;
                        return(n);
                }
                if (nrandom(3) == 1)
                        (void)printf("You don't have any of those!\n");
                else
                        (void)printf("You don't have any %s's!\n", cards[n]);
                if (nrandom(4) == 1)
                        (void)printf("No cheating!\n");
                (void)printf("Guess again.\n");
        }
}

int
compmove(void)
{
        static int lmove;

        if (promode)
                lmove = promove();
        else {
                do {
                        lmove = (lmove + 1) % RANKS;
                } while (!comphand[lmove] || comphand[lmove] == CARDS);
        }
        asked[lmove] = 1;

        (void)printf("I ask you for: %s.\n", cards[lmove]);
        return(lmove);
}

int
promove(void)
{
        int i, max;

        for (i = 0; i < RANKS; ++i)
                if (userasked[i] &&
                    comphand[i] > 0 && comphand[i] < CARDS) {
                        userasked[i] = 0;
                        return(i);
                }
        if (nrandom(3) == 1) {
                for (i = 0;; ++i)
                        if (comphand[i] && comphand[i] != CARDS) {
                                max = i;
                                break;
                        }
                while (++i < RANKS) 
                        if (comphand[i] != CARDS &&
                            comphand[i] > comphand[max])
                                max = i;
                return(max);
        } 
        if (nrandom(1024) == 723) {
                for (i = 0; i < RANKS; ++i)
                        if (userhand[i] && comphand[i])
                                return(i);
        }
        for (;;) {
                for (i = 0; i < RANKS; ++i)
                        if (comphand[i] && comphand[i] != CARDS &&
                            !asked[i])
                                return(i);
                for (i = 0; i < RANKS; ++i)
                        asked[i] = 0;
        }
}

int
drawcard(int player, int *hand)
{
        int card;

        ++hand[card = deck[--curcard]];
        if (player == USER || hand[card] == CARDS) {
                printplayer(player);
                (void)printf("drew %s", cards[card]);
                if (hand[card] == CARDS) {
                        (void)printf(" and made a book of %s's!\n",
                             cards[card]);
                        chkwinner(player, hand);
                } else
                        (void)printf(".\n");
        }
        return(card);
}

int
gofish(int askedfor, int player, int *hand)
{
        printplayer(OTHER(player));
        (void)printf("say \"GO FISH!\"\n");
        if (askedfor == drawcard(player, hand)) {
                printplayer(player);
                (void)printf("drew the guess!\n");
                printplayer(player);
                (void)printf("get to ask again!\n");
                return(1);
        }
        return(0);
}

void
goodmove(int player, int move, int *hand, int *opphand)
{
        printplayer(OTHER(player));
        (void)printf("have %d %s%s.\n",
            opphand[move], cards[move], opphand[move] == 1 ? "": "'s");

        hand[move] += opphand[move];
        opphand[move] = 0;

        if (hand[move] == CARDS) {
                printplayer(player);
                (void)printf("made a book of %s's!\n", cards[move]);
                chkwinner(player, hand);
        }

        chkwinner(OTHER(player), opphand);

        printplayer(player);
        (void)printf("get another guess!\n");
}

void
chkwinner(int player, const int *hand)
{
        int cb, i, ub;

        for (i = 0; i < RANKS; ++i)
                if (hand[i] > 0 && hand[i] < CARDS)
                        return;
        printplayer(player);
        (void)printf("don't have any more cards!\n");
        (void)printf("My books:");
        cb = countbooks(comphand);
        (void)printf("Your books:");
        ub = countbooks(userhand);
        (void)printf("\nI have %d, you have %d.\n", cb, ub);
        if (ub > cb) {
                (void)printf("\nYou win!!!\n");
                if (nrandom(1024) == 723)
                        (void)printf("Cheater, cheater, pumpkin eater!\n");
        } else if (cb > ub) {
                (void)printf("\nI win!!!\n");
                if (nrandom(1024) == 723)
                        (void)printf("Hah!  Stupid peasant!\n");
        } else
                (void)printf("\nTie!\n");
        exit(0);
}

void
printplayer(int player)
{
        switch (player) {
        case COMPUTER:
                (void)printf("I ");
                break;
        case USER:
                (void)printf("You ");
                break;
        }
}

void
printhand(const int *hand)
{
        int book, i, j;

        for (book = i = 0; i < RANKS; i++)
                if (hand[i] < CARDS)
                        for (j = hand[i]; --j >= 0;) 
                                PRC(i);
                else
                        ++book;
        if (book) {
                (void)printf(" + Book%s of", book > 1 ? "s" : "");
                for (i = 0; i < RANKS; i++)
                        if (hand[i] == CARDS)
                                PRC(i);
        }
        (void)putchar('\n');
}

int
countcards(const int *hand)
{
        int i, count;

        for (count = i = 0; i < RANKS; i++)
                count += *hand++;
        return(count);
}

int
countbooks(const int *hand)
{
        int i, count;

        for (count = i = 0; i < RANKS; i++)
                if (hand[i] == CARDS) {
                        ++count;
                        PRC(i);
                }
        if (!count)
                (void)printf(" none");
        (void)putchar('\n');
        return(count);
}

void
init(void)
{
        int i, j, temp;

        curcard = TOTCARDS;
        for (i = 0; i < TOTCARDS; ++i)
                deck[i] = i % RANKS;
        for (i = 0; i < TOTCARDS - 1; ++i) {
                j = nrandom(TOTCARDS-i);
                if (j == 0)
                        continue;
                temp = deck[i];
                deck[i] = deck[i+j];
                deck[i+j] = temp;
        }
        for (i = 0; i < HANDSIZE; ++i) {
                ++userhand[deck[--curcard]];
                ++comphand[deck[--curcard]];
        }
}

int
nrandom(int n)
{
        return(arc4random_uniform(n));
}

int
getans(const char *prompt)
{
        char buf[20];

        /*
         * simple routine to ask the yes/no question specified until the user
         * answers yes or no, then return 1 if they said 'yes' and 0 if they
         * answered 'no'.
         */
        for (;;) {
                (void)printf("%s", prompt);
                (void)fflush(stdout);
                if (!fgets(buf, sizeof(buf), stdin)) {
                        (void)printf("\n");
                        exit(0);
                }
                if (*buf == 'N' || *buf == 'n')
                        return(0);
                if (*buf == 'Y' || *buf == 'y')
                        return(1);
                (void)printf(
"I don't understand your answer; please enter 'y' or 'n'!\n");
        }
}

void
instructions(void)
{
        const char *pager;
        pid_t pid;
        int status;
        int input;
        int fd;

        if (getans("Would you like instructions (y or n)? ") == 0)
                return;

        if ((fd = open(_PATH_INSTR, O_RDONLY)) == -1)
                (void)printf("No instruction file found!\n");
        else {
                switch (pid = fork()) {
                case 0: /* child */
                        if (!isatty(1))
                                pager = "/bin/cat";
                        else {
                                if (!(pager = getenv("PAGER")) || (*pager == 0))
                                        pager = _PATH_MORE;
                        }
                        if (dup2(fd, 0) == -1)
                                err(1, "dup2");
                        (void)execl(_PATH_BSHELL, "sh", "-c", pager, (char *)NULL);
                        err(1, "exec sh -c %s", pager);
                        /* NOT REACHED */
                case -1:
                        err(1, "fork");
                        /* NOT REACHED */
                default:
                        (void)waitpid(pid, &status, 0);
                        close(fd);
                        break;
                }
        }

        (void)printf("Hit return to continue...\n");
        while ((input = getchar()) != EOF && input != '\n');
}

void
usage(void)
{
        (void)fprintf(stderr, "usage: %s [-p]\n", getprogname());
        exit(1);
}