/* $OpenBSD: tty-acs.c,v 1.13 2023/08/08 07:19:48 nicm Exp $ */

/*
 * Copyright (c) 2010 Nicholas Marriott <nicholas.marriott@gmail.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>

#include <stdlib.h>
#include <string.h>

#include "tmux.h"

/* Table mapping ACS entries to UTF-8. */
struct tty_acs_entry {
        u_char           key;
        const char      *string;
};
static const struct tty_acs_entry tty_acs_table[] = {
        { '+', "\342\206\222" },        /* arrow pointing right */
        { ',', "\342\206\220" },        /* arrow pointing left */
        { '-', "\342\206\221" },        /* arrow pointing up */
        { '.', "\342\206\223" },        /* arrow pointing down */
        { '0', "\342\226\256" },        /* solid square block */
        { '`', "\342\227\206" },        /* diamond */
        { 'a', "\342\226\222" },        /* checker board (stipple) */
        { 'b', "\342\220\211" },
        { 'c', "\342\220\214" },
        { 'd', "\342\220\215" },
        { 'e', "\342\220\212" },
        { 'f', "\302\260" },            /* degree symbol */
        { 'g', "\302\261" },            /* plus/minus */
        { 'h', "\342\220\244" },
        { 'i', "\342\220\213" },
        { 'j', "\342\224\230" },        /* lower right corner */
        { 'k', "\342\224\220" },        /* upper right corner */
        { 'l', "\342\224\214" },        /* upper left corner */
        { 'm', "\342\224\224" },        /* lower left corner */
        { 'n', "\342\224\274" },        /* large plus or crossover */
        { 'o', "\342\216\272" },        /* scan line 1 */
        { 'p', "\342\216\273" },        /* scan line 3 */
        { 'q', "\342\224\200" },        /* horizontal line */
        { 'r', "\342\216\274" },        /* scan line 7 */
        { 's', "\342\216\275" },        /* scan line 9 */
        { 't', "\342\224\234" },        /* tee pointing right */
        { 'u', "\342\224\244" },        /* tee pointing left */
        { 'v', "\342\224\264" },        /* tee pointing up */
        { 'w', "\342\224\254" },        /* tee pointing down */
        { 'x', "\342\224\202" },        /* vertical line */
        { 'y', "\342\211\244" },        /* less-than-or-equal-to */
        { 'z', "\342\211\245" },        /* greater-than-or-equal-to */
        { '{', "\317\200" },            /* greek pi */
        { '|', "\342\211\240" },        /* not-equal */
        { '}', "\302\243" },            /* UK pound sign */
        { '~', "\302\267" }             /* bullet */
};

/* Table mapping UTF-8 to ACS entries. */
struct tty_acs_reverse_entry {
        const char      *string;
        u_char           key;
};
static const struct tty_acs_reverse_entry tty_acs_reverse2[] = {
        { "\302\267", '~' }
};
static const struct tty_acs_reverse_entry tty_acs_reverse3[] = {
        { "\342\224\200", 'q' },
        { "\342\224\201", 'q' },
        { "\342\224\202", 'x' },
        { "\342\224\203", 'x' },
        { "\342\224\214", 'l' },
        { "\342\224\217", 'k' },
        { "\342\224\220", 'k' },
        { "\342\224\223", 'l' },
        { "\342\224\224", 'm' },
        { "\342\224\227", 'm' },
        { "\342\224\230", 'j' },
        { "\342\224\233", 'j' },
        { "\342\224\234", 't' },
        { "\342\224\243", 't' },
        { "\342\224\244", 'u' },
        { "\342\224\253", 'u' },
        { "\342\224\263", 'w' },
        { "\342\224\264", 'v' },
        { "\342\224\273", 'v' },
        { "\342\224\274", 'n' },
        { "\342\225\213", 'n' },
        { "\342\225\220", 'q' },
        { "\342\225\221", 'x' },
        { "\342\225\224", 'l' },
        { "\342\225\227", 'k' },
        { "\342\225\232", 'm' },
        { "\342\225\235", 'j' },
        { "\342\225\240", 't' },
        { "\342\225\243", 'u' },
        { "\342\225\246", 'w' },
        { "\342\225\251", 'v' },
        { "\342\225\254", 'n' },
};

/* UTF-8 double borders. */
static const struct utf8_data tty_acs_double_borders_list[] = {
        { "", 0, 0, 0 },
        { "\342\225\221", 0, 3, 1 }, /* U+2551 */
        { "\342\225\220", 0, 3, 1 }, /* U+2550 */
        { "\342\225\224", 0, 3, 1 }, /* U+2554 */
        { "\342\225\227", 0, 3, 1 }, /* U+2557 */
        { "\342\225\232", 0, 3, 1 }, /* U+255A */
        { "\342\225\235", 0, 3, 1 }, /* U+255D */
        { "\342\225\246", 0, 3, 1 }, /* U+2566 */
        { "\342\225\251", 0, 3, 1 }, /* U+2569 */
        { "\342\225\240", 0, 3, 1 }, /* U+2560 */
        { "\342\225\243", 0, 3, 1 }, /* U+2563 */
        { "\342\225\254", 0, 3, 1 }, /* U+256C */
        { "\302\267",     0, 2, 1 }  /* U+00B7 */
};

/* UTF-8 heavy borders. */
static const struct utf8_data tty_acs_heavy_borders_list[] = {
        { "", 0, 0, 0 },
        { "\342\224\203", 0, 3, 1 }, /* U+2503 */
        { "\342\224\201", 0, 3, 1 }, /* U+2501 */
        { "\342\224\217", 0, 3, 1 }, /* U+250F */
        { "\342\224\223", 0, 3, 1 }, /* U+2513 */
        { "\342\224\227", 0, 3, 1 }, /* U+2517 */
        { "\342\224\233", 0, 3, 1 }, /* U+251B */
        { "\342\224\263", 0, 3, 1 }, /* U+2533 */
        { "\342\224\273", 0, 3, 1 }, /* U+253B */
        { "\342\224\243", 0, 3, 1 }, /* U+2523 */
        { "\342\224\253", 0, 3, 1 }, /* U+252B */
        { "\342\225\213", 0, 3, 1 }, /* U+254B */
        { "\302\267",     0, 2, 1 }  /* U+00B7 */
};

/* UTF-8 rounded borders. */
static const struct utf8_data tty_acs_rounded_borders_list[] = {
        { "", 0, 0, 0 },
        { "\342\224\202", 0, 3, 1 }, /* U+2502 */
        { "\342\224\200", 0, 3, 1 }, /* U+2500 */
        { "\342\225\255", 0, 3, 1 }, /* U+256D */
        { "\342\225\256", 0, 3, 1 }, /* U+256E */
        { "\342\225\260", 0, 3, 1 }, /* U+2570 */
        { "\342\225\257", 0, 3, 1 }, /* U+256F */
        { "\342\224\263", 0, 3, 1 }, /* U+2533 */
        { "\342\224\273", 0, 3, 1 }, /* U+253B */
        { "\342\224\234", 0, 3, 1 }, /* U+2524 */
        { "\342\224\244", 0, 3, 1 }, /* U+251C */
        { "\342\225\213", 0, 3, 1 }, /* U+254B */
        { "\302\267",     0, 2, 1 }  /* U+00B7 */
};

/* Get cell border character for double style. */
const struct utf8_data *
tty_acs_double_borders(int cell_type)
{
        return (&tty_acs_double_borders_list[cell_type]);
}

/* Get cell border character for heavy style. */
const struct utf8_data *
tty_acs_heavy_borders(int cell_type)
{
        return (&tty_acs_heavy_borders_list[cell_type]);
}

/* Get cell border character for rounded style. */
const struct utf8_data *
tty_acs_rounded_borders(int cell_type)
{
        return (&tty_acs_rounded_borders_list[cell_type]);
}

static int
tty_acs_cmp(const void *key, const void *value)
{
        const struct tty_acs_entry      *entry = value;
        int                              test = *(u_char *)key;

        return (test - entry->key);
}

static int
tty_acs_reverse_cmp(const void *key, const void *value)
{
        const struct tty_acs_reverse_entry      *entry = value;
        const char                              *test = key;

        return (strcmp(test, entry->string));
}

/* Should this terminal use ACS instead of UTF-8 line drawing? */
int
tty_acs_needed(struct tty *tty)
{
        if (tty == NULL)
                return (0);

        /*
         * If the U8 flag is present, it marks whether a terminal supports
         * UTF-8 and ACS together.
         *
         * If it is present and zero, we force ACS - this gives users a way to
         * turn off UTF-8 line drawing.
         *
         * If it is nonzero, we can fall through to the default and use UTF-8
         * line drawing on UTF-8 terminals.
         */
        if (tty_term_has(tty->term, TTYC_U8) &&
            tty_term_number(tty->term, TTYC_U8) == 0)
                return (1);

        if (tty->client->flags & CLIENT_UTF8)
                return (0);
        return (1);
}

/* Retrieve ACS to output as UTF-8. */
const char *
tty_acs_get(struct tty *tty, u_char ch)
{
        const struct tty_acs_entry      *entry;

        /* Use the ACS set instead of UTF-8 if needed. */
        if (tty_acs_needed(tty)) {
                if (tty->term->acs[ch][0] == '\0')
                        return (NULL);
                return (&tty->term->acs[ch][0]);
        }

        /* Otherwise look up the UTF-8 translation. */
        entry = bsearch(&ch, tty_acs_table, nitems(tty_acs_table),
            sizeof tty_acs_table[0], tty_acs_cmp);
        if (entry == NULL)
                return (NULL);
        return (entry->string);
}

/* Reverse UTF-8 into ACS. */
int
tty_acs_reverse_get(__unused struct tty *tty, const char *s, size_t slen)
{
        const struct tty_acs_reverse_entry      *table, *entry;
        u_int                                    items;

        if (slen == 2) {
                table = tty_acs_reverse2;
                items = nitems(tty_acs_reverse2);
        } else if (slen == 3) {
                table = tty_acs_reverse3;
                items = nitems(tty_acs_reverse3);
        } else
                return (-1);
        entry = bsearch(s, table, items, sizeof table[0], tty_acs_reverse_cmp);
        if (entry == NULL)
                return (-1);
        return (entry->key);
}