/* $OpenBSD: utf8.c,v 1.70 2026/03/18 08:38:54 nicm Exp $ */

/*
 * Copyright (c) 2008 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 <ctype.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <vis.h>

#include "tmux.h"

struct utf8_width_item {
        wchar_t                         wc;
        u_int                           width;
        int                             allocated;

        RB_ENTRY(utf8_width_item)       entry;
};

static int
utf8_width_cache_cmp(struct utf8_width_item *uw1, struct utf8_width_item *uw2)
{
        if (uw1->wc < uw2->wc)
                return (-1);
        if (uw1->wc > uw2->wc)
                return (1);
        return (0);
}
RB_HEAD(utf8_width_cache, utf8_width_item);
RB_GENERATE_STATIC(utf8_width_cache, utf8_width_item, entry,
    utf8_width_cache_cmp);
static struct utf8_width_cache utf8_width_cache =
    RB_INITIALIZER(utf8_width_cache);

static struct utf8_width_item utf8_default_width_cache[] = {
        { .wc = 0x0261D, .width = 2 },
        { .wc = 0x026F9, .width = 2 },
        { .wc = 0x0270A, .width = 2 },
        { .wc = 0x0270B, .width = 2 },
        { .wc = 0x0270C, .width = 2 },
        { .wc = 0x0270D, .width = 2 },
        { .wc = 0x1F1E6, .width = 1 },
        { .wc = 0x1F1E7, .width = 1 },
        { .wc = 0x1F1E8, .width = 1 },
        { .wc = 0x1F1E9, .width = 1 },
        { .wc = 0x1F1EA, .width = 1 },
        { .wc = 0x1F1EB, .width = 1 },
        { .wc = 0x1F1EC, .width = 1 },
        { .wc = 0x1F1ED, .width = 1 },
        { .wc = 0x1F1EE, .width = 1 },
        { .wc = 0x1F1EF, .width = 1 },
        { .wc = 0x1F1F0, .width = 1 },
        { .wc = 0x1F1F1, .width = 1 },
        { .wc = 0x1F1F2, .width = 1 },
        { .wc = 0x1F1F3, .width = 1 },
        { .wc = 0x1F1F4, .width = 1 },
        { .wc = 0x1F1F5, .width = 1 },
        { .wc = 0x1F1F6, .width = 1 },
        { .wc = 0x1F1F7, .width = 1 },
        { .wc = 0x1F1F8, .width = 1 },
        { .wc = 0x1F1F9, .width = 1 },
        { .wc = 0x1F1FA, .width = 1 },
        { .wc = 0x1F1FB, .width = 1 },
        { .wc = 0x1F1FC, .width = 1 },
        { .wc = 0x1F1FD, .width = 1 },
        { .wc = 0x1F1FE, .width = 1 },
        { .wc = 0x1F1FF, .width = 1 },
        { .wc = 0x1F385, .width = 2 },
        { .wc = 0x1F3C2, .width = 2 },
        { .wc = 0x1F3C3, .width = 2 },
        { .wc = 0x1F3C4, .width = 2 },
        { .wc = 0x1F3C7, .width = 2 },
        { .wc = 0x1F3CA, .width = 2 },
        { .wc = 0x1F3CB, .width = 2 },
        { .wc = 0x1F3CC, .width = 2 },
        { .wc = 0x1F3FB, .width = 2 },
        { .wc = 0x1F3FC, .width = 2 },
        { .wc = 0x1F3FD, .width = 2 },
        { .wc = 0x1F3FE, .width = 2 },
        { .wc = 0x1F3FF, .width = 2 },
        { .wc = 0x1F442, .width = 2 },
        { .wc = 0x1F443, .width = 2 },
        { .wc = 0x1F446, .width = 2 },
        { .wc = 0x1F447, .width = 2 },
        { .wc = 0x1F448, .width = 2 },
        { .wc = 0x1F449, .width = 2 },
        { .wc = 0x1F44A, .width = 2 },
        { .wc = 0x1F44B, .width = 2 },
        { .wc = 0x1F44C, .width = 2 },
        { .wc = 0x1F44D, .width = 2 },
        { .wc = 0x1F44E, .width = 2 },
        { .wc = 0x1F44F, .width = 2 },
        { .wc = 0x1F450, .width = 2 },
        { .wc = 0x1F466, .width = 2 },
        { .wc = 0x1F467, .width = 2 },
        { .wc = 0x1F468, .width = 2 },
        { .wc = 0x1F469, .width = 2 },
        { .wc = 0x1F46B, .width = 2 },
        { .wc = 0x1F46C, .width = 2 },
        { .wc = 0x1F46D, .width = 2 },
        { .wc = 0x1F46E, .width = 2 },
        { .wc = 0x1F470, .width = 2 },
        { .wc = 0x1F471, .width = 2 },
        { .wc = 0x1F472, .width = 2 },
        { .wc = 0x1F473, .width = 2 },
        { .wc = 0x1F474, .width = 2 },
        { .wc = 0x1F475, .width = 2 },
        { .wc = 0x1F476, .width = 2 },
        { .wc = 0x1F477, .width = 2 },
        { .wc = 0x1F478, .width = 2 },
        { .wc = 0x1F47C, .width = 2 },
        { .wc = 0x1F481, .width = 2 },
        { .wc = 0x1F482, .width = 2 },
        { .wc = 0x1F483, .width = 2 },
        { .wc = 0x1F485, .width = 2 },
        { .wc = 0x1F486, .width = 2 },
        { .wc = 0x1F487, .width = 2 },
        { .wc = 0x1F48F, .width = 2 },
        { .wc = 0x1F491, .width = 2 },
        { .wc = 0x1F4AA, .width = 2 },
        { .wc = 0x1F574, .width = 2 },
        { .wc = 0x1F575, .width = 2 },
        { .wc = 0x1F57A, .width = 2 },
        { .wc = 0x1F590, .width = 2 },
        { .wc = 0x1F595, .width = 2 },
        { .wc = 0x1F596, .width = 2 },
        { .wc = 0x1F645, .width = 2 },
        { .wc = 0x1F646, .width = 2 },
        { .wc = 0x1F647, .width = 2 },
        { .wc = 0x1F64B, .width = 2 },
        { .wc = 0x1F64C, .width = 2 },
        { .wc = 0x1F64D, .width = 2 },
        { .wc = 0x1F64E, .width = 2 },
        { .wc = 0x1F64F, .width = 2 },
        { .wc = 0x1F6A3, .width = 2 },
        { .wc = 0x1F6B4, .width = 2 },
        { .wc = 0x1F6B5, .width = 2 },
        { .wc = 0x1F6B6, .width = 2 },
        { .wc = 0x1F6C0, .width = 2 },
        { .wc = 0x1F6CC, .width = 2 },
        { .wc = 0x1F90C, .width = 2 },
        { .wc = 0x1F90F, .width = 2 },
        { .wc = 0x1F918, .width = 2 },
        { .wc = 0x1F919, .width = 2 },
        { .wc = 0x1F91A, .width = 2 },
        { .wc = 0x1F91B, .width = 2 },
        { .wc = 0x1F91C, .width = 2 },
        { .wc = 0x1F91D, .width = 2 },
        { .wc = 0x1F91E, .width = 2 },
        { .wc = 0x1F91F, .width = 2 },
        { .wc = 0x1F926, .width = 2 },
        { .wc = 0x1F930, .width = 2 },
        { .wc = 0x1F931, .width = 2 },
        { .wc = 0x1F932, .width = 2 },
        { .wc = 0x1F933, .width = 2 },
        { .wc = 0x1F934, .width = 2 },
        { .wc = 0x1F935, .width = 2 },
        { .wc = 0x1F936, .width = 2 },
        { .wc = 0x1F937, .width = 2 },
        { .wc = 0x1F938, .width = 2 },
        { .wc = 0x1F939, .width = 2 },
        { .wc = 0x1F93D, .width = 2 },
        { .wc = 0x1F93E, .width = 2 },
        { .wc = 0x1F977, .width = 2 },
        { .wc = 0x1F9B5, .width = 2 },
        { .wc = 0x1F9B6, .width = 2 },
        { .wc = 0x1F9B8, .width = 2 },
        { .wc = 0x1F9B9, .width = 2 },
        { .wc = 0x1F9BB, .width = 2 },
        { .wc = 0x1F9CD, .width = 2 },
        { .wc = 0x1F9CE, .width = 2 },
        { .wc = 0x1F9CF, .width = 2 },
        { .wc = 0x1F9D1, .width = 2 },
        { .wc = 0x1F9D2, .width = 2 },
        { .wc = 0x1F9D3, .width = 2 },
        { .wc = 0x1F9D4, .width = 2 },
        { .wc = 0x1F9D5, .width = 2 },
        { .wc = 0x1F9D6, .width = 2 },
        { .wc = 0x1F9D7, .width = 2 },
        { .wc = 0x1F9D8, .width = 2 },
        { .wc = 0x1F9D9, .width = 2 },
        { .wc = 0x1F9DA, .width = 2 },
        { .wc = 0x1F9DB, .width = 2 },
        { .wc = 0x1F9DC, .width = 2 },
        { .wc = 0x1F9DD, .width = 2 },
        { .wc = 0x1FAC3, .width = 2 },
        { .wc = 0x1FAC4, .width = 2 },
        { .wc = 0x1FAC5, .width = 2 },
        { .wc = 0x1FAF0, .width = 2 },
        { .wc = 0x1FAF1, .width = 2 },
        { .wc = 0x1FAF2, .width = 2 },
        { .wc = 0x1FAF3, .width = 2 },
        { .wc = 0x1FAF4, .width = 2 },
        { .wc = 0x1FAF5, .width = 2 },
        { .wc = 0x1FAF6, .width = 2 },
        { .wc = 0x1FAF7, .width = 2 },
        { .wc = 0x1FAF8, .width = 2 }
};

struct utf8_item {
        RB_ENTRY(utf8_item)     index_entry;
        u_int                   index;

        RB_ENTRY(utf8_item)     data_entry;
        char                    data[UTF8_SIZE];
        u_char                  size;
};

static int
utf8_data_cmp(struct utf8_item *ui1, struct utf8_item *ui2)
{
        if (ui1->size < ui2->size)
                return (-1);
        if (ui1->size > ui2->size)
                return (1);
        return (memcmp(ui1->data, ui2->data, ui1->size));
}
RB_HEAD(utf8_data_tree, utf8_item);
RB_GENERATE_STATIC(utf8_data_tree, utf8_item, data_entry, utf8_data_cmp);
static struct utf8_data_tree utf8_data_tree = RB_INITIALIZER(utf8_data_tree);

static int
utf8_index_cmp(struct utf8_item *ui1, struct utf8_item *ui2)
{
        if (ui1->index < ui2->index)
                return (-1);
        if (ui1->index > ui2->index)
                return (1);
        return (0);
}
RB_HEAD(utf8_index_tree, utf8_item);
RB_GENERATE_STATIC(utf8_index_tree, utf8_item, index_entry, utf8_index_cmp);
static struct utf8_index_tree utf8_index_tree = RB_INITIALIZER(utf8_index_tree);

static int      utf8_no_width;
static u_int    utf8_next_index;

#define UTF8_GET_SIZE(uc) (((uc) >> 24) & 0x1f)
#define UTF8_GET_WIDTH(uc) (((uc) >> 29) - 1)

#define UTF8_SET_SIZE(size) (((utf8_char)(size)) << 24)
#define UTF8_SET_WIDTH(width) ((((utf8_char)(width)) + 1) << 29)

/* Get a UTF-8 item from data. */
static struct utf8_item *
utf8_item_by_data(const u_char *data, size_t size)
{
        struct utf8_item        ui;

        memcpy(ui.data, data, size);
        ui.size = size;

        return (RB_FIND(utf8_data_tree, &utf8_data_tree, &ui));
}

/* Get a UTF-8 item from data. */
static struct utf8_item *
utf8_item_by_index(u_int index)
{
        struct utf8_item        ui;

        ui.index = index;

        return (RB_FIND(utf8_index_tree, &utf8_index_tree, &ui));
}

/* Find a codepoint in the cache. */
static struct utf8_width_item *
utf8_find_in_width_cache(wchar_t wc)
{
        struct utf8_width_item  uw;

        uw.wc = wc;
        return RB_FIND(utf8_width_cache, &utf8_width_cache, &uw);
}

/* Add to width cache. */
static void
utf8_insert_width_cache(wchar_t wc, u_int width)
{
        struct utf8_width_item  *uw, *old;

        log_debug("Unicode width cache: %08X=%u", (u_int)wc, width);

        uw = xcalloc(1, sizeof *uw);
        uw->wc = wc;
        uw->width = width;
        uw->allocated = 1;

        old = RB_INSERT(utf8_width_cache, &utf8_width_cache, uw);
        if (old != NULL) {
                RB_REMOVE(utf8_width_cache, &utf8_width_cache, old);
                if (old->allocated)
                        free(old);
                RB_INSERT(utf8_width_cache, &utf8_width_cache, uw);
        }
}

/* Parse a single codepoint option. */
static void
utf8_add_to_width_cache(const char *s)
{
        char                    *copy, *cp, *endptr;
        u_int                    width;
        const char              *errstr;
        struct utf8_data        *ud;
        wchar_t                  wc, wc_start, wc_end;
        unsigned long long       n;

        copy = xstrdup(s);
        if ((cp = strchr(copy, '=')) == NULL) {
                free(copy);
                return;
        }
        *cp++ = '\0';

        width = strtonum(cp, 0, 2, &errstr);
        if (errstr != NULL) {
                free(copy);
                return;
        }

        if (strncmp(copy, "U+", 2) == 0) {
                errno = 0;
                n = strtoull(copy + 2, &endptr, 16);
                if (copy[2] == '\0' ||
                    n == 0 ||
                    n > WCHAR_MAX ||
                    (errno == ERANGE && n == ULLONG_MAX)) {
                        free(copy);
                        return;
                }
                wc_start = n;
                if (*endptr == '-') {
                        endptr++;
                        if (strncmp(endptr, "U+", 2) != 0) {
                                free(copy);
                                return;
                        }
                        errno = 0;
                        n = strtoull(endptr + 2, &endptr, 16);
                        if (*endptr != '\0' ||
                            n == 0 ||
                            n > WCHAR_MAX ||
                            (errno == ERANGE && n == ULLONG_MAX) ||
                            (wchar_t)n < wc_start) {
                                free(copy);
                                return;
                        }
                        wc_end = n;
                } else {
                        if (*endptr != '\0') {
                                free(copy);
                                return;
                        }
                        wc_end = wc_start;
                }

                for (wc = wc_start; wc <= wc_end; wc++)
                        utf8_insert_width_cache(wc, width);
        } else {
                utf8_no_width = 1;
                ud = utf8_fromcstr(copy);
                utf8_no_width = 0;
                if (ud[0].size == 0 || ud[1].size != 0) {
                        free(ud);
                        free(copy);
                        return;
                }
#ifdef HAVE_UTF8PROC
                if (utf8proc_mbtowc(&wc, ud[0].data, ud[0].size) <= 0) {
#else
                if (mbtowc(&wc, ud[0].data, ud[0].size) <= 0) {
#endif
                        free(ud);
                        free(copy);
                        return;
                }
                free(ud);

                utf8_insert_width_cache(wc, width);
        }

        free(copy);
}

/* Rebuild cache of widths. */
void
utf8_update_width_cache(void)
{
        struct utf8_width_item          *uw, *uw1;
        struct options_entry            *o;
        struct options_array_item       *a;
        u_int                            i;

        RB_FOREACH_SAFE (uw, utf8_width_cache, &utf8_width_cache, uw1) {
                RB_REMOVE(utf8_width_cache, &utf8_width_cache, uw);
                if (uw->allocated)
                        free(uw);
        }

        for (i = 0; i < nitems(utf8_default_width_cache); i++) {
                RB_INSERT(utf8_width_cache, &utf8_width_cache,
                    &utf8_default_width_cache[i]);
        }

        o = options_get(global_options, "codepoint-widths");
        a = options_array_first(o);
        while (a != NULL) {
                utf8_add_to_width_cache(options_array_item_value(a)->string);
                a = options_array_next(a);
        }
}

/* Add a UTF-8 item. */
static int
utf8_put_item(const u_char *data, size_t size, u_int *index)
{
        struct utf8_item        *ui;

        ui = utf8_item_by_data(data, size);
        if (ui != NULL) {
                *index = ui->index;
                log_debug("%s: found %.*s = %u", __func__, (int)size, data,
                    *index);
                return (0);
        }

        if (utf8_next_index == 0xffffff + 1)
                return (-1);

        ui = xcalloc(1, sizeof *ui);
        ui->index = utf8_next_index++;
        RB_INSERT(utf8_index_tree, &utf8_index_tree, ui);

        memcpy(ui->data, data, size);
        ui->size = size;
        RB_INSERT(utf8_data_tree, &utf8_data_tree, ui);

        *index = ui->index;
        log_debug("%s: added %.*s = %u", __func__, (int)size, data, *index);
        return (0);
}

/* Get UTF-8 character from data. */
enum utf8_state
utf8_from_data(const struct utf8_data *ud, utf8_char *uc)
{
        u_int   index;

        if (ud->width > 2)
                fatalx("invalid UTF-8 width: %u", ud->width);

        if (ud->size > UTF8_SIZE)
                goto fail;
        if (ud->size <= 3) {
                index = (((utf8_char)ud->data[2] << 16)|
                          ((utf8_char)ud->data[1] << 8)|
                          ((utf8_char)ud->data[0]));
        } else if (utf8_put_item(ud->data, ud->size, &index) != 0)
                goto fail;
        *uc = UTF8_SET_SIZE(ud->size)|UTF8_SET_WIDTH(ud->width)|index;
        log_debug("%s: (%d %d %.*s) -> %08x", __func__, ud->width, ud->size,
            (int)ud->size, ud->data, *uc);
        return (UTF8_DONE);

fail:
        if (ud->width == 0)
                *uc = UTF8_SET_SIZE(0)|UTF8_SET_WIDTH(0);
        else if (ud->width == 1)
                *uc = UTF8_SET_SIZE(1)|UTF8_SET_WIDTH(1)|0x20;
        else
                *uc = UTF8_SET_SIZE(1)|UTF8_SET_WIDTH(1)|0x2020;
        return (UTF8_ERROR);
}

/* Get UTF-8 data from character. */
void
utf8_to_data(utf8_char uc, struct utf8_data *ud)
{
        struct utf8_item        *ui;
        u_int                    index;

        memset(ud, 0, sizeof *ud);
        ud->size = ud->have = UTF8_GET_SIZE(uc);
        ud->width = UTF8_GET_WIDTH(uc);

        if (ud->size <= 3) {
                ud->data[2] = (uc >> 16);
                ud->data[1] = ((uc >> 8) & 0xff);
                ud->data[0] = (uc & 0xff);
        } else {
                index = (uc & 0xffffff);
                if ((ui = utf8_item_by_index(index)) == NULL)
                        memset(ud->data, ' ', ud->size);
                else
                        memcpy(ud->data, ui->data, ud->size);
        }

        log_debug("%s: %08x -> (%d %d %.*s)", __func__, uc, ud->width, ud->size,
            (int)ud->size, ud->data);
}

/* Get UTF-8 character from a single ASCII character. */
u_int
utf8_build_one(u_char ch)
{
        return (UTF8_SET_SIZE(1)|UTF8_SET_WIDTH(1)|ch);
}

/* Set a single character. */
void
utf8_set(struct utf8_data *ud, u_char ch)
{
        static const struct utf8_data empty = { { 0 }, 1, 1, 1 };

        memcpy(ud, &empty, sizeof *ud);
        *ud->data = ch;
}

/* Copy UTF-8 character. */
void
utf8_copy(struct utf8_data *to, const struct utf8_data *from)
{
        u_int   i;

        memcpy(to, from, sizeof *to);

        for (i = to->size; i < sizeof to->data; i++)
                to->data[i] = '\0';
}

/* Get width of Unicode character. */
static enum utf8_state
utf8_width(struct utf8_data *ud, int *width)
{
        struct utf8_width_item  *uw;
        wchar_t                  wc;

        if (utf8_towc(ud, &wc) != UTF8_DONE)
                return (UTF8_ERROR);
        uw = utf8_find_in_width_cache(wc);
        if (uw != NULL) {
                *width = uw->width;
                log_debug("cached width for %08X is %d", (u_int)wc, *width);
                return (UTF8_DONE);
        }

        *width = wcwidth(wc);
        log_debug("wcwidth(%05X) returned %d", (u_int)wc, *width);
        if (*width < 0) {
                /*
                 * C1 control characters are nonprintable, so they are always
                 * zero width.
                 */
                *width = (wc >= 0x80 && wc <= 0x9f) ? 0 : 1;
        }
        if (*width >= 0 && *width <= 0xff)
                return (UTF8_DONE);
        return (UTF8_ERROR);
}

/* Convert UTF-8 character to wide character. */
enum utf8_state
utf8_towc(const struct utf8_data *ud, wchar_t *wc)
{
        switch (mbtowc(wc, ud->data, ud->size)) {
        case -1:
                log_debug("UTF-8 %.*s, mbtowc() %d", (int)ud->size, ud->data,
                    errno);
                mbtowc(NULL, NULL, MB_CUR_MAX);
                return (UTF8_ERROR);
        case 0:
                return (UTF8_ERROR);
        }
        log_debug("UTF-8 %.*s is %05X", (int)ud->size, ud->data, (u_int)*wc);
        return (UTF8_DONE);
}

/* Convert wide character to UTF-8 character. */
enum utf8_state
utf8_fromwc(wchar_t wc, struct utf8_data *ud)
{
        int     size, width;

        size = wctomb(ud->data, wc);
        if (size < 0) {
                log_debug("UTF-8 %d, wctomb() %d", wc, errno);
                wctomb(NULL, 0);
                return (UTF8_ERROR);
        }
        if (size == 0)
                return (UTF8_ERROR);
        ud->size = ud->have = size;
        if (utf8_width(ud, &width) == UTF8_DONE) {
                ud->width = width;
                return (UTF8_DONE);
        }
        return (UTF8_ERROR);
}

/*
 * Open UTF-8 sequence.
 *
 * 11000010-11011111 C2-DF start of 2-byte sequence
 * 11100000-11101111 E0-EF start of 3-byte sequence
 * 11110000-11110100 F0-F4 start of 4-byte sequence
 */
enum utf8_state
utf8_open(struct utf8_data *ud, u_char ch)
{
        memset(ud, 0, sizeof *ud);
        if (ch >= 0xc2 && ch <= 0xdf)
                ud->size = 2;
        else if (ch >= 0xe0 && ch <= 0xef)
                ud->size = 3;
        else if (ch >= 0xf0 && ch <= 0xf4)
                ud->size = 4;
        else
                return (UTF8_ERROR);
        utf8_append(ud, ch);
        return (UTF8_MORE);
}

/* Append character to UTF-8, closing if finished. */
enum utf8_state
utf8_append(struct utf8_data *ud, u_char ch)
{
        int     width;

        if (ud->have >= ud->size)
                fatalx("UTF-8 character overflow");
        if (ud->size > sizeof ud->data)
                fatalx("UTF-8 character size too large");

        if (ud->have != 0 && (ch & 0xc0) != 0x80)
                ud->width = 0xff;

        ud->data[ud->have++] = ch;
        if (ud->have != ud->size)
                return (UTF8_MORE);

        if (!utf8_no_width) {
                if (ud->width == 0xff)
                        return (UTF8_ERROR);
                if (utf8_width(ud, &width) != UTF8_DONE)
                        return (UTF8_ERROR);
                ud->width = width;
        }

        return (UTF8_DONE);
}

/*
 * Encode len characters from src into dst, which is guaranteed to have four
 * bytes available for each character from src (for \abc or UTF-8) plus space
 * for \0.
 */
size_t
utf8_strvis(char *dst, const char *src, size_t len, int flag)
{
        struct utf8_data         ud;
        const char              *start = dst, *end = src + len;
        enum utf8_state          more;
        size_t                   i;

        while (src < end) {
                if ((more = utf8_open(&ud, *src)) == UTF8_MORE) {
                        while (++src < end && more == UTF8_MORE)
                                more = utf8_append(&ud, *src);
                        if (more == UTF8_DONE) {
                                /* UTF-8 character finished. */
                                for (i = 0; i < ud.size; i++)
                                        *dst++ = ud.data[i];
                                continue;
                        }
                        /* Not a complete, valid UTF-8 character. */
                        src -= ud.have;
                }
                if ((flag & VIS_DQ) && src[0] == '$' && src < end - 1) {
                        if (isalpha((u_char)src[1]) ||
                            src[1] == '_' ||
                            src[1] == '{')
                                *dst++ = '\\';
                        *dst++ = '$';
                } else if (src < end - 1)
                        dst = vis(dst, src[0], flag, src[1]);
                else if (src < end)
                        dst = vis(dst, src[0], flag, '\0');
                src++;
        }
        *dst = '\0';
        return (dst - start);
}

/* Same as utf8_strvis but allocate the buffer. */
size_t
utf8_stravis(char **dst, const char *src, int flag)
{
        char    *buf;
        size_t   len;

        buf = xreallocarray(NULL, 4, strlen(src) + 1);
        len = utf8_strvis(buf, src, strlen(src), flag);

        *dst = xrealloc(buf, len + 1);
        return (len);
}

/* Same as utf8_strvis but allocate the buffer. */
size_t
utf8_stravisx(char **dst, const char *src, size_t srclen, int flag)
{
        char    *buf;
        size_t   len;

        buf = xreallocarray(NULL, 4, srclen + 1);
        len = utf8_strvis(buf, src, srclen, flag);

        *dst = xrealloc(buf, len + 1);
        return (len);
}

/* Does this string contain anything that isn't valid UTF-8? */
int
utf8_isvalid(const char *s)
{
        struct utf8_data ud;
        const char      *end;
        enum utf8_state  more;

        end = s + strlen(s);
        while (s < end) {
                if ((more = utf8_open(&ud, *s)) == UTF8_MORE) {
                        while (++s < end && more == UTF8_MORE)
                                more = utf8_append(&ud, *s);
                        if (more == UTF8_DONE)
                                continue;
                        return (0);
                }
                if (*s < 0x20 || *s > 0x7e)
                        return (0);
                s++;
        }
        return (1);
}

/*
 * Sanitize a string, changing any UTF-8 characters to '_'. Caller should free
 * the returned string. Anything not valid printable ASCII or UTF-8 is
 * stripped.
 */
char *
utf8_sanitize(const char *src)
{
        char            *dst = NULL;
        size_t           n = 0;
        enum utf8_state  more;
        struct utf8_data ud;
        u_int            i;

        while (*src != '\0') {
                dst = xreallocarray(dst, n + 1, sizeof *dst);
                if ((more = utf8_open(&ud, *src)) == UTF8_MORE) {
                        while (*++src != '\0' && more == UTF8_MORE)
                                more = utf8_append(&ud, *src);
                        if (more == UTF8_DONE) {
                                dst = xreallocarray(dst, n + ud.width,
                                    sizeof *dst);
                                for (i = 0; i < ud.width; i++)
                                        dst[n++] = '_';
                                continue;
                        }
                        src -= ud.have;
                }
                if (*src > 0x1f && *src < 0x7f)
                        dst[n++] = *src;
                else
                        dst[n++] = '_';
                src++;
        }
        dst = xreallocarray(dst, n + 1, sizeof *dst);
        dst[n] = '\0';
        return (dst);
}

/* Get UTF-8 buffer length. */
size_t
utf8_strlen(const struct utf8_data *s)
{
        size_t  i;

        for (i = 0; s[i].size != 0; i++)
                /* nothing */;
        return (i);
}

/* Get UTF-8 string width. */
u_int
utf8_strwidth(const struct utf8_data *s, ssize_t n)
{
        ssize_t i;
        u_int   width = 0;

        for (i = 0; s[i].size != 0; i++) {
                if (n != -1 && n == i)
                        break;
                width += s[i].width;
        }
        return (width);
}

/*
 * Convert a string into a buffer of UTF-8 characters. Terminated by size == 0.
 * Caller frees.
 */
struct utf8_data *
utf8_fromcstr(const char *src)
{
        struct utf8_data        *dst = NULL;
        size_t                   n = 0;
        enum utf8_state          more;

        while (*src != '\0') {
                dst = xreallocarray(dst, n + 1, sizeof *dst);
                if ((more = utf8_open(&dst[n], *src)) == UTF8_MORE) {
                        while (*++src != '\0' && more == UTF8_MORE)
                                more = utf8_append(&dst[n], *src);
                        if (more == UTF8_DONE) {
                                n++;
                                continue;
                        }
                        src -= dst[n].have;
                }
                utf8_set(&dst[n], *src);
                n++;
                src++;
        }
        dst = xreallocarray(dst, n + 1, sizeof *dst);
        dst[n].size = 0;
        return (dst);
}

/* Convert from a buffer of UTF-8 characters into a string. Caller frees. */
char *
utf8_tocstr(struct utf8_data *src)
{
        char    *dst = NULL;
        size_t   n = 0;

        for(; src->size != 0; src++) {
                dst = xreallocarray(dst, n + src->size, 1);
                memcpy(dst + n, src->data, src->size);
                n += src->size;
        }
        dst = xreallocarray(dst, n + 1, 1);
        dst[n] = '\0';
        return (dst);
}

/* Get width of UTF-8 string. */
u_int
utf8_cstrwidth(const char *s)
{
        struct utf8_data        tmp;
        u_int                   width;
        enum utf8_state         more;

        width = 0;
        while (*s != '\0') {
                if ((more = utf8_open(&tmp, *s)) == UTF8_MORE) {
                        while (*++s != '\0' && more == UTF8_MORE)
                                more = utf8_append(&tmp, *s);
                        if (more == UTF8_DONE) {
                                width += tmp.width;
                                continue;
                        }
                        s -= tmp.have;
                }
                if (*s > 0x1f && *s != 0x7f)
                        width++;
                s++;
        }
        return (width);
}

/* Pad UTF-8 string to width on the left. Caller frees. */
char *
utf8_padcstr(const char *s, u_int width)
{
        size_t   slen;
        char    *out;
        u_int    n, i;

        n = utf8_cstrwidth(s);
        if (n >= width)
                return (xstrdup(s));

        slen = strlen(s);
        out = xmalloc(slen + 1 + (width - n));
        memcpy(out, s, slen);
        for (i = n; i < width; i++)
                out[slen++] = ' ';
        out[slen] = '\0';
        return (out);
}

/* Pad UTF-8 string to width on the right. Caller frees. */
char *
utf8_rpadcstr(const char *s, u_int width)
{
        size_t   slen;
        char    *out;
        u_int    n, i;

        n = utf8_cstrwidth(s);
        if (n >= width)
                return (xstrdup(s));

        slen = strlen(s);
        out = xmalloc(slen + 1 + (width - n));
        for (i = 0; i < width - n; i++)
                out[i] = ' ';
        memcpy(out + i, s, slen);
        out[i + slen] = '\0';
        return (out);
}

int
utf8_cstrhas(const char *s, const struct utf8_data *ud)
{
        struct utf8_data        *copy, *loop;
        int                      found = 0;

        copy = utf8_fromcstr(s);
        for (loop = copy; loop->size != 0; loop++) {
                if (loop->size != ud->size)
                        continue;
                if (memcmp(loop->data, ud->data, loop->size) == 0) {
                        found = 1;
                        break;
                }
        }
        free(copy);

        return (found);
}