/* $OpenBSD: lib_screen.c,v 1.5 2023/10/17 09:52:09 nicm Exp $ */

/****************************************************************************
 * Copyright 2019-2021,2023 Thomas E. Dickey                                *
 * Copyright 1998-2017,2018 Free Software Foundation, Inc.                  *
 *                                                                          *
 * Permission is hereby granted, free of charge, to any person obtaining a  *
 * copy of this software and associated documentation files (the            *
 * "Software"), to deal in the Software without restriction, including      *
 * without limitation the rights to use, copy, modify, merge, publish,      *
 * distribute, distribute with modifications, sublicense, and/or sell       *
 * copies of the Software, and to permit persons to whom the Software is    *
 * furnished to do so, subject to the following conditions:                 *
 *                                                                          *
 * The above copyright notice and this permission notice shall be included  *
 * in all copies or substantial portions of the Software.                   *
 *                                                                          *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
 * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
 *                                                                          *
 * Except as contained in this notice, the name(s) of the above copyright   *
 * holders shall not be used in advertising or otherwise to promote the     *
 * sale, use or other dealings in this Software without prior written       *
 * authorization.                                                           *
 ****************************************************************************/

/****************************************************************************
 *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
 *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
 *     and: Thomas E. Dickey                        1996 on                 *
 *     and: Juergen Pfeifer                         2009                    *
 ****************************************************************************/

#include <curses.priv.h>

#include <ctype.h>

#ifndef CUR
#define CUR SP_TERMTYPE
#endif

MODULE_ID("$Id: lib_screen.c,v 1.5 2023/10/17 09:52:09 nicm Exp $")

#define MAX_SIZE 0x3fff         /* 16k is big enough for a window or pad */

#define MARKER '\\'
#define APPEND '+'
#define GUTTER '|'
#define L_CURL '{'
#define R_CURL '}'

#if USE_STRING_HACKS && HAVE_SNPRINTF
#define ARG_SLIMIT(name) size_t name,
#else
#define ARG_SLIMIT(name)        /* nothing */
#endif

#define CUR_SLIMIT _nc_SLIMIT(limit - (size_t) (target - base))
#define TOP_SLIMIT _nc_SLIMIT(sizeof(buffer))

/*
 * Use 0x888888 as the magic number for new-format files, since it cannot be
 * mistaken for the _cury/_curx pair of 16-bit numbers which start the old
 * format.  It happens to be unused in the file 5.22 database (2015/03/07).
 */
static const char my_magic[] =
{'\210', '\210', '\210', '\210', 0};

#if NCURSES_EXT_PUTWIN
typedef enum {
    pINT                        /* int */
    ,pSHORT                     /* short */
    ,pBOOL                      /* bool */
    ,pATTR                      /* attr_t */
    ,pCHAR                      /* chtype */
    ,pSIZE                      /* NCURSES_SIZE_T */
#if NCURSES_WIDECHAR
    ,pCCHAR                     /* cchar_t */
#endif
} PARAM_TYPE;

typedef struct {
    const char name[11];
    attr_t attr;
} SCR_ATTRS;

typedef struct {
    const char name[17];
    PARAM_TYPE type;
    size_t offset;
} SCR_PARAMS;

#define DATA(name) { { #name }, A_##name }
static const SCR_ATTRS scr_attrs[] =
{
    DATA(NORMAL),
    DATA(STANDOUT),
    DATA(UNDERLINE),
    DATA(REVERSE),
    DATA(BLINK),
    DATA(DIM),
    DATA(BOLD),
    DATA(ALTCHARSET),
    DATA(INVIS),
    DATA(PROTECT),
    DATA(HORIZONTAL),
    DATA(LEFT),
    DATA(LOW),
    DATA(RIGHT),
    DATA(TOP),
    DATA(VERTICAL),

#ifdef A_ITALIC
    DATA(ITALIC),
#endif
};
#undef DATA

#define DATA(name, type) { { #name }, type, offsetof(WINDOW, name) }

static const SCR_PARAMS scr_params[] =
{
    DATA(_cury, pSIZE),
    DATA(_curx, pSIZE),
    DATA(_maxy, pSIZE),
    DATA(_maxx, pSIZE),
    DATA(_begy, pSIZE),
    DATA(_begx, pSIZE),
    DATA(_flags, pSHORT),
    DATA(_attrs, pATTR),
    DATA(_bkgd, pCHAR),
    DATA(_notimeout, pBOOL),
    DATA(_clear, pBOOL),
    DATA(_leaveok, pBOOL),
    DATA(_scroll, pBOOL),
    DATA(_idlok, pBOOL),
    DATA(_idcok, pBOOL),
    DATA(_immed, pBOOL),
    DATA(_sync, pBOOL),
    DATA(_use_keypad, pBOOL),
    DATA(_delay, pINT),
    DATA(_regtop, pSIZE),
    DATA(_regbottom, pSIZE),
    DATA(_pad._pad_y, pSIZE),
    DATA(_pad._pad_x, pSIZE),
    DATA(_pad._pad_top, pSIZE),
    DATA(_pad._pad_left, pSIZE),
    DATA(_pad._pad_bottom, pSIZE),
    DATA(_pad._pad_right, pSIZE),
    DATA(_yoffset, pSIZE),
#if NCURSES_WIDECHAR
    DATA(_bkgrnd, pCCHAR),
#if NCURSES_EXT_COLORS
    DATA(_color, pINT),
#endif
#endif
};
#undef DATA

static const NCURSES_CH_T blank = NewChar(BLANK_TEXT);

/*
 * Allocate and read a line of text.  Caller must free it.
 */
static char *
read_txt(FILE *fp)
{
    size_t limit = 1024;
    char *result = malloc(limit);
    char *buffer;

    if (result != 0) {
        int ch = 0;
        size_t used = 0;

        clearerr(fp);
        result[used] = '\0';
        do {
            if (used + 2 >= limit) {
                limit += 1024;
                buffer = realloc(result, limit);
                if (buffer == 0) {
                    free(result);
                    result = 0;
                    break;
                }
                result = buffer;
            }
            ch = fgetc(fp);
            if (ch == EOF)
                break;
            result[used++] = (char) ch;
            result[used] = '\0';
        } while (ch != '\n');

        if (ch == '\n') {
            result[--used] = '\0';
            TR(TRACE_IEVENT, ("READ:%s", result));
        } else if (used == 0) {
            free(result);
            result = 0;
        }
    }
    return result;
}

static char *
decode_attr(char *source, attr_t *target, int *color)
{
    bool found = FALSE;

    TR(TRACE_IEVENT, ("decode_attr   '%s'", source));

    while (*source) {
        if (source[0] == MARKER && source[1] == L_CURL) {
            source += 2;
            found = TRUE;
        } else if (source[0] == R_CURL) {
            source++;
            found = FALSE;
        } else if (found) {
            size_t n;
            char *next = source;

            if (source[0] == GUTTER) {
                ++next;
            } else if (*next == 'C') {
                int value = 0;
                unsigned pair;
                next++;
                while (isdigit(UChar(*next))) {
                    value = value * 10 + (*next++ - '0');
                }
                *target &= ~A_COLOR;
                pair = (unsigned) ((value > 256)
                                   ? COLOR_PAIR(255)
                                   : COLOR_PAIR(value));
                *target |= pair;
                *color = value;
            } else {
                while (isalnum(UChar(*next))) {
                    ++next;
                }
                for (n = 0; n < SIZEOF(scr_attrs); ++n) {
                    if ((size_t) (next - source) == strlen(scr_attrs[n].name)) {
                        if (scr_attrs[n].attr) {
                            *target |= scr_attrs[n].attr;
                        } else {
                            *target = A_NORMAL;
                        }
                        break;
                    }
                }
            }
            source = next;
        } else {
            break;
        }
    }
    return source;
}

static char *
decode_char(char *source, int *target)
{
    int limit = 0;
    int base = 16;
    const char digits[] = "0123456789abcdef";

    TR(TRACE_IEVENT, ("decode_char   '%s'", source));
    *target = ' ';
    switch (*source) {
    case MARKER:
        switch (*++source) {
        case APPEND:
            break;
        case MARKER:
            *target = MARKER;
            ++source;
            break;
        case 's':
            *target = ' ';
            ++source;
            break;
        case '0':
        case '1':
        case '2':
        case '3':
            base = 8;
            limit = 3;
            break;
        case 'u':
            limit = 4;
            ++source;
            break;
        case 'U':
            limit = 8;
            ++source;
            break;
        }
        if (limit) {
            *target = 0;
            while (limit-- > 0) {
                char *find = strchr(digits, *source++);
                int ch = (find != 0) ? (int) (find - digits) : -1;
                *target *= base;
                if (ch >= 0 && ch < base) {
                    *target += ch;
                }
            }
        }
        break;
    default:
        *target = *source++;
        break;
    }
    return source;
}

static char *
decode_chtype(char *source, chtype fillin, chtype *target)
{
    attr_t attr = ChAttrOf(fillin);
    int color = PAIR_NUMBER((int) attr);
    int value;

    TR(TRACE_IEVENT, ("decode_chtype '%s'", source));
    source = decode_attr(source, &attr, &color);
    source = decode_char(source, &value);
    *target = (ChCharOf(value) | attr | (chtype) COLOR_PAIR(color));
    /* FIXME - ignore combining characters */
    return source;
}

#if NCURSES_WIDECHAR
static char *
decode_cchar(char *source, cchar_t *fillin, cchar_t *target)
{
    int color;
    attr_t attr = fillin->attr;
    wchar_t chars[CCHARW_MAX];
    int append = 0;
    int value = 0;

    TR(TRACE_IEVENT, ("decode_cchar  '%s'", source));
    *target = blank;
#if NCURSES_EXT_COLORS
    color = fillin->ext_color;
#else
    color = (int) PAIR_NUMBER(attr);
#endif
    source = decode_attr(source, &attr, &color);
    memset(chars, 0, sizeof(chars));
    source = decode_char(source, &value);
    chars[0] = (wchar_t) value;
    /* handle combining characters */
    while (source[0] == MARKER && source[1] == APPEND) {
        source += 2;
        source = decode_char(source, &value);
        if (++append < CCHARW_MAX) {
            chars[append] = (wchar_t) value;
        }
    }
    setcchar(target, chars, attr, (short) color, &color);
    return source;
}
#endif

static int
read_win(WINDOW *win, FILE *fp)
{
    int code = ERR;
    size_t n;
    int color;
#if NCURSES_WIDECHAR
    NCURSES_CH_T prior;
#endif
    chtype prior2;

    memset(win, 0, sizeof(WINDOW));
    for (;;) {
        char *name;
        char *value;
        char *txt = read_txt(fp);

        if (txt == 0)
            break;
        if (!strcmp(txt, "rows:")) {
            free(txt);
            code = OK;
            break;
        }
        if ((value = strchr(txt, '=')) == 0) {
            free(txt);
            continue;
        }
        *value++ = '\0';
        name = !strcmp(txt, "flag") ? value : txt;
        for (n = 0; n < SIZEOF(scr_params); ++n) {
            if (!strcmp(name, scr_params[n].name)) {
                void *data = (void *) ((char *) win + scr_params[n].offset);

                switch (scr_params[n].type) {
                case pATTR:
                    (void) decode_attr(value, data, &color);
                    break;
                case pBOOL:
                    *(bool *) data = TRUE;
                    break;
                case pCHAR:
                    prior2 = ' ';
                    decode_chtype(value, prior2, data);
                    break;
                case pINT:
                    *(int *) data = atoi(value);
                    break;
                case pSHORT:
                    *(short *) data = (short) atoi(value);
                    break;
                case pSIZE:
                    *(NCURSES_SIZE_T *) data = (NCURSES_SIZE_T) atoi(value);
                    break;
#if NCURSES_WIDECHAR
                case pCCHAR:
                    prior = blank;
                    decode_cchar(value, &prior, data);
                    break;
#endif
                }
                break;
            }
        }
        free(txt);
    }
    return code;
}

static int
read_row(char *source, NCURSES_CH_T *prior, NCURSES_CH_T *target, int length)
{
    while (*source != '\0' && length > 0) {
#if NCURSES_WIDECHAR
        int len;

        source = decode_cchar(source, prior, target);
        len = _nc_wacs_width(target->chars[0]);
        if (len > 1) {
            int n;

            SetWidecExt(CHDEREF(target), 0);
            for (n = 1; n < len; ++n) {
                target[n] = target[0];
                SetWidecExt(CHDEREF(target), n);
            }
            target += (len - 1);
            length -= (len - 1);
        }
#else
        source = decode_chtype(source, *prior, target);
#endif
        *prior = *target;
        ++target;
        --length;
    }
    while (length-- > 0) {
        *target++ = blank;
    }
    /* FIXME - see what error conditions should apply if I need to return ERR */
    return 0;
}
#endif /* NCURSES_EXT_PUTWIN */

/*
 * Originally, getwin/putwin used fread/fwrite, because they used binary data.
 * The new format uses printable ASCII, which does not have as predictable
 * sizes.  Consequently, we use buffered I/O, e.g., fgetc/fprintf, which need
 * special handling if we want to read screen dumps from an older library.
 */
static int
read_block(void *target, size_t length, FILE *fp)
{
    int result = 0;
    char *buffer = target;

    clearerr(fp);
    while (length-- != 0) {
        int ch = fgetc(fp);
        if (ch == EOF) {
            result = -1;
            break;
        }
        *buffer++ = (char) ch;
    }
    return result;
}

NCURSES_EXPORT(WINDOW *)
NCURSES_SP_NAME(getwin) (NCURSES_SP_DCLx FILE *filep)
{
    WINDOW tmp, *nwin;
    bool old_format = FALSE;

    T((T_CALLED("getwin(%p)"), (void *) filep));

    if (filep == 0) {
        returnWin(0);
    }

    /*
     * Read the first 4 bytes to determine first if this is an old-format
     * screen-dump, or new-format.
     */
    if (read_block(&tmp, (size_t) 4, filep) < 0) {
        returnWin(0);
    }
    /*
     * If this is a new-format file, and we do not support it, give up.
     */
    if (!memcmp(&tmp, my_magic, (size_t) 4)) {
#if NCURSES_EXT_PUTWIN
        if (read_win(&tmp, filep) < 0)
#endif
            returnWin(0);
    } else if (read_block(((char *) &tmp) + 4, sizeof(WINDOW) - 4, filep) < 0) {
        returnWin(0);
    } else {
        old_format = TRUE;
    }

    /*
     * Check the window-size:
     */
    if (tmp._maxy == 0 ||
        tmp._maxy > MAX_SIZE ||
        tmp._maxx == 0 ||
        tmp._maxx > MAX_SIZE) {
        returnWin(0);
    }

    if (IS_PAD(&tmp)) {
        nwin = NCURSES_SP_NAME(newpad) (NCURSES_SP_ARGx
                                        tmp._maxy + 1,
                                        tmp._maxx + 1);
    } else {
        nwin = NCURSES_SP_NAME(newwin) (NCURSES_SP_ARGx
                                        tmp._maxy + 1,
                                        tmp._maxx + 1, 0, 0);
    }

    /*
     * We deliberately do not restore the _parx, _pary, or _parent
     * fields, because the window hierarchy within which they
     * made sense is probably gone.
     */
    if (nwin != 0) {
        int n;
        size_t linesize = sizeof(NCURSES_CH_T) * (size_t) (tmp._maxx + 1);

        nwin->_curx = tmp._curx;
        nwin->_cury = tmp._cury;
        nwin->_maxy = tmp._maxy;
        nwin->_maxx = tmp._maxx;
        nwin->_begy = tmp._begy;
        nwin->_begx = tmp._begx;
        nwin->_yoffset = tmp._yoffset;
        nwin->_flags = tmp._flags & ~(_SUBWIN);

        WINDOW_ATTRS(nwin) = WINDOW_ATTRS(&tmp);
        nwin->_nc_bkgd = tmp._nc_bkgd;

        nwin->_notimeout = tmp._notimeout;
        nwin->_clear = tmp._clear;
        nwin->_leaveok = tmp._leaveok;
        nwin->_idlok = tmp._idlok;
        nwin->_idcok = tmp._idcok;
        nwin->_immed = tmp._immed;
        nwin->_scroll = tmp._scroll;
        nwin->_sync = tmp._sync;
        nwin->_use_keypad = tmp._use_keypad;
        nwin->_delay = tmp._delay;

        nwin->_regtop = tmp._regtop;
        nwin->_regbottom = tmp._regbottom;

        if (IS_PAD(&tmp))
            nwin->_pad = tmp._pad;

        if (old_format) {
            T(("reading old-format screen dump"));
            for (n = 0; n <= nwin->_maxy; n++) {
                if (read_block(nwin->_line[n].text, linesize, filep) < 0) {
                    delwin(nwin);
                    returnWin(0);
                }
            }
        }
#if NCURSES_EXT_PUTWIN
        else {
            char *txt = 0;
            bool success = TRUE;
            NCURSES_CH_T prior = blank;

            T(("reading new-format screen dump"));
            for (n = 0; n <= nwin->_maxy; n++) {
                long row;
                char *next;

                if ((txt = read_txt(filep)) == 0) {
                    T(("...failed to read string for row %d", n + 1));
                    success = FALSE;
                    break;
                }
                row = strtol(txt, &next, 10);
                if (row != (n + 1) || *next != ':') {
                    T(("...failed to read row-number %d", n + 1));
                    success = FALSE;
                    break;
                }

                if (read_row(++next, &prior, nwin->_line[n].text, tmp._maxx
                             + 1) < 0) {
                    T(("...failed to read cells for row %d", n + 1));
                    success = FALSE;
                    break;
                }
                free(txt);
                txt = 0;
            }

            if (!success) {
                free(txt);
                delwin(nwin);
                returnWin(0);
            }
        }
#endif
        touchwin(nwin);
    }
    returnWin(nwin);
}

#if NCURSES_SP_FUNCS
NCURSES_EXPORT(WINDOW *)
getwin(FILE *filep)
{
    return NCURSES_SP_NAME(getwin) (CURRENT_SCREEN, filep);
}
#endif

#if NCURSES_EXT_PUTWIN
static void
encode_attr(char *target, ARG_SLIMIT(limit)
            attr_t source,
            attr_t prior,
            int source_color,
            int prior_color)
{
#if USE_STRING_HACKS && HAVE_SNPRINTF
    char *base = target;
#endif
    source &= ~A_CHARTEXT;
    prior &= ~A_CHARTEXT;

    *target = '\0';
    if ((source != prior) || (source_color != prior_color)) {
        size_t n;
        bool first = TRUE;

        *target++ = MARKER;
        *target++ = L_CURL;

        for (n = 0; n < SIZEOF(scr_attrs); ++n) {
            if ((source & scr_attrs[n].attr) != 0 ||
                ((source & ALL_BUT_COLOR) == 0 &&
                 (scr_attrs[n].attr == A_NORMAL))) {
                if (first) {
                    first = FALSE;
                } else {
                    *target++ = '|';
                }
                _nc_STRCPY(target, scr_attrs[n].name, limit);
                target += strlen(target);
            }
        }
        if (source_color != prior_color) {
            if (!first)
                *target++ = '|';
            _nc_SPRINTF(target, CUR_SLIMIT "C%d", source_color);
            target += strlen(target);
        }

        *target++ = R_CURL;
        *target = '\0';
    }
}

static void
encode_cell(char *target, ARG_SLIMIT(limit) CARG_CH_T source, CARG_CH_T previous)
{
#if USE_STRING_HACKS && HAVE_SNPRINTF
    char *base = target;
#endif
#if NCURSES_WIDECHAR
    size_t n;
    int source_pair = GetPair(*source);
    int previous_pair = GetPair(*previous);

    *target = '\0';
    if ((previous->attr != source->attr) || (previous_pair != source_pair)) {
        encode_attr(target, CUR_SLIMIT
                    source->attr,
                    previous->attr,
                    source_pair,
                    previous_pair);
    }
    target += strlen(target);
#if NCURSES_EXT_COLORS
    if (previous->ext_color != source->ext_color) {
        _nc_SPRINTF(target, CUR_SLIMIT
                    "%c%cC%d%c", MARKER, L_CURL, source->ext_color, R_CURL);
    }
#endif
    for (n = 0; n < SIZEOF(source->chars); ++n) {
        unsigned uch = (unsigned) source->chars[n];
        if (uch == 0)
            continue;
        if (n) {
            *target++ = MARKER;
            *target++ = APPEND;
        }
        *target++ = MARKER;
        if (uch > 0xffff) {
            _nc_SPRINTF(target, CUR_SLIMIT "U%08x", uch);
        } else if (uch > 0xff) {
            _nc_SPRINTF(target, CUR_SLIMIT "u%04x", uch);
        } else if (uch < 32 || uch >= 127) {
            _nc_SPRINTF(target, CUR_SLIMIT "%03o", uch & 0xff);
        } else {
            switch (uch) {
            case ' ':
                _nc_STRCPY(target, "s", limit);
                break;
            case MARKER:
                *target++ = MARKER;
                *target = '\0';
                break;
            default:
                --target;
                _nc_SPRINTF(target, CUR_SLIMIT "%c", uch);
                break;
            }
        }
        target += strlen(target);
    }
#else
    chtype ch = CharOfD(source);

    *target = '\0';
    if (AttrOfD(previous) != AttrOfD(source)) {
        encode_attr(target, CUR_SLIMIT
                    AttrOfD(source),
                    AttrOfD(previous),
                    GetPair(source),
                    GetPair(previous));
    }
    target += strlen(target);
    *target++ = MARKER;
    if (ch < 32 || ch >= 127) {
        _nc_SPRINTF(target, CUR_SLIMIT "%03o", UChar(ch));
    } else {
        switch (ch) {
        case ' ':
            _nc_STRCPY(target, "s", limit);
            break;
        case MARKER:
            *target++ = MARKER;
            *target = '\0';
            break;
        default:
            --target;
            _nc_SPRINTF(target, CUR_SLIMIT "%c", UChar(ch));
            break;
        }
    }
#endif
}
#endif

NCURSES_EXPORT(int)
putwin(WINDOW *win, FILE *filep)
{
    int code = ERR;

    T((T_CALLED("putwin(%p,%p)"), (void *) win, (void *) filep));

#if NCURSES_EXT_PUTWIN
    if (win != 0) {
        const char *version = curses_version();
        char buffer[1024];
        NCURSES_CH_T last_cell;
        int y;

        memset(&last_cell, 0, sizeof(last_cell));

        clearerr(filep);

        /*
         * Our magic number is technically nonprinting, but aside from that,
         * all of the file is printable ASCII.
         */
#define PUTS(s) if (fputs(s, filep) == EOF || ferror(filep)) returnCode(code)
        PUTS(my_magic);
        PUTS(version);
        PUTS("\n");
        for (y = 0; y < (int) SIZEOF(scr_params); ++y) {
            const char *name = scr_params[y].name;
            const char *data = (char *) win + scr_params[y].offset;
            const void *dp = (const void *) data;
            attr_t attr;

            *buffer = '\0';
            if (!strncmp(name, "_pad.", (size_t) 5) && !IS_PAD(win)) {
                continue;
            }
            switch (scr_params[y].type) {
            case pATTR:
                attr = (*(const attr_t *) dp) & ~A_CHARTEXT;
                encode_attr(buffer, TOP_SLIMIT
                            (*(const attr_t *) dp) & ~A_CHARTEXT,
                            A_NORMAL,
                            COLOR_PAIR((int) attr),
                            0);
                break;
            case pBOOL:
                if (!(*(const bool *) data)) {
                    continue;
                }
                _nc_STRCPY(buffer, name, sizeof(buffer));
                name = "flag";
                break;
            case pCHAR:
                attr = (*(const attr_t *) dp);
                encode_attr(buffer, TOP_SLIMIT
                            * (const attr_t *) dp,
                            A_NORMAL,
                            COLOR_PAIR((int) attr),
                            0);
                break;
            case pINT:
                if (!(*(const int *) dp))
                    continue;
                _nc_SPRINTF(buffer, TOP_SLIMIT
                            "%d", *(const int *) dp);
                break;
            case pSHORT:
                if (!(*(const short *) dp))
                    continue;
                _nc_SPRINTF(buffer, TOP_SLIMIT
                            "%d", *(const short *) dp);
                break;
            case pSIZE:
                if (!(*(const NCURSES_SIZE_T *) dp))
                    continue;
                _nc_SPRINTF(buffer, TOP_SLIMIT
                            "%d", *(const NCURSES_SIZE_T *) dp);
                break;
#if NCURSES_WIDECHAR
            case pCCHAR:
                encode_cell(buffer, TOP_SLIMIT
                            (CARG_CH_T) dp, CHREF(last_cell));
                break;
#endif
            }
            /*
             * Only write non-default data.
             */
            if (*buffer != '\0') {
                if (fprintf(filep, "%s=%s\n", name, buffer) <= 0
                    || ferror(filep))
                    returnCode(code);
            }
        }
        /* Write row-data */
        fprintf(filep, "rows:\n");
        for (y = 0; y <= win->_maxy; y++) {
            NCURSES_CH_T *data = win->_line[y].text;
            int x;
            if (fprintf(filep, "%d:", y + 1) <= 0
                || ferror(filep))
                returnCode(code);
            for (x = 0; x <= win->_maxx; x++) {
#if NCURSES_WIDECHAR
                int len = _nc_wacs_width(data[x].chars[0]);
                encode_cell(buffer, TOP_SLIMIT CHREF(data[x]), CHREF(last_cell));
                last_cell = data[x];
                PUTS(buffer);
                if (len > 1)
                    x += (len - 1);
#else
                encode_cell(buffer, TOP_SLIMIT CHREF(data[x]), CHREF(last_cell));
                last_cell = data[x];
                PUTS(buffer);
#endif
            }
            PUTS("\n");
        }
        code = OK;
    }
#else
    /*
     * This is the original putwin():
     * A straight binary dump is simple, but its format can depend on whether
     * ncurses is compiled with wide-character support, and also may depend
     * on the version of ncurses, e.g., if the WINDOW structure is extended.
     */
    if (win != 0) {
        size_t len = (size_t) (win->_maxx + 1);
        int y;

        clearerr(filep);
        if (fwrite(win, sizeof(WINDOW), (size_t) 1, filep) != 1
            || ferror(filep))
              returnCode(code);

        for (y = 0; y <= win->_maxy; y++) {
            if (fwrite(win->_line[y].text,
                       sizeof(NCURSES_CH_T), len, filep) != len
                || ferror(filep)) {
                returnCode(code);
            }
        }
        code = OK;
    }
#endif
    returnCode(code);
}

/*
 * Replace a window covering the whole screen, i.e., newscr or curscr.
 */
static WINDOW *
replace_window(WINDOW *target, FILE *source)
{
    WINDOW *result = getwin(source);
#if NCURSES_EXT_FUNCS
    if (result != NULL) {
        if (getmaxx(result) != getmaxx(target)
            || getmaxy(result) != getmaxy(target)) {
            int code = wresize(result,
                               1 + getmaxy(target),
                               1 + getmaxx(target));
            if (code != OK) {
                delwin(result);
                result = NULL;
            }
        }
    }
#endif
    delwin(target);
    return result;
}

NCURSES_EXPORT(int)
NCURSES_SP_NAME(scr_restore) (NCURSES_SP_DCLx const char *file)
{
    FILE *fp = 0;
    int code = ERR;

    T((T_CALLED("scr_restore(%p,%s)"), (void *) SP_PARM, _nc_visbuf(file)));

    if (_nc_access(file, R_OK) >= 0
        && (fp = safe_fopen(file, BIN_R)) != 0) {
        NewScreen(SP_PARM) = replace_window(NewScreen(SP_PARM), fp);
#if !USE_REENTRANT
        newscr = NewScreen(SP_PARM);
#endif
        (void) fclose(fp);
        if (NewScreen(SP_PARM) != 0) {
            code = OK;
        }
    }
    returnCode(code);
}

#if NCURSES_SP_FUNCS
NCURSES_EXPORT(int)
scr_restore(const char *file)
{
    return NCURSES_SP_NAME(scr_restore) (CURRENT_SCREEN, file);
}
#endif

NCURSES_EXPORT(int)
scr_dump(const char *file)
{
    int result;
    FILE *fp = 0;

    T((T_CALLED("scr_dump(%s)"), _nc_visbuf(file)));

    if (_nc_access(file, W_OK) < 0
        || (fp = safe_fopen(file, BIN_W)) == 0) {
        result = ERR;
    } else {
        (void) putwin(newscr, fp);
        (void) fclose(fp);
        result = OK;
    }
    returnCode(result);
}

NCURSES_EXPORT(int)
NCURSES_SP_NAME(scr_init) (NCURSES_SP_DCLx const char *file)
{
    int code = ERR;

    T((T_CALLED("scr_init(%p,%s)"), (void *) SP_PARM, _nc_visbuf(file)));

    if (SP_PARM != 0 &&
#ifdef USE_TERM_DRIVER
        InfoOf(SP_PARM).caninit
#else
        !(exit_ca_mode && non_rev_rmcup)
#endif
        ) {
        FILE *fp = 0;

        if (_nc_access(file, R_OK) >= 0
            && (fp = safe_fopen(file, BIN_R)) != 0) {
            CurScreen(SP_PARM) = replace_window(CurScreen(SP_PARM), fp);
#if !USE_REENTRANT
            curscr = CurScreen(SP_PARM);
#endif
            (void) fclose(fp);
            if (CurScreen(SP_PARM) != 0) {
                code = OK;
            }
        }
    }
    returnCode(code);
}

#if NCURSES_SP_FUNCS
NCURSES_EXPORT(int)
scr_init(const char *file)
{
    return NCURSES_SP_NAME(scr_init) (CURRENT_SCREEN, file);
}
#endif

NCURSES_EXPORT(int)
NCURSES_SP_NAME(scr_set) (NCURSES_SP_DCLx const char *file)
{
    int code = ERR;

    T((T_CALLED("scr_set(%p,%s)"), (void *) SP_PARM, _nc_visbuf(file)));

    if (NCURSES_SP_NAME(scr_init) (NCURSES_SP_ARGx file) == OK) {
        delwin(NewScreen(SP_PARM));
        NewScreen(SP_PARM) = dupwin(curscr);
#if !USE_REENTRANT
        newscr = NewScreen(SP_PARM);
#endif
        if (NewScreen(SP_PARM) != 0) {
            code = OK;
        }
    }
    returnCode(code);
}

#if NCURSES_SP_FUNCS
NCURSES_EXPORT(int)
scr_set(const char *file)
{
    return NCURSES_SP_NAME(scr_set) (CURRENT_SCREEN, file);
}
#endif