/* $OpenBSD: wresize.c,v 1.6 2023/10/17 09:52:09 nicm Exp $ */

/****************************************************************************
 * Copyright 2019-2020,2021 Thomas E. Dickey                                *
 * Copyright 1998-2010,2011 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: Thomas E. Dickey 1996-on                                        *
 *     and: Juergen Pfeifer                                                 *
 ****************************************************************************/

#include <curses.priv.h>

MODULE_ID("$Id: wresize.c,v 1.6 2023/10/17 09:52:09 nicm Exp $")

static int
cleanup_lines(struct ldat *data, int length)
{
    while (--length >= 0)
        FreeAndNull(data[length].text);
    free(data);
    return ERR;
}

/*
 * If we have reallocated the ldat structs, we will have to repair pointers
 * used in subwindows.
 */
static void
repair_subwindows(WINDOW *cmp)
{
    WINDOWLIST *wp;
    struct ldat *pline = cmp->_line;
    int row;
#ifdef USE_SP_WINDOWLIST
    SCREEN *sp = _nc_screen_of(cmp);
#endif

    _nc_lock_global(curses);

    for (each_window(SP_PARM, wp)) {
        WINDOW *tst = &(wp->win);

        if (tst->_parent == cmp) {

#define REPAIR1(field, limit) \
            if (tst->field > cmp->limit) \
                tst->field = cmp->limit

            REPAIR1(_pary, _maxy);
            REPAIR1(_parx, _maxx);

#define REPAIR2(field, limit) \
            if (tst->limit + tst->field > cmp->limit) \
                tst->limit = (NCURSES_SIZE_T) (cmp->limit - tst->field)

            REPAIR2(_pary, _maxy);
            REPAIR2(_parx, _maxx);

#define REPAIR3(field, limit) \
            if (tst->field > tst->limit) \
                tst->field = tst->limit

            REPAIR3(_cury, _maxy);
            REPAIR3(_curx, _maxx);

            REPAIR3(_regtop, _maxy);
            REPAIR3(_regbottom, _maxy);

            for (row = 0; row <= tst->_maxy; ++row) {
                tst->_line[row].text = &pline[tst->_pary + row].text[tst->_parx];
            }
            repair_subwindows(tst);
        }
    }
    _nc_unlock_global(curses);
}

/*
 * Reallocate a curses WINDOW struct to either shrink or grow to the specified
 * new lines/columns.  If it grows, the new character cells are filled with
 * blanks.  The application is responsible for repainting the blank area.
 */
NCURSES_EXPORT(int)
wresize(WINDOW *win, int ToLines, int ToCols)
{
    int col, row, size_x, size_y;
    struct ldat *pline;
    struct ldat *new_lines = 0;

#ifdef TRACE
    T((T_CALLED("wresize(%p,%d,%d)"), (void *) win, ToLines, ToCols));
    if (win) {
        TR(TRACE_UPDATE, ("...beg (%ld, %ld), max(%ld,%ld), reg(%ld,%ld)",
                          (long) win->_begy, (long) win->_begx,
                          (long) win->_maxy, (long) win->_maxx,
                          (long) win->_regtop, (long) win->_regbottom));
        if (USE_TRACEF(TRACE_UPDATE)) {
            _tracedump("...before", win);
            _nc_unlock_global(tracef);
        }
    }
#endif

    if (!win || --ToLines < 0 || --ToCols < 0)
        returnCode(ERR);

    size_x = win->_maxx;
    size_y = win->_maxy;

    if (ToLines == size_y
        && ToCols == size_x)
        returnCode(OK);

    if (IS_SUBWIN(win)) {
        /*
         * Check if the new limits will fit into the parent window's size.  If
         * not, do not resize.  We could adjust the location of the subwindow,
         * but the application may not like that.
         */
        if (win->_pary + ToLines > win->_parent->_maxy
            || win->_parx + ToCols > win->_parent->_maxx) {
            returnCode(ERR);
        }
        pline = win->_parent->_line;
    } else {
        pline = 0;
    }

    /*
     * Allocate new memory as needed.  Do the allocations without modifying
     * the original window, in case an allocation fails.  Always allocate
     * (at least temporarily) the array pointing to the individual lines.
     */
    new_lines = typeCalloc(struct ldat, (unsigned) (ToLines + 1));
    if (new_lines == 0)
        returnCode(ERR);

    /*
     * For each line in the target, allocate or adjust pointers for the
     * corresponding text, depending on whether this is a window or a
     * subwindow.
     */
    for (row = 0; row <= ToLines; ++row) {
        int begin = (row > size_y) ? 0 : (size_x + 1);
        int end = ToCols;
        NCURSES_CH_T *s;

        if (!IS_SUBWIN(win)) {
            if (row <= size_y) {
                if (ToCols != size_x) {
                    s = typeMalloc(NCURSES_CH_T, (unsigned) ToCols + 1);
                    if (s == 0)
                        returnCode(cleanup_lines(new_lines, row));
                    for (col = 0; col <= ToCols; ++col) {
                        bool valid = (col <= size_x);
                        if_WIDEC({
                            if (col == ToCols
                                && col < size_x
                                && isWidecBase(win->_line[row].text[col])) {
                                valid = FALSE;
                            }
                        });
                        s[col] = (valid
                                  ? win->_line[row].text[col]
                                  : win->_nc_bkgd);
                    }
                } else {
                    s = win->_line[row].text;
                }
            } else {
                s = typeMalloc(NCURSES_CH_T, (unsigned) ToCols + 1);
                if (s == 0)
                    returnCode(cleanup_lines(new_lines, row));
                for (col = 0; col <= ToCols; ++col)
                    s[col] = win->_nc_bkgd;
            }
        } else if (pline != 0 && pline[win->_pary + row].text != 0) {
            s = &pline[win->_pary + row].text[win->_parx];
        } else {
            s = 0;
        }

        if_USE_SCROLL_HINTS(new_lines[row].oldindex = row);
        if (row <= size_y) {
            new_lines[row].firstchar = win->_line[row].firstchar;
            new_lines[row].lastchar = win->_line[row].lastchar;
        }
        if ((ToCols != size_x) || (row > size_y)) {
            if (end >= begin) { /* growing */
                if (new_lines[row].firstchar < begin)
                    new_lines[row].firstchar = (NCURSES_SIZE_T) begin;
            } else {            /* shrinking */
                new_lines[row].firstchar = 0;
            }
            new_lines[row].lastchar = (NCURSES_SIZE_T) ToCols;
        }
        new_lines[row].text = s;
    }

    /*
     * Dispose of unwanted memory.
     */
    if (!(win->_flags & _SUBWIN)) {
        if (ToCols == size_x) {
            for (row = ToLines + 1; row <= size_y; row++) {
                FreeAndNull(win->_line[row].text);
            }
        } else {
            for (row = 0; row <= size_y; row++) {
                FreeAndNull(win->_line[row].text);
            }
        }
    }

    FreeAndNull(win->_line);
    win->_line = new_lines;

    /*
     * Finally, adjust the parameters showing screen size and cursor
     * position:
     */
    win->_maxx = (NCURSES_SIZE_T) ToCols;
    win->_maxy = (NCURSES_SIZE_T) ToLines;

    if (win->_regtop > win->_maxy)
        win->_regtop = win->_maxy;
    if (win->_regbottom > win->_maxy
        || win->_regbottom == size_y)
        win->_regbottom = win->_maxy;

    if (win->_curx > win->_maxx)
        win->_curx = win->_maxx;
    if (win->_cury > win->_maxy)
        win->_cury = win->_maxy;

    /*
     * Check for subwindows of this one, and readjust pointers to our text,
     * if needed.
     */
    repair_subwindows(win);

#ifdef TRACE
    TR(TRACE_UPDATE, ("...beg (%ld, %ld), max(%ld,%ld), reg(%ld,%ld)",
                      (long) win->_begy, (long) win->_begx,
                      (long) win->_maxy, (long) win->_maxx,
                      (long) win->_regtop, (long) win->_regbottom));
    if (USE_TRACEF(TRACE_UPDATE)) {
        _tracedump("...after:", win);
        _nc_unlock_global(tracef);
    }
#endif
    returnCode(OK);
}