/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1983, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * 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.
 */



/*
 * The window 'manager', initializes curses and handles the actual
 * displaying of text
 */
#include <ctype.h>
#include <unistd.h>
#include <wctype.h>
#define _XOPEN_SOURCE_EXTENDED
#include <curses.h>

#include "talk.h"

void    display(xwin_t *, wchar_t *);

xwin_t  my_win;
xwin_t  his_win;
WINDOW  *line_win;

int     curses_initialized = 0;

/*
 * max HAS to be a function, it is called with
 * an argument of the form --foo at least once.
 */
int
max(int a, int b)
{

        return (a > b ? a : b);
}

static cchar_t *
makecchar(wchar_t in)
{
        static cchar_t cc;
        wchar_t wc[2];

        wc[0] = in;
        wc[1] = L'\0';

        if (setcchar(&cc, wc, A_NORMAL, 0, NULL) != OK)
                p_error("settchar(3) failure");

        return (&cc);
}

/*
 * Display a symbol on somebody's window, processing some control
 * characters while we are at it.
 */
void
display(xwin_t *win, wchar_t *wc)
{

        /*
         * Alas, can't use variables in C switch statement.
         * Workaround these 3 cases with goto.
         */
        if (*wc == win->kill)
                goto kill;
        else if (*wc == win->cerase)
                goto cerase;
        else if (*wc == win->werase)
                goto werase;

        switch (*wc) {
        case L'\n':
        case L'\r':
                wadd_wch(win->x_win, makecchar(L'\n'));
                getyx(win->x_win, win->x_line, win->x_col);
                wrefresh(win->x_win);
                return;

        case 004:
                if (win == &my_win) {
                        /* Ctrl-D clears the screen. */
                        werase(my_win.x_win);
                        getyx(my_win.x_win, my_win.x_line, my_win.x_col);
                        wrefresh(my_win.x_win);
                        werase(his_win.x_win);
                        getyx(his_win.x_win, his_win.x_line, his_win.x_col);
                        wrefresh(his_win.x_win);
                }
                return;

        /* Erase character. */
        case 010:       /* BS */
        case 0177:      /* DEL */
cerase:
                wmove(win->x_win, win->x_line, max(--win->x_col, 0));
                getyx(win->x_win, win->x_line, win->x_col);
                waddch(win->x_win, ' ');
                wmove(win->x_win, win->x_line, win->x_col);
                getyx(win->x_win, win->x_line, win->x_col);
                wrefresh(win->x_win);
                return;

        case 027:       /* ^W */
werase:
            {
                /*
                 * On word erase search backwards until we find
                 * the beginning of a word or the beginning of
                 * the line.
                 */
                int endcol, xcol, c;

                endcol = win->x_col;
                xcol = endcol - 1;
                while (xcol >= 0) {
                        c = readwin(win->x_win, win->x_line, xcol);
                        if (c != ' ')
                                break;
                        xcol--;
                }
                while (xcol >= 0) {
                        c = readwin(win->x_win, win->x_line, xcol);
                        if (c == ' ')
                                break;
                        xcol--;
                }
                wmove(win->x_win, win->x_line, xcol + 1);
                for (int i = xcol + 1; i < endcol; i++)
                        waddch(win->x_win, ' ');
                wmove(win->x_win, win->x_line, xcol + 1);
                getyx(win->x_win, win->x_line, win->x_col);
                wrefresh(win->x_win);
                return;
            }

        case 025:       /* ^U */
kill:
                wmove(win->x_win, win->x_line, 0);
                wclrtoeol(win->x_win);
                getyx(win->x_win, win->x_line, win->x_col);
                wrefresh(win->x_win);
                return;

        case L'\f':
                if (win == &my_win)
                        wrefresh(curscr);
                return;

        case L'\7':
                write(STDOUT_FILENO, wc, sizeof(*wc));
                return;
        }


        if (iswprint(*wc) || *wc == L'\t')
                wadd_wch(win->x_win, makecchar(*wc));
        else
                beep();

        getyx(win->x_win, win->x_line, win->x_col);
        wrefresh(win->x_win);
}

/*
 * Read the character at the indicated position in win
 */
int
readwin(WINDOW *win, int line, int col)
{
        int oldline, oldcol;
        int c;

        getyx(win, oldline, oldcol);
        wmove(win, line, col);
        c = winch(win);
        wmove(win, oldline, oldcol);
        return (c);
}