/*      $OpenBSD: display.c,v 1.18 2016/02/01 07:29:25 mestre Exp $     */
/*      $NetBSD: display.c,v 1.3 1994/12/09 02:14:13 jtc Exp $  */

/*
 * 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 "talk.h"

xwin_t  my_win;
xwin_t  his_win;
WINDOW  *line_win;

int     curses_initialized;
int     high_print;
bool    smooth_scroll;

/*
 * 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);
}

/*
 * Display some text on somebody's window, processing some control
 * characters while we are at it.
 */
void
display(xwin_t *win, char *text, int size)
{
        int i;
        char cch;

        for (i = 0; i < size; i++) {
                /*
                 * Since we do not use curses's input routines we must
                 * convert '\r' -> '\n' ourselves.
                 */
                if (*text == '\r')
                        *text = '\n';
                if (*text == '\n') {
                        xscroll(win, 0);
                        text++;
                        continue;
                }
                /* erase character */
                if (*text == win->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);
                        text++;
                        continue;
                }
                /*
                 * On word erase search backwards until we find
                 * the beginning of a word or the beginning of
                 * the line.
                 */
                if (*text == win->werase) {
                        int endcol, xcol, i, 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 (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);
                        text++;
                        continue;
                }
                /* line kill */
                if (*text == win->kill) {
                        wmove(win->x_win, win->x_line, 0);
                        wclrtoeol(win->x_win);
                        getyx(win->x_win, win->x_line, win->x_col);
                        text++;
                        continue;
                }
                if (*text == '\f') {
                        if (win == &my_win)
                                wrefresh(curscr);
                        text++;
                        continue;
                }
                if (win->x_col == COLS-1) {
                        /* check for wraparound */
                        xscroll(win, 0);
                }
                if (*text != '\t' &&
                    ((!high_print && !isprint((unsigned char)*text)) ||
                      iscntrl((unsigned char)*text))) {
                        waddch(win->x_win, '^');
                        getyx(win->x_win, win->x_line, win->x_col);
                        if (win->x_col == COLS-1) /* check for wraparound */
                                xscroll(win, 0);
                        cch = (*text & 63) + 64;
                        waddch(win->x_win, cch);
                } else
                        waddch(win->x_win, (unsigned char)(*text));
                getyx(win->x_win, win->x_line, win->x_col);
                text++;
        }
        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);
}

/*
 * Scroll a window, blanking out the line following the current line
 * so that the current position is obvious
 */
void
xscroll(xwin_t *win, int flag)
{

        if (flag == -1) {
                wmove(win->x_win, 0, 0);
                win->x_line = 0;
                win->x_col = 0;
                return;
        }
        win->x_col = 0;
        if (smooth_scroll) {
                if (++win->x_line == win->x_nlines) {
                        --win->x_line;
                        scroll(win->x_win);
                }
        } else {
                win->x_line = (win->x_line + 1) % win->x_nlines;
                wmove(win->x_win, win->x_line, win->x_col);
                wclrtoeol(win->x_win);
                wmove(win->x_win, (win->x_line + 1) % win->x_nlines,
                    win->x_col);
                wclrtoeol(win->x_win);
        }
        wmove(win->x_win, win->x_line, win->x_col);
}