/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 1997 Sandro Sigala, Brescia, Italy.
 * Copyright (c) 1997 Chris Shenton
 * Copyright (c) 1995 Søren Schmidt
 * 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
 *    in this position and unchanged.
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/module.h>
#include <sys/malloc.h>
#include <sys/jail.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/consio.h>
#include <sys/fbio.h>

#include <machine/pc/display.h>

#include <dev/fb/fbreg.h>
#include <dev/fb/splashreg.h>
#include <dev/syscons/syscons.h>

#define DAEMON_MAX_WIDTH        32
#define DAEMON_MAX_HEIGHT       19

static u_char *message;
static int messagelen;
static int blanked;
static int attr_mask;

#define ATTR(attr)      (((attr) & attr_mask) << 8)

/* Who is the author of this ASCII pic? */

static u_char *daemon_pic[] = {
        "             ,        ,",
        "            /(        )`",
        "            \\ \\___   / |",
        "            /- _  `-/  '",
        "           (/\\/ \\ \\   /\\",
        "           / /   | `    \\",
        "           O O   ) /    |",
        "           `-^--'`<     '",
        "          (_.)  _  )   /",
        "           `.___/`    /",
        "             `-----' /",
        "<----.     __ / __   \\",
        "<----|====O)))==) \\) /====",
        "<----'    `--' `.__,' \\",
        "             |        |",
        "              \\       /       /\\",
        "         ______( (_  / \\______/",
        "       ,'  ,-----'   |",
        "       `--{__________)",
        NULL
};

static u_char *daemon_attr[] = {
        "             R        R",
        "            RR        RR",
        "            R RRRR   R R",
        "            RR W  RRR  R",
        "           RWWW W R   RR",
        "           W W   W R    R",
        "           B B   W R    R",
        "           WWWWWWRR     R",
        "          RRRR  R  R   R",
        "           RRRRRRR    R",
        "             RRRRRRR R",
        "YYYYYY     RR R RR   R",
        "YYYYYYYYYYRRRRYYR RR RYYYY",
        "YYYYYY    RRRR RRRRRR R",
        "             R        R",
        "              R       R       RR",
        "         CCCCCCR RR  R RRRRRRRR",
        "       CC  CCCCCCC   C",
        "       CCCCCCCCCCCCCCC",
        NULL
};

/*
 * Reverse a graphics character, or return unaltered if no mirror;
 * should do alphanumerics too, but I'm too lazy. <cshenton@it.hq.nasa.gov>
 */

static u_char
xflip_symbol(u_char symbol)
{
        static const u_char lchars[] = "`'(){}[]\\/<>";
        static const u_char rchars[] = "'`)(}{][/\\><";
        int pos;

        for (pos = 0; lchars[pos] != '\0'; pos++)
                if (lchars[pos] == symbol)
                        return rchars[pos];

        return symbol;
}

static void
clear_daemon(sc_softc_t *sc, int xpos, int ypos, int dxdir, int xoff, int yoff, 
            int xlen, int ylen)
{
        int y;

        if (xlen <= 0)
                return;
        for (y = yoff; y < ylen; y++) {
                sc_vtb_erase(&sc->cur_scp->scr,
                             (ypos + y)*sc->cur_scp->xsize + xpos + xoff,
                             xlen - xoff,
                             sc->scr_map[0x20], ATTR(FG_LIGHTGREY | BG_BLACK));
        }
}

static void
draw_daemon(sc_softc_t *sc, int xpos, int ypos, int dxdir, int xoff, int yoff, 
            int xlen, int ylen)
{
        int x, y;
        int px;
        int attr;

        for (y = yoff; y < ylen; y++) {
                if (dxdir < 0)
                        px = xoff;
                else
                        px = DAEMON_MAX_WIDTH - xlen;
                if (px >= strlen(daemon_pic[y]))
                        continue;
                for (x = xoff; (x < xlen) && (daemon_pic[y][px] != '\0'); x++, px++) {
                        switch (daemon_attr[y][px]) {
                        case 'R': attr = FG_LIGHTRED | BG_BLACK; break;
                        case 'Y': attr = FG_YELLOW | BG_BLACK; break;
                        case 'B': attr = FG_LIGHTBLUE | BG_BLACK; break;
                        case 'W': attr = FG_LIGHTGREY | BG_BLACK; break;
                        case 'C': attr = FG_CYAN | BG_BLACK; break;
                        default: attr = FG_WHITE | BG_BLACK; break;
                        }
                        if (dxdir < 0) {        /* Moving left */
                                sc_vtb_putc(&sc->cur_scp->scr,
                                            (ypos + y)*sc->cur_scp->xsize
                                                 + xpos + x,
                                            sc->scr_map[daemon_pic[y][px]],
                                            ATTR(attr));
                        } else {                /* Moving right */
                                sc_vtb_putc(&sc->cur_scp->scr,
                                            (ypos + y)*sc->cur_scp->xsize
                                                + xpos + DAEMON_MAX_WIDTH 
                                                - px - 1,
                                            sc->scr_map[xflip_symbol(daemon_pic[y][px])], 
                                            ATTR(attr));
                        }
                }
        }
}

static void
clear_string(sc_softc_t *sc, int xpos, int ypos, int xoff, char *s, int len)
{
        if (len <= 0)
                return;
        sc_vtb_erase(&sc->cur_scp->scr,
                     ypos*sc->cur_scp->xsize + xpos + xoff, len - xoff,
                     sc->scr_map[0x20], ATTR(FG_LIGHTGREY | BG_BLACK));
}

static void
draw_string(sc_softc_t *sc, int xpos, int ypos, int xoff, u_char *s, int len)
{
        int x;

        for (x = xoff; x < len; x++)
                sc_vtb_putc(&sc->cur_scp->scr,
                            ypos*sc->cur_scp->xsize + xpos + x,
                            sc->scr_map[s[x]], ATTR(FG_LIGHTGREEN | BG_BLACK));
}

static int
daemon_saver(video_adapter_t *adp, int blank)
{
        static int txpos = 10, typos = 10;
        static int txdir = -1, tydir = -1;
        static int dxpos = 0, dypos = 0;
        static int dxdir = 1, dydir = 1;
        static int moved_daemon = 0;
        static int xoff, yoff, toff;
        static int xlen, ylen, tlen;
        sc_softc_t *sc;
        scr_stat *scp;
        int min, max;

        sc = sc_find_softc(adp, NULL);
        if (sc == NULL)
                return EAGAIN;
        scp = sc->cur_scp;

        if (blank) {
                if (adp->va_info.vi_flags & V_INFO_GRAPHICS)
                        return EAGAIN;
                if (blanked == 0) {
                        /* clear the screen and set the border color */
                        sc_vtb_clear(&scp->scr, sc->scr_map[0x20],
                                     ATTR(FG_LIGHTGREY | BG_BLACK));
                        vidd_set_hw_cursor(adp, -1, -1);
                        sc_set_border(scp, 0);
                        xlen = ylen = tlen = 0;
                }
                if (blanked++ < 2)
                        return 0;
                blanked = 1;

                clear_daemon(sc, dxpos, dypos, dxdir, xoff, yoff, xlen, ylen);
                clear_string(sc, txpos, typos, toff, message, tlen);

                if (++moved_daemon) {
                        /*
                         * The daemon picture may be off the screen, if
                         * screen size is chagened while the screen
                         * saver is inactive. Make sure the origin of
                         * the picture is between min and max.
                         */
                        if (scp->xsize <= DAEMON_MAX_WIDTH) {
                                /*
                                 * If the screen width is too narrow, we
                                 * allow part of the picture go off
                                 * the screen so that the daemon won't
                                 * flip too often.
                                 */
                                min = scp->xsize - DAEMON_MAX_WIDTH - 10;
                                max = 10;
                        } else {
                                min = 0;
                                max = scp->xsize - DAEMON_MAX_WIDTH;
                        }
                        if (dxpos <= min) {
                                dxpos = min;
                                dxdir = 1;
                        } else if (dxpos >= max) {
                                dxpos = max;
                                dxdir = -1;
                        }

                        if (scp->ysize <= DAEMON_MAX_HEIGHT) {
                                min = scp->ysize - DAEMON_MAX_HEIGHT - 10;
                                max = 10;
                        } else {
                                min = 0;
                                max = scp->ysize - DAEMON_MAX_HEIGHT;
                        }
                        if (dypos <= min) {
                                dypos = min;
                                dydir = 1;
                        } else if (dypos >= max) {
                                dypos = max;
                                dydir = -1;
                        }

                        moved_daemon = -1;
                        dxpos += dxdir; dypos += dydir;

                        /* clip the picture */
                        xoff = 0;
                        xlen = DAEMON_MAX_WIDTH;
                        if (dxpos + xlen <= 0)
                                xlen = 0;
                        else if (dxpos < 0)
                                xoff = -dxpos;
                        if (dxpos >= scp->xsize)
                                xlen = 0;
                        else if (dxpos + xlen > scp->xsize)
                                xlen = scp->xsize - dxpos;
                        yoff = 0;
                        ylen = DAEMON_MAX_HEIGHT;
                        if (dypos + ylen <= 0)
                                ylen = 0;
                        else if (dypos < 0)
                                yoff = -dypos;
                        if (dypos >= scp->ysize)
                                ylen = 0;
                        else if (dypos + ylen > scp->ysize)
                                ylen = scp->ysize - dypos;
                }

                if (scp->xsize <= messagelen) {
                        min = scp->xsize - messagelen - 10;
                        max = 10;
                } else {
                        min = 0;
                        max = scp->xsize - messagelen;
                }
                if (txpos <= min) {
                        txpos = min;
                        txdir = 1;
                } else if (txpos >= max) {
                        txpos = max;
                        txdir = -1;
                }
                if (typos <= 0) {
                        typos = 0;
                        tydir = 1;
                } else if (typos >= scp->ysize - 1) {
                        typos = scp->ysize - 1;
                        tydir = -1;
                }
                txpos += txdir; typos += tydir;

                toff = 0;
                tlen = messagelen;
                if (txpos + tlen <= 0)
                        tlen = 0;
                else if (txpos < 0)
                        toff = -txpos;
                if (txpos >= scp->xsize)
                        tlen = 0;
                else if (txpos + tlen > scp->xsize)
                        tlen = scp->xsize - txpos;

                draw_daemon(sc, dxpos, dypos, dxdir, xoff, yoff, xlen, ylen);
                draw_string(sc, txpos, typos, toff, message, tlen);
        } else
                blanked = 0;

        return 0;
}

static int
daemon_init(video_adapter_t *adp)
{
        size_t hostlen;

        mtx_lock(&prison0.pr_mtx);
        for (;;) {
                hostlen = strlen(prison0.pr_hostname);
                mtx_unlock(&prison0.pr_mtx);

                messagelen = hostlen + 3 + strlen(ostype) + 1 +
                    strlen(osrelease);
                message = malloc(messagelen + 1, M_DEVBUF, M_WAITOK);
                mtx_lock(&prison0.pr_mtx);
                if (hostlen < strlen(prison0.pr_hostname)) {
                        free(message, M_DEVBUF);
                        continue;
                }
                break;
        }
        sprintf(message, "%s - %s %s", prison0.pr_hostname, ostype, osrelease);
        mtx_unlock(&prison0.pr_mtx);
        blanked = 0;
        attr_mask = ~0;

        return 0;
}

static int
daemon_term(video_adapter_t *adp)
{
        free(message, M_DEVBUF);
        return 0;
}

static scrn_saver_t daemon_module = {
        "daemon_saver", daemon_init, daemon_term, daemon_saver, NULL,
};

SAVER_MODULE(daemon_saver, daemon_module);