/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2009 The FreeBSD Foundation
 *
 * This software was developed by Ed Schouten under sponsorship from the
 * FreeBSD Foundation.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 */

#include <sys/param.h>
#include <sys/cons.h>
#include <sys/consio.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/stdarg.h>
#include <sys/systm.h>
#include <sys/terminal.h>
#include <sys/tty.h>

static MALLOC_DEFINE(M_TERMINAL, "terminal", "terminal device");

/*
 * Locking.
 *
 * Normally we don't need to lock down the terminal emulator, because
 * the TTY lock is already held when calling teken_input().
 * Unfortunately this is not the case when the terminal acts as a
 * console device, because cnputc() can be called at the same time.
 * This means terminals may need to be locked down using a spin lock.
 */
#define TERMINAL_LOCK(tm)       do {                                    \
        if ((tm)->tm_flags & TF_CONS)                                   \
                mtx_lock_spin(&(tm)->tm_mtx);                           \
        else if ((tm)->tm_tty != NULL)                                  \
                tty_lock((tm)->tm_tty);                                 \
} while (0)
#define TERMINAL_UNLOCK(tm)     do {                                    \
        if ((tm)->tm_flags & TF_CONS)                                   \
                mtx_unlock_spin(&(tm)->tm_mtx);                         \
        else if ((tm)->tm_tty != NULL)                                  \
                tty_unlock((tm)->tm_tty);                               \
} while (0)
#define TERMINAL_LOCK_TTY(tm)   do {                                    \
        if ((tm)->tm_flags & TF_CONS)                                   \
                mtx_lock_spin(&(tm)->tm_mtx);                           \
} while (0)
#define TERMINAL_UNLOCK_TTY(tm) do {                                    \
        if ((tm)->tm_flags & TF_CONS)                                   \
                mtx_unlock_spin(&(tm)->tm_mtx);                         \
} while (0)
#define TERMINAL_LOCK_CONS(tm)          mtx_lock_spin(&(tm)->tm_mtx)
#define TERMINAL_UNLOCK_CONS(tm)        mtx_unlock_spin(&(tm)->tm_mtx)

/*
 * TTY routines.
 */

static tsw_open_t       termtty_open;
static tsw_close_t      termtty_close;
static tsw_outwakeup_t  termtty_outwakeup;
static tsw_ioctl_t      termtty_ioctl;
static tsw_mmap_t       termtty_mmap;

static struct ttydevsw terminal_tty_class = {
        .tsw_open       = termtty_open,
        .tsw_close      = termtty_close,
        .tsw_outwakeup  = termtty_outwakeup,
        .tsw_ioctl      = termtty_ioctl,
        .tsw_mmap       = termtty_mmap,
};

/*
 * Terminal emulator routines.
 */

static tf_bell_t        termteken_bell;
static tf_cursor_t      termteken_cursor;
static tf_putchar_t     termteken_putchar;
static tf_fill_t        termteken_fill;
static tf_copy_t        termteken_copy;
static tf_pre_input_t   termteken_pre_input;
static tf_post_input_t  termteken_post_input;
static tf_param_t       termteken_param;
static tf_respond_t     termteken_respond;

static teken_funcs_t terminal_drawmethods = {
        .tf_bell        = termteken_bell,
        .tf_cursor      = termteken_cursor,
        .tf_putchar     = termteken_putchar,
        .tf_fill        = termteken_fill,
        .tf_copy        = termteken_copy,
        .tf_pre_input   = termteken_pre_input,
        .tf_post_input  = termteken_post_input,
        .tf_param       = termteken_param,
        .tf_respond     = termteken_respond,
};

/* Kernel message formatting. */
static teken_attr_t kernel_message = {
        .ta_fgcolor     = TCHAR_FGCOLOR(TERMINAL_KERN_ATTR),
        .ta_bgcolor     = TCHAR_BGCOLOR(TERMINAL_KERN_ATTR),
        .ta_format      = TCHAR_FORMAT(TERMINAL_KERN_ATTR)
};

static teken_attr_t default_message = {
        .ta_fgcolor     = TCHAR_FGCOLOR(TERMINAL_NORM_ATTR),
        .ta_bgcolor     = TCHAR_BGCOLOR(TERMINAL_NORM_ATTR),
        .ta_format      = TCHAR_FORMAT(TERMINAL_NORM_ATTR)
};

/* Fudge fg brightness as TF_BOLD (shifted). */
#define TCOLOR_FG_FUDGED(color) __extension__ ({                        \
        teken_color_t _c;                                               \
                                                                        \
        _c = (color);                                                   \
        TCOLOR_FG(_c & 7) | ((_c & 8) << 18);                           \
})

/* Fudge bg brightness as TF_BLINK (shifted). */
#define TCOLOR_BG_FUDGED(color) __extension__ ({                        \
        teken_color_t _c;                                               \
                                                                        \
        _c = (color);                                                   \
        TCOLOR_BG(_c & 7) | ((_c & 8) << 20);                           \
})

#define TCOLOR_256TO16(color) __extension__ ({                          \
        teken_color_t _c;                                               \
                                                                        \
        _c = (color);                                                   \
        if (_c >= 16)                                                   \
                _c = teken_256to16(_c);                                 \
        _c;                                                             \
})

#define TCHAR_CREATE(c, a)      ((c) | TFORMAT((a)->ta_format) |        \
        TCOLOR_FG_FUDGED(TCOLOR_256TO16((a)->ta_fgcolor)) |             \
        TCOLOR_BG_FUDGED(TCOLOR_256TO16((a)->ta_bgcolor)))

static void
terminal_init(struct terminal *tm)
{
        int fg, bg;

        if (tm->tm_flags & TF_CONS)
                mtx_init(&tm->tm_mtx, "trmlck", NULL, MTX_SPIN);

        teken_init(&tm->tm_emulator, &terminal_drawmethods, tm);

        fg = bg = -1;
        TUNABLE_INT_FETCH("teken.fg_color", &fg);
        TUNABLE_INT_FETCH("teken.bg_color", &bg);

        if (fg != -1) {
                default_message.ta_fgcolor = fg;
                kernel_message.ta_fgcolor = fg;
        }
        if (bg != -1) {
                default_message.ta_bgcolor = bg;
                kernel_message.ta_bgcolor = bg;
        }

        if (default_message.ta_bgcolor == TC_WHITE) {
                default_message.ta_bgcolor |= TC_LIGHT;
                kernel_message.ta_bgcolor |= TC_LIGHT;
        }

        if (default_message.ta_bgcolor == TC_BLACK &&
            default_message.ta_fgcolor < TC_NCOLORS)
                kernel_message.ta_fgcolor |= TC_LIGHT;
        teken_set_defattr(&tm->tm_emulator, &default_message);
}

struct terminal *
terminal_alloc(const struct terminal_class *tc, void *softc)
{
        struct terminal *tm;

        tm = malloc(sizeof(struct terminal), M_TERMINAL, M_WAITOK|M_ZERO);
        terminal_init(tm);

        tm->tm_class = tc;
        tm->tm_softc = softc;

        return (tm);
}

static void
terminal_sync_ttysize(struct terminal *tm)
{
        struct tty *tp;

        tp = tm->tm_tty;
        if (tp == NULL)
                return;

        tty_lock(tp);
        tty_set_winsize(tp, &tm->tm_winsize);
        tty_unlock(tp);
}

void
terminal_maketty(struct terminal *tm, const char *fmt, ...)
{
        struct tty *tp;
        char name[8];
        va_list ap;

        va_start(ap, fmt);
        vsnrprintf(name, sizeof name, 32, fmt, ap);
        va_end(ap);

        tp = tty_alloc(&terminal_tty_class, tm);
        tty_makedev(tp, NULL, "%s", name);
        tm->tm_tty = tp;
        terminal_sync_ttysize(tm);
}

void
terminal_set_cursor(struct terminal *tm, const term_pos_t *pos)
{

        teken_set_cursor(&tm->tm_emulator, pos);
}

void
terminal_set_winsize_blank(struct terminal *tm, const struct winsize *size,
    int blank, const term_attr_t *attr)
{
        term_rect_t r;

        tm->tm_winsize = *size;

        r.tr_begin.tp_row = r.tr_begin.tp_col = 0;
        r.tr_end.tp_row = size->ws_row;
        r.tr_end.tp_col = size->ws_col;

        TERMINAL_LOCK(tm);
        if (blank == 0)
                teken_set_winsize_noreset(&tm->tm_emulator, &r.tr_end);
        else
                teken_set_winsize(&tm->tm_emulator, &r.tr_end);
        TERMINAL_UNLOCK(tm);

        if ((blank != 0) && !(tm->tm_flags & TF_MUTE))
                tm->tm_class->tc_fill(tm, &r,
                    TCHAR_CREATE((teken_char_t)' ', attr));

        terminal_sync_ttysize(tm);
}

void
terminal_set_winsize(struct terminal *tm, const struct winsize *size)
{

        terminal_set_winsize_blank(tm, size, 1,
            (const term_attr_t *)&default_message);
}

/*
 * XXX: This function is a kludge.  Drivers like vt(4) need to
 * temporarily stop input when resizing, etc.  This should ideally be
 * handled within the driver.
 */

void
terminal_mute(struct terminal *tm, int yes)
{

        TERMINAL_LOCK(tm);
        if (yes)
                tm->tm_flags |= TF_MUTE;
        else
                tm->tm_flags &= ~TF_MUTE;
        TERMINAL_UNLOCK(tm);
}

void
terminal_input_char(struct terminal *tm, term_char_t c)
{
        struct tty *tp;

        tp = tm->tm_tty;
        if (tp == NULL)
                return;

        /*
         * Strip off any attributes. Also ignore input of second part of
         * CJK fullwidth characters, as we don't want to return these
         * characters twice.
         */
        if (TCHAR_FORMAT(c) & TF_CJK_RIGHT)
                return;
        c = TCHAR_CHARACTER(c);

        tty_lock(tp);
        /*
         * Conversion to UTF-8.
         */
        if (c < 0x80) {
                ttydisc_rint(tp, c, 0);
        } else if (c < 0x800) {
                char str[2] = {
                        0xc0 | (c >> 6),
                        0x80 | (c & 0x3f)
                };

                ttydisc_rint_simple(tp, str, sizeof str);
        } else if (c < 0x10000) {
                char str[3] = {
                        0xe0 | (c >> 12),
                        0x80 | ((c >> 6) & 0x3f),
                        0x80 | (c & 0x3f)
                };

                ttydisc_rint_simple(tp, str, sizeof str);
        } else {
                char str[4] = {
                        0xf0 | (c >> 18),
                        0x80 | ((c >> 12) & 0x3f),
                        0x80 | ((c >> 6) & 0x3f),
                        0x80 | (c & 0x3f)
                };

                ttydisc_rint_simple(tp, str, sizeof str);
        }
        ttydisc_rint_done(tp);
        tty_unlock(tp);
}

void
terminal_input_raw(struct terminal *tm, char c)
{
        struct tty *tp;

        tp = tm->tm_tty;
        if (tp == NULL)
                return;

        tty_lock(tp);
        ttydisc_rint(tp, c, 0);
        ttydisc_rint_done(tp);
        tty_unlock(tp);
}

void
terminal_input_special(struct terminal *tm, unsigned int k)
{
        struct tty *tp;
        const char *str;

        tp = tm->tm_tty;
        if (tp == NULL)
                return;

        str = teken_get_sequence(&tm->tm_emulator, k);
        if (str == NULL)
                return;

        tty_lock(tp);
        ttydisc_rint_simple(tp, str, strlen(str));
        ttydisc_rint_done(tp);
        tty_unlock(tp);
}

/*
 * Binding with the TTY layer.
 */

static int
termtty_open(struct tty *tp)
{
        struct terminal *tm = tty_softc(tp);

        tm->tm_class->tc_opened(tm, 1);
        return (0);
}

static void
termtty_close(struct tty *tp)
{
        struct terminal *tm = tty_softc(tp);

        tm->tm_class->tc_opened(tm, 0);
}

static void
termtty_outwakeup(struct tty *tp)
{
        struct terminal *tm = tty_softc(tp);
        char obuf[128];
        size_t olen;
        unsigned int flags = 0;

        while ((olen = ttydisc_getc(tp, obuf, sizeof obuf)) > 0) {
                TERMINAL_LOCK_TTY(tm);
                if (!(tm->tm_flags & TF_MUTE)) {
                        tm->tm_flags &= ~TF_BELL;
                        teken_input(&tm->tm_emulator, obuf, olen);
                        flags |= tm->tm_flags;
                }
                TERMINAL_UNLOCK_TTY(tm);
        }

        TERMINAL_LOCK_TTY(tm);
        if (!(tm->tm_flags & TF_MUTE))
                tm->tm_class->tc_done(tm);
        TERMINAL_UNLOCK_TTY(tm);
        if (flags & TF_BELL)
                tm->tm_class->tc_bell(tm);
}

static int
termtty_ioctl(struct tty *tp, u_long cmd, caddr_t data, struct thread *td)
{
        struct terminal *tm = tty_softc(tp);
        int error;

        switch (cmd) {
        case CONS_GETINFO: {
                vid_info_t *vi = (vid_info_t *)data;
                const teken_pos_t *p;
                int fg, bg;

                if (vi->size != sizeof(vid_info_t))
                        return (EINVAL);

                /* Already help the console driver by filling in some data. */
                p = teken_get_cursor(&tm->tm_emulator);
                vi->mv_row = p->tp_row;
                vi->mv_col = p->tp_col;

                p = teken_get_winsize(&tm->tm_emulator);
                vi->mv_rsz = p->tp_row;
                vi->mv_csz = p->tp_col;

                teken_get_defattr_cons25(&tm->tm_emulator, &fg, &bg);
                vi->mv_norm.fore = fg;
                vi->mv_norm.back = bg;
                /* XXX: keep vidcontrol happy; bold backgrounds. */
                vi->mv_rev.fore = bg;
                vi->mv_rev.back = fg & 0x7;
                break;
        }
        }

        /*
         * Unlike various other drivers, this driver will never
         * deallocate TTYs.  This means it's safe to temporarily unlock
         * the TTY when handling ioctls.
         */
        tty_unlock(tp);
        error = tm->tm_class->tc_ioctl(tm, cmd, data, td);
        tty_lock(tp);
        if ((error == 0) && (cmd == CONS_CLRHIST)) {
                /*
                 * Scrollback history has been successfully cleared,
                 * so reset the cursor position to the top left of the screen.
                 */
                teken_pos_t p;
                p.tp_row = 0;
                p.tp_col = 0;
                teken_set_cursor(&tm->tm_emulator, &p);
        }
        return (error);
}

static int
termtty_mmap(struct tty *tp, vm_ooffset_t offset, vm_paddr_t * paddr,
    int nprot, vm_memattr_t *memattr)
{
        struct terminal *tm = tty_softc(tp);

        return (tm->tm_class->tc_mmap(tm, offset, paddr, nprot, memattr));
}

/*
 * Binding with the kernel and debug console.
 */

static cn_probe_t       termcn_cnprobe;
static cn_init_t        termcn_cninit;
static cn_term_t        termcn_cnterm;
static cn_getc_t        termcn_cngetc;
static cn_putc_t        termcn_cnputc;
static cn_grab_t        termcn_cngrab;
static cn_ungrab_t      termcn_cnungrab;

const struct consdev_ops termcn_cnops = {
        .cn_probe       = termcn_cnprobe,
        .cn_init        = termcn_cninit,
        .cn_term        = termcn_cnterm,
        .cn_getc        = termcn_cngetc,
        .cn_putc        = termcn_cnputc,
        .cn_grab        = termcn_cngrab,
        .cn_ungrab      = termcn_cnungrab,
};

void
termcn_cnregister(struct terminal *tm)
{
        struct consdev *cp;

        cp = tm->consdev;
        if (cp == NULL) {
                cp = malloc(sizeof(struct consdev), M_TERMINAL,
                    M_WAITOK|M_ZERO);
                cp->cn_ops = &termcn_cnops;
                cp->cn_arg = tm;
                cp->cn_pri = CN_INTERNAL;
                sprintf(cp->cn_name, "ttyv0");

                tm->tm_flags = TF_CONS;
                tm->consdev = cp;

                terminal_init(tm);
        }

        /* Attach terminal as console. */
        cnadd(cp);
}

static void
termcn_cngrab(struct consdev *cp)
{
        struct terminal *tm = cp->cn_arg;

        tm->tm_class->tc_cngrab(tm);
}

static void
termcn_cnungrab(struct consdev *cp)
{
        struct terminal *tm = cp->cn_arg;

        tm->tm_class->tc_cnungrab(tm);
}

static void
termcn_cnprobe(struct consdev *cp)
{
        struct terminal *tm = cp->cn_arg;

        if (tm == NULL) {
                cp->cn_pri = CN_DEAD;
                return;
        }

        tm->consdev = cp;
        terminal_init(tm);

        tm->tm_class->tc_cnprobe(tm, cp);
}

static void
termcn_cninit(struct consdev *cp)
{

}

static void
termcn_cnterm(struct consdev *cp)
{

}

static int
termcn_cngetc(struct consdev *cp)
{
        struct terminal *tm = cp->cn_arg;

        return (tm->tm_class->tc_cngetc(tm));
}

static void
termcn_cnputc(struct consdev *cp, int c)
{
        struct terminal *tm = cp->cn_arg;
        teken_attr_t backup;
        char cv = c;

        TERMINAL_LOCK_CONS(tm);
        if (!(tm->tm_flags & TF_MUTE)) {
                backup = *teken_get_curattr(&tm->tm_emulator);
                teken_set_curattr(&tm->tm_emulator, &kernel_message);
                teken_input(&tm->tm_emulator, &cv, 1);
                teken_set_curattr(&tm->tm_emulator, &backup);
                tm->tm_class->tc_done(tm);
        }
        TERMINAL_UNLOCK_CONS(tm);
}

/*
 * Binding with the terminal emulator.
 */

static void
termteken_bell(void *softc)
{
        struct terminal *tm = softc;

        tm->tm_flags |= TF_BELL;
}

static void
termteken_cursor(void *softc, const teken_pos_t *p)
{
        struct terminal *tm = softc;

        tm->tm_class->tc_cursor(tm, p);
}

static void
termteken_putchar(void *softc, const teken_pos_t *p, teken_char_t c,
    const teken_attr_t *a)
{
        struct terminal *tm = softc;

        tm->tm_class->tc_putchar(tm, p, TCHAR_CREATE(c, a));
}

static void
termteken_fill(void *softc, const teken_rect_t *r, teken_char_t c,
    const teken_attr_t *a)
{
        struct terminal *tm = softc;

        tm->tm_class->tc_fill(tm, r, TCHAR_CREATE(c, a));
}

static void
termteken_copy(void *softc, const teken_rect_t *r, const teken_pos_t *p)
{
        struct terminal *tm = softc;

        tm->tm_class->tc_copy(tm, r, p);
}

static void
termteken_pre_input(void *softc)
{
        struct terminal *tm = softc;

        tm->tm_class->tc_pre_input(tm);
}

static void
termteken_post_input(void *softc)
{
        struct terminal *tm = softc;

        tm->tm_class->tc_post_input(tm);
}

static void
termteken_param(void *softc, int cmd, unsigned int arg)
{
        struct terminal *tm = softc;

        tm->tm_class->tc_param(tm, cmd, arg);
}

static void
termteken_respond(void *softc, const void *buf, size_t len)
{
#if 0
        struct terminal *tm = softc;
        struct tty *tp;

        /*
         * Only inject a response into the TTY if the data actually
         * originated from the TTY.
         *
         * XXX: This cannot be done right now.  The TTY could pick up
         * other locks.  It could also in theory cause loops, when the
         * TTY performs echoing of a command that generates even more
         * input.
         */
        tp = tm->tm_tty;
        if (tp == NULL)
                return;

        ttydisc_rint_simple(tp, buf, len);
        ttydisc_rint_done(tp);
#endif
}