/* $Id: input.c,v 1.49 2008-06-04 19:20:09 nicm Exp $ */

/*
 * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>

#include <stdint.h>
#include <stdlib.h>
#include <string.h>

#include "tmux.h"

#define INPUT_C0CONTROL(ch) 	(ch <= 0x1f)
#define INPUT_INTERMEDIATE(ch)	(ch == 0xa0 || (ch >= 0x20 && ch <= 0x2f))
#define INPUT_PARAMETER(ch)	(ch >= 0x30 && ch <= 0x3f)
#define INPUT_UPPERCASE(ch)	(ch >= 0x40 && ch <= 0x5f)
#define INPUT_LOWERCASE(ch)	(ch >= 0x60 && ch <= 0x7e)
#define INPUT_DELETE(ch)	(ch == 0x7f)
#define INPUT_C1CONTROL(ch)	(ch >= 0x80 && ch <= 0x9f)
#define INPUT_G1DISPLAYABLE(ch)	(ch >= 0xa1 && ch <= 0xfe)
#define INPUT_SPECIAL(ch)	(ch == 0xff)

int	 input_get_argument(struct input_ctx *, u_int, uint16_t *, uint16_t);
int	 input_new_argument(struct input_ctx *);
int	 input_add_argument(struct input_ctx *, u_char);

void	 input_start_string(struct input_ctx *, int);
void	 input_abort_string(struct input_ctx *);
int	 input_add_string(struct input_ctx *, u_char);
char	*input_get_string(struct input_ctx *);

void	 input_state(struct input_ctx *, void *);

void	 input_state_first(u_char, struct input_ctx *);
void	 input_state_escape(u_char, struct input_ctx *);
void	 input_state_intermediate(u_char, struct input_ctx *);
void	 input_state_title_first(u_char, struct input_ctx *);
void	 input_state_title_second(u_char, struct input_ctx *);
void	 input_state_title_next(u_char, struct input_ctx *);
void	 input_state_sequence_first(u_char, struct input_ctx *);
void	 input_state_sequence_next(u_char, struct input_ctx *);
void	 input_state_sequence_intermediate(u_char, struct input_ctx *);
void	 input_state_string_next(u_char, struct input_ctx *);
void	 input_state_string_escape(u_char, struct input_ctx *);

void	 input_handle_character(u_char, struct input_ctx *);
void	 input_handle_c0_control(u_char, struct input_ctx *);
void	 input_handle_c1_control(u_char, struct input_ctx *);
void	 input_handle_private_two(u_char, struct input_ctx *);
void	 input_handle_standard_two(u_char, struct input_ctx *);
void	 input_handle_sequence(u_char, struct input_ctx *);

void	 input_handle_sequence_cuu(struct input_ctx *);
void	 input_handle_sequence_cud(struct input_ctx *);
void	 input_handle_sequence_cuf(struct input_ctx *);
void	 input_handle_sequence_cub(struct input_ctx *);
void	 input_handle_sequence_dch(struct input_ctx *);
void	 input_handle_sequence_dl(struct input_ctx *);
void	 input_handle_sequence_ich(struct input_ctx *);
void	 input_handle_sequence_il(struct input_ctx *);
void	 input_handle_sequence_vpa(struct input_ctx *);
void	 input_handle_sequence_hpa(struct input_ctx *);
void	 input_handle_sequence_cup(struct input_ctx *);
void	 input_handle_sequence_cup(struct input_ctx *);
void	 input_handle_sequence_ed(struct input_ctx *);
void	 input_handle_sequence_el(struct input_ctx *);
void	 input_handle_sequence_sm(struct input_ctx *);
void	 input_handle_sequence_rm(struct input_ctx *);
void	 input_handle_sequence_decstbm(struct input_ctx *);
void	 input_handle_sequence_sgr(struct input_ctx *);
void	 input_handle_sequence_dsr(struct input_ctx *);

int
input_new_argument(struct input_ctx *ictx)
{
	struct input_arg       *arg;

	ARRAY_EXPAND(&ictx->args, 1);

	arg = &ARRAY_LAST(&ictx->args);
	arg->used = 0;

	return (0);
}

int
input_add_argument(struct input_ctx *ictx, u_char ch)
{
	struct input_arg       *arg;

	if (ARRAY_LENGTH(&ictx->args) == 0)
		return (0);

	arg = &ARRAY_LAST(&ictx->args);
	if (arg->used > (sizeof arg->data) - 1)
		return (-1);
	arg->data[arg->used++] = ch;

	return (0);
}

int
input_get_argument(struct input_ctx *ictx, u_int i, uint16_t *n, uint16_t d)
{
	struct input_arg	*arg;
	const char		*errstr;

	*n = d;
	if (i >= ARRAY_LENGTH(&ictx->args))
		return (0);

	arg = &ARRAY_ITEM(&ictx->args, i);
	if (*arg->data == '\0')
		return (0);

	*n = strtonum(arg->data, 0, UINT16_MAX, &errstr);
	if (errstr != NULL)
		return (-1);
	return (0);
}

void
input_start_string(struct input_ctx *ictx, int type)
{
	ictx->string_type = type;
	ictx->string_len = 0;
}

void
input_abort_string(struct input_ctx *ictx)
{
	xfree(ictx->string_buf);
	ictx->string_buf = NULL;
}

int
input_add_string(struct input_ctx *ictx, u_char ch)
{
	ictx->string_buf = xrealloc(ictx->string_buf, 1, ictx->string_len + 1);
	ictx->string_buf[ictx->string_len++] = ch;

	if (ictx->string_len >= MAXSTRINGLEN) {
		input_abort_string(ictx);
		return (1);
	}

	return (0);
}

char *
input_get_string(struct input_ctx *ictx)
{
	char	*s;

	if (ictx->string_buf == NULL)
		return (xstrdup(""));

	input_add_string(ictx, '\0');
	s = ictx->string_buf;
	ictx->string_buf = NULL;
	return (s);
}

void
input_state(struct input_ctx *ictx, void *state)
{
	ictx->state = state;
}

void
input_init(struct window *w)
{
	ARRAY_INIT(&w->ictx.args);

	w->ictx.string_len = 0;
	w->ictx.string_buf = NULL;

	input_state(&w->ictx, input_state_first);
}

void
input_free(struct window *w)
{
	if (w->ictx.string_buf != NULL)
		xfree(w->ictx.string_buf);

	ARRAY_FREE(&w->ictx.args);
}

void
input_parse(struct window *w)
{
	struct input_ctx	*ictx = &w->ictx;
	u_char			 ch;

	if (BUFFER_USED(w->in) == 0)
		return;

	ictx->buf = BUFFER_OUT(w->in);
	ictx->len = BUFFER_USED(w->in);
	ictx->off = 0;

	ictx->w = w;

	log_debug2("entry; buffer=%zu", ictx->len);

	if (w->mode == NULL)
		screen_write_start(&ictx->ctx, &w->base, tty_write_window, w);
	else
		screen_write_start(&ictx->ctx, &w->base, NULL, NULL);

	if (ictx->off != ictx->len)
		w->flags |= WINDOW_ACTIVITY;
	while (ictx->off < ictx->len) {
		ch = ictx->buf[ictx->off++];
		ictx->state(ch, ictx);
	}

	screen_write_stop(&ictx->ctx);

	buffer_remove(w->in, ictx->len);
}

void
input_state_first(u_char ch, struct input_ctx *ictx)
{
	if (INPUT_C0CONTROL(ch)) {
		if (ch == 0x1b)
			input_state(ictx, input_state_escape);
		else
			input_handle_c0_control(ch, ictx);
		return;
	}

  	if (INPUT_C1CONTROL(ch)) {
		ch -= 0x40;
		if (ch == '[')
			input_state(ictx, input_state_sequence_first);
		else if (ch == ']')
			input_state(ictx, input_state_title_first);
		else
			input_handle_c1_control(ch, ictx);
		return;
	}

	input_handle_character(ch, ictx);
}

void
input_state_escape(u_char ch, struct input_ctx *ictx)
{
	/* Treat C1 control and G1 displayable as 7-bit equivalent. */
	if (INPUT_C1CONTROL(ch) || INPUT_G1DISPLAYABLE(ch))
		ch &= 0x7f;

	if (INPUT_C0CONTROL(ch)) {
		input_handle_c0_control(ch, ictx);
		return;
	}

	if (INPUT_INTERMEDIATE(ch)) {
		input_state(ictx, input_state_intermediate);
		return;
	}

	if (INPUT_PARAMETER(ch)) {
		input_state(ictx, input_state_first);
		input_handle_private_two(ch, ictx);
		return;
	}

	if (INPUT_UPPERCASE(ch)) {
		if (ch == '[')
			input_state(ictx, input_state_sequence_first);
		else if (ch == ']')
			input_state(ictx, input_state_title_first);
		else {
			input_state(ictx, input_state_first);
			input_handle_c1_control(ch, ictx);
		}
		return;
	}

	if (INPUT_LOWERCASE(ch)) {
		input_state(ictx, input_state_first);
		input_handle_standard_two(ch, ictx);
		return;
	}

	input_state(ictx, input_state_first);
}

void
input_state_title_first(u_char ch, struct input_ctx *ictx)
{
	if (ch >= '0' && ch <= '9') {
		if (ch == '0')
			input_start_string(ictx, STRING_TITLE);
		else
			input_start_string(ictx, STRING_IGNORE);
		input_state(ictx, input_state_title_second);
		return;
	}

	input_state(ictx, input_state_first);
}

void
input_state_title_second(u_char ch, struct input_ctx *ictx)
{
	if (ch == ';') {
		input_state(ictx, input_state_title_next);
		return;
	}

	input_state(ictx, input_state_first);
}

void
input_state_title_next(u_char ch, struct input_ctx *ictx)
{
	if (ch == '\007') {
		if (ictx->string_type == STRING_TITLE) {
			screen_write_set_title(
			    &ictx->ctx, input_get_string(ictx));
		} else
			input_abort_string(ictx);
		input_state(ictx, input_state_first);
		return;
	}

	if (ch >= 0x20 && ch != 0x7f) {
		if (input_add_string(ictx, ch) != 0)
			input_state(ictx, input_state_first);
		return;
	}

	input_state(ictx, input_state_first);
}

void
input_state_intermediate(u_char ch, struct input_ctx *ictx)
{
	if (INPUT_INTERMEDIATE(ch))
		return;

	if (INPUT_PARAMETER(ch)) {
		input_state(ictx, input_state_first);
		input_handle_private_two(ch, ictx);
		return;
	}

	if (INPUT_UPPERCASE(ch) || INPUT_LOWERCASE(ch)) {
		input_state(ictx, input_state_first);
		input_handle_standard_two(ch, ictx);
		return;
	}

	input_state(ictx, input_state_first);
}

void
input_state_sequence_first(u_char ch, struct input_ctx *ictx)
{
	ictx->private = '\0';
	ARRAY_CLEAR(&ictx->args);

	input_state(ictx, input_state_sequence_next);

	if (INPUT_PARAMETER(ch)) {
		input_new_argument(ictx);
		if (ch >= 0x3c && ch <= 0x3f) {
			/* Private control sequence. */
			ictx->private = ch;
			return;
		}
	}

	/* Pass character on directly. */
	input_state_sequence_next(ch, ictx);
}

void
input_state_sequence_next(u_char ch, struct input_ctx *ictx)
{
	if (INPUT_INTERMEDIATE(ch)) {
		if (input_add_argument(ictx, '\0') != 0)
			input_state(ictx, input_state_first);
		else
			input_state(ictx, input_state_sequence_intermediate);
		return;
	}

	if (INPUT_PARAMETER(ch)) {
		if (ch == ';') {
			if (input_add_argument(ictx, '\0') != 0)
				input_state(ictx, input_state_first);
			else
				input_new_argument(ictx);
		} else if (input_add_argument(ictx, ch) != 0)
			input_state(ictx, input_state_first);
		return;
	}

	if (INPUT_UPPERCASE(ch) || INPUT_LOWERCASE(ch)) {
		if (input_add_argument(ictx, '\0') != 0)
			input_state(ictx, input_state_first);
		else {
			input_state(ictx, input_state_first);
			input_handle_sequence(ch, ictx);
		}
		return;
	}

	input_state(ictx, input_state_first);
}

void
input_state_sequence_intermediate(u_char ch, struct input_ctx *ictx)
{
	if (INPUT_INTERMEDIATE(ch))
		return;

	if (INPUT_UPPERCASE(ch) || INPUT_LOWERCASE(ch)) {
		input_state(ictx, input_state_first);
		input_handle_sequence(ch, ictx);
		return;
	}

	input_state(ictx, input_state_first);
}

void
input_state_string_next(u_char ch, struct input_ctx *ictx)
{
	if (ch == 0x1b) {
		input_state(ictx, input_state_string_escape);
		return;
	}

	if (ch >= 0x20 && ch != 0x7f) {
		if (input_add_string(ictx, ch) != 0)
			input_state(ictx, input_state_first);
		return;
	}
}

void
input_state_string_escape(u_char ch, struct input_ctx *ictx)
{
	if (ch == '\\') {
		input_state(ictx, input_state_first);
		switch (ictx->string_type) {
		case STRING_NAME:
			xfree(ictx->w->name);
			ictx->w->name = input_get_string(ictx);
			server_status_window(ictx->w);
			break;
		}
		return;
	}

	input_state(ictx, input_state_string_next);
	input_state_string_next(ch, ictx);
}

void
input_handle_character(u_char ch, struct input_ctx *ictx)
{
	log_debug2("-- ch %zu: %hhu (%c)", ictx->off, ch, ch);

	screen_write_put_character(&ictx->ctx, ch);
}

void
input_handle_c0_control(u_char ch, struct input_ctx *ictx)
{
	struct screen	*s = ictx->ctx.s;
	u_char		 attr;

	log_debug2("-- c0 %zu: %hhu", ictx->off, ch);

	switch (ch) {
	case '\0':	/* NUL */
		break;
	case '\n':	/* LF */
		screen_write_cursor_down_scroll(&ictx->ctx);
		break;
	case '\r':	/* CR */
		screen_write_move_cursor(&ictx->ctx, 0, s->cy);
		break;
	case '\007':	/* BELL */
		ictx->w->flags |= WINDOW_BELL;
		break;
	case '\010': 	/* BS */
		screen_write_cursor_left(&ictx->ctx, 1);
		break;
	case '\011': 	/* TAB */
		s->cx = ((s->cx / 8) * 8) + 8;
		if (s->cx > screen_last_x(s)) {
			s->cx = 0;
			screen_write_cursor_down(&ictx->ctx, 1);
		}
		screen_write_move_cursor(&ictx->ctx, s->cx, s->cy);
		break;
	case '\016':	/* SO */
		attr = s->attr | ATTR_CHARSET;
		screen_write_set_attributes(&ictx->ctx, attr, s->colr);
		break;
	case '\017':	/* SI */
		attr = s->attr & ~ATTR_CHARSET;
		screen_write_set_attributes(&ictx->ctx, attr, s->colr);
		break;
	default:
		log_debug("unknown c0: %hhu", ch);
		break;
	}
}

void
input_handle_c1_control(u_char ch, struct input_ctx *ictx)
{
	log_debug2("-- c1 %zu: %hhu (%c)", ictx->off, ch, ch);

	switch (ch) {
	case 'M':	/* RI */
		screen_write_cursor_up_scroll(&ictx->ctx);
		break;
	default:
		log_debug("unknown c1: %hhu", ch);
		break;
	}
}

void
input_handle_private_two(u_char ch, struct input_ctx *ictx)
{
	struct screen	*s = ictx->ctx.s;

	log_debug2("-- p2 %zu: %hhu (%c)", ictx->off, ch, ch);

	switch (ch) {
	case '=':	/* DECKPAM */
		screen_write_set_mode(&ictx->ctx, MODE_KKEYPAD);
		log_debug("kkeypad on");
		break;
	case '>':	/* DECKPNM*/
		screen_write_clear_mode(&ictx->ctx, MODE_KKEYPAD);
		log_debug("kkeypad off");
		break;
	case '7':	/* DECSC */
		s->saved_cx = s->cx;
		s->saved_cy = s->cy;
		s->saved_attr = s->attr;
		s->saved_colr = s->colr;
		s->mode |= MODE_SAVED;
		break;
	case '8':	/* DECRC */
		if (!(s->mode & MODE_SAVED))
			break;
		screen_write_set_attributes(
		    &ictx->ctx, s->saved_attr, s->saved_colr);
		screen_write_move_cursor(&ictx->ctx, s->saved_cx, s->saved_cy);
		break;
	default:
		log_debug("unknown p2: %hhu", ch);
		break;
	}
}

void
input_handle_standard_two(u_char ch, struct input_ctx *ictx)
{
	log_debug2("-- s2 %zu: %hhu (%c)", ictx->off, ch, ch);

	switch (ch) {
	case 'k':
		input_start_string(ictx, STRING_NAME);
		input_state(ictx, input_state_string_next);
		break;
	default:
		log_debug("unknown s2: %hhu", ch);
		break;
	}
}

void
input_handle_sequence(u_char ch, struct input_ctx *ictx)
{
	static const struct {
		u_char	ch;
		void	(*fn)(struct input_ctx *);
	} table[] = {
		{ '@', input_handle_sequence_ich },
		{ 'A', input_handle_sequence_cuu },
		{ 'B', input_handle_sequence_cud },
		{ 'C', input_handle_sequence_cuf },
		{ 'D', input_handle_sequence_cub },
		{ 'G', input_handle_sequence_hpa },
		{ 'H', input_handle_sequence_cup },
		{ 'J', input_handle_sequence_ed },
		{ 'K', input_handle_sequence_el },
		{ 'L', input_handle_sequence_il },
		{ 'M', input_handle_sequence_dl },
		{ 'P', input_handle_sequence_dch },
		{ 'd', input_handle_sequence_vpa },
		{ 'f', input_handle_sequence_cup },
		{ 'h', input_handle_sequence_sm },
		{ 'l', input_handle_sequence_rm },
		{ 'm', input_handle_sequence_sgr },
		{ 'n', input_handle_sequence_dsr },
		{ 'r', input_handle_sequence_decstbm },
	};
	struct screen	 *s = ictx->ctx.s;
	u_int		  i;
	struct input_arg *iarg;

	log_debug2("-- sq %zu: %hhu (%c): %u [sx=%u, sy=%u, cx=%u, cy=%u, "
	    "ru=%u, rl=%u]", ictx->off, ch, ch, ARRAY_LENGTH(&ictx->args),
	    screen_size_x(s), screen_size_y(s), s->cx, s->cy, s->rupper,
	    s->rlower);
	for (i = 0; i < ARRAY_LENGTH(&ictx->args); i++) {
		iarg = &ARRAY_ITEM(&ictx->args, i);
		if (*iarg->data != '\0')
			log_debug2("      ++ %u: %s", i, iarg->data);
	}

	/* XXX bsearch? */
	for (i = 0; i < (sizeof table / sizeof table[0]); i++) {
		if (table[i].ch == ch) {
			table[i].fn(ictx);
			return;
		}
	}

	log_debug("unknown sq: %c (%hhu %hhu)", ch, ch, ictx->private);
}

void
input_handle_sequence_cuu(struct input_ctx *ictx)
{
	uint16_t	n;

	if (ictx->private != '\0')
		return;

	if (ARRAY_LENGTH(&ictx->args) > 1)
		return;
	if (input_get_argument(ictx, 0, &n, 1) != 0)
		return;
	if (n == 0)
		n = 1;

	screen_write_cursor_up(&ictx->ctx, n);
}

void
input_handle_sequence_cud(struct input_ctx *ictx)
{
	uint16_t	n;

	if (ictx->private != '\0')
		return;

	if (ARRAY_LENGTH(&ictx->args) > 1)
		return;
	if (input_get_argument(ictx, 0, &n, 1) != 0)
		return;
	if (n == 0)
		n = 1;

	screen_write_cursor_down(&ictx->ctx, n);
}

void
input_handle_sequence_cuf(struct input_ctx *ictx)
{
	uint16_t n;

	if (ictx->private != '\0')
		return;

	if (ARRAY_LENGTH(&ictx->args) > 1)
		return;
	if (input_get_argument(ictx, 0, &n, 1) != 0)
		return;
	if (n == 0)
		n = 1;

	screen_write_cursor_right(&ictx->ctx, n);
}

void
input_handle_sequence_cub(struct input_ctx *ictx)
{
	uint16_t	n;

	if (ictx->private != '\0')
		return;

	if (ARRAY_LENGTH(&ictx->args) > 1)
		return;
	if (input_get_argument(ictx, 0, &n, 1) != 0)
		return;
	if (n == 0)
		n = 1;

	screen_write_cursor_left(&ictx->ctx, n);
}

void
input_handle_sequence_dch(struct input_ctx *ictx)
{
	uint16_t	n;

	if (ictx->private != '\0')
		return;

	if (ARRAY_LENGTH(&ictx->args) > 1)
		return;
	if (input_get_argument(ictx, 0, &n, 1) != 0)
		return;
	if (n == 0)
		n = 1;

	screen_write_delete_characters(&ictx->ctx, n);
}

void
input_handle_sequence_dl(struct input_ctx *ictx)
{
	uint16_t	n;

	if (ictx->private != '\0')
		return;

	if (ARRAY_LENGTH(&ictx->args) > 1)
		return;
	if (input_get_argument(ictx, 0, &n, 1) != 0)
		return;
	if (n == 0)
		n = 1;

	screen_write_delete_lines(&ictx->ctx, n);
}

void
input_handle_sequence_ich(struct input_ctx *ictx)
{
	uint16_t	n;

	if (ictx->private != '\0')
		return;

	if (ARRAY_LENGTH(&ictx->args) > 1)
		return;
	if (input_get_argument(ictx, 0, &n, 1) != 0)
		return;
	if (n == 0)
		n = 1;

	screen_write_insert_characters(&ictx->ctx, n);
}

void
input_handle_sequence_il(struct input_ctx *ictx)
{
	uint16_t	n;

	if (ictx->private != '\0')
		return;

	if (ARRAY_LENGTH(&ictx->args) > 1)
		return;
	if (input_get_argument(ictx, 0, &n, 1) != 0)
		return;
	if (n == 0)
		n = 1;

	screen_write_insert_lines(&ictx->ctx, n);
}

void
input_handle_sequence_vpa(struct input_ctx *ictx)
{
	struct screen  *s = ictx->ctx.s;
	uint16_t	n;

	if (ictx->private != '\0')
		return;

	if (ARRAY_LENGTH(&ictx->args) > 1)
		return;
	if (input_get_argument(ictx, 0, &n, 1) != 0)
		return;
	if (n == 0)
		n = 1;

	screen_write_move_cursor(&ictx->ctx, s->cx, n - 1);
}

void
input_handle_sequence_hpa(struct input_ctx *ictx)
{
	struct screen  *s = ictx->ctx.s;
	uint16_t	n;

	if (ictx->private != '\0')
		return;

	if (ARRAY_LENGTH(&ictx->args) > 1)
		return;
	if (input_get_argument(ictx, 0, &n, 1) != 0)
		return;
	if (n == 0)
		n = 1;

	screen_write_move_cursor(&ictx->ctx, n - 1, s->cy);
}

void
input_handle_sequence_cup(struct input_ctx *ictx)
{
	uint16_t	n, m;

	if (ictx->private != '\0')
		return;

	if (ARRAY_LENGTH(&ictx->args) > 2)
		return;
	if (input_get_argument(ictx, 0, &n, 1) != 0)
		return;
	if (input_get_argument(ictx, 1, &m, 1) != 0)
		return;
	if (n == 0)
		n = 1;
	if (m == 0)
		m = 1;

	screen_write_move_cursor(&ictx->ctx, m - 1, n - 1);
}

void
input_handle_sequence_ed(struct input_ctx *ictx)
{
	uint16_t	n;

	if (ictx->private != '\0')
		return;

	if (ARRAY_LENGTH(&ictx->args) > 1)
		return;
	if (input_get_argument(ictx, 0, &n, 0) != 0)
		return;
	if (n > 2)
		return;

	switch (n) {
	case 0:
		screen_write_fill_end_of_screen(&ictx->ctx);
		break;
	case 2:
		screen_write_fill_screen(&ictx->ctx);
		break;
	}
}

void
input_handle_sequence_el(struct input_ctx *ictx)
{
	uint16_t	n;

	if (ictx->private != '\0')
		return;

	if (ARRAY_LENGTH(&ictx->args) > 1)
		return;
	if (input_get_argument(ictx, 0, &n, 0) != 0)
		return;
	if (n > 2)
		return;

	switch (n) {
	case 0:
		screen_write_fill_end_of_line(&ictx->ctx);
		break;
	case 1:
		screen_write_fill_start_of_line(&ictx->ctx);
		break;
	case 2:
		screen_write_fill_line(&ictx->ctx);
		break;
	}
}

void
input_handle_sequence_sm(struct input_ctx *ictx)
{
	uint16_t	n;

	if (ARRAY_LENGTH(&ictx->args) > 1)
		return;
	if (input_get_argument(ictx, 0, &n, 0) != 0)
		return;

	if (ictx->private == '?') {
		switch (n) {
		case 1:		/* GATM */
			screen_write_set_mode(&ictx->ctx, MODE_KCURSOR);
			log_debug("kcursor on");
			break;
		case 25:	/* TCEM */
			screen_write_set_mode(&ictx->ctx, MODE_CURSOR);
			log_debug("cursor on");
			break;
		case 1000:
			screen_write_set_mode(&ictx->ctx, MODE_MOUSE);
			log_debug("mouse on");
			break;
		default:
			log_debug("unknown SM [%hhu]: %u", ictx->private, n);
			break;
		}
	} else {
		switch (n) {
		case 4:		/* IRM */
			screen_write_set_mode(&ictx->ctx, MODE_INSERT);
			log_debug("insert on");
			break;
		case 34:
			/* Cursor high visibility not supported. */
			break;
		default:
			log_debug("unknown SM [%hhu]: %u", ictx->private, n);
			break;
		}
	}
}

void
input_handle_sequence_rm(struct input_ctx *ictx)
{
	uint16_t	 n;

	if (ARRAY_LENGTH(&ictx->args) > 1)
		return;
	if (input_get_argument(ictx, 0, &n, 0) != 0)
		return;

	if (ictx->private == '?') {
		switch (n) {
		case 1:		/* GATM */
			screen_write_clear_mode(&ictx->ctx, MODE_KCURSOR);
			log_debug("kcursor off");
			break;
		case 25:	/* TCEM */
			screen_write_clear_mode(&ictx->ctx, MODE_CURSOR);
			log_debug("cursor off");
			break;
		case 1000:
			screen_write_clear_mode(&ictx->ctx, MODE_MOUSE);
			log_debug("mouse off");
			break;
		default:
			log_debug("unknown RM [%hhu]: %u", ictx->private, n);
			break;
		}
	} else if (ictx->private == '\0') {
		switch (n) {
		case 4:		/* IRM */
			screen_write_clear_mode(&ictx->ctx, MODE_INSERT);
			log_debug("insert off");
			break;
		case 34:
			/* Cursor high visibility not supported. */
			break;
		default:
			log_debug("unknown RM [%hhu]: %u", ictx->private, n);
			break;
		}
	}
}

void
input_handle_sequence_dsr(struct input_ctx *ictx)
{
	struct screen  *s = ictx->ctx.s;
	uint16_t	n;
	char		reply[32];

	if (ARRAY_LENGTH(&ictx->args) > 1)
		return;
	if (input_get_argument(ictx, 0, &n, 0) != 0)
		return;

	if (ictx->private == '\0') {
		switch (n) {
		case 6:	/* cursor position */
			xsnprintf(reply, sizeof reply,
			    "\033[%u;%uR", s->cy + 1, s->cx + 1);
			log_debug("cursor request, reply: %s", reply);
			buffer_write(ictx->w->out, reply, strlen(reply));
			break;
		}
	}

}

void
input_handle_sequence_decstbm(struct input_ctx *ictx)
{
	struct screen  *s = ictx->ctx.s;
	uint16_t	n, m;

	if (ictx->private != '\0')
		return;

	if (ARRAY_LENGTH(&ictx->args) > 2)
		return;
	if (input_get_argument(ictx, 0, &n, 0) != 0)
		return;
	if (input_get_argument(ictx, 1, &m, 0) != 0)
		return;
	if (n == 0)
		n = 1;
	if (m == 0)
		m = screen_size_y(s);

	screen_write_set_region(&ictx->ctx, n - 1, m - 1);
}

void
input_handle_sequence_sgr(struct input_ctx *ictx)
{
	struct screen  *s = ictx->ctx.s;
	u_int		i, n;
	uint16_t	m;
	u_char		attr, colr;

	n = ARRAY_LENGTH(&ictx->args);
	if (n == 0) {
		attr = 0;
		colr = SCREEN_DEFCOLR;
	} else {
		attr = s->attr;
		colr = s->colr;
		for (i = 0; i < n; i++) {
			if (input_get_argument(ictx, i, &m, 0) != 0)
				return;
			switch (m) {
			case 0:
			case 10:
				attr &= ATTR_CHARSET;
				colr = SCREEN_DEFCOLR;
				break;
			case 1:
				attr |= ATTR_BRIGHT;
				break;
			case 2:
				attr |= ATTR_DIM;
				break;
			case 3:
				attr |= ATTR_ITALICS;
				break;
			case 4:
				attr |= ATTR_UNDERSCORE;
				break;
			case 5:
				attr |= ATTR_BLINK;
				break;
			case 7:
				attr |= ATTR_REVERSE;
				break;
			case 8:
				attr |= ATTR_HIDDEN;
				break;
			case 23:
				attr &= ~ATTR_ITALICS;
				break;
			case 24:
				attr &= ~ATTR_UNDERSCORE;
				break;
			case 30:
			case 31:
			case 32:
			case 33:
			case 34:
			case 35:
			case 36:
			case 37:
				colr &= 0x0f;
				colr |= (m - 30) << 4;
				break;
			case 39:
				colr &= 0x0f;
				colr |= 0x80;
				break;
			case 40:
			case 41:
			case 42:
			case 43:
			case 44:
			case 45:
			case 46:
			case 47:
				colr &= 0xf0;
				colr |= m - 40;
				break;
			case 49:
				colr &= 0xf0;
				colr |= 0x08;
				break;
			}
		}
	}
	screen_write_set_attributes(&ictx->ctx, attr, colr);
}