/* ----------------------------------------------------------------------- *
 *
 *   Copyright 2004-2008 H. Peter Anvin - All Rights Reserved
 *
 *   Permission is hereby granted, free of charge, to any person
 *   obtaining a copy of this software and associated documentation
 *   files (the "Software"), to deal in the Software without
 *   restriction, including without limitation the rights to use,
 *   copy, modify, merge, publish, distribute, sublicense, and/or
 *   sell copies of the Software, and to permit persons to whom
 *   the Software is furnished to do so, subject to the following
 *   conditions:
 *
 *   The above copyright notice and this permission notice shall
 *   be included in all copies or substantial portions of the Software.
 *
 *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 *   OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 *   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 *   HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 *   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 *   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 *   OTHER DEALINGS IN THE SOFTWARE.
 *
 * ----------------------------------------------------------------------- */

/*
 * vesacon_write.c
 *
 * Write to the screen using ANSI control codes (about as capable as
 * DOS' ANSI.SYS.)
 */

#include <errno.h>
#include <string.h>
#include <com32.h>
#include <minmax.h>
#include <colortbl.h>
#include <console.h>
#include <klibc/compiler.h>
#include "ansi.h"
#include "file.h"
#include "vesa/video.h"

static void vesacon_erase(const struct term_state *, int, int, int, int);
static void vesacon_write_char(int, int, uint8_t, const struct term_state *);
static void vesacon_showcursor(const struct term_state *);
static void vesacon_scroll_up(const struct term_state *);

static struct term_state ts;
static struct ansi_ops op = {
  .erase	= vesacon_erase,
  .write_char	= vesacon_write_char,
  .showcursor   = vesacon_showcursor,
  .set_cursor   = __vesacon_set_cursor,	/* in drawtxt.c */
  .scroll_up    = vesacon_scroll_up,
};

static struct term_info ti =
  {
    .cols = TEXT_PIXEL_COLS/FONT_WIDTH,
    .disabled = 0,
    .ts = &ts,
    .op = &op
  };

/* Reference counter to the screen, to keep track of if we need reinitialization. */
static int vesacon_counter = 0;

/* Common setup */
int __vesacon_open(struct file_info *fp)
{
  static com32sys_t ireg;	/* Auto-initalized to all zero */
  com32sys_t oreg;

  (void)fp;

  if (!vesacon_counter) {
    /* Are we disabled? */
    ireg.eax.w[0] = 0x000b;
    __intcall(0x22, &ireg, &oreg);

    if ( (signed char)oreg.ebx.b[1] < 0 ) {
      ti.disabled = 1;
    } else {
      /* Switch mode */
      if (__vesacon_init()) {
	vesacon_counter = -1;
	return EAGAIN;
      }

      /* Initial state */
      __ansi_init(&ti);
      ti.rows = __vesacon_text_rows;
    }
  } else if (vesacon_counter == -1) {
    return EAGAIN;
  }

  fp->o.rows = ti.rows;
  fp->o.cols = ti.cols;

  vesacon_counter++;
  return 0;
}

int __vesacon_close(struct file_info *fp)
{
  (void)fp;

  vesacon_counter--;
  return 0;
}

/* Erase a region of the screen */
static void vesacon_erase(const struct term_state *st,
			  int x0, int y0, int x1, int y1)
{
  __vesacon_erase(x0, y0, x1, y1, st->cindex);
}

/* Draw text on the screen */
static void vesacon_write_char(int x, int y, uint8_t ch,
			       const struct term_state *st)
{
  __vesacon_write_char(x, y, ch, st->cindex);
}

/* Show or hide the cursor */
static void vesacon_showcursor(const struct term_state *st)
{
  __vesacon_set_cursor(st->xy.x, st->xy.y, st->cursor);
}

static void vesacon_scroll_up(const struct term_state *st)
{
  __vesacon_scroll_up(1, st->cindex);
}

ssize_t __vesacon_write(struct file_info *fp, const void *buf, size_t count)
{
  const unsigned char *bufp = buf;
  size_t n = 0;

  (void)fp;

  if ( ti.disabled )
    return n;			/* Nothing to do */

  /* This only updates the shadow text buffer... */
  while ( count-- ) {
    __ansi_putchar(&ti, *bufp++);
    n++;
  }

  /* This actually draws it */
  __vesacon_doit();

  return n;
}

const struct output_dev dev_vesacon_w = {
  .dev_magic  = __DEV_MAGIC,
  .flags      = __DEV_TTY | __DEV_OUTPUT,
  .fileflags  = O_WRONLY | O_CREAT | O_TRUNC | O_APPEND,
  .write      = __vesacon_write,
  .close      = __vesacon_close,
  .open       = __vesacon_open,
  .fallback   = &dev_ansicon_w,
};
