/*****************************************************************************************
 Copyright (c) 2002-2004 The UbixOS Project
 All rights reserved.

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 permitted provided that the following conditions are met:

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 form must reproduce the above copyright notice, this list of conditions, the following
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 OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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 $Id: tty.c 54 2016-01-11 01:29:55Z reddawg $

*****************************************************************************************/

#include <ubixos/tty.h>
#include <ubixos/kpanic.h>
#include <ubixos/spinlock.h>
#include <lib/kprintf.h>
#include <lib/kmalloc.h>
#include <sys/io.h>
#include <string.h>

static tty_term  *terms          = 0x0;
tty_term         *tty_foreground = 0x0;
static spinLock_t tty_spinLock   = SPIN_LOCK_INITIALIZER;

int tty_init() {
  int i = 0x0;

  /* Allocate memory for terminals */
  terms = (tty_term *)kmalloc(sizeof(tty_term)*TTY_MAX_TERMS);
  if (terms == 0x0)
    kpanic("tty_init: Failed to allocate memory. File: %s, Line: %i\n",__FILE__,__LINE__);

  /* Set up all default terminal information */
  for (i = 0;i < TTY_MAX_TERMS;i++) {
    terms[i].tty_buffer = (char *)kmalloc(80*60*2);
    if (terms[i].tty_buffer == 0x0)
      kpanic("tty_init: Failed to allocate buffer memory. File: %s, Line: %i\n",__FILE__,__LINE__);

    terms[i].tty_pointer = terms[i].tty_buffer;   /* Set up tty pointer to internal buffer */
    terms[i].tty_x       = 0x0;                   /* Set up default X position             */
    terms[i].tty_y       = 0x0;                   /* Set up default Y position             */
    terms[i].tty_colour  = 0x0A + i;              /* Set up default tty text colour        */
    }

  /* Read tty0 current position (to migrate from kprintf). */
  outportByte(0x3D4, 0x0e);
  terms[0].tty_y = inportByte(0x3D5);
  outportByte(0x3D4, 0x0f);
  terms[0].tty_x = inportByte(0x3D5);


  /* Set up pointer for the foreground tty */
  tty_foreground = &terms[0];

  /* Set up the foreground ttys information */
  tty_foreground->tty_pointer = (char *)0xB8000;

  /* Return to let kernel know initialization is complete */
  kprintf("tty0 - Initialized\n");

  return(0x0);
  }


 /*
  This will change the specified tty. It ultimately copies the screen
  to the foreground buffer copies the new ttys buffer to the screen and
  adjusts a couple pointers and we are good to go.
 */
int tty_change(uInt16 tty) {

  if (tty > TTY_MAX_TERMS)
    kpanic("Error: Changing to an invalid tty. File: %s, Line: %i\n",__FILE__,__LINE__);

  /* Copy display buffer to tty buffer */
  memcpy(tty_foreground->tty_buffer,(char *)0xB8000,(80*60*2));

  /* Copy new tty buffer to display buffer */
  memcpy((char *)0xB8000,terms[tty].tty_buffer,(80*60*2));

  /*
   Set the tty_pointer to the internal buffer so I can continue 
   writing to what it believes is the screen
  */
  tty_foreground->tty_pointer = tty_foreground->tty_buffer;

  terms[tty].tty_pointer = (char *)0xB8000;

  /* set new foreground tty */
  tty_foreground = &terms[tty];

  /* Adjust cursor when we change consoles */
  outportByte(0x3D4, 0x0F);
  outportByte(0x3D5, tty_foreground->tty_x);
  outportByte(0x3D4, 0x0E);
  outportByte(0x3D5, tty_foreground->tty_y);

  return(0x0);
  }

int tty_print(char *string,tty_term *term) {
  unsigned int    bufferOffset = 0x0, character = 0x0, i = 0x0;
  spinLock(&tty_spinLock);

  /* We Need To Get The Y Position */
  bufferOffset = term->tty_y;
  bufferOffset <<= 8;

  /* Then We Need To Add The X Position */
  bufferOffset += term->tty_x;
  bufferOffset <<= 1;

  while ((character = *string++)) {
    switch (character) {
    case '\n':
      bufferOffset = (bufferOffset / 160) * 160 + 160;
      break;
    default:
      term->tty_pointer[bufferOffset++] = character;
      term->tty_pointer[bufferOffset++] = term->tty_colour;
      break;
    }  /* switch */

    /* Check To See If We Are Out Of Bounds */
    if (bufferOffset >= 160 * 25) {
      for (i = 0; i < 160 * 24; i++) {
        term->tty_pointer[i] = term->tty_pointer[i + 160];
        }
      for (i = 0; i < 80; i++) {
        term->tty_pointer[(160 * 24) + (i * 2)] = 0x20;
        term->tty_pointer[(160 * 24) + (i * 2) + 1] = term->tty_colour;
        }
      bufferOffset -= 160;
      }
    }

  bufferOffset >>= 1;  /* Set the new cursor position  */
  term->tty_x = (bufferOffset &  0xFF);
  term->tty_y = (bufferOffset >> 0x8);

  if (term == tty_foreground) {
    outportByte(0x3D4, 0x0f);
    outportByte(0x3D5, term->tty_x);
    outportByte(0x3D4, 0x0e);
    outportByte(0x3D5, term->tty_y);
    }

  spinUnlock(&tty_spinLock);

  return(0x0);
  }

tty_term *tty_find(uInt16 tty) {
  return(&terms[tty]);
  }

/***
 END
 ***/