/* parc
 * Copyright (C) 2025 Ekaitz Zarraga <ekaitz@elenq.tech>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/*
 * XTERM escape sequence reference:
 * https://invisible-island.net/xterm/ctlseqs/ctlseqs.html
 * Good summary:
 * https://en.wikipedia.org/wiki/ANSI_escape_code
 *
 * also:
 *    man console_codes
 */

#include <stdio.h>
#include <stdlib.h>
#include <termios.h>
#include <string.h>
#include "tui-internals.h"

#define ESC '\x1b'

const char CSI_LEAD[3] = { ESC, '[', '\0'};

void
tui_cursor_save (void)
{
  printf ("%ss", CSI_LEAD);
  fflush (stdout);
}

void
tui_cursor_restore (void)
{
  printf ("%su", CSI_LEAD);
  fflush (stdout);
}

void
tui_mouse_enable (void)
{
  printf ("%s?1000h", CSI_LEAD);
  fflush (stdout);
}
void
tui_mouse_disable (void)
{
  printf ("%s?1000l", CSI_LEAD);
  fflush (stdout);
}

void
tui_cursor_move (int x, int y)
{
  /*
   * Also valid with CSI<L>;<C>f being <L> and <C> line number and column
   * number respectively. In ttys, cursor starts at 1,1
   */
  printf ("%s%d;%dH", CSI_LEAD, y, x);
  fflush (stdout);
}

void
tui_cursor_show (void)
{
  printf ("%s?25h", CSI_LEAD);
  fflush (stdout);
}

void
tui_cursor_hide (void)
{
  printf ("%s?25l", CSI_LEAD);
  fflush (stdout);
}

void
tui_screen_erase (void)
{
  printf ("%s2J", CSI_LEAD);
  fflush (stdout);
}

void
tui_alternate_buffer_enable (void)
{
  printf ("%s?1049h", CSI_LEAD);
  fflush (stdout);
}

void
tui_alternate_buffer_disable (void)
{
  printf ("%s?1049l", CSI_LEAD);
  fflush (stdout);
}

tui *
tui_create (void)
{
  tui *ui = malloc (sizeof *ui);
  /* Get interface configuration to reset it later */
  tcgetattr (0, &ui->term_old_config);

  /* Get interface configuration to edit */
  tcgetattr (0, &ui->term_config);

  /* Set the new configuration */
  ui->term_config.c_lflag &= ~ (ECHO | ECHONL | ICANON | IEXTEN | ISIG);
  ui->term_config.c_cc[VMIN]  = 1;   /* Wait until 1 character is in buffer */
  ui->term_config.c_cc[VTIME] = 0;   /* Wait indefinitely */
  /* TCSANOW makes the change occur immediately */
  tcsetattr (0, TCSANOW, &ui->term_config);
  tui_alternate_buffer_enable ();
  tui_cursor_move (0, 0);
  tui_mouse_enable ();
  return ui;
}

void
tui_destroy (tui *ui)
{
  /* Set old configuration again and exit. */
  /* If it's not set back the normal configuration of the */
  /* terminal will be broken later! */
  tcsetattr (0, TCSANOW, &ui->term_old_config);
  tui_alternate_buffer_disable ();
  free (ui);
}

void
tui_input_sequence_consume (void)
{
  int c, x, y;
  c = getchar ();
  if (ESC == c)
    {
      /* TODO: parse escape sequence */
      c = getchar ();
      if (c == '[')
        {
          c = getchar ();
          switch (c)
            {
            case 'M':
              /*https://invisible-island.net/xterm/ctlseqs/ctlseqs.html#h3-Normal-tracking-mode*/
              /* They add 32 to the coordinates */
              c = getchar () - 32;
              x = getchar () - 32;
              y = getchar () - 32;
              printf ("%d, %d, %d\n", c, x, y);
              break;

            case 'I':
              /* Gained focus */
              break;
            case 'O':
              /* Lost focus */
              break;

            default:
              break;
            }
        }
    }
  else
    ;
    /* return key event */
}

void
tui_loop (tui *ui)
{
  char input_buf [100];
  memset (input_buf, 0, 100);
  while (1)
    {
      tui_input_sequence_consume ();
    }
}