/*
 * Authors (alphabetical order)
 * - Andre Bernet <bernet.andre@gmail.com>
 * - Andreas Weitl
 * - Bertrand Songis <bsongis@gmail.com>
 * - Bryan J. Rentoul (Gruvin) <gruvin@gmail.com>
 * - Cameron Weeks <th9xer@gmail.com>
 * - Erez Raviv
 * - Gabriel Birkus
 * - Jean-Pierre Parisy
 * - Karl Szmutny
 * - Michael Blandford
 * - Michal Hlavinka
 * - Pat Mackenzie
 * - Philip Moss
 * - Rob Thomson
 * - Romolo Manfredini <romolo.manfredini@gmail.com>
 * - Thomas Husterer
 *
 * opentx is based on code named
 * gruvin9x by Bryan J. Rentoul: http://code.google.com/p/gruvin9x/,
 * er9x by Erez Raviv: http://code.google.com/p/er9x/,
 * and the original (and ongoing) project by
 * Thomas Husterer, th9x: http://code.google.com/p/th9x/
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * 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.
 *
 */

#include "../opentx.h"

#define TEXT_FILENAME_MAXLEN  40
#define TEXT_FILE_MAXSIZE     1000

char s_text_file[TEXT_FILENAME_MAXLEN];
char s_text_screen[LCD_LINES-1][LCD_COLS+1];

void readTextFile(int & lines_count)
{
  FIL file;
  int result;
  char c;
  unsigned int sz;
  int line_length = 0;
  int escape = 0;
  char escape_chars[2];
  int current_line = 0;

  memset(s_text_screen, 0, sizeof(s_text_screen));

  result = f_open(&file, s_text_file, FA_OPEN_EXISTING | FA_READ);
  if (result == FR_OK) {
    for (int i=0; i<TEXT_FILE_MAXSIZE && f_read(&file, &c, 1, &sz)==FR_OK && sz==1 && (lines_count==0 || current_line-s_pgOfs<LCD_LINES-1); i++) {
      if (c == '\n') {
        ++current_line;
        line_length = 0;
        escape = 0;
      }
      else if (c!='\r' && current_line>=s_pgOfs && current_line-s_pgOfs<LCD_LINES-1 && line_length<LCD_COLS) {
        if (c=='\\' && escape==0) {
          escape = 1;
          continue;
        }
        else if (c!='\\' && escape>0 && escape<3) {
          escape_chars[escape-1] = c;
          if (escape == 2 && !strncmp(escape_chars, "up", 2)) {
            c = '\300';
          }
          else if (escape == 2 && !strncmp(escape_chars, "dn", 2)) {
            c = '\301';
          }
          else {
            escape++;
            continue;
          }
        }
        escape = 0;
        s_text_screen[current_line-s_pgOfs][line_length++] = c;
      }
    }
    f_close(&file);
  }

  if (lines_count == 0) {
    lines_count = current_line;
  }
}

void menuTextView(uint8_t event)
{
  static int lines_count;

  switch (event) {
    case EVT_ENTRY:
      s_pgOfs = 0;
      lines_count = 0;
      readTextFile(lines_count);
      break;

    case EVT_KEY_BREAK(KEY_UP):
      if (s_pgOfs == 0)
        break;
      else
        s_pgOfs--;
        // no break;

    case EVT_KEY_BREAK(KEY_DOWN):
      if (event == EVT_KEY_BREAK(KEY_DOWN)) {
        if (s_pgOfs+LCD_LINES-1 >= lines_count)
          break;
        else
          ++s_pgOfs;
      }
      readTextFile(lines_count);
      break;

    case EVT_KEY_BREAK(KEY_EXIT):
      popMenu();
      return;
  }

  for (int i=0; i<LCD_LINES-1; i++) {
    lcd_puts(0, i*FH+FH+1, s_text_screen[i]);
  }

  char *title = s_text_file;
#if defined(SIMU)
  if (!strncmp(title, "./", 2)) title += 2;
#else
  // TODO?
#endif
  lcd_puts(LCD_W/2-strlen(title)*FW/2, 0, title);
  lcd_invert_line(0);

  if (lines_count > LCD_LINES-1) {
    displayScrollbar(LCD_W-1, FH, LCD_H-FH, s_pgOfs, lines_count, LCD_LINES-1);
  }
}

void pushMenuTextView(const char *filename)
{
  if (strlen(filename) < TEXT_FILENAME_MAXLEN) {
    strcpy(s_text_file, filename);
    pushMenu(menuTextView);
  }
}