#define _GNU_SOURCE

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <pthread.h>

#include "fonts.h"
#include "input_gadgets.h"
#include "multiplexer.h"

void drop_privileges();

int main(int argc, char **argv)
{
  pthread_t thread_id;
  t_display_data display_data;
  int ret_val;
  unsigned char *text_buffer;

  // Set up gpi pointer for direct register access
  ret_val = multiplexer_setup_root();
  if (ret_val)
    exit(ret_val);

  // Drop root privileges
  drop_privileges();

 /************************************************************************\
  * You are about to change the GPIO settings of your computer.          *
  * Mess this up and it will stop working!                               *
  * It might be a good idea to 'sync' before running this program        *
  * so at least you still have your code changes written to the SD-card! *
 \************************************************************************/

  // configure the gpio pins and start the multiplexer thread
  thread_id = multiplexer_setup_non_root(&display_data);

  int i,j,k;

  text_buffer = malloc(8);
  if (text_buffer == NULL) {
    fprintf(stderr, "malloc failed to allocate 8 bytes\n");
    exit(EXIT_FAILURE);
  }

  for (i=0; i<20; i++) {
//    usleep(2500000);
//    if (i & 0x01) {
      ret_val = gadgets_retrieve_temperature(text_buffer,sizeof(text_buffer));
      if (ret_val) {
        free(text_buffer);
        exit(ret_val);
      }
      for (j=0; j<39; j++)
        display_data.buf[(display_data.should_buf+1)%3][j] = 0x00;
      for (j=0; (j<7) && (text_buffer[j]); j++) {
        text_buffer[j] = text_buffer[j] & 0xff;
        printf("%02x %c\n",text_buffer[j],text_buffer[j]);
        if (text_buffer[j] >= 0x7f) {
          if (text_buffer[j] <= 0xaf)
            continue;
          text_buffer[j] -= 0xaf - 0x7f + 1;
        }
        text_buffer[j] -= 0x20;
        if ((text_buffer[j] < 0) || (text_buffer[j] >= (sizeof(symbols)/5))) {
          printf("EXCESS: %d %d %d\n", text_buffer[j], (text_buffer[j] < 0), (text_buffer[j] >= (sizeof(symbols)/5)));
          continue;
        }
        for (k=0; k<5; k++)
          display_data.buf[(display_data.should_buf+1)%3][6*j+k] = symbols[5*(text_buffer[j])+k];
//      }
    }
    display_data.should_buf = (display_data.should_buf+1)%3;
  }

  free(text_buffer);
  display_data.keep_running = 0;
  pthread_join(thread_id, NULL);

  return 0;

} // main

//
// Drop (root) privileges
//
void drop_privileges()
{
   /*  Drop superuser privileges in correct order */

   if (setgid(99) == -1) {
      perror("can't drop group privileges");
      exit(-1);
   }
   if (setuid(99) == -1) {
      perror("can't drop user privileges");
      exit(-1);
   }
} // drop_root