#include "int.h"
#include "sys.h"


int main() {
  // Test the write syscall
  intptr_t n = write(STDOUT, "Hello\n", 6);
  if(n != 6) return n;

  // Test the fork syscall
  uint64_t pid = fork();
  // Print the pid in hex
  char msg[17] = {' '};
  msg[16] = '\n';
  for(int i = 0; i < 16; ++i) {
    char nibble = (pid >> ((15 - i) * 4)) & 0xf;
    char c;
    if (nibble > 9) {c = nibble + '7';}
    else {c = nibble + '0';}
    msg[i] = c;
  }
  write(STDOUT, msg, 17);

  // Child process exits
  if(pid == 0) return 0;
  //TODO: wait on child to remove zombie process

  // Test the read syscall
  #define INPUT_BUFFER_LEN 4096
  char input_buffer[INPUT_BUFFER_LEN] = {0};
  int32_t fout = openc("outfile", O_RDWR | O_CREAT | O_TRUNC, 0664);

  write(STDOUT, "Enter some text:", 16);
  intptr_t n_read = read(STDIN, input_buffer, INPUT_BUFFER_LEN);
  write(STDOUT, input_buffer, n_read);
  if(fout > 0) {
    write(fout, input_buffer, n_read);
    fsync(fout);
    close(fout);
  }

  // Test the open syscall
  int32_t file = open("/proc/version", O_RDONLY);
  if (file > 0) {
    int i = read(file, input_buffer, INPUT_BUFFER_LEN);
    while(i > 0) {
      write(STDOUT, input_buffer, i);
      i = read(file, input_buffer, INPUT_BUFFER_LEN);
    }
  } else {
    write(STDOUT, "Could not open /proc/version\n", 29);
  }

  // Test sleep
  write(STDOUT, "Sleeping for 5 secs\n", 20);
  struct timespec sleeptime;
  sleeptime.tv_sec = 5;
  while (nanosleep(&sleeptime, &sleeptime) != 0) {}
  write(STDOUT, "DONE\n", 5);

  return 69;
}

void __libc_start_main() {exit(main());}

void _start() {
  __libc_start_main();
}

void __start() {
  _start();
}