#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <stdio.h>
#include <pthread.h>

int sfork();
int forkFib(int fibNumber);
int *threadFib(int *fibNumber);

int main(int argc, char **argv){           
  int fibNumber;
  int fibResult;
  int threadResult = 0;
  int test;
  char type;
  
  if (argc > 3 || argc < 3){
    printf("Usage: fibFork type fibLength\n");
    printf("           type = f or t (fork or threaded)\n");
    printf("           fibLength = integer value\n");
    return 1;
  }
  if (sscanf(argv[2], "%d", &test) == 0){
    printf("Usage: fibFork type fibLength\n");
    printf("           type = f or t (forked or threaded)\n");
    printf("           fibLength = integer value\n");
    return 1;
  }
  if (strlen(argv[1]) > 1){
    printf("type must be a single character!\n");
    exit(1);
  }
  sscanf(argv[1], "%c", &type);
  sscanf(argv[2], "%d", &fibNumber);
  
  if (type == 't'){
    threadResult = *threadFib(&fibNumber);
    printf("FibThread = %d\n", threadResult);
  }else if (type == 'f'){
    fibResult = forkFib(fibNumber);
    printf("FIBFINAL: %d\n", fibResult);
  }else{
    printf("Type must be f or t\n");
    exit(1);
  }
  
  printf("DONE\n");
  return 0;
}

int sfork(){
  int pid;
  pid = fork();
  if (pid == -1){
    perror("Fork error");
    exit(1);
  }else
    return pid;
}

int forkFib(int fibNumber){
  int pid1 = 0, pid2 = 0;
  int status1, status2;
  
  if(fibNumber == 0)
    return 0;
  else if (fibNumber == 1 || fibNumber == 2)
    return 1;
  else{
    if((pid1=sfork()) == 0){
      exit(forkFib(fibNumber-1));
    }
    if((pid2=sfork()) == 0){
      exit(forkFib(fibNumber-2));
    }
    waitpid(pid1, &status1, 0);
    waitpid(pid2, &status2, 0);
    return (WEXITSTATUS(status1) + WEXITSTATUS(status2));
  }
}

int *threadFib(int *fibNumber){
  printf("FIB NUMBER: %d\n", *fibNumber);
  pthread_t thread1, thread2;
  int num1,num2;
  int retVal1, retVal2;
  int *returnVal1, *returnVal2;
  int *x;
  num1 = 0;
  num2 = 0;
  retVal1 = 0;
  retVal2 = 0;
  
  
  if (*fibNumber == 0){
    return (int*)0;
  }else if (*fibNumber == 1 || *fibNumber == 2){
    return (int*)1;
  }else{
    num1 = *fibNumber - 1;
    num2 = *fibNumber - 2;
    printf("FIB1: %d FIB2: %d\n", num1, num2);
    if((pthread_create(&thread1, NULL, (void*)threadFib, &num1)) != 0){
      perror("Thread 1");
      exit(1);
    }
    if((pthread_create(&thread2, NULL, (void*)threadFib, &num2)) != 0){
      perror("Thread 2");
      exit(1);
    }
    
    pthread_join(thread1, (void**)&returnVal1);
    printf("THREAD1 Joined\n");
    pthread_join(thread2, (void**)&returnVal2);
    printf("THREAD2 Joined\n");
    printf("RETVAL1: %d\nRETVAL2: %d\n", returnVal1, returnVal2);
    printf("AFTERTHREADS\n");
    *x = (int)returnVal1 + (int)returnVal2;
    printf("BLAH\n");
  }
  printf("X = %d\n", *x);
  return x;
}