#include <stdlib.h>
#include <stdio.h>

/**
 * Test reading integers.
 */
unsigned long long sumints(FILE* in) {
  long long int sum =0;
  int i;
  while (fscanf(in, "%d ", &i) >= 1) {
    sum = sum + (long long)i;
  }
  return sum;
}

int compare(const void* aa, const void* bb) {
  int *a = (int*)aa, *b = (int*)bb;
  if(*a == *b) return 0;
  else if(*a < *b) return -1;
  else return 1;
}

/**
 * Test reading integers, and growing and sorting a vector.
 */
int median(FILE* in) {
  int vector_size = 4;
  int* vector = malloc(sizeof(int) * vector_size); 
  int vector_length = 0;

  int i;
  while (fscanf(in, "%d ", &i) >= 1) {
    vector_length++;
    if(vector_length > vector_size) {
      vector_size *= 2;
      vector = realloc(vector, sizeof(int)*vector_size);
    }
    vector[vector_length-1] = i;
  }
  
  qsort(vector, vector_length, sizeof(int), &compare);
  
  if(/* odd */ vector_length % 2)
    return vector[vector_length/2];
  else
    return ((vector[vector_length/2] + vector[vector_length/2-1]) / 2);
}


/** Result struct for wc test. */
typedef struct {
  int chars, words, lines;
} WordCount;

/**
 * Test reading integers (or something else), and growing and sorting a
 * vector.
 */
void CountWords(FILE* in, WordCount* result) {
  int inword = 0;
  int getvalue;

  if(!in) {
    fprintf(stderr, "No input stream in CountWords\n");
    exit(1);
  }
  if(!result) {
    fprintf(stderr, "No result struct in CountWords\n");
    exit(1);
  }

  result->chars = 0;
  result->words = 0;
  result->lines = 0;
  
  while((getvalue = getc(in)) != EOF) {
    char ch = (char)getvalue;
    if(!(ch == ' ' || ch == '\t' || ch == '\n' || ch == '\r')) {
      inword = 1;
    } else {
      if(inword) {
	result->words++;
	inword = 0;
      }
    }
    
    if(ch == '\n') result->lines++;
    
    result->chars++;
  }
  
}

int main(int argc, char *argv[]) {
  int iterations = 1;
  int do_median = 0, do_sum = 0, do_wc = 0;
  int i;
  
  for(i = 1; i < argc; ++i) {
    if(argv[i][0] == '-') switch(argv[i][1]) {
    case 'i':  iterations = atoi(argv[++i]);
      break;
      
    case 'm':  do_median = 1;
      break;
      
    case 's':  do_sum = 1;
      break;
      
    case 'w':  do_wc = 1;
      break;
      
    default:
      fprintf(stderr, "Unknown flag: %s\n", argv[i]);
      exit(1);
    }
    else {
      fprintf(stderr, "Unknown argument: %s\n", argv[i]);
      exit(1);
    }
  }
  
  for(i = 0; i < iterations; ++i) {
    if(do_median) {
      FILE* data = fopen("numbers.txt", "r");
      if(!data) {
	fprintf(stderr, "No data.\n");
	exit(1);
      }
      printf("Median: %d\n", median(data));
    }
    if(do_sum) {
      FILE* data = fopen("numbers.txt", "r");
      if(!data) {
	fprintf(stderr, "No data.\n");
	exit(1);
      }
      printf("Sum: %lld\n", sumints(data));
    }
    if(do_wc) { 
      FILE* data = fopen("numbers.txt", "r");
      WordCount wc;
      if(!data) {
	fprintf(stderr, "No data.\n");
	exit(1);
      }
      CountWords(data, &wc);
      printf(" %d %d %d %s\n", wc.lines, wc.words, wc.chars, "numbers.txt");
    }
  }
  return 0;
}