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

#include "string_util.h"
#include "ismap.h"
#include "usdot.h"


int int_hash_identity(int n);
int int_hash_knuth(int n);
void free_value(int key, char *value, void *);
void print_entry(int key, char *value, void *);
void count_od(int key, char *value, void *);

struct count_info
{
  int count;
  char *match;
};

#define CODE_LENGTH 3

int main(int argc, char **argv)
{
  ismap *routes = ismap_create(int_hash_knuth);

  int id, seq, tot;
  char origin[CODE_LENGTH + 1];
  char destination[CODE_LENGTH + 1];
  while (read_segment(stdin, &id, &seq, &tot, origin, destination))
    {
      if (!ismap_contains_key(routes, id))
	{
	  // key is not present; add it with empty route of
	  // approriate size (3 chars for each airport in the route);
	  char *route = malloc(sizeof(char) * CODE_LENGTH * (tot + 1) + 1);
	  for (int i = 0; i < CODE_LENGTH * (tot + 1); i++)
	    {
	      route[i] = ' ';
	    }
	  route[CODE_LENGTH * (tot + 1)] = '\0';

	  ismap_put(routes, id, route);
	}
      
      // key should be present now; get value and update it
      char *route = ismap_get(routes, id);
      
      if (route != NULL)
	{
	  // make sure sequence numbers work out
	  if (strlen(route) >= (tot + 1) * CODE_LENGTH)
	    {
	      // copy origin and destination airports into appropriate
	      // location in route
	      strncpy(route + (seq - 1) * CODE_LENGTH, origin, CODE_LENGTH);
	      strncpy(route + seq * CODE_LENGTH, destination, CODE_LENGTH);
	    }
	}
    }

  ismap_for_each(routes, print_entry, NULL);

  if (argc > 1)
    {
      // need to pass two things into count_od: count and airport to match
      // so pack into a struct and pass a pointer to that struct ti
      // ismap_for_each so it can pass it along to count_od
      struct count_info info;
      info.count = 0;
      info.match = argv[1];
      
      ismap_for_each(routes, count_od, &info);
      
      printf("%s: %d\n", argv[1], info.count);
    }

  // free allocated memory
  ismap_for_each(routes, free_value, NULL);

  
  ismap_destroy(routes);
}

void count_od(int key, char *value, void *arg)
{
  struct count_info *info = arg;
  if (strncmp(value, info->match, CODE_LENGTH) == 0)
    {
      info->count++;
    }
  if (strncmp(value + strlen(value) - CODE_LENGTH, info->match, CODE_LENGTH) == 0)
    {
      info->count++;
    }
}
    

/**
 * Prints the given map entry to standard output.
 */
void print_entry(int key, char *value, void *arg)
{
  printf("%d=%s\n", key, value);
}

/**
 * Frees the value in the given map entry.
 */
void free_value(int key, char *value, void *arg)
{
  free(value);
}

/**
 * A very, very bad hash function for integers.
 */
int int_hash_identity(int n)
{
  return n;
}

int int_hash_knuth(int n)
{
  return n * 2654435761;
}