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

#define MAXWORD      40
#define DELIMITER_SET	" /|\\\"\t\n\r,;:~!#%^*()=+[]{}<>?"

struct wordnode
{

   char word[MAXWORD];
   int num;
   struct wordnode *next;
};

typedef struct wordnode WordPtr;

void sorted_insert(struct wordnode **hd, WordPtr *elem);
WordPtr *ins_sort(WordPtr *list);
WordPtr *newWord(void);
void setWordData(WordPtr *list, char *word, int num);
WordPtr *insert(WordPtr *list, WordPtr *element);
void printWord(WordPtr *list, char *filename);
WordPtr *deleteAll(WordPtr *list);
FILE *openFile(char *filename, char *mode);
void fileToStruct(char *fileName);

int main(int argc, char *argv[])
{
   if (argc != 2)
   {
      printf("Syntax : wordcount filename\n");
      exit(0);
   }
   fileToStruct(argv[1]);
   return 0;
}

void sorted_insert(struct wordnode **hd, WordPtr *elem)
{
   while (*hd && strcmp((*hd)->word, elem->word) <= 0)
   {
      hd = &(*hd)->next;
   } 
   elem->next =  *hd;
   *hd = elem;
}

/* insertion sort for linked lists */
WordPtr *ins_sort(WordPtr *list)
{
   WordPtr *sorted = 0;
   WordPtr *t;

   while (list != 0)
   {
      t = list;
      list = list->next;
      sorted_insert(&sorted, t);
   }
   return sorted;
}

void fileToStruct(char *fileName)
{
   FILE *fin = openFile(fileName, "r");
   char string[MAXWORD];
   char *longstring;
   char *tokagain;
   WordPtr *head = NULL, *tmp = NULL;
   int same;
   char line[150];

   while (fscanf(fin, "%s", line) != EOF)
   {
      /* set the word is not in the list yet */
      same = 0;

      longstring = strtok(line, DELIMITER_SET);
      while (longstring != NULL)
      {
         strcpy(string, longstring);
         //printf ("%s\n",string);
         tokagain = strtok (string, ".");
         printf ("tok again = %s \n",tokagain);
         if (head == NULL)
         {
            /* insert string, 1, tmp into linked list as the head */
            head = newWord(); 

            /* set a new struct */
            setWordData(head, string, 1);
         }
         else
         {
            for (tmp = head; tmp != NULL; tmp = tmp->next)
            {
               if ((strcmp((tmp->word), string)) == 0)
               {
                  tmp->num++;

                  /* set the word is in the list already */
                  same = 1;
               }
            }
            tmp = NULL;

            /* If the word is not in the list yet, add it */
            if (same != 1)
            {
               tmp = newWord();
               setWordData(tmp, string, 1);
               head = insert(head, tmp);

               /* insert string, 1, tmp, into the back of the linked list */
            }
         }
         longstring = strtok(NULL, DELIMITER_SET);
      }
   }

   head = ins_sort(head);
   printWord(head, fileName);
   head = deleteAll(head);
   fclose(fin);
}

FILE *openFile(char *filename, char *mode)
{
   /* open a FILE stream to filename with given mode */

   FILE *file = fopen(filename, mode);

   if (file == NULL)
   {
      printf("ERROR - Unable to access %s\n", filename);
      exit(0);
   }

   return file;
}

/* a function to form a new structure */
WordPtr *newWord(void)
{
   WordPtr *element; 

   /* initialise a pointer */
   element = (WordPtr*)malloc(sizeof(WordPtr)); 

   /* aloocate a memory */
   if (element == NULL)
   {
      printf("\nWARNING - Memory allocation error\n");
      exit(0);
   }
   element->next = NULL;
   return (element);
}

/* set the input data into the struct */
void setWordData(WordPtr *list, char *word, int num)
{
   strcpy(list->word, word);
   list->num = num;
   return ;
}

/* a function to join a list with another existing list */
WordPtr *insert(WordPtr *list, WordPtr *element)
{
   element->next = list;
   return (element);
}

/* a function to print out the structure */
void printWord(WordPtr *list, char *filename)
{
   WordPtr *tmp;
   int size = 0;
   int total = 0;

   for (tmp = list; tmp != NULL; tmp = tmp->next)
   {
      total += tmp->num;
      size += 1;
   }

   printf("\nfilename : %s\n", filename);
   printf("\n");
   printf("COUNT | WORD\n");
   printf("------+------\n");

   for (tmp = list; tmp != NULL; tmp = tmp->next)
   {
      printf("%4d  | %s \n", tmp->num, tmp->word);
   }
   printf("\n");
   printf("Number of unique words in %s is %d\n", filename, size);
   printf("Total number of words in %s is  %-2d\n", filename, total);

   size = 0;
   total = 0;
   return ;
}

/* a function to free the aloocated memory */
WordPtr *deleteAll(WordPtr *list)
{
   WordPtr *tmp;

   for (; list != NULL; list = tmp)
   {
      tmp = list->next;
      free(list);
   }
   return (NULL);
}