// Implements a dictionary's functionality

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


#include "dictionary.h"

// Represents a node in a hash table
typedef struct node
{
    char word[LENGTH + 1];
    struct node *next;
}
node;

// Number of buckets in hash table
const unsigned int N = 50000;




// Hash table
node *table[N];

// Returns true if word is in dictionary else false
bool check(const char *word)
{
    int index = hash(word);
    
    
    for (node *cursor = table[index]; cursor != NULL; cursor = cursor->next)
    {
     int check = strcasecmp(cursor -> word, word);
     if(check == 0)
     {
         return true;
     }
        
    }
    
    return false;
}

// Hashes word to a number
// this hash function is based on a hash function called djb2 and it is from http://www.cse.yorku.ca/~oz/hash.html
unsigned int hash(const char *word)
{
    
    unsigned long hash = 5381;
    int c;

    while ((c = *word++))
    {
       
        hash = ((hash << 5) + hash) + tolower(c);
      
    }
    return hash % N;
} 

    
 

// Loads dictionary into memory, returning true if successful else false
bool load(const char *dictionary)
{
    char word[LENGTH + 1];
   FILE *file = fopen(dictionary, "r");
    if (!file)
    {
        return false;
    }
    
    while (fscanf(file, "%s", word) != EOF)
    {
      int index = hash(word);
      
      node *new_ = malloc(sizeof(node));
      
      if (new_ == NULL)
      {
        return 1;  
      }
      strcpy(new_->word, word);
      
      new_->next= table[index];
      
      new_ = table[index]  ; 
        
    }
    fclose(file);
    return true; 
}
    
    


// Returns number of words in dictionary if loaded else 0 if not yet loaded
unsigned int size(void)
{
    int count = 0;
    for (int o = 0; o< N;o++)
    {
        for (node *temp = table[o]; temp != NULL; temp = temp->next)
    {
        count ++;
        temp = temp -> next;
        
    }
    
    }

    return count;
}

// Unloads dictionary from memory, returning true if successful else false
bool unload(void)
{
    for (int o = 0; o< N;o++)
    {
        node *cursor2 = table[o];
        
     while(cursor2 != NULL)
     {
         node *temp = cursor2;
         
         cursor2 = cursor2->next;
         
         free(temp);
     }
    }
    return true;
 }