// 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;

// TODO: Choose number of buckets in hash table
const unsigned int N = LENGTH;

// Hash table
node *table[N];

// For size function
int amount;

// Loads dictionary into memory, returning true if successful, else false
bool load(const char *dictionary)
{
    char words[LENGTH + 1];
    int counter = 0;

    // Open dictionary file
    FILE *source = fopen(dictionary, "r");
    if (source == NULL)
    {
        return false;
    }

    // Read strings from file
    while (fscanf(source, "%s", words) != EOF)
    {
        // Create a new node
        node *n = malloc(sizeof(node));
        if (n == NULL)
        {
            return false;
        }

        // Fill in new node
        strcpy(n->word, words);
        n->next = NULL;

        // Find phrase bucket
        int bucket = hash(words);

        table[bucket] = malloc(sizeof(node));
        table[bucket]->next = NULL;

        // Insert node into hash table
        if (counter == 0)
        {
            table[bucket]->next = n;
        }
        else
        {
            n->next = table[bucket]->next;
            table[bucket]->next = n;
        }
        counter++;
        amount++;
    }

    // Close dictionary file
    fclose(source);

    return true;
}

// Hashes word to a number
unsigned int hash(const char *word)
{
    // TODO: Improve this hash function
    return strlen(word);
}

// Returns number of words in dictionary if loaded, else 0 if not yet loaded
unsigned int size(void)
{
    return amount;
}

// Returns true if word is in dictionary, else false
bool check(const char *word)
{
    // Create cursor
    node *cursor = malloc(sizeof(node));
    if (cursor == NULL)
    {
        return false;
    }

    // Hash word for value
    int value = hash(word);

    table[value] = malloc(sizeof(node));
    table[value]->next = NULL;

    // Access linked list at index
    cursor = table[value]->next;

    // Traverse linked list
    while (cursor != NULL)
    {
        if (strcasecmp(cursor->word, word) == 0)
        {
            return true;
        }
        else
        {
            cursor = cursor->next;
        }
    }

    return false;
}

// Unloads dictionary from memory, returning true if successful, else false
bool unload(void)
{
    node *cursor = malloc(sizeof(node));
    if (cursor == NULL)
    {
        return false;
    }
    node *tmp = malloc(sizeof(node));
    if (tmp == NULL)
    {
        return false;
    }

    for (int i = 0; i < LENGTH; i++)
    {
        table[i] = malloc(sizeof(node));
        table[i]->next = NULL;

        cursor = table[i]->next;
        tmp = cursor;
        while (cursor != NULL)
        {
            cursor = cursor->next;
            free(tmp);
            tmp = cursor;
        }
    }
    return true;
}