#include "ht.h"
#include <string.h>
#include <stdlib.h>

unsigned int ht_default_hash_func(void* data){
    const unsigned int fnv_prime = 16777619;
    const unsigned int fnv_offset_basis = 2166136261;
    unsigned int hash;
    char* string;
    hash = fnv_offset_basis;
    string = data;
    while (*string) {
        hash = hash * fnv_prime;
        hash = hash ^ (*(string++));
    }
    return hash;
}
int ht_default_cmp_func(void* a, void* b){
    return strcmp(a, b) == 0;
}
void* ht_default_copy_func(void* from) {
    void* copy = malloc(sizeof(char) * (strlen(from) + 1));
    if(copy) {
        strcpy(copy, from);
    }
    return copy;
}
void ht_default_free_func(void* data){
    free(data);
}

void ht_init(ht* ht){
    ht->cmp_func = ht_default_cmp_func;
    ht->copy_func = ht_default_copy_func;
    ht->free_func = ht_default_free_func;
    ht->hash_func = ht_default_hash_func;
    memset(ht->data, 0, sizeof(ht->data));
}
void ht_free(ht* ht){
    int index = 0;
    for(; index < LIBDS_HT_SIZE; index++){
        ht_node* head = ht->data[index];
        while(head){
            ht_node* to_delete = head;
            head = head->next;
            ht->free_func(to_delete->key);
            free(to_delete);
        }
    }
}

libds_result ht_put(ht* ht, void* key, void* data){
    libds_result result = SUCCESS;
    ht_node* new_node = NULL;
    unsigned int key_int = ht->hash_func(key) % LIBDS_HT_SIZE;


    new_node = malloc(sizeof(*new_node));
    if(new_node) {
        new_node->data = data;
        new_node->key = ht->copy_func(key);
        if(new_node->key == NULL){
            result = MALLOC;
        }
    } else {
        result = MALLOC;
    }

    if(result != SUCCESS) {
        if(new_node) {
            free(new_node);
            new_node = NULL;
        }
    } else {
        new_node->next = ht->data[key_int];
        ht->data[key_int] = new_node;
    }

    return result;
}
void* ht_get(ht* ht, void* key) {
    void* data = NULL;
    ht_node* search_node;
    unsigned int key_int = ht->hash_func(key) % LIBDS_HT_SIZE;

    search_node =  ht->data[key_int];
    while(search_node && data == NULL){
        if(ht->cmp_func(search_node->key, key)) {
            data = search_node->data;
        }
        search_node = search_node->next;
    }

    return data;
}
void ht_remove(ht* ht, void* key){
    ht_node** search_ptr;
    unsigned int key_int = ht->hash_func(key) % LIBDS_HT_SIZE;

    search_ptr = &ht->data[key_int];
    while(*search_ptr){
        if(ht->cmp_func((*search_ptr)->key, key)){
            ht_node* to_delete = *search_ptr;
            *search_ptr = (*search_ptr)->next;
            ht->free_func(to_delete->key);
            free(to_delete);
        } else {
            search_ptr = &(*search_ptr)->next;
        }
    }
}

int ht_foreach(ht* ht, void* data, compare_func compare, foreach_func foreach, ...){
    int index = 0;
    int return_code = 0;
    va_list args;
    for(; index < LIBDS_HT_SIZE && return_code == 0; index++){
        ht_node* search_node = ht->data[index];
        while(search_node && return_code == 0){
            if(compare(data, search_node->data)) {
                va_start(args, foreach);
                return_code = foreach(search_node->data, args);
                va_end(args);
            }
            search_node = search_node->next;
        }
    }
    return return_code;
}