// hashmap.c
#include "hashmap.h"
#include <stdlib.h>
#include <string.h>

// DJB2哈希算法
static unsigned long hash(const char* str) {
    unsigned long hash = 5381;
    int c;
    while ((c = *str++))
        hash = ((hash << 5) + hash) + c; /* hash * 33 + c */
    return hash % HMAP_SIZE;
}

void hmap_init(HashMap* map) {
    memset(map->buckets, 0, sizeof(map->buckets));
}

void hmap_put(HashMap* map, const char* key, void* value) {
    unsigned long idx = hash(key);
    HashMapEntry* entry = malloc(sizeof(HashMapEntry));
    entry->key = strdup(key);
    entry->value = value;
    entry->next = map->buckets[idx];
    map->buckets[idx] = entry;
}

void* hmap_get(HashMap* map, const char* key) {
    unsigned long idx = hash(key);
    HashMapEntry* entry = map->buckets[idx];
    while (entry) {
        if (strcmp(entry->key, key) == 0) 
            return entry->value;
        entry = entry->next;
    }
    return NULL;
}

int hmap_contains(HashMap* map, const char* key) {
    return hmap_get(map, key) != NULL;
}

void hmap_destroy(HashMap* map) {
    for (int i = 0; i < HMAP_SIZE; i++) {
        HashMapEntry* entry = map->buckets[i];
        while (entry) {
            HashMapEntry* next = entry->next;
            free(entry->key);
            free(entry);
            entry = next;
        }
    }
}