#include "ht.h"

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

#define FNV_BASIS 0x811c9dc5 
#define FNV_PRIME 0x01000193

// fnv-1a
static uint32_t hash(char *s) {
	uint32_t h = FNV_BASIS;
	for(;;) {
		h ^= *s;
		h *= FNV_PRIME;
		if (*s == '\0') break;
		s++;
	}
	return h;
}

Ht ht_new() {
	Ht h;
	h.len = 0;
	for (int i = 0; i < HT_SIZE; i++) {
		h.b[i] = (HtEntry){ .k = NULL, .v=0 };
	}
	return h;
}

void ht_put(Ht *h, char *k, int v) {
	uint32_t hv = hash(k);
	int start = hv%HT_SIZE;
	for (int cur = start; cur != start - 1; cur = (cur+1)%HT_SIZE) {
		HtEntry *ent = &h->b[cur];
		if (ent->k == NULL)  {
			printf(" p %d\n",cur);
			ent->k = strdup(k);
			ent->v = v;
			h->len++;
			break;
		} else if (0 == strcmp(k, ent->k)) {
			printf(" r %d\n",cur);
			ent->v = v;
			break;
		} else {
			printf(" n %d\n",cur);
		}
	}
}

int ht_get(Ht *h, char *k, int *v) {
	uint32_t hv = hash(k);
	int start = hv%HT_SIZE;
	for (int cur = start; cur != start - 1; cur = (cur+1)%HT_SIZE) {
		HtEntry *ent = &h->b[cur];
		if (ent->k == NULL) {
			return 0; // not found
		} else if (0 == strncmp(ent->k, k, 80)) {
			*v = ent->v;
			return 1;
		}
	}
	return 0; // exhausted
}

void ht_dump(Ht *h) {
	printf("#%d:\n",h->len);
	for (int i = 0; i < HT_SIZE; i++) {
		HtEntry ent = h->b[i];
		if (ent.k != NULL) {
			printf(" %s:%d\n",ent.k,ent.v);
		}
	}
}