/* Apache License, Version 2.0 */

#include "testing/testing.h"

#define GHASH_INTERNAL_API

extern "C" {
#include "BLI_utildefines.h"
#include "BLI_ghash.h"
#include "BLI_rand.h"
}

#define TESTCASE_SIZE 10000

/* Only keeping this in case here, for now. */
#define PRINTF_GHASH_STATS(_gh) \
{ \
	double q, lf, var, pempty, poverloaded; \
	int bigb; \
	q = BLI_ghash_calc_quality_ex((_gh), &lf, &var, &pempty, &poverloaded, &bigb); \
	printf("GHash stats (%d entries):\n\t" \
	       "Quality (the lower the better): %f\n\tVariance (the lower the better): %f\n\tLoad: %f\n\t" \
	       "Empty buckets: %.2f%%\n\tOverloaded buckets: %.2f%% (biggest bucket: %d)\n", \
	       BLI_ghash_len(_gh), q, var, lf, pempty * 100.0, poverloaded * 100.0, bigb); \
} void (0)

/* Note: for pure-ghash testing, nature of the keys and data have absolutely no importance! So here we just use mere
 *       random integers stored in pointers. */

static void init_keys(unsigned int keys[TESTCASE_SIZE], const int seed)
{
	RNG *rng = BLI_rng_new(seed);
	unsigned int *k;
	int i;

	for (i = 0, k = keys; i < TESTCASE_SIZE; ) {
		/* Risks of collision are low, but they do exist.
		 * And we cannot use a GSet, since we test that here! */
		int j, t = BLI_rng_get_uint(rng);
		for (j = i; j--; ) {
			if (keys[j] == t) {
				continue;
			}
		}
		*k = t;
		i++;
		k++;
	}
	BLI_rng_free(rng);
}

/* Here we simply insert and then lookup all keys, ensuring we do get back the expected stored 'data'. */
TEST(ghash, InsertLookup)
{
	GHash *ghash = BLI_ghash_new(BLI_ghashutil_inthash_p, BLI_ghashutil_intcmp, __func__);
	unsigned int keys[TESTCASE_SIZE], *k;
	int i;

	init_keys(keys, 0);

	for (i = TESTCASE_SIZE, k = keys; i--; k++) {
		BLI_ghash_insert(ghash, POINTER_FROM_UINT(*k), POINTER_FROM_UINT(*k));
	}

	EXPECT_EQ(BLI_ghash_len(ghash), TESTCASE_SIZE);

	for (i = TESTCASE_SIZE, k = keys; i--; k++) {
		void *v = BLI_ghash_lookup(ghash, POINTER_FROM_UINT(*k));
		EXPECT_EQ(POINTER_AS_UINT(v), *k);
	}

	BLI_ghash_free(ghash, NULL, NULL);
}

/* Here we simply insert and then remove all keys, ensuring we do get an empty, unshrinked ghash. */
TEST(ghash, InsertRemove)
{
	GHash *ghash = BLI_ghash_new(BLI_ghashutil_inthash_p, BLI_ghashutil_intcmp, __func__);
	unsigned int keys[TESTCASE_SIZE], *k;
	int i, bkt_size;

	init_keys(keys, 10);

	for (i = TESTCASE_SIZE, k = keys; i--; k++) {
		BLI_ghash_insert(ghash, POINTER_FROM_UINT(*k), POINTER_FROM_UINT(*k));
	}

	EXPECT_EQ(BLI_ghash_len(ghash), TESTCASE_SIZE);
	bkt_size = BLI_ghash_buckets_len(ghash);

	for (i = TESTCASE_SIZE, k = keys; i--; k++) {
		void *v = BLI_ghash_popkey(ghash, POINTER_FROM_UINT(*k), NULL);
		EXPECT_EQ(POINTER_AS_UINT(v), *k);
	}

	EXPECT_EQ(BLI_ghash_len(ghash), 0);
	EXPECT_EQ(BLI_ghash_buckets_len(ghash), bkt_size);

	BLI_ghash_free(ghash, NULL, NULL);
}

/* Same as above, but this time we allow ghash to shrink. */
TEST(ghash, InsertRemoveShrink)
{
	GHash *ghash = BLI_ghash_new(BLI_ghashutil_inthash_p, BLI_ghashutil_intcmp, __func__);
	unsigned int keys[TESTCASE_SIZE], *k;
	int i, bkt_size;

	BLI_ghash_flag_set(ghash, GHASH_FLAG_ALLOW_SHRINK);
	init_keys(keys, 20);

	for (i = TESTCASE_SIZE, k = keys; i--; k++) {
		BLI_ghash_insert(ghash, POINTER_FROM_UINT(*k), POINTER_FROM_UINT(*k));
	}

	EXPECT_EQ(BLI_ghash_len(ghash), TESTCASE_SIZE);
	bkt_size = BLI_ghash_buckets_len(ghash);

	for (i = TESTCASE_SIZE, k = keys; i--; k++) {
		void *v = BLI_ghash_popkey(ghash, POINTER_FROM_UINT(*k), NULL);
		EXPECT_EQ(POINTER_AS_UINT(v), *k);
	}

	EXPECT_EQ(BLI_ghash_len(ghash), 0);
	EXPECT_LT(BLI_ghash_buckets_len(ghash), bkt_size);

	BLI_ghash_free(ghash, NULL, NULL);
}

/* Check copy. */
TEST(ghash, Copy)
{
	GHash *ghash = BLI_ghash_new(BLI_ghashutil_inthash_p, BLI_ghashutil_intcmp, __func__);
	GHash *ghash_copy;
	unsigned int keys[TESTCASE_SIZE], *k;
	int i;

	init_keys(keys, 30);

	for (i = TESTCASE_SIZE, k = keys; i--; k++) {
		BLI_ghash_insert(ghash, POINTER_FROM_UINT(*k), POINTER_FROM_UINT(*k));
	}

	EXPECT_EQ(BLI_ghash_len(ghash), TESTCASE_SIZE);

	ghash_copy = BLI_ghash_copy(ghash, NULL, NULL);

	EXPECT_EQ(BLI_ghash_len(ghash_copy), TESTCASE_SIZE);
	EXPECT_EQ(BLI_ghash_buckets_len(ghash_copy), BLI_ghash_buckets_len(ghash));

	for (i = TESTCASE_SIZE, k = keys; i--; k++) {
		void *v = BLI_ghash_lookup(ghash_copy, POINTER_FROM_UINT(*k));
		EXPECT_EQ(POINTER_AS_UINT(v), *k);
	}

	BLI_ghash_free(ghash, NULL, NULL);
	BLI_ghash_free(ghash_copy, NULL, NULL);
}

/* Check pop. */
TEST(ghash, Pop)
{
	GHash *ghash = BLI_ghash_new(BLI_ghashutil_inthash_p, BLI_ghashutil_intcmp, __func__);
	unsigned int keys[TESTCASE_SIZE], *k;
	int i;

	BLI_ghash_flag_set(ghash, GHASH_FLAG_ALLOW_SHRINK);
	init_keys(keys, 30);

	for (i = TESTCASE_SIZE, k = keys; i--; k++) {
		BLI_ghash_insert(ghash, POINTER_FROM_UINT(*k), POINTER_FROM_UINT(*k));
	}

	EXPECT_EQ(BLI_ghash_len(ghash), TESTCASE_SIZE);

	GHashIterState pop_state = {0};

	for (i = TESTCASE_SIZE / 2; i--; ) {
		void *k, *v;
		bool success = BLI_ghash_pop(ghash, &pop_state, &k, &v);
		EXPECT_EQ(k, v);
		EXPECT_TRUE(success);

		if (i % 2) {
			BLI_ghash_insert(ghash, POINTER_FROM_UINT(i * 4), POINTER_FROM_UINT(i * 4));
		}
	}

	EXPECT_EQ(BLI_ghash_len(ghash), (TESTCASE_SIZE - TESTCASE_SIZE / 2 + TESTCASE_SIZE / 4));

	{
		void *k, *v;
		while (BLI_ghash_pop(ghash, &pop_state, &k, &v)) {
			EXPECT_EQ(k, v);
		}
	}
	EXPECT_EQ(BLI_ghash_len(ghash), 0);

	BLI_ghash_free(ghash, NULL, NULL);
}