/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */

/*
 * Copyright 2025 Oxide Computer Company
 */

/*
 * Basic tests for the ilstr string handling routines.
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <strings.h>
#include <errno.h>
#include <upanic.h>
#include <umem.h>
#include <sys/ilstr.h>
#include <sys/sysmacros.h>
#include <sys/debug.h>

#define	VERIFYSTRING(ils, expected)				\
	do {							\
		const char *check = ilstr_cstr(ils);		\
		VERIFY(check != NULL);				\
		if (strcmp(check, (expected)) != 0) {		\
			char buf[2048];				\
			(void) snprintf(buf, sizeof (buf),	\
			    "\"%s\" != expected \"%s\"",	\
			    check, (expected));			\
			assfail(buf, __FILE__, __LINE__);	\
		}						\
	} while (0)

typedef enum ilstr_test_types {
	ITT_STD = 0x01,
	ITT_PRE = 0x02,
} ilstr_test_types_t;

#define	ITT_ALL	(ITT_STD | ITT_PRE)

typedef struct ilstr_test {
	char *ist_name;
	int (*ist_func)(ilstr_t *ils);
	uint_t ist_trials;
	ilstr_test_types_t ist_types;
} ilstr_test_t;

#define	PREALLOC_SZ	1024
static char ilsbuf[PREALLOC_SZ];

const char *
_umem_debug_init(void)
{
	return ("default,verbose");
}

const char *
_umem_logging_init(void)
{
	return ("transaction,contents,fail");
}

int
ist_empty(ilstr_t *ils)
{
	VERIFY3U(ilstr_len(ils), ==, 0);
	VERIFY(ilstr_is_empty(ils));
	VERIFY(ilstr_cstr(ils) != NULL);
	VERIFY3U(ilstr_cstr(ils)[0], ==, '\0');
	VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_OK);

	return (0);
}

int
ist_prealloc_toobig(ilstr_t *ils)
{
	/*
	 * Fill the buffer all the way up with characters:
	 */
	for (uint_t n = 0; n < PREALLOC_SZ - 1; n++) {
		ilstr_append_str(ils, "A");
	}
	VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_OK);

	/*
	 * Confirm that we cannot append strings:
	 */
	ilstr_append_str(ils, "A");
	VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_NOMEM);

	ilstr_append_str(ils, "A");
	VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_NOMEM);

	/*
	 * Confirm that we cannot prepend a character:
	 */
	ilstr_prepend_char(ils, 'A');
	VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_NOMEM);

	/*
	 * Clear out the string and make sure we can start again:
	 */
	ilstr_reset(ils);

	ilstr_append_str(ils, "B");
	VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_OK);
	VERIFYSTRING(ils, "B");

	/*
	 * Fill the buffer all the way up with characters:
	 */
	ilstr_reset(ils);
	for (uint_t n = 0; n < PREALLOC_SZ - 1; n++) {
		ilstr_append_str(ils, "C");
	}
	VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_OK);

	/*
	 * Confirm that we cannot prepend strings:
	 */
	ilstr_prepend_str(ils, "D");
	VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_NOMEM);

	ilstr_prepend_str(ils, "D");
	VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_NOMEM);

	/*
	 * Confirm that we cannot append a character:
	 */
	ilstr_append_char(ils, 'D');
	VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_NOMEM);

	return (0);
}

int
ist_standard_toobig(ilstr_t *ils)
{
	/*
	 * Pack the buffer with characters, so that we've been forced to
	 * allocate at least one extra chunk:
	 */
	for (uint_t n = 0; n < PREALLOC_SZ - 1; n++) {
		ilstr_append_str(ils, "A");
	}
	VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_OK);

	/*
	 * Continue adding characters until we hit apparent memory exhaustion:
	 */
	for (uint_t n = 0; n < PREALLOC_SZ - 1; n++) {
		/*
		 * Use the umem fault injection facility to fail any
		 * allocations made while we append to the string:
		 */
		umem_setmtbf(1);
		ilstr_append_str(ils, "A");
		umem_setmtbf(0);

		if (ilstr_errno(ils) == ILSTR_ERROR_NOMEM) {
			break;
		}

		VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_OK);
	}

	/*
	 * Confirm that we ran out of memory along the way, and didn't write
	 * too many characters in the process:
	 */
	VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_NOMEM);
	VERIFY3U(ilstr_len(ils), <, 2 * PREALLOC_SZ);

	return (0);
}

int
ist_huge(ilstr_t *ils)
{
	/*
	 * Build a 26MB string by repeating the alphabet over and over:
	 */
	uint_t target = 26 * 1024 * 1024;

	for (uint_t n = 0; n < target / 26; n++) {
		ilstr_append_str(ils, "abcdefghijklmnopqrstuvwxyz");

		if (ilstr_errno(ils) == ILSTR_ERROR_NOMEM) {
			return (ENOMEM);
		}
		VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_OK);
	}

	VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_OK);
	VERIFY3U(ilstr_len(ils), ==, target);
	VERIFY(!ilstr_is_empty(ils));

	return (0);
}

int
ist_printf_1(ilstr_t *ils)
{
	const char *want = "a\nb\n1000\ntest string\n";

	ilstr_aprintf(ils, "a\nb\n%u\n%s\n", 1000, "test string");
	VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_OK);
	VERIFYSTRING(ils, want);

	return (0);
}

int
ist_printf_2(ilstr_t *ils)
{
	int r = 0;

	const char *lorem = "Lorem ipsum dolor sit amet, consectetur "
	    "adipiscing elit, sed do eiusmod tempor incididunt ut labore "
	    "et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud "
	    "exercitation ullamco laboris nisi ut aliquip ex ea commodo "
	    "consequat.";
	char *want;

	if (asprintf(&want, "%s\n\tnumber 1\n%s\n\n%s\n   number 100000000\n",
	    lorem, lorem, lorem) < 0) {
		return (errno);
	}

	ilstr_aprintf(ils, "%s\n\t", lorem);
	ilstr_append_str(ils, "number");
	ilstr_aprintf(ils, " %u\n%s\n\n", 1, lorem);
	ilstr_append_str(ils, lorem);
	ilstr_aprintf(ils, "\n   number %lld\n", (long long)100000000);

	VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_OK);
	if (strcmp(ilstr_cstr(ils), want) != 0) {
		printf("want: %s\n", want);
		printf("got:  %s\n", ilstr_cstr(ils));
		r = ENOENT;
	}

	free(want);

	return (r);
}

int
ist_resets(ilstr_t *ils)
{
	VERIFYSTRING(ils, "");

	ilstr_reset(ils);
	VERIFYSTRING(ils, "");

	ilstr_append_str(ils, "abc");
	VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_OK);
	VERIFYSTRING(ils, "abc");

	ilstr_append_str(ils, "def");
	VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_OK);
	VERIFYSTRING(ils, "abcdef");

	ilstr_reset(ils);
	VERIFYSTRING(ils, "");

	ilstr_append_str(ils, "xyz");
	VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_OK);
	VERIFYSTRING(ils, "xyz");

	ilstr_reset(ils);
	VERIFY(strcmp(ilstr_cstr(ils), "") == 0);
	VERIFYSTRING(ils, "");

	return (0);
}

int
ist_random(ilstr_t *ils)
{
	char *work;
	uint_t target = 256 + arc4random_uniform(1024 - 256);

	printf(" - target string length %u\n", target);
	if ((work = calloc(1, 1024 + 1)) == NULL) {
		return (errno);
	}

	VERIFY3U(ilstr_len(ils), ==, 0);
	VERIFY(ilstr_is_empty(ils));
	VERIFY3U(ilstr_cstr(ils)[0], ==, '\0');
	VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_OK);

	for (uint_t n = 0; n < target; n++) {
		char c[2] = { arc4random_uniform('Z' - 'A') + 'A', '\0' };

		work[n] = c[0];
		ilstr_append_str(ils, c);

		VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_OK);
		VERIFY3U(ilstr_len(ils), ==, n + 1);
		VERIFY(!ilstr_is_empty(ils));
		VERIFYSTRING(ils, work);
	}

	VERIFY(!ilstr_is_empty(ils));
	VERIFY3U(ilstr_len(ils), ==, target);
	VERIFYSTRING(ils, work);
	printf(" - final string: %s\n", work);

	free(work);
	return (0);
}

int
ist_prepend_char(ilstr_t *ils)
{
	ilstr_append_str(ils, "ackwards");
	ilstr_prepend_char(ils, 'B');
	ilstr_append_char(ils, '!');

	VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_OK);
	VERIFYSTRING(ils, "Backwards!");

	return (0);
}

int
ist_prepend_str(ilstr_t *ils)
{
	ilstr_prepend_str(ils, "string was prepended");
	VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_OK);
	VERIFYSTRING(ils, "string was prepended");

	ilstr_prepend_str(ils, "this ");
	VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_OK);
	VERIFYSTRING(ils, "this string was prepended");

	ilstr_append_str(ils, ", successfully");
	VERIFY3U(ilstr_errno(ils), ==, ILSTR_ERROR_OK);
	VERIFYSTRING(ils, "this string was prepended, successfully");

	return (0);
}

int
ist_building_list(ilstr_t *ils)
{
	const char *items[] = { "one", "two", "three" };
	const char *expect[] = {
		"empty list",
		"populated list (one)",
		"populated list (one, two)",
		"populated list (one, two, three)",
	};

	for (uint_t n = 0; n <= 3; n++) {
		ilstr_reset(ils);

		for (uint_t i = 0; i < n; i++) {
			if (!ilstr_is_empty(ils)) {
				ilstr_append_str(ils, ", ");
			}

			ilstr_append_str(ils, items[i]);
		}

		if (ilstr_is_empty(ils)) {
			ilstr_append_str(ils, "empty list");
		} else {
			ilstr_prepend_str(ils, "populated list (");
			ilstr_append_str(ils, ")");
		}

		VERIFYSTRING(ils, expect[n]);
	}

	return (0);
}

uint_t
ist_drive_test(const ilstr_test_t *ist)
{
	uint_t nfails = 0;
	int r;
	ilstr_t ils;

	for (uint_t n = 0; n < ist->ist_trials; n++) {
		if (ist->ist_types & ITT_STD) {
			ilstr_init(&ils, 0);
			printf("STD[%s]... run %d\n", ist->ist_name, n);
			if ((r = ist->ist_func(&ils)) != 0) {
				(void) fprintf(stderr,
				    "TEST FAILED: STD[%s]: %s\n",
				    ist->ist_name, strerror(r));
				nfails += 1;
			} else {
				printf("TEST PASSED: STD[%s]\n",
				    ist->ist_name);
			}
			ilstr_fini(&ils);
			printf("\n");
		}

		if (ist->ist_types & ITT_PRE) {
			ilstr_init_prealloc(&ils, ilsbuf, sizeof (ilsbuf));
			printf("PRE[%s]... run %d\n", ist->ist_name, n);
			if ((r = ist->ist_func(&ils)) != 0) {
				(void) fprintf(stderr,
				    "TEST FAILED: PRE[%s]: %s\n",
				    ist->ist_name, strerror(r));
				nfails += 1;
			} else {
				printf("TEST PASSED: PRE[%s]\n",
				    ist->ist_name);
			}
			ilstr_fini(&ils);
			printf("\n");
		}
	}

	return (nfails);
}

static const ilstr_test_t ilstr_tests[] = {
	{ "empty",		ist_empty,		1,	ITT_ALL },
	{ "resets",		ist_resets,		1,	ITT_ALL },
	{ "printf-1",		ist_printf_1,		1,	ITT_ALL },
	{ "printf-2",		ist_printf_2,		1,	ITT_ALL },
	{ "prealloc_toobig",	ist_prealloc_toobig,	1,	ITT_PRE },
	{ "standard_toobig",	ist_standard_toobig,	1,	ITT_STD },
	{ "prepend_char",	ist_prepend_char,	1,	ITT_ALL },
	{ "prepend_str",	ist_prepend_str,	1,	ITT_ALL },
	{ "building_list",	ist_building_list,	1,	ITT_ALL },
	/*
	 * Run the random generation test many times, as an attempt at fuzzing:
	 */
	{ "random",		ist_random,		1000,	ITT_ALL },
	/*
	 * Run the huge allocation test some number of times to try to make
	 * sure we exercise allocation and free of different buffer sizes, and
	 * to increase the likelihood of detecting any heap corruption:
	 */
	{ "huge",		ist_huge,		100,	ITT_STD },
};

int
main(void)
{
	uint_t nfails = 0;

	for (uint_t i = 0; i < ARRAY_SIZE(ilstr_tests); i++) {
		nfails += ist_drive_test(&ilstr_tests[i]);
	}

	char *aoe;
	if ((aoe = getenv("PANIC_ON_EXIT")) != NULL && strcmp(aoe, "1") == 0) {
		const char *msg = "PANIC_ON_EXIT set; panicking for findleaks";
		upanic(msg, strlen(msg));
	}

	return (nfails == 0 ? 0 : 1);
}