// SPDX-License-Identifier: GPL-2.0
/*
 * KUnit API to save and access test attributes
 *
 * Copyright (C) 2023, Google LLC.
 * Author: Rae Moar <rmoar@google.com>
 */

#include <kunit/test.h>
#include <kunit/attributes.h>

/* Options for printing attributes:
 * PRINT_ALWAYS - attribute is printed for every test case and suite if set
 * PRINT_SUITE - attribute is printed for every suite if set but not for test cases
 * PRINT_NEVER - attribute is never printed
 */
enum print_ops {
	PRINT_ALWAYS,
	PRINT_SUITE,
	PRINT_NEVER,
};

/**
 * struct kunit_attr - represents a test attribute and holds flexible
 * helper functions to interact with attribute.
 *
 * @name: name of test attribute, eg. speed
 * @get_attr: function to return attribute value given a test
 * @to_string: function to return string representation of given
 * attribute value
 * @filter: function to indicate whether a given attribute value passes a
 * filter
 */
struct kunit_attr {
	const char *name;
	void *(*get_attr)(void *test_or_suite, bool is_test);
	const char *(*to_string)(void *attr, bool *to_free);
	int (*filter)(void *attr, const char *input, int *err);
	void *attr_default;
	enum print_ops print;
};

/* String Lists for enum Attributes */

static const char * const speed_str_list[] = {"unset", "very_slow", "slow", "normal"};

/* To String Methods */

static const char *attr_enum_to_string(void *attr, const char * const str_list[], bool *to_free)
{
	long val = (long)attr;

	*to_free = false;
	if (!val)
		return NULL;
	return str_list[val];
}

static const char *attr_speed_to_string(void *attr, bool *to_free)
{
	return attr_enum_to_string(attr, speed_str_list, to_free);
}

static const char *attr_string_to_string(void *attr, bool *to_free)
{
	*to_free = false;
	return (char *) attr;
}

/* Filter Methods */

static const char op_list[] = "<>!=";

/*
 * Returns whether the inputted integer value matches the filter given
 * by the operation string and inputted integer.
 */
static int int_filter(long val, const char *op, int input, int *err)
{
	if (!strncmp(op, "<=", 2))
		return (val <= input);
	else if (!strncmp(op, ">=", 2))
		return (val >= input);
	else if (!strncmp(op, "!=", 2))
		return (val != input);
	else if (!strncmp(op, ">", 1))
		return (val > input);
	else if (!strncmp(op, "<", 1))
		return (val < input);
	else if (!strncmp(op, "=", 1))
		return (val == input);
	*err = -EINVAL;
	pr_err("kunit executor: invalid filter operation: %s\n", op);
	return false;
}

/*
 * Returns whether the inputted enum value "attr" matches the filter given
 * by the input string. Note: the str_list includes the corresponding string
 * list to the enum values.
 */
static int attr_enum_filter(void *attr, const char *input, int *err,
		const char * const str_list[], int max)
{
	int i, j, input_int;
	long test_val = (long)attr;
	const char *input_val = NULL;

	for (i = 0; input[i]; i++) {
		if (!strchr(op_list, input[i])) {
			input_val = input + i;
			break;
		}
	}

	if (!input_val) {
		*err = -EINVAL;
		pr_err("kunit executor: filter value not found: %s\n", input);
		return false;
	}

	for (j = 0; j <= max; j++) {
		if (!strcmp(input_val, str_list[j]))
			input_int = j;
	}

	if (!input_int) {
		*err = -EINVAL;
		pr_err("kunit executor: invalid filter input: %s\n", input);
		return false;
	}

	return int_filter(test_val, input, input_int, err);
}

static int attr_speed_filter(void *attr, const char *input, int *err)
{
	return attr_enum_filter(attr, input, err, speed_str_list, KUNIT_SPEED_MAX);
}

/*
 * Returns whether the inputted string value (attr) matches the filter given
 * by the input string.
 */
static int attr_string_filter(void *attr, const char *input, int *err)
{
	char *str = attr;

	if (!strncmp(input, "<", 1)) {
		*err = -EINVAL;
		pr_err("kunit executor: invalid filter input: %s\n", input);
		return false;
	} else if (!strncmp(input, ">", 1)) {
		*err = -EINVAL;
		pr_err("kunit executor: invalid filter input: %s\n", input);
		return false;
	} else if (!strncmp(input, "!=", 2)) {
		return (strcmp(input + 2, str) != 0);
	} else if (!strncmp(input, "=", 1)) {
		return (strcmp(input + 1, str) == 0);
	}
	*err = -EINVAL;
	pr_err("kunit executor: invalid filter operation: %s\n", input);
	return false;
}


/* Get Attribute Methods */

static void *attr_speed_get(void *test_or_suite, bool is_test)
{
	struct kunit_suite *suite = is_test ? NULL : test_or_suite;
	struct kunit_case *test = is_test ? test_or_suite : NULL;

	if (test)
		return ((void *) test->attr.speed);
	else
		return ((void *) suite->attr.speed);
}

static void *attr_module_get(void *test_or_suite, bool is_test)
{
	struct kunit_suite *suite = is_test ? NULL : test_or_suite;
	struct kunit_case *test = is_test ? test_or_suite : NULL;

	// Suites get their module attribute from their first test_case
	if (test)
		return ((void *) test->module_name);
	else
		return ((void *) suite->test_cases[0].module_name);
}

/* List of all Test Attributes */

static struct kunit_attr kunit_attr_list[] = {
	{
		.name = "speed",
		.get_attr = attr_speed_get,
		.to_string = attr_speed_to_string,
		.filter = attr_speed_filter,
		.attr_default = (void *)KUNIT_SPEED_NORMAL,
		.print = PRINT_ALWAYS,
	},
	{
		.name = "module",
		.get_attr = attr_module_get,
		.to_string = attr_string_to_string,
		.filter = attr_string_filter,
		.attr_default = (void *)"",
		.print = PRINT_SUITE,
	}
};

/* Helper Functions to Access Attributes */

const char *kunit_attr_filter_name(struct kunit_attr_filter filter)
{
	return filter.attr->name;
}

void kunit_print_attr(void *test_or_suite, bool is_test, unsigned int test_level)
{
	int i;
	bool to_free;
	void *attr;
	const char *attr_name, *attr_str;
	struct kunit_suite *suite = is_test ? NULL : test_or_suite;
	struct kunit_case *test = is_test ? test_or_suite : NULL;

	for (i = 0; i < ARRAY_SIZE(kunit_attr_list); i++) {
		if (kunit_attr_list[i].print == PRINT_NEVER ||
				(test && kunit_attr_list[i].print == PRINT_SUITE))
			continue;
		attr = kunit_attr_list[i].get_attr(test_or_suite, is_test);
		if (attr) {
			attr_name = kunit_attr_list[i].name;
			attr_str = kunit_attr_list[i].to_string(attr, &to_free);
			if (test) {
				kunit_log(KERN_INFO, test, "%*s# %s.%s: %s",
					KUNIT_INDENT_LEN * test_level, "", test->name,
					attr_name, attr_str);
			} else {
				kunit_log(KERN_INFO, suite, "%*s# %s: %s",
					KUNIT_INDENT_LEN * test_level, "", attr_name, attr_str);
			}

			/* Free to_string of attribute if needed */
			if (to_free)
				kfree(attr_str);
		}
	}
}

/* Helper Functions to Filter Attributes */

int kunit_get_filter_count(char *input)
{
	int i, comma_index, count = 0;

	for (i = 0; input[i]; i++) {
		if (input[i] == ',') {
			if ((i - comma_index) > 1)
				count++;
			comma_index = i;
		}
	}
	if ((i - comma_index) > 0)
		count++;
	return count;
}

struct kunit_attr_filter kunit_next_attr_filter(char **filters, int *err)
{
	struct kunit_attr_filter filter = {};
	int i, j, comma_index, new_start_index;
	int op_index = -1, attr_index = -1;
	char op;
	char *input = *filters;

	/* Parse input until operation */
	for (i = 0; input[i]; i++) {
		if (op_index < 0 && strchr(op_list, input[i])) {
			op_index = i;
		} else if (!comma_index && input[i] == ',') {
			comma_index = i;
		} else if (comma_index && input[i] != ' ') {
			new_start_index = i;
			break;
		}
	}

	if (op_index <= 0) {
		*err = -EINVAL;
		pr_err("kunit executor: filter operation not found: %s\n", input);
		return filter;
	}

	/* Temporarily set operator to \0 character. */
	op = input[op_index];
	input[op_index] = '\0';

	/* Find associated kunit_attr object */
	for (j = 0; j < ARRAY_SIZE(kunit_attr_list); j++) {
		if (!strcmp(input, kunit_attr_list[j].name)) {
			attr_index = j;
			break;
		}
	}

	input[op_index] = op;

	if (attr_index < 0) {
		*err = -EINVAL;
		pr_err("kunit executor: attribute not found: %s\n", input);
	} else {
		filter.attr = &kunit_attr_list[attr_index];
	}

	if (comma_index) {
		input[comma_index] = '\0';
		filter.input = input + op_index;
		input = input + new_start_index;
	} else {
		filter.input = input + op_index;
		input = NULL;
	}

	*filters = input;

	return filter;
}

struct kunit_suite *kunit_filter_attr_tests(const struct kunit_suite *const suite,
		struct kunit_attr_filter filter, char *action, int *err)
{
	int n = 0;
	struct kunit_case *filtered, *test_case;
	struct kunit_suite *copy;
	void *suite_val, *test_val;
	bool suite_result, test_result, default_result, result;

	/* Allocate memory for new copy of suite and list of test cases */
	copy = kmemdup(suite, sizeof(*copy), GFP_KERNEL);
	if (!copy)
		return ERR_PTR(-ENOMEM);

	kunit_suite_for_each_test_case(suite, test_case) { n++; }

	filtered = kcalloc(n + 1, sizeof(*filtered), GFP_KERNEL);
	if (!filtered) {
		kfree(copy);
		return ERR_PTR(-ENOMEM);
	}

	n = 0;

	/* Save filtering result on default value */
	default_result = filter.attr->filter(filter.attr->attr_default, filter.input, err);
	if (*err) {
		kfree(copy);
		kfree(filtered);
		return NULL;
	}

	/* Save suite attribute value and filtering result on that value */
	suite_val = filter.attr->get_attr((void *)suite, false);
	suite_result = filter.attr->filter(suite_val, filter.input, err);
	if (*err) {
		kfree(copy);
		kfree(filtered);
		return NULL;
	}

	/* For each test case, save test case if passes filtering. */
	kunit_suite_for_each_test_case(suite, test_case) {
		test_val = filter.attr->get_attr((void *) test_case, true);
		test_result = filter.attr->filter(filter.attr->get_attr(test_case, true),
				filter.input, err);
		if (*err) {
			kfree(copy);
			kfree(filtered);
			return NULL;
		}

		/*
		 * If attribute value of test case is set, filter on that value.
		 * If not, filter on suite value if set. If not, filter on
		 * default value.
		 */
		result = false;
		if (test_val) {
			if (test_result)
				result = true;
		} else if (suite_val) {
			if (suite_result)
				result = true;
		} else if (default_result) {
			result = true;
		}

		if (result) {
			filtered[n++] = *test_case;
		} else if (action && strcmp(action, "skip") == 0) {
			test_case->status = KUNIT_SKIPPED;
			filtered[n++] = *test_case;
		}
	}

	if (n == 0) {
		kfree(copy);
		kfree(filtered);
		return NULL;
	}

	copy->test_cases = filtered;

	return copy;
}