// 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
 * @attr_default: default attribute value used during filtering
 * @print: value of enum print_ops to indicate when to print attribute
 */
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_bool_to_string(void *attr, bool *to_free)
{
        bool val = (bool)attr;

        *to_free = false;
        if (val)
                return "true";
        return "false";
}

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 = -1;
        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 < 0) {
                *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;
}

static int attr_bool_filter(void *attr, const char *input, int *err)
{
        int i, input_int = -1;
        long val = (long)attr;
        const char *input_str = NULL;

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

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

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

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

/* 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 if (kunit_suite_num_test_cases(suite) > 0)
                return ((void *) suite->test_cases[0].module_name);
        else
                return (void *) "";
}

static void *attr_is_init_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 *) NULL);
        else
                return ((void *) suite->is_init);
}

/* 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,
        },
        {
                .name = "is_init",
                .get_attr = attr_is_init_get,
                .to_string = attr_bool_to_string,
                .filter = attr_bool_filter,
                .attr_default = (void *)false,
                .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 = false;
        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 = 0, 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 = 0, new_start_index = 0;
        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 > 0) {
                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 = kzalloc_objs(*filtered, n + 1);
        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)
                goto err;

        /* 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)
                goto err;

        /* 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)
                        goto err;

                /*
                 * 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;
                }
        }

err:
        if (n == 0 || *err) {
                kfree(copy);
                kfree(filtered);
                return NULL;
        }

        copy->test_cases = filtered;

        return copy;
}