// SPDX-License-Identifier: GPL-2.0
/*
 * KUnit tests for HFS string operations
 *
 * Copyright (C) 2025 Viacheslav Dubeyko <slava@dubeyko.com>
 */

#include <kunit/test.h>
#include <linux/dcache.h>
#include "hfs_fs.h"

/* Test hfs_strcmp function */
static void hfs_strcmp_test(struct kunit *test)
{
        /* Test equal strings */
        KUNIT_EXPECT_EQ(test, 0, hfs_strcmp("hello", 5, "hello", 5));
        KUNIT_EXPECT_EQ(test, 0, hfs_strcmp("test", 4, "test", 4));
        KUNIT_EXPECT_EQ(test, 0, hfs_strcmp("", 0, "", 0));

        /* Test unequal strings */
        KUNIT_EXPECT_NE(test, 0, hfs_strcmp("hello", 5, "world", 5));
        KUNIT_EXPECT_NE(test, 0, hfs_strcmp("test", 4, "testing", 7));

        /* Test different lengths */
        KUNIT_EXPECT_LT(test, hfs_strcmp("test", 4, "testing", 7), 0);
        KUNIT_EXPECT_GT(test, hfs_strcmp("testing", 7, "test", 4), 0);

        /* Test case insensitive comparison (HFS should handle case) */
        KUNIT_EXPECT_EQ(test, 0, hfs_strcmp("Test", 4, "TEST", 4));
        KUNIT_EXPECT_EQ(test, 0, hfs_strcmp("hello", 5, "HELLO", 5));

        /* Test with special characters */
        KUNIT_EXPECT_EQ(test, 0, hfs_strcmp("file.txt", 8, "file.txt", 8));
        KUNIT_EXPECT_NE(test, 0, hfs_strcmp("file.txt", 8, "file.dat", 8));

        /* Test boundary cases */
        KUNIT_EXPECT_EQ(test, 0, hfs_strcmp("a", 1, "a", 1));
        KUNIT_EXPECT_NE(test, 0, hfs_strcmp("a", 1, "b", 1));
}

/* Test hfs_hash_dentry function */
static void hfs_hash_dentry_test(struct kunit *test)
{
        struct qstr test_name1, test_name2, test_name3;
        struct dentry dentry = {};
        char name1[] = "testfile";
        char name2[] = "TestFile";
        char name3[] = "different";

        /* Initialize test strings */
        test_name1.name = name1;
        test_name1.len = strlen(name1);
        test_name1.hash = 0;

        test_name2.name = name2;
        test_name2.len = strlen(name2);
        test_name2.hash = 0;

        test_name3.name = name3;
        test_name3.len = strlen(name3);
        test_name3.hash = 0;

        /* Test hashing */
        KUNIT_EXPECT_EQ(test, 0, hfs_hash_dentry(&dentry, &test_name1));
        KUNIT_EXPECT_EQ(test, 0, hfs_hash_dentry(&dentry, &test_name2));
        KUNIT_EXPECT_EQ(test, 0, hfs_hash_dentry(&dentry, &test_name3));

        /* Case insensitive names should hash the same */
        KUNIT_EXPECT_EQ(test, test_name1.hash, test_name2.hash);

        /* Different names should have different hashes */
        KUNIT_EXPECT_NE(test, test_name1.hash, test_name3.hash);
}

/* Test hfs_compare_dentry function */
static void hfs_compare_dentry_test(struct kunit *test)
{
        struct qstr test_name;
        struct dentry dentry = {};
        char name[] = "TestFile";

        test_name.name = name;
        test_name.len = strlen(name);

        /* Test exact match */
        KUNIT_EXPECT_EQ(test, 0, hfs_compare_dentry(&dentry, 8,
                                                    "TestFile", &test_name));

        /* Test case insensitive match */
        KUNIT_EXPECT_EQ(test, 0, hfs_compare_dentry(&dentry, 8,
                                                    "testfile", &test_name));
        KUNIT_EXPECT_EQ(test, 0, hfs_compare_dentry(&dentry, 8,
                                                    "TESTFILE", &test_name));

        /* Test different names */
        KUNIT_EXPECT_EQ(test, 1, hfs_compare_dentry(&dentry, 8,
                                                    "DiffFile", &test_name));

        /* Test different lengths */
        KUNIT_EXPECT_EQ(test, 1, hfs_compare_dentry(&dentry, 7,
                                                    "TestFil", &test_name));
        KUNIT_EXPECT_EQ(test, 1, hfs_compare_dentry(&dentry, 9,
                                                    "TestFiles", &test_name));

        /* Test empty string */
        test_name.name = "";
        test_name.len = 0;
        KUNIT_EXPECT_EQ(test, 0, hfs_compare_dentry(&dentry, 0, "", &test_name));

        /* Test HFS_NAMELEN boundary */
        test_name.name = "This_is_a_very_long_filename_that_exceeds_normal_limits";
        test_name.len = strlen(test_name.name);
        KUNIT_EXPECT_EQ(test, 0, hfs_compare_dentry(&dentry, HFS_NAMELEN,
                        "This_is_a_very_long_filename_th", &test_name));
}

static struct kunit_case hfs_string_test_cases[] = {
        KUNIT_CASE(hfs_strcmp_test),
        KUNIT_CASE(hfs_hash_dentry_test),
        KUNIT_CASE(hfs_compare_dentry_test),
        {}
};

static struct kunit_suite hfs_string_test_suite = {
        .name = "hfs_string",
        .test_cases = hfs_string_test_cases,
};

kunit_test_suite(hfs_string_test_suite);

MODULE_DESCRIPTION("KUnit tests for HFS string operations");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING");