/*
 * test_json_serialization.c - Unit tests for JSON serialization
 */

#include <stdarg.h>
#include <stddef.h>
#include <setjmp.h>
#include <cmocka.h>
#include <string.h>
#include <stdio.h>
#include <apr_strings.h>
#include <apr_time.h>
#include <apr_lib.h>

/* Mock JSON string escaping function for testing */
static void append_json_string(apr_pool_t *pool, apr_strbuf_t *buf, const char *str)
{
    if (str == NULL) {
        return;
    }
    
    for (const char *p = str; *p; p++) {
        char c = *p;
        switch (c) {
            case '"':  apr_strbuf_append(buf, "\\\"", 2); break;
            case '\\': apr_strbuf_append(buf, "\\\\", 2); break;
            case '\b': apr_strbuf_append(buf, "\\b", 2); break;
            case '\f': apr_strbuf_append(buf, "\\f", 2); break;
            case '\n': apr_strbuf_append(buf, "\\n", 2); break;
            case '\r': apr_strbuf_append(buf, "\\r", 2); break;
            case '\t': apr_strbuf_append(buf, "\\t", 2); break;
            default:
                if ((unsigned char)c < 0x20) {
                    char unicode[8];
                    apr_snprintf(unicode, sizeof(unicode), "\\u%04x", (unsigned char)c);
                    apr_strbuf_append(buf, unicode, -1);
                } else {
                    apr_strbuf_append_char(buf, c);
                }
                break;
        }
    }
}

/* Test: Empty string */
static void test_json_escape_empty_string(void **state)
{
    apr_pool_t *pool;
    apr_pool_create(&pool, NULL);
    
    apr_strbuf_t buf;
    char *initial = apr_palloc(pool, 256);
    apr_strbuf_init(pool, &buf, initial, 256);
    
    append_json_string(pool, &buf, "");
    
    assert_string_equal(buf.buf, "");
    
    apr_pool_destroy(pool);
}

/* Test: Simple string without special characters */
static void test_json_escape_simple_string(void **state)
{
    apr_pool_t *pool;
    apr_pool_create(&pool, NULL);
    
    apr_strbuf_t buf;
    char *initial = apr_palloc(pool, 256);
    apr_strbuf_init(pool, &buf, initial, 256);
    
    append_json_string(pool, &buf, "hello world");
    
    assert_string_equal(buf.buf, "hello world");
    
    apr_pool_destroy(pool);
}

/* Test: String with double quotes */
static void test_json_escape_quotes(void **state)
{
    apr_pool_t *pool;
    apr_pool_create(&pool, NULL);
    
    apr_strbuf_t buf;
    char *initial = apr_palloc(pool, 256);
    apr_strbuf_init(pool, &buf, initial, 256);
    
    append_json_string(pool, &buf, "hello \"world\"");
    
    assert_string_equal(buf.buf, "hello \\\"world\\\"");
    
    apr_pool_destroy(pool);
}

/* Test: String with backslashes */
static void test_json_escape_backslashes(void **state)
{
    apr_pool_t *pool;
    apr_pool_create(&pool, NULL);
    
    apr_strbuf_t buf;
    char *initial = apr_palloc(pool, 256);
    apr_strbuf_init(pool, &buf, initial, 256);
    
    append_json_string(pool, &buf, "path\\to\\file");
    
    assert_string_equal(buf.buf, "path\\\\to\\\\file");
    
    apr_pool_destroy(pool);
}

/* Test: String with newlines and tabs */
static void test_json_escape_newlines_tabs(void **state)
{
    apr_pool_t *pool;
    apr_pool_create(&pool, NULL);
    
    apr_strbuf_t buf;
    char *initial = apr_palloc(pool, 256);
    apr_strbuf_init(pool, &buf, initial, 256);
    
    append_json_string(pool, &buf, "line1\nline2\ttab");
    
    assert_string_equal(buf.buf, "line1\\nline2\\ttab");
    
    apr_pool_destroy(pool);
}

/* Test: String with control characters */
static void test_json_escape_control_chars(void **state)
{
    apr_pool_t *pool;
    apr_pool_create(&pool, NULL);
    
    apr_strbuf_t buf;
    char *initial = apr_palloc(pool, 256);
    apr_strbuf_init(pool, &buf, initial, 256);
    
    /* Test with bell character (0x07) */
    append_json_string(pool, &buf, "test\bell");
    
    /* Should contain unicode escape */
    assert_true(strstr(buf.buf, "\\u0007") != NULL);
    
    apr_pool_destroy(pool);
}

/* Test: NULL string */
static void test_json_escape_null_string(void **state)
{
    apr_pool_t *pool;
    apr_pool_create(&pool, NULL);
    
    apr_strbuf_t buf;
    char *initial = apr_palloc(pool, 256);
    apr_strbuf_init(pool, &buf, initial, 256);
    
    append_json_string(pool, &buf, NULL);
    
    assert_string_equal(buf.buf, "");
    
    apr_pool_destroy(pool);
}

/* Test: Complex user agent string */
static void test_json_escape_user_agent(void **state)
{
    apr_pool_t *pool;
    apr_pool_create(&pool, NULL);
    
    apr_strbuf_t buf;
    char *initial = apr_palloc(pool, 512);
    apr_strbuf_init(pool, &buf, initial, 512);
    
    const char *ua = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) \"Test\"";
    append_json_string(pool, &buf, ua);
    
    assert_true(strstr(buf.buf, "\\\"Test\\\"") != NULL);
    
    apr_pool_destroy(pool);
}

int main(void)
{
    const struct CMUnitTest tests[] = {
        cmocka_unit_test(test_json_escape_empty_string),
        cmocka_unit_test(test_json_escape_simple_string),
        cmocka_unit_test(test_json_escape_quotes),
        cmocka_unit_test(test_json_escape_backslashes),
        cmocka_unit_test(test_json_escape_newlines_tabs),
        cmocka_unit_test(test_json_escape_control_chars),
        cmocka_unit_test(test_json_escape_null_string),
        cmocka_unit_test(test_json_escape_user_agent),
    };
    
    return cmocka_run_group_tests(tests, NULL, NULL);
}