// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
 *
 * Module Name: osunixdir - Unix directory access interfaces
 *
 * Copyright (C) 2000 - 2025, Intel Corp.
 *
 *****************************************************************************/

#include <acpi/acpi.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <dirent.h>
#include <fnmatch.h>
#include <ctype.h>
#include <sys/stat.h>

/*
 * Allocated structure returned from os_open_directory
 */
typedef struct external_find_info {
        char *dir_pathname;
        DIR *dir_ptr;
        char temp_buffer[256];
        char *wildcard_spec;
        char requested_file_type;

} external_find_info;

/*******************************************************************************
 *
 * FUNCTION:    acpi_os_open_directory
 *
 * PARAMETERS:  dir_pathname        - Full pathname to the directory
 *              wildcard_spec       - string of the form "*.c", etc.
 *
 * RETURN:      A directory "handle" to be used in subsequent search operations.
 *              NULL returned on failure.
 *
 * DESCRIPTION: Open a directory in preparation for a wildcard search
 *
 ******************************************************************************/

void *acpi_os_open_directory(char *dir_pathname,
                             char *wildcard_spec, char requested_file_type)
{
        struct external_find_info *external_info;
        DIR *dir;

        /* Allocate the info struct that will be returned to the caller */

        external_info = calloc(1, sizeof(struct external_find_info));
        if (!external_info) {
                return (NULL);
        }

        /* Get the directory stream */

        dir = opendir(dir_pathname);
        if (!dir) {
                fprintf(stderr, "Cannot open directory - %s\n", dir_pathname);
                free(external_info);
                return (NULL);
        }

        /* Save the info in the return structure */

        external_info->wildcard_spec = wildcard_spec;
        external_info->requested_file_type = requested_file_type;
        external_info->dir_pathname = dir_pathname;
        external_info->dir_ptr = dir;
        return (external_info);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_os_get_next_filename
 *
 * PARAMETERS:  dir_handle          - Created via acpi_os_open_directory
 *
 * RETURN:      Next filename matched. NULL if no more matches.
 *
 * DESCRIPTION: Get the next file in the directory that matches the wildcard
 *              specification.
 *
 ******************************************************************************/

char *acpi_os_get_next_filename(void *dir_handle)
{
        struct external_find_info *external_info = dir_handle;
        struct dirent *dir_entry;
        char *temp_str;
        int str_len;
        struct stat temp_stat;
        int err;

        while ((dir_entry = readdir(external_info->dir_ptr))) {
                if (!fnmatch
                    (external_info->wildcard_spec, dir_entry->d_name, 0)) {
                        if (dir_entry->d_name[0] == '.') {
                                continue;
                        }

                        str_len = strlen(dir_entry->d_name) +
                            strlen(external_info->dir_pathname) + 2;

                        temp_str = calloc(str_len, 1);
                        if (!temp_str) {
                                fprintf(stderr,
                                        "Could not allocate buffer for temporary string\n");
                                return (NULL);
                        }

                        strcpy(temp_str, external_info->dir_pathname);
                        strcat(temp_str, "/");
                        strcat(temp_str, dir_entry->d_name);

                        err = stat(temp_str, &temp_stat);
                        if (err == -1) {
                                fprintf(stderr,
                                        "Cannot stat file (should not happen) - %s\n",
                                        temp_str);
                                free(temp_str);
                                return (NULL);
                        }

                        free(temp_str);

                        if ((S_ISDIR(temp_stat.st_mode)
                             && (external_info->requested_file_type ==
                                 REQUEST_DIR_ONLY))
                            || ((!S_ISDIR(temp_stat.st_mode)
                                 && external_info->requested_file_type ==
                                 REQUEST_FILE_ONLY))) {

                                /* copy to a temp buffer because dir_entry struct is on the stack */

                                strcpy(external_info->temp_buffer,
                                       dir_entry->d_name);
                                return (external_info->temp_buffer);
                        }
                }
        }

        return (NULL);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_os_close_directory
 *
 * PARAMETERS:  dir_handle          - Created via acpi_os_open_directory
 *
 * RETURN:      None.
 *
 * DESCRIPTION: Close the open directory and cleanup.
 *
 ******************************************************************************/

void acpi_os_close_directory(void *dir_handle)
{
        struct external_find_info *external_info = dir_handle;

        /* Close the directory and free allocations */

        closedir(external_info->dir_ptr);
        free(dir_handle);
}