/*
 * Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
 *                         University Research and Technology
 *                         Corporation.  All rights reserved.
 * Copyright (c) 2004-2005 The University of Tennessee and The University
 *                         of Tennessee Research Foundation.  All rights
 *                         reserved.
 * Copyright (c) 2004-2005 High Performance Computing Center Stuttgart, 
 *                         University of Stuttgart.  All rights reserved.
 * Copyright (c) 2004-2005 The Regents of the University of California.
 *                         All rights reserved.
 * $COPYRIGHT$
 * 
 * Additional copyrights may follow
 * 
 * $HEADER$
 */


#include "opal_config.h"

#include <string.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_LIBGEN_H
#include <libgen.h>
#endif
#include <stdlib.h>
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_DIRENT_H
#include <dirent.h>
#endif

#include "opal/util/os_dirpath.h"
#include "opal/util/argv.h"
#include "opal/util/os_path.h"
#include "opal/constants.h"

#ifdef __WINDOWS__
#define PATH_SEP "\\"
#else
#define PATH_SEP "/"
#endif

static const char *path_sep = PATH_SEP;


int opal_os_dirpath_create(const char *path, const mode_t mode)
{
    struct stat buf;
    char **parts, *tmp;
    int i, len;

    if (NULL == path) { /* protect ourselves from errors */
        return(OPAL_ERROR);
    }

    if (0 == stat(path, &buf)) { /* already exists */
        if (mode == (mode & buf.st_mode)) { /* has correct mode */
            return(OPAL_SUCCESS);
        }
        if (0 == chmod(path, (buf.st_mode | mode))) { /* successfully change mode */
            return(OPAL_SUCCESS);
        }
        return(OPAL_ERROR); /* can't set correct mode */
    }

    /* quick -- try to make directory */
    if (0 == mkdir(path, mode)) {
        return(OPAL_SUCCESS);
    }

    /* didnt work, so now have to build our way down the tree */
    /* Split the requested path up into its individual parts */

    parts = opal_argv_split(path, path_sep[0]);

    /* Ensure to allocate enough space for tmp: the strlen of the
       incoming path + 1 (for \0) */

    tmp = malloc(strlen(path) + 1);
    tmp[0] = '\0';

    /* Iterate through all the subdirectory names in the path,
       building up a directory name.  Check to see if that dirname
       exists.  If it doesn't, create it. */

    /* Notes about stat(): Windows has funny definitions of what will
       return 0 from stat().  "C:" will return failure, while "C:\"
       will return success.  Similarly, "C:\foo" will return success,
       while "C:\foo\" will return failure (assuming that a folder
       named "foo" exists under C:\).

       POSIX implementations of stat() are generally a bit more
       forgiving; most will return true for "/foo" and "/foo/"
       (assuming /foo exists).  But we might as well abide by the same
       rules as Windows and generally disallow checking for names
       ending with path_sep (the only possible allowable one is
       checking for "/", which is the root directory, and is
       guaranteed to exist on valid POSIX filesystems, and is
       therefore not worth checking for). */

    len = opal_argv_count(parts);
    for (i = 0; i < len; ++i) {
        if (i == 0) {

#ifdef __WINDOWS__
            /* In the Windows case, check for "<drive>:" case (i.e.,
               an absolute pathname).  If this is the case, ensure
               that it ends in a path_sep. */

            if (2 == strlen(parts[0]) && isalpha(parts[0][0]) &&
                ':' == parts[0][1]) {
                strcat(tmp, parts[i]);
                strcat(tmp, path_sep);
            }
            
            /* Otherwise, it's a relative path.  Per the comment
               above, we don't want a '\' at the end, so just append
               this part. */

            else {
                strcat(tmp, parts[i]);
            }
#else
            /* If in POSIX-land, ensure that we never end a directory
               name with path_sep */

            if ('/' == path[0]) {
                strcat(tmp, path_sep);
            }
            strcat(tmp, parts[i]);
#endif
        }

        /* If it's not the first part, ensure that there's a
           preceeding path_sep and then append this part */

        else {
            if (path_sep[0] != tmp[strlen(tmp) - 1]) {
                strcat(tmp, path_sep);
            }
            strcat(tmp, parts[i]);
        }

        /* Now that we finally have the name to check, check it.
           Create it if it doesn't exist. */

        if (0 != stat(tmp, &buf)) {
            if (0 != mkdir(tmp, mode) && 0 != stat(tmp, &buf)) { 
                opal_argv_free(parts);
                free(tmp);
                return OPAL_ERROR;
            }
        }
    }

    /* All done */

    opal_argv_free(parts);
    free(tmp);
    return OPAL_SUCCESS;
}

int opal_os_dirpath_destroy(const char *path,
                            bool recursive,
                            opal_os_dirpath_destroy_callback_fn_t cbfunc)
{
    int rc, exit_status = OPAL_SUCCESS;
    bool is_dir = false;

#ifndef WIN32
    DIR *dp;
    struct dirent *ep;
    char *filenm;
#ifndef HAVE_STRUCT_DIRENT_D_TYPE 
    int ret;
    struct stat buf;
#endif

    if (NULL == path) {  /* protect against error */
        return OPAL_ERROR;
    }

    /*
     * Make sure we have access to the the base directory
     */
    if( OPAL_SUCCESS != (rc = opal_os_dirpath_access(path, 0) ) ) {
        exit_status = rc;
        goto cleanup;
    }

    /*
     * Open up the directory
     */
    dp = opendir(path);
    if (NULL == dp) {
        return OPAL_ERROR;
    }

    while (NULL != (ep = readdir(dp)) ) {
        /* skip:
         *  - . and ..
         */
        if ((0 == strcmp(ep->d_name, ".")) ||
            (0 == strcmp(ep->d_name, "..")) ) {
            continue;
        }
        
        /* Check to see if it is a directory */
        is_dir = false;
#ifdef HAVE_STRUCT_DIRENT_D_TYPE
        if (DT_DIR == ep->d_type) {
            is_dir = true;
        }
#else /* have dirent.d_type */
        rc = stat(filenm, &buf);
        if (rc < 0 || S_ISDIR(buf.st_mode)) {
            is_dir = true;
        }
#endif /* have dirent.d_type */        

        /*
         * If not recursively decending, then if we find a directory then fail
         * since we were not told to remove it.
         */
        if( is_dir && !recursive) {
            /* Set the error indicating that we found a directory,
             * but continue removing files
             */
            exit_status = OPAL_ERROR;
            continue;
        }

        /* Will the caller allow us to remove this file/directory? */
        if(NULL != cbfunc) {
            /*
             * Caller does not wish to remove this file/directory,
             * continue with the rest of the entries
             */
            if( ! (cbfunc(path, ep->d_name)) ) {
                continue;
            }
        }
        /* Directories are recursively destroyed */
        filenm = opal_os_path(false, path, ep->d_name, NULL);
        if(is_dir) {
            if( OPAL_SUCCESS != (rc = opal_os_dirpath_destroy(filenm,
                                                              recursive,
                                                              cbfunc) ) ) {
                exit_status = rc;
                goto cleanup;
            }
        }
        /* Files are removed right here */
        else {
            if( 0 != (rc = unlink(filenm) ) ) {
                exit_status = OPAL_ERROR;
            }
            free(filenm);
        }
    }
    
    /*
     * Done with this directory
     */
    closedir(dp);
#else
    bool empty = false;
    char search_path[MAX_PATH];
    HANDLE file;
    WIN32_FIND_DATA file_data;
    TCHAR *file_name;
    
    if (NULL == path) {
        return OPAL_ERROR;
    }
    
    strncpy(search_path, path, strlen(path)+1);
    strncat (search_path, "\\*", 3);
    file = FindFirstFile(search_path, &file_data);
    
    if (INVALID_HANDLE_VALUE == file) {
        FindClose(&file_data);
        return;
    } 
    
    do {
        /*
         * Skip
         * - . and ..
         */
        if ((0 == strcmp(file_data.cFileName, ".")) ||
            (0 == strcmp(file_data.cFileName, "..")) ) {
            continue;
        }
        
        is_dir = false;
        if(file_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
            is_dir = true;
        } 
        /*
         * If not recursively decending, then if we find a directory then fail
         * since we were not told to remove it.
         */
        if( is_dir && !recursive) {
            /* Set the error indicating that we found a directory,
             * but continue removing files
             */
            exit_status = OPAL_ERROR;
            continue;
        }
        
        /* Will the caller allow us to remove this file/directory */
        if( NULL != cbfunc) {
            if( !cbfunc(path, file_data.cFileName) ) {
                continue;
            }
        }

        file_name = opal_os_path(false, path, file_data.cFileName, NULL);
        if( is_dir ) {
            if( OPAL_SUCCESS != (rc = opal_os_dirpath_destroy(file_name,
                                                              recursive,
                                                              cbfunc) ) ) {
                exit_status = rc;
                goto cleanup;
            }
        }
        else {
            DeleteFile(file_name);
        }
        
        /*
         * Are we done yet?
         */
        if (0 == FindNextFile(file, &file_data)) {
            empty = true;
        }
        
    } while(!empty);
    
    FindClose(&file_data);
#endif
    
 cleanup:
    
    /*
     * If the directory is empty, them remove it
     */
    if(opal_os_dirpath_is_empty(path)) {
        rmdir(path);
    }

    return exit_status;
}

bool opal_os_dirpath_is_empty(const char *path ) {
#ifndef __WINDOWS__
    DIR *dp;
    struct dirent *ep;
    
    if (NULL != path) {  /* protect against error */
    	dp = opendir(path);
    	if (NULL != dp) {
    	    while ((ep = readdir(dp))) {
        		if ((0 != strcmp(ep->d_name, ".")) &&
        		    (0 != strcmp(ep->d_name, ".."))) {
                            closedir(dp);
        		    return false;
        		}
    	    }
    	    closedir(dp);
    	    return true;
    	}
    	return false;
    }

    return true;
#else 
    char search_path[MAX_PATH];
    HANDLE file;
    WIN32_FIND_DATA file_data;

    if (NULL != path) {
        strncpy(search_path, path, strlen(path)+1);
        strncat (search_path, "\\*", 3);

        file = FindFirstFile(search_path, &file_data);
        if (INVALID_HANDLE_VALUE == file) {
            FindClose(&file_data);
            return true;
        }

        if (0 != strcmp(file_data.cFileName, ".") || 0 != strcmp(file_data.cFileName, "..")) {
            FindClose(&file_data);
            return false;
        }

        while (0 != FindNextFile(file, &file_data)) {
            if (0 != strcmp(file_data.cFileName, ".") || 0 != strcmp(file_data.cFileName, "..")) {
                FindClose(&file_data);
                return false;
            }
        }
    }

    FindClose(&file_data);
    return true;
#endif /* ifndef __WINDOWS__ */
}

int opal_os_dirpath_access(const char *path, const mode_t in_mode ) {
#ifndef __WINDOWS__
    struct stat buf;
    mode_t loc_mode = S_IRWXU;  /* at the least, I need to be able to do anything */
#else
    struct __stat64 buf;
    mode_t loc_mode = _S_IREAD | _S_IWRITE | _S_IEXEC;
#endif

    /*
     * If there was no mode specified, use the default mode
     */
    if( 0 != in_mode ) {
        loc_mode = in_mode;
    }

#ifndef __WINDOWS__
    if (0 == stat(path, &buf)) { /* exists - check access */
#else
    if (0 == _stat64(path, &buf)) { /* exist -- check */
#endif
        if ((buf.st_mode & loc_mode) == loc_mode) { /* okay, I can work here */
            return(OPAL_SUCCESS);
        }
        else {
            /* Don't have access rights to the existing path */
            return(OPAL_ERROR);
        }
    }
    else {
        /* We could not find the path */
        return( OPAL_ERR_NOT_FOUND );
    }
}