/*

 * Copy a file out of a filesystem.

 *

 * Copyright (C) 2019, 2022 Paul Boddie <paul@boddie.org.uk>

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License as

 * published by the Free Software Foundation; either version 2 of

 * the License, or (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor,

 * Boston, MA  02110-1301, USA

 */

#include <stdio.h>

#include <string.h>

#include <sys/stat.h>

#include <ext2fs/ext2fs.h>

#include "file.h"

#include "image.h"

#include "path.h"

#include "session.h"

/* Copy buffer size. */

static int BUFSIZE = 4096;

/* Alternative metadata set by options. */

extern struct metadata md;

/* Copy a file out of the filesystem image. */

static int _copy_file_out(const char *target, const char *filename,

                          int target_is_file, ext2_filsys fs,

                          ext2_ino_t ino_file)

{

    int retval = 0;

    ext2_file_t file;

    /* Copying details. */

    FILE *fp;

    char buf[BUFSIZE];

    unsigned int got;

    size_t written;

    /* Open the file in the source directory. */

    if (ext2fs_file_open(fs, ino_file, 0, &file))

        return 1;

    /* Open a file in the target directory. */

    if (target_is_file)

        fp = fopen(target, "w");

    else

        fp = open_file_in_dir(target, path_basename(filename), "w");

    /* Copy the file content. */

    if (fp != NULL)

    {

        do

        {

            if (ext2fs_file_read(file, buf, BUFSIZE, &got))

            {

                retval = 1;

                goto close_files;

            }

            while (got)

            {

                written = fwrite(buf, sizeof(char), got, fp);

                got -= written;

            }

        } while (got);

    }

close_files:

    fclose(fp);

    ext2fs_file_close(file);

    return retval;

}

/* Make a new directory in the external environment. */

static int _make_directory(const char *target, const char *basename,

                           ext2_filsys fs, ext2_ino_t ino)

{

    errcode_t retval;

    struct ext2_inode inode;

    char target_path[strlen(target) + strlen(basename) + 2];

    sprintf(target_path, "%s/%s", target, basename);

    retval = ext2fs_read_inode(fs, ino, &inode);

    if (retval)

        return retval;

    return mkdir(target_path, inode.i_mode);

}

/* Copy a file from the filesystem into the external environment. */

static int _copy_out(ext2_filsys fs, const char *source, const char *target,

                     int target_is_file)

{

    ext2_ino_t ino_source;

    if (image_find_by_path(fs, source, &ino_source))

    {

        fprintf(stderr, "Failed to find file: %s\n", source);

        return 1;

    }

    /* Test whether the filename references a file. */

    if (image_isdir_by_path(fs, source))

    {

        if (_make_directory(target, path_basename(source), fs, ino_source))

        {

            fprintf(stderr, "Failed to make directory: %s/%s\n", target,

                    path_basename(source));

            return 1;

        }

    }

    else if (image_isfile_by_path(fs, source))

    {

        if (_copy_file_out(target, source, target_is_file, fs, ino_source))

        {

            fprintf(stderr, "Failed to read from file: %s\n", source);

            return 1;

        }

    }

    else

    {

        fprintf(stderr, "Object type not supported: %s\n", source);

        return 1;

    }

    /* NOTE: Overwrite/update metadata where appropriate. */

    return 0;

}

/* Copy source files out of the filesystem image into the external environment. */

int copy_out(ext2_filsys fs, int argc, char *argv[])

{

    int i;

    /* Target filename details. */

    char *target = argv[argc - 1];

    int target_is_file;

    /* Locate the target and test whether it is a directory. */

    if (!isdir(target))

    {

        /* Only a new or existing file in an existing directory is permitted. */

        if (isfile(target) || isdir_dirname(target))

            target_is_file = 1;

        else

        {

            fprintf(stderr, "Target is not a directory: %s\n", target);

            return 1;

        }

        /* Only permit a target file when one source file is given. */

        if (argc > 2)

        {

            fprintf(stderr, "Target can only be a file when copying a single file: %s\n", target);

            return 1;

        }

    }

    else

        target_is_file = 0;

    /* Copy each source file to the target directory. */

    for (i = 0; i < argc - 1; i++)

        if (_copy_out(fs, argv[i], target, target_is_file))

            return 1;

    return 0;

}

/* vim: tabstop=4 expandtab shiftwidth=4

*/