#!/usr/bin/env python3

# Copyright (C) 2018-2021  Chris Lalancette <clalancette@gmail.com>

# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation;
# version 2.1 of the License.

# This library 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
# Lesser General Public License for more details.

# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

"""
The main code for the pycdlib-extract-files tool, which can extract all or a
subset of files from an ISO.
"""

import argparse
import collections
import os
import sys

import pycdlib


def parse_arguments():
    """
    A function to parse all of the arguments passed to the executable.

    Parameters:
     None.
    Returns:
     An ArgumentParser object with the parsed command-line arguments.
    """
    parser = argparse.ArgumentParser()
    parser.add_argument('-path-type', help='Which path type to use for extraction', action='store', choices=['auto', 'iso', 'joliet', 'rockridge', 'udf'], default='auto')
    parser.add_argument('-start-path', help='Path on ISO to start extraction from', action='store', default='/')
    parser.add_argument('-extract-to', help='Path to extract ISO contents to', action='store', default='.')
    parser.add_argument('iso', help='ISO to open', action='store')
    return parser.parse_args()


def main():
    """
    The main function for this executable that does the work of extracting
    files from an ISO given the parameters specified by the user.
    """
    args = parse_arguments()

    iso = pycdlib.PyCdlib()
    print('Opening %s' % (args.iso))
    iso.open(args.iso)

    if args.path_type == 'auto':
        if iso.has_udf():
            pathname = 'udf_path'
        elif iso.has_rock_ridge():
            pathname = 'rr_path'
        elif iso.has_joliet():
            pathname = 'joliet_path'
        else:
            pathname = 'iso_path'
    elif args.path_type == 'rockridge':
        if not iso.has_rock_ridge():
            print('Can only extract Rock Ridge paths from a Rock Ridge ISO')
            return 1
        pathname = 'rr_path'
    elif args.path_type == 'joliet':
        if not iso.has_joliet():
            print('Can only extract Joliet paths from a Joliet ISO')
            return 2
        pathname = 'joliet_path'
    elif args.path_type == 'udf':
        if not iso.has_udf():
            print('Can only extract UDF paths from a UDF ISO')
            return 3
        pathname = 'udf_path'
    else:
        pathname = 'iso_path'

    print("Using path type of '%s'" % (pathname))

    root_entry = iso.get_record(**{pathname: args.start_path})

    dirs = collections.deque([root_entry])
    while dirs:
        dir_record = dirs.popleft()
        ident_to_here = iso.full_path_from_dirrecord(dir_record,
                                                     rockridge=pathname == 'rr_path')
        relname = ident_to_here[len(args.start_path):]
        if relname and relname[0] == '/':
            relname = relname[1:]
        print(relname)
        if dir_record.is_dir():
            if relname != '':
                os.makedirs(os.path.join(args.extract_to, relname))
            child_lister = iso.list_children(**{pathname: ident_to_here})

            for child in child_lister:
                if child is None or child.is_dot() or child.is_dotdot():
                    continue
                dirs.append(child)
        else:
            if dir_record.is_symlink():
                fullpath = os.path.join(args.extract_to, relname)
                local_dir = os.path.dirname(fullpath)
                local_link_name = os.path.basename(fullpath)
                old_dir = os.getcwd()
                os.chdir(local_dir)
                os.symlink(dir_record.rock_ridge.symlink_path(), local_link_name)
                os.chdir(old_dir)
            else:
                iso.get_file_from_iso(os.path.join(args.extract_to, relname), **{pathname: ident_to_here})

    iso.close()
    return 0


if __name__ == '__main__':
    sys.exit(main())