#! /data/shared/fli4l/.fbr/fbr-4.0-trunk-x86_64/buildroot/output/host/bin/python
"""
UC1541 Virtual filesystem

Author: Roman 'gryf' Dobosz <gryf73@gmail.com>
Date: 2014-01-04
Version: 2.8
Licence: BSD
source: https://bitbucket.org/gryf/uc1541
mirror: https://github.com/gryf/uc1541
"""

import sys
import re
import os
import gzip
from subprocess import Popen, PIPE

if os.getenv('UC1541_DEBUG'):
    import logging
    LOG = logging.getLogger('UC1541')
    LOG.setLevel(logging.DEBUG)
    FILE_HANDLER = logging.FileHandler("/tmp/uc1541.log")
    FILE_FORMATTER = logging.Formatter("%(asctime)s %(levelname)-8s "
                                       "%(lineno)s %(funcName)s - %(message)s")
    FILE_HANDLER.setFormatter(FILE_FORMATTER)
    FILE_HANDLER.setLevel(logging.DEBUG)
    LOG.addHandler(FILE_HANDLER)
else:
    class LOG(object):
        """
        Dummy logger object. Does nothing.
        """
        @classmethod
        def debug(*args, **kwargs):
            pass

        @classmethod
        def info(*args, **kwargs):
            pass

        @classmethod
        def warning(*args, **kwargs):
            pass

        @classmethod
        def error(*args, **kwargs):
            pass

        @classmethod
        def critical(*args, **kwargs):
            pass


class D64(object):
    """
    Implement d64 directory reader
    """
    CHAR_MAP = {32: ' ', 33: '!', 34: '"', 35: '#', 37: '%', 38: '&', 39: "'",
                40: '(', 41: ')', 42: '*', 43: '+', 44: ',', 45: '-', 46: '.',
                47: '/', 48: '0', 49: '1', 50: '2', 51: '3', 52: '4', 53: '5',
                54: '6', 55: '7', 56: '8', 57: '9', 59: ';', 60: '<', 61: '=',
                62: '>', 63: '?', 64: '@', 65: 'a', 66: 'b', 67: 'c', 68: 'd',
                69: 'e', 70: 'f', 71: 'g', 72: 'h', 73: 'i', 74: 'j', 75: 'k',
                76: 'l', 77: 'm', 78: 'n', 79: 'o', 80: 'p', 81: 'q', 82: 'r',
                83: 's', 84: 't', 85: 'u', 86: 'v', 87: 'w', 88: 'x', 89: 'y',
                90: 'z', 91: '[', 93: ']', 97: 'A', 98: 'B', 99: 'C',
                100: 'D', 101: 'E', 102: 'F', 103: 'G', 104: 'H', 105: 'I',
                106: 'J', 107: 'K', 108: 'L', 109: 'M', 110: 'N', 111: 'O',
                112: 'P', 113: 'Q', 114: 'R', 115: 'S', 116: 'T', 117: 'U',
                118: 'V', 119: 'W', 120: 'X', 121: 'Y', 122: 'Z', 193: 'A',
                194: 'B', 195: 'C', 196: 'D', 197: 'E', 198: 'F', 199: 'G',
                200: 'H', 201: 'I', 202: 'J', 203: 'K', 204: 'L', 205: 'M',
                206: 'N', 207: 'O', 208: 'P', 209: 'Q', 210: 'R', 211: 'S',
                212: 'T', 213: 'U', 214: 'V', 215: 'W', 216: 'X', 217: 'Y',
                218: 'Z'}

    FILE_TYPES = {0b000: 'del',
                  0b001: 'seq',
                  0b010: 'prg',
                  0b011: 'usr',
                  0b100: 'rel'}

    def __init__(self, dimage):
        """
        Init
        """
        LOG.debug('image: %s', dimage)
        self.raw = None
        self.current_sector_data = None
        self.next_sector = 0
        self.next_track = None
        self._dir_contents = []
        self._already_done = []

        self._get_raw(dimage)

    def _get_raw(self, dimage):
        """Try to get contents of the D64 image either it's gzip compressed or
        not."""
        fobj = gzip.open(dimage)
        # Although the common approach with gzipped files is to check the
        # magic number, in this case there is no guarantee that first track
        # does not contain exactly the same byte sequence as the magic number.
        # So the only way left is to actually try to uncompress the file.
        try:
            self.raw = fobj.read()
        except IOError:
            fobj.close()
            fobj = open(dimage)
            self.raw = fobj.read()
            fobj.close()

    def _map_filename(self, string):
        """
        Transcode filename to ASCII compatible. Replace not supported
        characters with jokers.
        """

        filename = list()

        for chr_ in string:
            if ord(chr_) == 160:  # shift+space character; $a0
                break

            character = D64.CHAR_MAP.get(ord(chr_), '?')
            filename.append(character)

        # special cases
        if filename[0] == "-":
            filename[0] = "?"

        LOG.debug("string: ``%s'' mapped to: ``%s''", string,
                  "".join(filename))
        return "".join(filename)

    def _go_to_next_sector(self):
        """
        Fetch (if exist) next sector from a directory chain
        Return False if the chain ends, True otherwise
        """

        # Well, self.next_sector _should_ have value $FF, but apparently there
        # are the cases where it is not, therefore checking for that will not
        # be performed and value of $00 on the next track will end the
        # directory
        if self.next_track == 0:
            LOG.debug("End of directory")
            return False

        if self.next_track is None:
            LOG.debug("Going to the track: 18,1")
            offset = self._get_d64_offset(18, 1)
        else:
            offset = self._get_d64_offset(self.next_track, self.next_sector)
            LOG.debug("Going to the track: %s,%s", self.next_track,
                      self.next_sector)

        self.current_sector_data = self.raw[offset:offset + 256]

        # Guard for reading data out of bound - that happened for discs which
        # store only raw data, even on 18 track
        if not self.current_sector_data:
            return False

        self.next_track = ord(self.current_sector_data[0])
        self.next_sector = ord(self.current_sector_data[1])

        if (self.next_track, self.next_sector) in self._already_done:
            # Just a failsafe. Endless loop is not what is expected.
            LOG.debug("Loop in track/sector pointer at %d,%d",
                      self.next_track, self.next_sector)
            self._already_done = []
            return False

        self._already_done.append((self.next_track, self.next_sector))
        LOG.debug("Next track: %s,%s", self.next_track, self.next_sector)
        return True

    def _get_ftype(self, num):
        """
        Get filetype as a string
        """
        return D64.FILE_TYPES.get(int("%d%d%d" % (num & 4 and 1,
                                                  num & 2 and 1,
                                                  num & 1), 2), '???')

    def _get_d64_offset(self, track, sector):
        """
        Return offset (in bytes) for specified track and sector.
        """

        offset = 0
        truncate_track = 0

        if track > 17:
            offset = 17 * 21 * 256
            truncate_track = 17

        if track > 24:
            offset += 6 * 19 * 256
            truncate_track = 24

        if track > 30:
            offset += 5 * 18 * 256
            truncate_track = 30

        track = track - truncate_track
        offset += track * sector * 256

        return offset

    def _harvest_entries(self):
        """
        Traverse through sectors and store entries in _dir_contents
        """
        sector = self.current_sector_data
        for dummy in range(8):
            entry = sector[:32]
            ftype = ord(entry[2])

            if ftype == 0:  # deleted
                sector = sector[32:]
                continue

            type_verbose = self._get_ftype(ftype)

            protect = ord(entry[2]) & 64 and "<" or " "
            fname = entry[5:21]
            if ftype == 'rel':
                size = ord(entry[23])
            else:
                size = ord(entry[30]) + ord(entry[31]) * 226

            self._dir_contents.append({'fname': self._map_filename(fname),
                                       'ftype': type_verbose,
                                       'size': size,
                                       'protect': protect})
            sector = sector[32:]

    def list_dir(self):
        """
        Return directory list as list of dict with keys:
            fname, ftype, protect and size
        """
        while self._go_to_next_sector():
            self._harvest_entries()

        return self._dir_contents


class Uc1541(object):
    """
    Class for interact with c1541 program and MC
    """
    PRG = re.compile(r'(\d+)\s+"([^"]*)".+?\s(del|prg|rel|seq|usr)([\s<])')

    def __init__(self, archname):
        self.arch = archname
        self.out = ''
        self.err = ''
        self._verbose = os.getenv("UC1541_VERBOSE", False)
        self._hide_del = os.getenv("UC1541_HIDE_DEL", False)

        self.pyd64 = D64(archname).list_dir()
        self.file_map = {}
        self.directory = []

    def list(self):
        """
        Output list contents of D64 image.
        Convert filenames to be Unix filesystem friendly
        Add suffix to show user what kind of file do he dealing with.
        """
        LOG.info("List contents of %s", self.arch)
        directory = self._get_dir()

        # If there is an error reading directory, show the reason to the user
        if self.out.startswith("Error"):
            sys.stderr.write(self.out.split("\n")[0] + "\n")
            return 2

        for entry in directory:
            sys.stdout.write("%(perms)s   1 %(uid)-8d %(gid)-8d %(size)8d "
                             "Jan 01 1980 %(display_name)s\n" % entry)
        return 0

    def rm(self, dst):
        """
        Remove file from D64 image
        """
        LOG.info("Removing file %s", dst)
        dst = self._get_masked_fname(dst)

        if not self._call_command('delete', dst=dst):
            return self._show_error()

        # During removing, a message containing ERRORCODE is sent to stdout
        # instead of stderr. Everything other than 'ERRORCODE 1' (which means:
        # 'everything fine') is actually a failure. In case of verbose error
        # output it is needed to copy self.out to self.err.
        if '\nERRORCODE 1\n' not in self.out:
            self.err = self.out
            return self._show_error()

        return 0

    def copyin(self, dst, src):
        """
        Copy file to the D64 image. Destination filename has to be corrected.
        """
        LOG.info("Copy into D64 %s as %s", src, dst)
        dst = self._correct_fname(dst)

        if not self._call_command('write', src=src, dst=dst):
            return self._show_error()

        return 0

    def copyout(self, src, dst):
        """
        Copy file form the D64 image. Source filename has to be corrected,
        since it's representation differ from the real one inside D64 image.
        """
        LOG.info("Copy form D64 %s as %s", src, dst)
        if not src.endswith(".prg"):
            return "cannot read"

        src = self._get_masked_fname(src)

        if not self._call_command('read', src=src, dst=dst):
            return self._show_error()

        return 0

    def mkdir(self, dirname):
        """Not supported"""
        self.err = "D64 format doesn't support directories"
        return self._show_error()

    def run(self, fname):
        """Not supported"""
        self.err = "Not supported, unless you are using MC on real C64 ;)"
        return self._show_error()

    def _correct_fname(self, fname):
        """
        Return filename with mapped characters, without .prg extension.
        Characters like $, *, + in filenames are perfectly legal, but c1541
        program seem to have issues with it while writing, so it will also be
        replaced.
        """
        char_map = {'|': "/",
                    "\\": "/",
                    "~": " ",
                    "$": "?",
                    "*": "?"}

        if fname.lower().endswith(".prg"):
            fname = fname[:-4]

        new_fname = []
        for char in fname:
            trans = char_map.get(char)
            new_fname.append(trans if trans else char)

        return "".join(new_fname)

    def _get_masked_fname(self, fname):
        """
        Return masked filename with '?' jokers instead of non ASCII
        characters, useful for copying or deleting files with c1541. In case
        of several files with same name exists in directory, only first one
        will be operative (first as appeared in directory).

        Warning! If there are two different names but the only difference is in
        non-ASCII characters (some PET ASCII or control characters) there is
        a risk that one can remove both files.
        """
        directory = self._get_dir()

        for entry in directory:
            if entry['display_name'] == fname:
                return entry['pattern_name']

    def _get_dir(self):
        """
        Retrieve directory via c1541 program
        """
        directory = []

        uid = os.getuid()
        gid = os.getgid()

        if not self._call_command('list'):
            return self._show_error()

        idx = 0
        for line in self.out.split("\n"):
            if Uc1541.PRG.match(line):
                blocks, fname, ext, rw = Uc1541.PRG.match(line).groups()

                if ext == 'del' and self._hide_del:
                    continue

                display_name = ".".join([fname, ext])
                pattern_name = self.pyd64[idx]['fname']

                if '/' in display_name:
                    display_name = display_name.replace('/', '|')

                # workaround for space and dash at the beggining of the
                # filename
                char_map = {' ': '~',
                            '-': '_'}
                display_name = "".join([char_map.get(display_name[0],
                                                     display_name[0]),
                                        display_name[1:]])

                if ext == 'del':
                    perms = "----------"
                else:
                    perms = "-r%s-r--r--" % (rw.strip() and "-" or "w")

                directory.append({'pattern_name': pattern_name,
                                  'display_name': display_name,
                                  'uid': uid,
                                  'gid': gid,
                                  'size': int(blocks) * 256,
                                  'perms': perms})
                idx += 1
        return directory

    def _show_error(self):
        """
        Pass out error output from c1541 execution
        """
        if self._verbose:
            return self.err
        else:
            return 1

    def _call_command(self, cmd, src=None, dst=None):
        """
        Return status of the provided command, which can be one of:
            write
            read
            delete
            dir/list
        """
        command = ['c1541', '-attach', self.arch, '-%s' % cmd]
        if src:
            command.append(src)
        if dst:
            command.append(dst)

        self.out, self.err = Popen(command, stdout=PIPE,
                                   stderr=PIPE).communicate()
        return not self.err


CALL_MAP = {'list': lambda a: Uc1541(a.arch).list(),
            'copyin': lambda a: Uc1541(a.arch).copyin(a.src, a.dst),
            'copyout': lambda a: Uc1541(a.arch).copyout(a.src, a.dst),
            'mkdir': lambda a: Uc1541(a.arch).mkdir(a.dst),
            'rm': lambda a: Uc1541(a.arch).rm(a.dst),
            'run': lambda a: Uc1541(a.arch).run(a.dst)}


def parse_args():
    """Use ArgumentParser to check for script arguments and execute."""
    parser = ArgumentParser()
    subparsers = parser.add_subparsers(help='supported commands')
    parser_list = subparsers.add_parser('list', help="List contents of D64 "
                                        "image")
    parser_copyin = subparsers.add_parser('copyin', help="Copy file into D64 "
                                          "image")
    parser_copyout = subparsers.add_parser('copyout', help="Copy file out of "
                                           "D64 image")
    parser_rm = subparsers.add_parser('rm', help="Delete file from D64 image")
    parser_mkdir = subparsers.add_parser('mkdir', help="Create directory in "
                                         "archive")
    parser_run = subparsers.add_parser('run', help="Execute archived file")

    parser_list.add_argument('arch', help="D64 Image filename")
    parser_list.set_defaults(func=CALL_MAP['list'])

    parser_copyin.add_argument('arch', help="D64 Image filename")
    parser_copyin.add_argument('src', help="Source filename")
    parser_copyin.add_argument('dst', help="Destination filename (to be "
                               "written into D64 image)")
    parser_copyin.set_defaults(func=CALL_MAP['copyin'])

    parser_copyout.add_argument('arch', help="D64 Image filename")
    parser_copyout.add_argument('src', help="Source filename (to be read from"
                                " D64 image")
    parser_copyout.add_argument('dst', help="Destination filename")
    parser_copyout.set_defaults(func=CALL_MAP['copyout'])

    parser_rm.add_argument('arch', help="D64 Image filename")
    parser_rm.add_argument('dst', help="File inside D64 image to be deleted")
    parser_rm.set_defaults(func=CALL_MAP['rm'])

    parser_mkdir.add_argument('arch', help="archive filename")
    parser_mkdir.add_argument('dst', help="Directory name inside archive to "
                              "be created")
    parser_mkdir.set_defaults(func=CALL_MAP['mkdir'])

    parser_run.add_argument('arch', help="archive filename")
    parser_run.add_argument('dst', help="File to be executed")
    parser_run.set_defaults(func=CALL_MAP['run'])

    args = parser.parse_args()
    return args.func(args)


def no_parse():
    """Failsafe argument "parsing". Note, that it blindly takes positional
    arguments without checking them. In case of wrong arguments it will
    silently exit"""
    try:
        if sys.argv[1] not in ('list', 'copyin', 'copyout', 'rm', 'mkdir',
                               "run"):
            sys.exit(2)
    except IndexError:
        sys.exit(2)

    class Arg(object):
        """Mimic argparse object"""
        dst = None
        src = None
        arch = None

    arg = Arg()

    try:
        arg.arch = sys.argv[2]
        if sys.argv[1] in ('copyin', 'copyout'):
            arg.src = sys.argv[3]
            arg.dst = sys.argv[4]
        elif sys.argv[1] in ('rm', 'run', 'mkdir'):
            arg.dst = sys.argv[3]
    except IndexError:
        sys.exit(2)

    return CALL_MAP[sys.argv[1]](arg)

if __name__ == "__main__":
    LOG.debug("Script params: %s", str(sys.argv))
    try:
        from argparse import ArgumentParser
        PARSE_FUNC = parse_args
    except ImportError:
        PARSE_FUNC = no_parse

    sys.exit(PARSE_FUNC())