#To run
#python dl.py k /mnt/k
#

#!/usr/bin/env python

from __future__ import with_statement

import os
import sys
import errno

from fuse import FUSE, FuseOSError, Operations


class Passthrough(Operations):
    mask=""
    def __init__(self, root):
        self.root = root

    # Helpers
    # =======

    def _full_path(self, partial):
	self.mask=""
        if partial.startswith("/"):
            partial = partial[1:]
	if partial.find(':')>0:
		self.mask=partial.split(':')[1]
		partial=partial.split(':')[0]
	else:
		self.mask=None
        path = os.path.join(self.root, partial)


        return path

    # Filesystem methods
    # ==================

    def access(self, path, mode):
        full_path = self._full_path(path)

        if not os.access(full_path, mode):
            raise FuseOSError(errno.EACCES)

    def chmod(self, path, mode):
        full_path = self._full_path(path)
        return os.chmod(full_path, mode)

    def chown(self, path, uid, gid):
        full_path = self._full_path(path)
        return os.chown(full_path, uid, gid)

    def getattr(self, path, fh=None):
        full_path = self._full_path(path)
        st = os.lstat(full_path)
        return dict((key, getattr(st, key)) for key in ('st_atime', 'st_ctime',
                     'st_gid', 'st_mode', 'st_mtime', 'st_nlink', 'st_size', 'st_uid'))

    def readdir(self, path, fh):
        full_path = self._full_path(path)

        dirents = ['.', '..']
        if os.path.isdir(full_path):
            dirents.extend(os.listdir(full_path))
        for r in dirents:
            yield r

    def readlink(self, path):
        pathname = os.readlink(self._full_path(path))
        if pathname.startswith("/"):
            # Path name is absolute, sanitize it.
            return os.path.relpath(pathname, self.root)
        else:
            return pathname

    def mknod(self, path, mode, dev):
        return os.mknod(self._full_path(path), mode, dev)

    def rmdir(self, path):
        full_path = self._full_path(path)
        return os.rmdir(full_path)

    def mkdir(self, path, mode):
        return os.mkdir(self._full_path(path), mode)

    def statfs(self, path):
        full_path = self._full_path(path)
        stv = os.statvfs(full_path)
        return dict((key, getattr(stv, key)) for key in ('f_bavail', 'f_bfree',
            'f_blocks', 'f_bsize', 'f_favail', 'f_ffree', 'f_files', 'f_flag',
            'f_frsize', 'f_namemax'))

    def unlink(self, path):
        return os.unlink(self._full_path(path))

    def symlink(self, name, target):
        return os.symlink(target, self._full_path(name))

    def rename(self, old, new):
        return os.rename(self._full_path(old), self._full_path(new))

    def link(self, target, name):
        return os.link(self._full_path(name), self._full_path(target))

    def utimens(self, path, times=None):
        return os.utime(self._full_path(path), times)

    # File methods
    # ============

    def open(self, path, flags):
	#print("open")
        full_path = self._full_path(path)
        return os.open(full_path, flags)

    def create(self, path, mode, fi=None):
        full_path = self._full_path(path)
        return os.open(full_path, os.O_WRONLY | os.O_CREAT, mode)

    def read(self, path, length, offset, fh):
	#print("read")
        os.lseek(fh, offset, os.SEEK_SET)
	data=os.read(fh, length)
	#print(self.mask)
	m=self.mask
	if m is None:
		return data
	else:
		m=m.split(',')
		if len(m)>=1:
			lines=data.split('\n')
			data_=""
			for l in lines:
				d=l.split(',')
				#print ("line:"+l+str(len(m))+" "+str(len(d)))
				l_=['']*len(m)
				i=0
				for m_ in m:
					i_=int(m_)
					if i_< len(d):
						l_[i]=d[i_]

					i=i+1
				d_=','.join(l_)
				data_=data_+d_+"\n"

        return data_

    #This is for only demo purposes, we need
    def write(self, path, buf, offset, fh):
        os.lseek(fh, offset, os.SEEK_SET)
        return os.write(fh, buf)

    def truncate(self, path, length, fh=None):
        full_path = self._full_path(path)
        with open(full_path, 'r+') as f:
            f.truncate(length)

    def flush(self, path, fh):
        return os.fsync(fh)

    def release(self, path, fh):
        return os.close(fh)

    def fsync(self, path, fdatasync, fh):
        return self.flush(path, fh)


def main(mountpoint, root):
    FUSE(Passthrough(root), mountpoint, nothreads=True, foreground=True)

if __name__ == '__main__':
    main(sys.argv[2], sys.argv[1])