/stdhome

# command.py

#

# Copyright (C) 2014 Tim Marston <tim@edm.am>

#

# This file is part of stdhome (hereafter referred to as "this program").

# See http://ed.am/dev/stdhome for more information.

#

# 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 3 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, see <http://www.gnu.org/licenses/>.

import os

import stdhome.the as the

from stdhome.walker.walker import Walker

class Command:

	"""Base class for command classes.

	"""

	@staticmethod

	def resolve_homedir_file( file ):

		"""Given a filename, which could be absolute or relative to the CWD, this

		returns a pair of 'resolved' filenames: the name of the file relative to

		the homedir and the full, absolute filename.  Neither of the returned

		filenames are guaranteed nor required to exist.  But the supplied

		filename will cause an error if it is not iteself or when resolved (if

		it is a symlink) under the homedirectory.

		"""

		home_dir_prefix = os.path.realpath( the.full_home_dir ) + os.sep

		# obtain absolute filename

		abs_file = os.path.abspath( file )

		# if absolute filename is not under home directory, attempt to

		# resolve symlinks

		if abs_file[ : len( home_dir_prefix ) ] != home_dir_prefix:

			parts = os.path.split( file )

			if os.path.exists( parts[ 0 ] ):

				abs_file = os.path.join(

					os.path.realpath( parts[ 0 ] ), parts[ 1 ] )

		# absolute file must now be under home directory and exist

		if abs_file[ : len( home_dir_prefix ) ] != home_dir_prefix:

			raise the.program.FatalError(

					'not under home directory: %s' % file )

		# relative file

		rel_file = abs_file[ len( home_dir_prefix ) : ]

		return ( rel_file, abs_file )

	@staticmethod

	def expand_files( files, recurse = True ):

		"""Returns a unique, sorted list of relative files, calculated from the list

		provided, which is made up from individual files and directories

		relative to the CWD (and which must be contained within the home

		directory, although the files need not actually exist in the home

		directory).  All files must exist in the repository.  Directories are

		recursed in to as required.

		"""

		ret = set()

		# iterate through file list

		for file in files:

			( rel_file, abs_file ) = self.resolve_homedir_file( file )

			# check that file exists in repository

			repo_file = os.path.join( the.repo.full_dir, rel_file )

			if not os.path.lexists( repo_file ):

				raise the.program.FatalError(

					'not managed by stdhome: %s' % rel_file )

			# append the file or directory tree

			ret.update( Walker.generate_walk_list(

				the.repo.full_dir, rel_file, recurse ) )

		return sorted( set ( ret ) )