/stdhome

# copy_base.py

#

# Copyright (C) 2013 to 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 filecmp, os, shutil

from walker import Walker

import stdhome.the as the

class CopyBaseWalker( Walker ):

	"""The copy-base walker traverses a walklist ruthlessly mirroring src to dst.

	It is designed to be the base class of both the copy-in and copy-out walker,

	both of which are specialisations of this purpose.  See them for more

	information.  The print_op method, derived in those classes, takes, in

	addition to the relative filename, a source file type, an operation, and a

	sestination file type.  Valid file types are f (file), l (symlink), d

	(directory) and _ (non-existant).  Valid operations are * (modify), = (skip:

	same), @ (skip: symlink substitute) and # (skip: ignored).

	"""

	def __init__( self ):

		self.check_src_symlinks = False

		self.check_dst_symlinks = False

		self.check_dst_ignores = False

	def process( self, rel_file, src, dst ):

		# ignore?

		if self.check_dst_ignores and the.config.ignores.matches( rel_file ):

			self.print_op( rel_file, src.type, '#', dst.type )

			return True

		# src entity is directory

		if src.type == 'd':

			# if dst entity doesn't exist, create directory (no need to recurse,

			# since we're copying the whole directory)

			if dst.type == '_':

				self.print_op( rel_file, 'd', '*', '_' )

				shutil.copytree( src.file, dst.file, True )

			# if dst entity is a directory, copy permissions, as required (and

			# recurse)

			elif dst.type == 'd':

				# TODO: should check permission and only do as necessary

				self.print_op( rel_file, 'd', '*', 'd' )

				shutil.copystat( src.file, dst.file )

				return True

			# if dst entity is a symlink to a directory, and this is an

			# acceptable substitute, just recurse

			elif self.check_dst_symlinks and dst.link_type == 'd' and \

					the.config.symlinks.matches( rel_file ):

				self.print_op( rel_file, 'd', '@', 'd' )

				return True

			# if dst entity is a file or symlink in home dir, replace it with

			# directory (no need to recurse, since we're copying the whole

			# directory)

			elif dst.type == 'f' or dst.type == 'l':

				self.print_op( rel_file, 'd', '*', dst.type )

				os.unlink( dst.file )

				shutil.copytree( src.file, dst.file, True )

			else:

				raise NotImplementedError()

		# src entity is file

		elif src.type == 'f':

			# if dst entity doesn't exist, copy file

			if dst.type == '_':

				self.print_op( rel_file, 'f', '*', '_' )

				shutil.copy( src.file, dst.file )

				shutil.copystat( src.file, dst.file )

			# if dst entity is a file, replace it only if it differs

			elif dst.type == 'f':

				if not filecmp.cmp( src.file, dst.file ):

					self.print_op( rel_file, 'f', '*', 'f' )

					os.unlink( dst.file )

					shutil.copy( src.file, dst.file )

					shutil.copystat( src.file, dst.file )

				else:

					self.print_op( rel_file, 'f', '=', 'f' )

			# if dst entity is a directory, replace it with file

			elif dst.type == 'd':

				self.print_op( rel_file, 'f', '*', 'd' )

				shutil.rmtree( dst.file )

				shutil.copy( src.file, dst.file )

				shutil.copystat( src.file, dst.file )

			# if dst entity is a symlink, replace it with file

			elif dst.type == 'l':

				self.print_op( rel_file, 'f', '*', 'l' )

				os.unlink( dst.file )

				shutil.copy( src.file, dst.file )

				shutil.copystat( src.file, dst.file )

			else:

				raise NotImplementedError()

		# src entity is a symlink

		elif src.type == 'l':

			# if dst entity doesn't exist, copy symlink

			if dst.type == '_':

				self.print_op( rel_file, 'l', '*', '_' )

				os.symlink( os.readlink( src.file ), dst.file )

			# if dst entity is a symlink, replace it only if it differs

			elif dst.type == 'l':

				if os.readlink( src.file ) != os.readlink( dst.file ):

					self.print_op( rel_file, 'l', '*', 'l' )

					os.unlink( dst.file )

					os.symlink( os.readlink( src.file ), dst.file )

				else:

					self.print_op( rel_file, 'l', '=', 'l' )

			# if dst entity is a file, replace it with symlink

			elif dst.type == 'f':

				self.print_op( rel_file, 'l', '*', 'f' )

				os.unlink( dst.file )

				os.symlink( os.readlink( src.file ), dst.file )

			# if dst entity is a directory...

			elif dst.type == 'd':

				# if src entity is a symlink to a directory, and this is an

				# acceptable substitute, just recurse

				if self.check_src_symlinks and src.link_type == 'd' and \

						the.config.symlinks.matches( rel_file ):

					self.print_op( rel_file, 'd', '@', 'd' )

					return True

				# else replace it with a symlink

				self.print_op( rel_file, 'l', '*', 'd' )

				shutil.rmtree( dst.file )

				os.symlink( os.readlink( src.file ), dst.file )

			else:

				raise NotImplementedError()

		# src entity is missing

		elif src.type == '_':

			# if dst entity doesn't exist, we're good

			if dst.type == '_':

				pass;

			# if dst entity is a file or symlink, delete it

			elif dst.type == 'f' or dst.type == 'l':

				self.print_op( rel_file, '_', '*', dst.type )

				os.unlink( dst.file )

			# if dst entity is a directory, delete it

			elif dst.type == 'd':

				self.print_op( rel_file, '_', '*', 'd' )

				shutil.rmtree( dst.file )

			else:

				raise NotImplementedError()

		# if we got here, we don't want to recurse...

		return False