#
# ElementTree
# $Id: ElementInclude.py 3375 2008年02月13日 08:05:08Z fredrik $
#
# limited xinclude support for element trees
#
# history:
# 2003年08月15日 fl created
# 2003年11月14日 fl fixed default loader
#
# Copyright (c) 2003-2004 by Fredrik Lundh. All rights reserved.
#
# fredrik@pythonware.com
# http://www.pythonware.com
#
# --------------------------------------------------------------------
# The ElementTree toolkit is
#
# Copyright (c) 1999-2008 by Fredrik Lundh
#
# By obtaining, using, and/or copying this software and/or its
# associated documentation, you agree that you have read, understood,
# and will comply with the following terms and conditions:
#
# Permission to use, copy, modify, and distribute this software and
# its associated documentation for any purpose and without fee is
# hereby granted, provided that the above copyright notice appears in
# all copies, and that both that copyright notice and this permission
# notice appear in supporting documentation, and that the name of
# Secret Labs AB or the author not be used in advertising or publicity
# pertaining to distribution of the software without specific, written
# prior permission.
#
# SECRET LABS AB AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
# TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANT-
# ABILITY AND FITNESS. IN NO EVENT SHALL SECRET LABS AB OR THE AUTHOR
# BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY
# DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
# WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
# ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
# OF THIS SOFTWARE.
# --------------------------------------------------------------------

# Licensed to PSF under a Contributor Agreement.
# See http://www.python.org/psf/license for licensing details.

##
# Limited XInclude support for the ElementTree package.
##

import copy
from . import ElementTree

XINCLUDE = "{http://www.w3.org/2001/XInclude}"

XINCLUDE_INCLUDE = XINCLUDE + "include"
XINCLUDE_FALLBACK = XINCLUDE + "fallback"

##
# Fatal include error.

class FatalIncludeError(SyntaxError):
 pass

##
# Default loader. This loader reads an included resource from disk.
#
# @param href Resource reference.
# @param parse Parse mode. Either "xml" or "text".
# @param encoding Optional text encoding (UTF-8 by default for "text").
# @return The expanded resource. If the parse mode is "xml", this
# is an ElementTree instance. If the parse mode is "text", this
# is a Unicode string. If the loader fails, it can return None
# or raise an OSError exception.
# @throws OSError If the loader fails to load the resource.

def default_loader(href, parse, encoding=None):
 if parse == "xml":
 with open(href, 'rb') as file:
 data = ElementTree.parse(file).getroot()
 else:
 if not encoding:
 encoding = 'UTF-8'
 with open(href, 'r', encoding=encoding) as file:
 data = file.read()
 return data

##
# Expand XInclude directives.
#
# @param elem Root element.
# @param loader Optional resource loader. If omitted, it defaults
# to {@link default_loader}. If given, it should be a callable
# that implements the same interface as <b>default_loader</b>.
# @throws FatalIncludeError If the function fails to include a given
# resource, or if the tree contains malformed XInclude elements.
# @throws OSError If the function fails to load a given resource.

def include(elem, loader=None):
 if loader is None:
 loader = default_loader
 # look for xinclude elements
 i = 0
 while i < len(elem):
 e = elem[i]
 if e.tag == XINCLUDE_INCLUDE:
 # process xinclude directive
 href = e.get("href")
 parse = e.get("parse", "xml")
 if parse == "xml":
 node = loader(href, parse)
 if node is None:
 raise FatalIncludeError(
 "cannot load %r as %r" % (href, parse)
 )
 node = copy.copy(node)
 if e.tail:
 node.tail = (node.tail or "") + e.tail
 elem[i] = node
 elif parse == "text":
 text = loader(href, parse, e.get("encoding"))
 if text is None:
 raise FatalIncludeError(
 "cannot load %r as %r" % (href, parse)
 )
 if i:
 node = elem[i-1]
 node.tail = (node.tail or "") + text + (e.tail or "")
 else:
 elem.text = (elem.text or "") + text + (e.tail or "")
 del elem[i]
 continue
 else:
 raise FatalIncludeError(
 "unknown parse type in xi:include tag (%r)" % parse
 )
 elif e.tag == XINCLUDE_FALLBACK:
 raise FatalIncludeError(
 "xi:fallback tag must be child of xi:include (%r)" % e.tag
 )
 else:
 include(e, loader)
 i = i + 1