#!/bin/bash
#
# help_restoreCrossReferences.sh -- This function looks inside
# texinfo source files, from section level on, and restores any cross
# reference related to a documentation entry. This function is used in
# those cases where documentation entries are created/recreated to
# documentation structure. It is a verification that looks for
# matching documentation entries previously defined as removed by
# help_deleteCrossReferences function. The
# help_restoreCrossReferences function relays in the removed
# message format produced by help_deleteCrossReferences
# function, in order to return them back into the link format. 
#
# Copyright (C) 2009, 2010, 2011 The CentOS Artwork SIG
#
# 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 2 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, write to the Free Software
# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
#
# ----------------------------------------------------------------------
# $Id$
# ----------------------------------------------------------------------

function help_restoreCrossReferences {

    local -a PATTERN
    local -a REPLACE

    # Define documentation entry.
    local MANUAL_ENTRY="$1"

    # Verify documentation entry. If documentation entry is empty,
    # stop script execution with an error message.
    if [[ $MANUAL_ENTRY == '' ]];then
        cli_printMessage "`gettext "The first positional parameter cannot be empty."`" --as-error-line
    fi

    # Build the node string using entry location.
    local NODE=$(${FUNCNAM}_getNode "$MANUAL_ENTRY")

    # Define regular expression patterns to match removed message
    # format produced by message_removeCrossReferences function.
    PATTERN[0]="--- @strong\{`gettext "Removed"`\}\((pxref|xref|ref):(${NODE})\) ---"
    PATTERN[1]="^@comment --- `gettext "Removed"`\((\* ${NODE}:(.*)?:(.*)?)\) ---$"

    # Define replacement string to turn removed message back to cross
    # reference link.
    REPLACE[0]='@\1{\2}'
    REPLACE[1]='\1'

    # Define list of entries to process.
    local MANUAL_ENTRIES=$(cli_getFilesList ${MANUAL_BASEDIR} \
        --pattern=".*\.${MANUAL_EXTENSION}")

    # Update node-related cross references. The node-related cross
    # reference definition, long ones specially, could require more
    # than one line to be set. By default, GNU sed does not matches 
    # newline characters in the pattern space, so we need to make use
    # of `label' feature and the `N' command in order to build a
    # pattern space that includes the newline character in it. Here we
    # use the `a' letter to name the label we use, followed by N
    # command to add a newline to the pattern space, the s command to
    # make the pattern replacement using the `g' flag to make it
    # global and finaly the command `b' to branch label named `a'.
    #
    # Inside the pattern space, the `\<' and `\>' are used to restrict
    # the match pattern to a word boundary. The word boundary
    # restriction applied here is required to avoid undesired
    # replacements when we replace singular words with their plurals.
    # For example, if we need to change the word `Manual' to its
    # plular (i.e., `Manuals'), and no boundary restriction is used in
    # the pattern space to do that, we might end up having words like
    # `Manualsssss'. This is because this sed command might be applied
    # to the same file many times; and each time it is applied a new
    # `Manuals' replaces the previous `Manuals' replacement to form
    # `Manualss', `Manualsss', and so on for each interaction.
    sed -r -i ":a;N;s!\<${PATTERN[0]}\>!${REPLACE[0]}!g;ba" ${MANUAL_ENTRIES}

    # Update menu-related cross references. Menu-related cross
    # references hardly appear in more than one line, so there is no
    # need to complicate the replacement command.
    sed -r -i "s!\<${PATTERN[1]}\>!${REPLACE[1]}!" ${MANUAL_ENTRIES}

}