#!/bin/bash

#

# texinfo_deleteCrossReferences.sh -- This function looks inside

# texinfo source files, from section level on, and removes all cross

# referece definitions related to a documentation entry. Use this

# function in coordination with texinfo_deleteEntry function, in order

# to keep cross reference information, inside the documentation

# manual, syncronized.

#

# 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 texinfo_deleteCrossReferences {

    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=$(${FLAG_BACKEND}_getNode "$MANUAL_ENTRY")

    # Define regular expression patterns for texinfo cross reference

    # commands.

    PATTERN[0]="@(pxref|xref|ref)\{(${NODE})\}"

    PATTERN[1]="^(\* ${NODE}:(.*)?:(.*)?)$"

    # Define replacement string for missing entries. It is convenient

    # to keep missing entries in documentation for documentation team

    # to know. Removing the missing cross reference may intorudce

    # confussion. Imagine that! you are spending lots of hours in an

    # article and suddenly one of your cross refereces disappears with

    # no visible reason, with the next working copy update you

    # perform. That's frustrating. Instead, when centos-art.sh script

    # finds a missing cross reference it removes the link and remark

    # the issue for you to act on it.

    REPLACE[0]='--- @strong{'`gettext "Removed"`'}(\1:\2) ---'

    REPLACE[1]='@comment --- '`gettext "Removed"`'(\1) ---'

    # Define list of entries to process.

    local MANUAL_ENTRIES=$(cli_getFilesList ${MANUAL_BASEDIR} --pattern=".*\.${FLAG_BACKEND}")

    # 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 much the replacement command.

    sed -r -i "s!\<${PATTERN[1]}\>!${REPLACE[1]}!" ${MANUAL_ENTRIES}

}