#!/bin/bash
######################################################################
#
#   tcar_getPathComponent.sh -- This function standardizes the way
#   directory structures are organized inside the working copy of
#   CentOS Artwork Repository. You can use this function to retrieve
#   information from paths (e.g., releases, architectures and theme
#   artistic motifs) or the patterns used to build the paths.
#
#   Written by: 
#   * Alain Reguera Delgado <al@centos.org.cu>, 2009-2013
#     Key fingerprint = D67D 0F82 4CBD 90BC 6421  DF28 7CCE 757C 17CA 3951
#
# Copyright (C) 2009-2013 The CentOS Project
#
# 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.
#
######################################################################

function tcar_getPathComponent {

    # Define short options.
    local ARGSS=''

    # Define long options.
    local ARGSL='release,release-major,release-minor,release-pattern,architecture,architecture-pattern,motif,motif-name,motif-release,motif-pattern,repo-dir'

    # Define release pattern.
    local RELEASE="(([[:digit:]]+)(\.([[:digit:]]+))?)"

    # Define architecture pattern. Make it match the architectures the
    # CentOS distribution is able to be installed on.
    local ARCHITECTURE="(i386|x86_64)"

    # Define regular expression pattern that match the theme artistic
    # motif component inside the path strings.
    local THEME_MOTIF="Identity/Images/Themes/(([[:alnum:]]+)/(${RELEASE}))"

    # Initialize arguments with an empty value and set it as local
    # variable to this function scope. Doing this is very important to
    # avoid any clash with higher execution environments.
    local TCAR_ARGUMENTS=''

    # Process all arguments currently available in this function
    # environment. If either ARGSS or ARGSL local variables have been
    # defined, argument processing goes through getopt for validation.
    tcar_setArguments "${@}"

    # Redefine positional parameters using TCAR_ARGUMENTS variable.
    eval set -- "${TCAR_ARGUMENTS}"

    # Define location we want to apply verifications to.
    local LOCATION=$(echo ${@} | sed -r 's!^.*--[[:space:]](.+)$!\1!')

    # Look for options passed through positional parameters.
    while true;do

        case "${1}" in

            --release )
                echo "${LOCATION}" | egrep "${RELEASE}" | sed -r "s!.*/${RELEASE}/.*!\1!"
                shift 1
                break
                ;;

            --release-major )
                echo "${LOCATION}" | egrep "${RELEASE}" | sed -r "s!.*/${RELEASE}/.*!\2!"
                shift 1
                break
                ;;

            --release-minor )
                echo "${LOCATION}" | egrep "${RELEASE}" | sed -r "s!.*/${RELEASE}/.*!\4!"
                shift 1
                break
                ;;

            --release-pattern )
                echo "${RELEASE}"
                shift 1
                break
                ;;

            --architecture )
                echo "${LOCATION}" | egrep "${ARCHITECTURE}" | sed -r "s!${ARCHITECTURE}!\1!"
                shift 1
                break
                ;;

            --architecture-pattern )
                echo "${ARCHITECTURE}"
                shift 1
                break
                ;;

            --motif )
                echo "${LOCATION}" | egrep "${THEME_MOTIF}" | sed -r "s!.*${THEME_MOTIF}.*!\1!"
                shift 1
                break
                ;;

            --motif-name )
                echo "${LOCATION}" | egrep "${THEME_MOTIF}" | sed -r "s!.*${THEME_MOTIF}.*!\2!"
                shift 1
                break
                ;;

            --motif-release )
                echo "${LOCATION}" | egrep "${THEME_MOTIF}" | sed -r "s!.*${THEME_MOTIF}.*!\3!"
                shift 1
                break
                ;;

            --motif-pattern )
                echo "${THEME_MOTIF}"
                shift 1
                break
                ;;

            --repo-dir )
                echo "${LOCATION}" | sed "s,${TCAR_USER_WRKDIR}/,,"
                shift 1
                break
                ;;

        esac

    done

}