#! /bin/sh
#----------------------------------------------------------------------------
# master-diff-config - master file for config file camparison
#
# Creation:     2003-12-24  ap
# Last Update:  $Id$
#
# Copyright (c) 2001-2011 Ansgar Puester, Ansgar.Puester(at)T-Online(dot).de
#               2012-@@YEAR@@ the eisfair team, team(at)eisfair(dot)org
#
# 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.
#----------------------------------------------------------------------------

#
# The following links have to be created
#  link               type  usage
#  template-diff-bb   bb    Show difference between two backup configurations
#  template-diff-cb   cb    Show difference between current and a backup configuration
#  template-diff-cd   cd    Show difference between current and default configuration
#  template-diff-db   db    Show difference between default and a backup configuration
#

# include eislib
. /var/install/include/eislib

# include function library
. /var/install/bin/config_shlib

# ---------------------------------------------------------------------------
# halt(): debugging procedure
# ---------------------------------------------------------------------------
halt()
{
    echo "+++ halt:"
    read a < /dev/tty
}

# ---------------------------------------------------------------------------
# header_md(): header display
# ---------------------------------------------------------------------------
header_md()
{
    clrhome
    mecho --info "${MD_TITLE}"
    mecho "${MD_SUBTITLE}"
    mecho
}

# ---------------------------------------------------------------------------
# footer(): show footer
# ---------------------------------------------------------------------------
footer()
{
    mecho
    mecho
    anykey
}

# ---------------------------------------------------------------------------
# strip_file(): show footer
#   $1  input file
#   $2  output file
#   Input file should contain a valid eisfair-1 configuration
#   - all leading blanks will be erased
#   - all trailing blanks lines will be erased
#   - remaining blanks will be set to ~
#     this will help to have _one_ varval eg. 'This~is~a~string~with~spaces'
#   - only lines starting with capital lettters will be used
#   - equal sign (=) will be set to space
#   - comments after varvals will be erased
#     \1 contains everything including first '
#     \2 contains everything from this point to '
#     => comment will be gone
#   Result is
#     varname 'value'
#   E.G.
#     SYSLOGD_LOG_COUNT '10'
# ---------------------------------------------------------------------------
strip_file()
{
    in=$1
    out=$2

    cat ${in} |
    sed 's|^[[:blank:]]*||' |
    sed 's|[[:blank:]]*$||' |
    sed 's| |~|g'           |
    grep '^[A-Z]'           |
    sed 's|=| |'            |
    sed "s|^\([^']*'\)\([^']*'\)\(.*\)|\1\2|"> ${out}
    chmod og-rw $out
}

# ---------------------------------------------------------------------------
# echo_x(): show a value with maxumum length max_len
#   $1  line to display
# ---------------------------------------------------------------------------
echo_x()
{
    val="$1                                                                                "
    mecho "${val:0:max_len}\c"
}

# ---------------------------------------------------------------------------
# get_max_len(): calculate max_len
#   $left  variables and values "left" file
#   $right variables and values "right" file
#   calculate maximum length
# E.g.
#   START_NGINX 'yes'
#   NGINX_VAL   '1024'
#   ########### => 10
#   add place for 2 spaces
# ---------------------------------------------------------------------------
get_max_len()
{
    max_len=0
    while read var val
    do
        [ ${#var} -gt $max_len ] && max_len=${#var}
    done < $left
    while read var val
    do
        [ ${#var} -gt $max_len ] && max_len=${#var}
    done < $right
    max_len=$(expr $max_len + 2)
}

# ---------------------------------------------------------------------------
# file_differ(): check if files differ
#   $left  variables and values "left" file
#   $right variables and values "right" file
# ---------------------------------------------------------------------------
file_differ()
{
    # sort files
    sort < $left > $left_sort
    sort < $right > $right_sort
    chmod og-rw $left_sort $right_sort
    # then check difference
    diff $left_sort $right_sort >/dev/null 2>&1
    rc=$?
    return $rc
}

# ---------------------------------------------------------------------------
# clean(): erase all intermediate files
# ---------------------------------------------------------------------------
clean()
{
    rm -f $right
    rm -f $left
    rm -f $right_sort
    rm -f $left_sort
    rm -f $diff_file
    rm -f $both_ucont
    rm -f $both_cont
}

# ---------------------------------------------------------------------------
# set_old(): save varname to o_varname / varval to o_varval
# ---------------------------------------------------------------------------
set_old ()
{
    o_varname=$varname
    o_varval=$varval
}

# ---------------------------------------------------------------------------
# set_new(): save varname to n_varname / varval to n_varval
# ---------------------------------------------------------------------------
set_new ()
{
    n_varname=$varname
    n_varval=$varval
}

# ---------------------------------------------------------------------------
# env_diff(): compare two files containing environment variables
#   $1  variables and values "left" file
#   $2  variables and values "right" file
# ---------------------------------------------------------------------------
env_diff()
{
    # add 'new ' to every line of "left" file
    sed 's/.*/new &/' < $1 > $both_ucont
    # add 'old ' to every line of "right" file
    sed 's/.*/old &/' < $2 >> $both_ucont
    chmod og-rw $both_ucont
    # sort combined file: key 2, that is varname
    sort -k 2,2 < $both_ucont > $both_cont
    chmod og-rw $both_cont

    # indicator for new-line and old-line
    n_val=0
    o_val=0

    # read file
    while read ind varname varval
    do
        # new indicator
        if [ $ind = 'new' ]
        then
            if [ $n_val = 1 ]
            then
                echo "> $n_varname $n_varval"
                set_new
            else
                set_new
                n_val=1
            fi
        fi

        # old indicator
        if [ $ind = 'old' ]
        then
            if [ $o_val = 1 ]
            then
                echo "$o_varname $o_varval <"
                set_old
            else
                set_old
                o_val=1
            fi
        fi

        # both value are set
        if [ $n_val = 1 -a $o_val = 1 ]
        then
            if [ $n_varname = $o_varname ]
            then
                # identical names
                if [ "$n_varval" = "$o_varval" ]
                then
                    echo "$o_varname $o_varval $n_varname $n_varval"
                else
                    echo "$o_varname $o_varval | $n_varname $n_varval"
                fi
                o_val=0
                n_val=0
            else
                if [[ $n_varname < $o_varname ]]
                then
                    echo "> $n_varname $n_varval"
                    n_val=0
                else
                    echo "$o_varname $o_varval <"
                    o_val=0
                fi
            fi
        fi
    done < $both_cont

    # check remaining names
    if [ $n_val -eq 1 ]
    then
        echo "> $n_varname $n_varval"
        n_val=0
    fi

    if [ $o_val -eq 1 ]
    then
        echo "$o_varname $o_varval <"
        o_val=0
    fi
}

# ---------------------------------------------------------------------------
# show_detail(): show details of the difference
# ---------------------------------------------------------------------------
show_detail()
{
    # max len from variable
    get_max_len

    header_md
    row=5
    max_row=9
    gotoyx $row 1
    #diff -y $left $right > $diff_file
    env_diff $left_sort $right_sort > $diff_file
    chmod og-rw $diff_file
    # read from file desciptor 9 to make ask work
    while read -u 9 line
    do
        set -- $line
        v1="$1"
        v2="$2"
        v3="$3"
        v4="$4"
        v5="$5"
        case $# in
        3)  if [ "$v1" = ">" ]
            then
                echo_x $v2
                mecho   "1: - undefined -"
                echo_x ""
                mecho   '2: '$v3 | sed 's|~| |g'
                row=$(expr $row + 2)
                max_row=$(expr $max_row + 2)
            else
                if [ "$v3" = "<" ]
                then
                    echo_x $v1
                    mecho   '1: '$v2 | sed 's|~| |g'
                    echo_x ""
                    mecho   "2: - undefined -"
                    row=$(expr $row + 2)
                    max_row=$(expr $max_row + 2)
                else
                    mecho "Error(3): $line"
                    row=$(expr $row + 1)
                    max_row=$(expr $max_row + 1)
                fi
            fi
            ;;
        4)  if [ "$v2" != "$v4" ]
            then
                echo_x $v1
                mecho   '1: '$v2 | sed 's|~| |g'
                echo_x ""
                mecho   '2: '$v5 | sed 's|~| |g'
                row=$(expr $row + 2)
                max_row=$(expr $max_row + 2)
            fi
            ;;
        5)  case $v3 in
            \|) echo_x $v1
                mecho   '1: '$v2 | sed 's|~| |g'
                echo_x ""
                mecho   '2: '$v5 | sed 's|~| |g'
                row=$(expr $row + 2)
                max_row=$(expr $max_row + 2)
                ;;
            *)  mecho "Error(5): $line"
                row=$(expr $row + 1)
                max_row=$(expr $max_row + 1)
                ;;
            esac
            ;;
        *)  mecho "Error($#): $line"
            row=$(expr $row + 1)
            max_row=$(expr $max_row + 1)
            ;;
        esac

        # $SCROLL comes from env
        # show pages, but pages can not scroll back :-(
        if [ "${SCROLL}" = "no" ]
        then
            # use actual screensize
            if [ ${max_row} -gt ${_EISLIB_SCREENSIZE_Y} ]
            then
                max_row=9
                mecho
                _ask_tmpfile=$(mktemp -t XXXXXXXXXXXXX)
                /var/install/bin/ask 'View' '' 'n=next page' "^$=Return" '0=Exit' > ${_ask_tmpfile}
                rc=${?}
                read answer < ${_ask_tmpfile}
                rm -f ${_ask_tmpfile}

                if [ ${rc} = 255 ]
                then
                    answer=0
                fi

                case "${answer}" in
                '')
                    clean
                    exit 0
                    ;;
                0)
                    clean
                    exit 127
                    ;;
                n|N)
                    header_md </dev/tty
                    row=5
                    gotoyx $row 1
                    ;;
                esac
            fi
        fi

    done 9< $diff_file

    # $SCROLL comes from env
    # show all lines and can scroll back :-)
    if [ "${SCROLL}" = "yes" ]
    then
        if [ "${max_row}" -gt 23 ]
        then
            mecho
            mecho --info 'Use SHIFT + PAGE-UP to scroll up'
        fi

        mecho
         _ask_tmpfile=$(mktemp -t XXXXXXXXXXXXX)
        /var/install/bin/ask 'View' '' "^$=Return" '0=Exit' > ${_ask_tmpfile}
        rc=${?}
        read answer < ${_ask_tmpfile}
        rm -f ${_ask_tmpfile}

        if [ ${rc} = 255 ]
        then
            answer=0
        fi

        case "${answer}" in
        '')
            clean
            exit 0
            ;;
        0)
            clean
            exit 127
            ;;
        esac
    fi
}

# ---------------------------------------------------------------------------
# main
# ---------------------------------------------------------------------------

# ---------------------------------------------------------------------------
# set title strings
# ---------------------------------------------------------------------------
MD_TITLE_bb='Show difference between two backup configurations'
MD_TITLE_cb='Show difference between current and a backup configuration'
MD_TITLE_cd='Show difference between current and default configuration'
MD_TITLE_db='Show difference between default and a backup configuration'

filename=`basename $0`
# get package name from filename PACKAGE-diff-XY
package=`echo $filename | sed "s|-diff-[cdb][cdb]$||"`
type=`echo $filename | sed "s|^${package}-diff-||"`

# if package is template
#    take package from $PACKAGE
[ "$package" = 'template' ] && package="$PACKAGE"

#debug echo "+++ TEST filename: $filename"
#debug echo "         PACKAGE:  $PACKAGE"
#debug echo "         package:  $package"
#debug echo "         type:     $type"
#debug read answ < /dev/tty

    case $type in
    cd) l_source=$configd/$package
        r_source=$defaultd/$package
        ;;
    cb) l_source=$configd/$package
        r_source="-"
        ;;
    db) l_source=$defaultd/$package
        r_source="-"
        ;;
    bb) l_source="-"
        r_source="-"
        ;;
    *)  mecho "Error: illegal call $filename"
        footer
        exit
       ;;
    esac

# set MD_TITLE and  MD_SUBTITLE
eval MD_TITLE="\$MD_TITLE_${type}"
MD_SUBTITLE=" line 1: $r_source \n line 2: $l_source"
# export for use in config_shlib (choose)
export MD_TITLE
export MD_SUBTITLE

# r_source is still missing
if  [ $l_source = '-' ]
then
    select_file

    case "${answer}" in
    '') exit 0     ;;
    0)  exit 127   ;;
    *)
        eval l_source='${bfile_'${answer}'}'
        omit_file=${l_source}
        ;;
    esac
    # change MD_SUBTITLE
    MD_SUBTITLE=" line 1: $r_source \n line 2: $l_source"
fi

# l_source is still missing
if  [ $r_source = '-' ]
then
    select_file

    case "${answer}" in
    '') exit 0     ;;
    0)  exit 127   ;;
    *)
        eval r_source='${bfile_'${answer}'}'
        ;;
    esac
    # change MD_SUBTITLE
    MD_SUBTITLE=" line 1: $r_source \n line 2: $l_source"
fi

# make shure the file exists and is a regular file
if [ $l_source != '-' -a ! -f $l_source ]
then
    header_md
    mecho
    mecho --error "File $l_source does not exist."
    l_source='-'
    footer
fi

# make shure the file exists and is a regular file
if [ $r_source != '-' -a ! -f $r_source ]
then
    header_md
    mecho
    mecho --error "File $r_source does not exist."
    r_source='-'
    footer
fi

# O.K., we have two files
if [ $l_source != '-' -a $r_source != '-' ]
then
    header_md
    tmp_dir=/tmp
    right=$tmp_dir/right.$$
    left=$tmp_dir/left.$$
    diff_file=$tmp_dir/diff_file.$$
    right_sort=$tmp_dir/right.srt.$$
    left_sort=$tmp_dir/left.srt.$$
    both_ucont=$tmp_dir/both.ucont.$$
    both_cont=$tmp_dir/both.cont.$$

    # strip both files for comparison
    strip_file ${l_source} $left
    strip_file ${r_source} $right

    mecho
    mecho "Files are compared without any comments. Unused leading and trailing"
    mecho "spaces are removed. The files are sorted alphabetically for all(!)"
    mecho "comparisons to get an optimal result."
    mecho "This means that the order of differencies shown is not the same"
    mecho "order than the variables appear in the configuration file."
    mecho
    if ! file_differ
    then
        mecho --error "The two files are different."
        mecho
        _ask_tmpfile=$(mktemp -t XXXXXXXXXXXXX)
        /var/install/bin/ask 'Show differencies' >${_ask_tmpfile}
        rc=${?}
        read answer < ${_ask_tmpfile}
        rm -f ${_ask_tmpfile}

        # handle CTRL-C
        if [ ${rc} = 255 ]
        then
            answer=no
        fi

        case "${answer}" in
        yes)
            show_detail
            ;;
        *)
            clean
            exit 0
            ;;
        esac
    else
        mecho --info "The two files are identical."
    fi
else
    header_md
    mecho --error "Too few files selected"
fi

clean
footer

exit
# ---------------------------------------------------------------------------
# end
# ---------------------------------------------------------------------------