# Copyright (C) 2017, Red Hat, Inc.

#

# Core configuration file library.

# Configurations are determined by sha values.  The way to determine is by

# the special text:

# $FILE_COMMENT_TYPE -*- cfg-sha: $SHA256 -*-

export LC_ALL=C

# check required binaries

__check_reqd_binaries() {

    local BIN __binaries=("egrep" "sort" "sha256sum" "sed")

    for BIN in $__binaries; do

        if ! type -P $BIN >/dev/null 2>&1; then

            echo "Binary $BIN not found.  Please install."

            exit 1

        fi

    done

}

# Calculates a sha from a file

# The algorithm for generating a sha from a config is thus:

#

# 1. Remove all comment lines and blank lines

# 2. Sort the content

# 3. generate the sha-256 sum

#

# From a script perspective, this means:

#   egrep -v ^\# %file% | egrep -v ^$ | sort -u | sha256sum

#

# Params:

#  $1 = output variable

#  $2 = file to use to calculate the shasum

#  $3 = file comment type (defaults to # if unspecified)

calc_sha() {

    __check_reqd_binaries

    if [ "$1" == "" ]; then

        echo "Please pass in a storage variable."

        return 1

    fi

    local __resultvar=$1

    __retval=1

    shift

    local __file=$1

    local cmnt=${2:-#}

    if [ -f "$__file" ]; then

        local __shasum=$(egrep -v ^"$cmnt" "$__file" | egrep -v ^$ | sort -u | sha256sum -t | cut -d" " -f1)

        eval $__resultvar="'$__shasum'"

        __retval=0

    fi

    return $__retval

}

# Retrieves a sha stored in a file

# Param:

#  $1 = output variable

#  $2 = file to use to calculate the shasum

#  $3 = file comment type (defaults to # if unspecified)

retr_sha() {

    __check_reqd_binaries

    if [ "$1" == "" ]; then

        echo "Please pass in a storage variable."

        return 1

    fi

    local __resultvar=$1

    __retval=1

    shift

    local __file=$1

    local cmnt=${2:-#}

    if [ -f "$__file" ]; then

        if grep -q "$cmnt -\*- cfg-sha:" "$__file"; then

            local __shasum=$(grep "$cmnt -\*- cfg-sha:" "$__file" | sed -e "s@$cmnt -\*- cfg-sha: @@" | cut -d" " -f1)

            eval $__resultvar="'$__shasum'"

            __retval=0

        fi

    fi

    return $__retval

}

# Set a config value

# set_conf dpdk_build_tree parameter value

# dpdk_build_tree is the directory where the .config lives

# parameter is the config parameter

# value is the value to set for the config parameter

set_conf() {

    c="$1/.config"

    shift

    if grep -q "$1" "$c"; then

        sed -i "s:^$1=.*$:$1=$2:g" $c

    else

        echo $1=$2 >> "$c"

    fi

}