#!/bin/bash

# Copyright: 2023 Virtuozzo International GmbH

# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at

# http://www.apache.org/licenses/LICENSE-2.0

# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

[ -n "${CONFIGLIB_VERSION:-}" ] && return 0;
CONFIGLIB_VERSION="0.1";

function __storeConfigHeader() {
    local configfile=${1};
    echo "# Configuration file for manage utility" > ${configfile};
    echo "# This file has been automatically generated." >> ${configfile};
    #echo "[general]" >> ${configfile};
}

function storeConfig() {
    [[ ${#@} -ge 2 ]] || die;
    local configfile=${1} key=${2} value content vars line="" changed=0;
    shift 2;
    value=${@};

    [[ ! -e ${configfile} ]] && { mkdir -p ${configfile%/*} || die -q  "Couldn't create directory ${configfile%/*}: $?"; }
    [[ ! -f ${configfile} ]] && {
        __storeConfigHeader ${configfile};
        echo "${key}=\"${value}\"" >> ${configfile};
        return;
    }

    content=$(<${configfile})

    [[ -z ${content} ]] && {
        __storeConfigHeader ${configfile};
        echo "${key}=\"${value}\"" >> ${configfile}
        return;
    }
    (
        local ifs_save=${IFS-$' \t\n'}
        IFS=$'\n'
        for line in ${content} ; do
            [[ ${line/=/} != ${line} ]] || continue;
            line=${line/=*/};
            local ${line}="";
            vars=(${vars[@]} ${line});
        done
        IFS=${ifs_save};

        source ${configfile} 2>&1 > /dev/null || die "Failed to source ${configfile}."
        __storeConfigHeader ${configfile};
        for var in ${vars[@]} ; do
            [[ ${var} == ${key} ]] && {
                echo "${var}=\"${value}\"" >> ${configfile};
                changed=1;
            } || {
                echo "${var}=\"${!var}\""  >> ${configfile};
            }
        done
        [[ ${changed} == 1 ]] || echo "${key}=\"${value}\"" >> ${configfile};
    )
}

function loadConfig() {
    [[ ${#@} -eq 2 ]] || die;
    local configfile key value

    configfile=${1}
    key=${2}
    [[ ! -e ${configfile} ]] && return 1;
    value=$(unset ${key}; source ${configfile} 1>&2 > /dev/null || die "Failed to source ${configfile}.";echo "${!key}");
    echo "${value}";
}

function loadINISection() {
    local inifile=${1} section=${2} ini
    grep -q -E "^\[$section]" $inifile || return
    ini="$( awk -F= \
    '{
        st = index($0,"=");
        if (length($1)!=0) {
            if (st!=0) {
                line=substr($0,st)
                gsub("[.]","_",$1);
                print $1 line;
            } else {
                print $0
            }
        }
    }' $inifile  )"
    ini="${ini//[/\\[}";
    ini="${ini//]/\\]}";
    OIFS=${IFS};
    IFS=$'\n' && ini=( ${ini} );
    ini=( ${ini[*]//;*/} );
    ini=( ${ini[*]/\    =/=} );
    ini=( ${ini[*]/=\   /=} );
    ini=( ${ini[*]/\ =\ /=} );
    ini=( ${ini[*]/#\\[/\}$'\n'config.section.} );
    ini=( ${ini[*]/%\\]/ \(} );
    ini=( ${ini[*]/=/=\( } );
    ini=( ${ini[*]/\ =/=} );
    ini=( ${ini[*]/%/ \)} );
    ini=( ${ini[*]/%\\ \)/ \\} );
    ini=( ${ini[*]/%\( \)/\(\) \{} );
    ini=( ${ini[*]/%\} \)/\}} );
    ini=( ${ini[*]/\>/\\>} );
    ini=( ${ini[*]/\</\\<} );
    ini[0]="";
    ini[${#ini[*]} + 1]='}';
    ini=( $(sed -nr -e '/^/H' -e '${g; s/(\n[[:blank:]]*[^[:blank:]]+[[:blank:]]*[(][[:blank:]]*[)][[:blank:]]*[{][[:blank:]]*[\n]?[[:blank:]]*)([}])/\1\ttrue;\n\2/g; p}' <<<"${ini[*]}") )
    eval "$(echo "${ini[*]}")";
    IFS=${OIFS};
    iniVarNames=( $(declare -f config.section.${section} | sed -rn 's/([^=])=.*/\1/p') )
    config.section.${section} 2>/dev/null
}

function appendConfig() {
    [[ ${#@} -gt 2 ]] || die
    local configfile=${1} key=${2} item oldvalue newvalue
    shift 2
    item="$@"
    oldvalue=$(load_config ${configfile} ${key})
    if ! has ${item} ${oldvalue[@]} ; then
        newvalue=( ${oldvalue[@]} ${item} )
        storeConfig ${configfile} ${key} ${newvalue[@]}
    fi
}

function render_template() {
    template="$1"
    [[ ! -z "$template" ]] || {
        log "Template is not defined" 
        return 255
    }
    [[ -f "$template" ]] || {
        log "No such template"
        return 255
    }
    eval "echo \"$(cat ${template})\""
}