#!/bin/bash

# set -x

compute_md5 () {
        exec {fd}< <(md5sum "$1")   # open fd readable for P.S.
        cs_pid=$!                   # remember pid of P.S.
        md5="" 
        while read t <&$fd; do
            if ! [ -z "$t" ]; then
                t=($t)              # md5sum returns two values:
                                    # the hash plus the filename
                md5="${md5}$t"
            fi
        done

        exec {fd}>&-                # close fd (i.e. process substitution)
        wait $cs_pid                # wait for the subshell to finish
        echo $md5
}

md5_for_ini_files() {
        ini_directory="$1"
        ini_files=("ISMASMgr.ini" "sysconfig.ini" "SystemControl.ini")
    
        local data="\"ini\": {"$'\n'

        for f in "${ini_files[@]}"; do
            ini_file=${ini_directory}/$f
            md5=`compute_md5 $ini_file`
            data+="\"$ini_file\":\"$md5\","
        done
        
        if [[ "$data" =~ ^.*,$ ]]; then
            data=${data%?}
        fi

        data+="},"
        echo $data
}

md5_for_conf_files() {
        conf_directory="$1"
        conf_files=("emp.conf" "printer.conf" "device.conf")
    
        local data="\"conf\": {"$'\n'

        for f in "${conf_files[@]}"; do
            conf_file=${conf_directory}/$f
            md5=`compute_md5 $conf_file`
            data+="\"$conf_file\":\"$md5\","
        done
        
        if [[ "$data" =~ ^.*,$ ]]; then
            data=${data%?}
        fi

        data+="},"
        echo $data
}

write_config() {
        local path="$1"
        if [ "${path: -1}" == "/" ]; then  # remove trailing '/'
            path=${path%?}
        fi 

        local data="{ "$'\n'
        data+=`md5_for_ini_files "$path/opt/app/sysconfig"`
        data+=`md5_for_conf_files "$path/etc/psa_config"`
        data+="
    \"opkg\"  : {"
        local cnt=0
        for package_name in $(opkg list-installed); # list names of installed packages
        do 
                if ! grep -q "^[a-zA-Z]" <<< $package_name; then
                        continue
                fi
                
                if [ -z "$package_name" ]; then
                        continue
                fi
                
                cnt=$((cnt+1))

                printf "%3d:%s\n" "$cnt" "$package_name"

                #       Format of package info:
                #
                #       Package: openssh-scp
                #       Version: 7.8p1+git-r0
                #       Depends: libc6 (>= 2.28), update-alternatives-opkg
                #       Status: install ok installed
                #       Section: console/network
                #       Architecture: cortexa9t2hf-neon
                #       Maintainer: Poky <poky@yoctoproject.org>
                #       MD5Sum: dfffcbb088cd5f180be5e9ee2ad030fe
                #       Size: 32700
                #       Filename: openssh-scp_7.8p1+git-r0_cortexa9t2hf-neon.ipk
                #       Source: openssh_7.8p1+git.bb
                #       Description: A suite of security-related network....
                #       Installed-Size: 58920
                #       Installed-Time: 1654699615
                #       
                # process substitution (P.S):
                # run 'opkg info' synchronously to parent script

                exec {fd}< <(opkg info "$package_name") # open fd readable for P.S.
                cs_pid=$!                               # remember pid of P.S.

                while read package_info_line <&$fd; do
                        if [[ $package_info_line == Package* ]]; then
                                package=(${package_info_line// / })
                                package="\"${package[1]}\": {"
                        elif [[ $package_info_line == MD5Sum* ]]; then
                                md5sum=(${package_info_line// / })
                                md5sum="\"${md5sum[0]%?}\": \"${md5sum[1]}\"," 
                        elif [[ $package_info_line == Filename* ]]; then
                                filename=(${package_info_line// / })
                                filename="\"${filename[0]%?}\": \"${filename[1]}\"," 
                        elif [[ $package_info_line == Installed-Time* ]]; then
                                installed_time=(${package_info_line// / })
                                installed_time="\"${installed_time[0]%?}\": \"${installed_time[1]}\"
        }," 
                        fi
                done

                exec {fd}>&-                            # close fd (i.e. process substitution)
                wait $cs_pid                            # wait for the subshell to finish

        # use 8 spaces
                data="$data
        $package
            $md5sum
            $filename
            $installed_time"

            # break
        done

        if [[ "$data" =~ ^.*,$ ]]; then
            data=${data%?}
        fi
        
        data="$data
    }
}"
    echo "$data" > "${path}/$2"
    # echo $(cat "/tmp/test.txt" | jq -C --indent 4 '.') > /tmp/test2.txt
}

write_config "/home/root/szeged/customer_281/szeged/1/1/" "test.txt"