#!/bin/bash
pomoc() {
    echo "Uporaba: $1 akcija parametri"
    echo "Akcije: leto, fib, info, tocke, pomoc"

}
status(){
    stev1=$1
    stev2=$2
    flag=1

    until [ "$flag" -eq 0 ];
        do
            let "flag = $stev1 % $stev2"

            stev1=$stev2
            stev2=$flag
        done
    exit $stev1
}
leto() {
    leto=$1
    if [[ $((leto%4)) == 0 ]]; then
        if [[ $((leto%100)) == 0 ]]; then
            if [[ $((leto%400)) == 0 ]]; then
                echo "Leto $leto je prestopno."
            else
                echo "Leto $leto ni prestopno."
            fi
        else
            echo "Leto $leto je prestopno."
        fi
    else
        echo "Leto $leto ni prestopno."
    fi

}

fib() {
    stevilo=$1
    rezultat=0 a=1
    for (( i=0; i<stevilo; i++ ))
       do
          rezultat=$(($rezultat+$a))
          a=$(($rezultat-$a))
       done
    echo "$stevilo: $rezultat"
}
userinfo() {

    uporabnik=$1
    obstaja=""
    enaka=""
    error=""
    stSkupin=0;
    numGroups=""



    if id -u $uporabnik >/dev/null 2>&1; then

        idUporabnik=$(id -u $uporabnik)
        idGroup=$(id -g $uporabnik)
        numGroups=$(groups $uporabnik)

        for i in $numGroups
            do
                stSkupin=$(( $stSkupin+1 ))
            done


    else
        error="err"
    fi

    if [[ "$idUporabnik" -eq "$idGroup"  ]]; then
        enaka="enaka"
    fi

    if [[ -d "/home/$uporabnik" ]]; then
        obstaja="obstaja"
    fi

        if [[ $error == "err" ]]; then
            echo "$uporabnik: $error"
        else
            stSkupin=$(( $stSkupin-2 ))
            echo "$uporabnik: $enaka $obstaja $stSkupin "
        fi
}


neznana() {
    echo "Napacna uporaba skripte!"
    echo "Uporaba: $1 akcija parametri"
    echo "Akcije: leto, fib, info, tocke, pomoc"
}
drevo() {

    FILES="$1"
    globina="$2"
    stevec=$3;
    crtice="---"
    for  (( i=1; i<stevec; i++ ))
        do
            crtice+="----"
        done

    if [ "$FILES" != "0" ];then
        cd "$FILES"
    fi
    for FILE in *
        do
                    if [[ -L $FILE ]]; then
                        echo "$crtice-LINK  $FILE"

                    elif [[ -d $FILE ]]; then
                        echo "$crtice-DIR   $FILE"

                    if (( "$stevec" <= "$2" )); then

                         stevec=$(( $stevec +1 ));

                         cd "$FILE"
                            drevo 0 $2 $stevec
                         stevec=$(( $stevec - 1 ));
                         cd ..
                         if [ $stevec -lt "1" ];then
                            stevec=1;
                            crtice="---"
                         fi
                       fi

                    crtice="---";
                    for  (( i=1; i<stevec; i++ ))
                    do
                        crtice+="----"
                    done
                    elif [[ -c $FILE ]]; then
                        echo "$crtice-CHAR  $FILE)"
                    elif [[ -b $FILE ]]; then
                        echo "$crtice-BLOCK $FILE"
                    elif [[ -p $FILE ]]; then
                        echo "$crtice-PIPE  $FILE"
                    elif [[ -S $FILE ]]; then
                        echo "$crtice-SOCK  $FILE"
                    elif [[ -f $FILE ]]; then
                        echo "$crtice-FILE  $FILE"
                    fi
        done
}

if [[ "$1" == "leto" ]]; then
    for i in ${@:2}
        do
            leto $i
        done
    exit 0
elif [[ "$1" == "status" ]]; then
        status $2 $3
    exit 0
elif [[ "$1" == "fib" ]]; then
    for i in ${@:2}
        do
            fib $i
        done
    exit 0
elif [[ "$1" == "userinfo" ]]; then
    if [ $# == 1 ]; then
        allUsers=$(cat /etc/passwd|cut -d: -f1|egrep -v '^s'|sort -n)
        for i in $allUsers
            do
                userinfo $i
            done
    else
        for i in ${@:2}
            do
                userinfo $i
            done
    fi
    exit 0


elif [[ "$1" == "pomoc" ]]; then
    pomoc $0
    exit 0
elif [[ "$1" == "drevo" ]];then
    echo "DIR   $2"
    defaultGlobina=2;
    defaultStevec=1;
    if [ -z "$2" ] && [ -z "$3" ]; then
       drevo "$PWD" "$defaultGlobina" $defaultStevec
    elif [ -z "$2" ] && [ -n "$3" ]; then
       drevo "$PWD" "$3" $defaultStevec
    elif [ -n "$2" ] && [ -z "$3" ];  then
       drevo "$2" $defaultGlobina $defaultStevec
    elif [ -n "$2" ] && [ -n "$3" ]; then
       drevo "$2" "$3" $defaultStevec
    else
        pomoc $0
    fi
    exit 0
fi