if [ -n "$PS1" ]; then
    function term_colors(){
        for i in {0..15}; do 
            for j in {0..15}; do 
                c=$((i*16+j)); 
                printf " $(tput setab $c)%04d" $c; 
            done; 
            printf "$(tput sgr0)\n"; 
        done 
        for i in {0..15}; do 
            for j in {0..15}; do 
                c=$((i*16+j)); 
                printf " $(tput setaf $c)%04d" $c; 
            done; 
            printf "$(tput sgr0)\n"; 
        done 
    }
fi

#
#   Prompt if interactive
#
if [ -n "$PS1" ]; then
    #
    #   Number of colors and standard colors.
    #
    c_num=$(tput colors)

    #
    #   Set better colors if available.
    #
    if [ $c_num -ge 256 ]; then
        c_reset="$(tput sgr0)"
        c_user="$(tput setaf 203)"    #Some bright color
        c_host="$(tput setaf 112)"    #Green
        c_cwd="$(tput setaf 99)"
        c_time="$(tput setaf 33)"   #Light blue
        c_branch="$(tput setaf 138)"
        c_error="$(tput setaf 203)"    #Red
        c_info="$(tput setaf 220)"  #Yellow
    else
        c_reset="$(tput sgr0)"
        c_user="$(tput setaf 1)"    #
        c_host="$(tput setaf 2)"    #Green
        c_cwd="$(tput setaf 7)"     #White
        c_time="$(tput setaf 6)"    #Cyan
        c_branch="$(tput setaf 6)"  #Cyan
        c_error="$(tput setaf 1)"    #Red
        c_info="$(tput setaf 3)"    #Yellow
    fi

    [ -n "$(which svn)" ] && prompt_check_svn=true
    [ -n "$(which git)" ] && prompt_check_git=true

    if [ -n "$ZSH_VERSION" ]; then
        s_host="%m"
        s_user="%n"
        s_cwd="%/"
        s_time="%t"
    fi
    if [ -n "$BASH_VERSION" ]; then
        export PROMPT_COMMAND="__prompt_command"
        s_host="\h"
        s_user="\u"
        s_cwd="\w"
        s_time="\t"
        # Turn on checkwinsize
        shopt -s checkwinsize
    fi
    # For hg from FB
    if [ -f /usr/share/scm/scm-prompt.sh ]; then
        source /usr/share/scm/scm-prompt.sh
        prompt_check_hg=true
    elif [ -f /opt/facebook/hg/share/scm-prompt ]; then
        source /opt/facebook/hg/share/scm-prompt
        prompt_check_hg=true
    fi

    # zsh
    function precmd() {
        __prompt_command
    }

    function __prompt_command() {
        #
        # get exit code before any command is run.  TODO: doesn't work on pi.
        #
        local exit_code="$?"
        prompt_extra=""
        PS1=""
        if [ "$USER" != "vahagnk" -a "$USER" != "vahagn" ]; then
            PS1+="\[${c_user}\]${s_user}@"         # username@
        fi
        PS1+="\[${c_host}\]${s_host}:"           # hostname
        PS1+="\[${c_time}\]${s_time}"            # time
        PS1+=" \[${c_cwd}\]${s_cwd}"            # working_dir
        #
        # git branch if exist
        #
        if [ -n "$prompt_check_git" ]; then
            local git_branch=$(git rev-parse --abbrev-ref HEAD 2> /dev/null | tr -d ' ') 
            if [ -n "$git_branch" ]; then
                PS1+="\[${c_branch}\]@${git_branch}"
            fi
        fi
        #
        # hg branch if exist
        #
        if [ -n "$prompt_check_hg" -a -z "$git_branch" ]; then
            local hg_branch=$(_scm_prompt %s)
            if [ -n "$hg_branch" ]; then
                PS1+="\[${c_branch}\]@${hg_branch}"
            fi
        fi
        #
        # svn branch if exist
        #
        if [ -n "$prompt_check_svn" ]; then 
            local svn_rev=$(svn info . 2> /dev/null | awk -F ':' '/Revision:/ { print $2 }')
            if [ -n "$svn_rev" ]; then
                PS1+="\[${c_branch}\]@${svn_rev}"      # svn revision
            fi
        fi
        #
        #   Python venv
        #
        local jobs_bg=$(jobs -r | wc -l | tr -d ' ') 
        if [ -n "$VIRTUAL_ENV" ]; then
            # PS1+=",\[${c_info}\]$(realpath --relative-to=$PWD $VIRTUAL_ENV)"
            PS1+=",\[${c_info}\]$(basename $VIRTUAL_ENV)"
        fi
        #
        #   Info about jobs.
        #
        local jobs_bg=$(jobs -r | wc -l | tr -d ' ') 
        if [ $jobs_bg -gt 0 ]; then
            PS1+=",\[${c_info}\]bg=${jobs_bg}"
        fi
        local jobs_stopped=$(jobs -s | wc -l | tr -d ' ')
        if [ $jobs_stopped -gt 0 ]; then
            PS1+=",\[${c_info}\]stp=${jobs_stopped}"
        fi
        #
        # exit code if not zero
        #
        if [ "$exit_code" -ne "0" ]; then
            PS1+=",\[${c_error}\]rc=${exit_code}"
        fi

        #
        # Colors should be set here and surrounded with \[\]otherwise bash fails to
        # calculate prompt length. The text is set through PROMPT_COMMAND
        PS1+="\[${c_reset}\]\$ "              # reset colors and print $
    }
fi