__set-title ()
{
    local title
    local path=$(git root 2> /dev/null)

    if [ ${path} ]
    then
        title=$(basename ${path})
    else
        title="${USER}:${PWD/~/\~}"
    fi

    echo -ne "\033]2;${title}\007"
}

__start-nonprinting ()
{
    if [ ${BUILDING_PS1} ]
    then
        echo -en '\['
    fi
}

__end-nonprinting ()
{
    if [ ${BUILDING_PS1} ]
    then
        echo -en '\]'
    fi
}

__fontify ()
{
    local -A codes
    codes[red]='31'
    codes[green]='32'
    codes[blue]='34'
    codes[white]='37'
    codes[bold]='1'
    codes[dim]='2'
    codes[clear]='0'

    local text=$1
    shift

    # We need to add \[ \] around CSI sequences so that Bash can tell which
    # characters are non-printing.

    output=$(__start-nonprinting)
    output+='\033['

    local attributes=($@)

    for ((i=0; i<$#; i++))
    do
        a=${attributes[${i}]}
        output+=${codes[${a}]}

        if ((i<$#-1))
        then
            output+=';'
        else
            output+='m'
        fi
    done

    output+=$(__end-nonprinting)

    output+="${text}"
    output+=$(__start-nonprinting)
    output+='\033[0m'
    output+=$(__end-nonprinting)

    echo -en "${output}"
}

__set-prompt ()
{
    BUILDING_PS1=t

    local last_status=$1

    PS1=''

    if [ ${last_status} -ne 0 ]
    then
        PS1+=$(__fontify "${last_status} " bold red) 
    fi

    PS1+=$(__fontify '\u' green)
    PS1+=$(__fontify : bold white)
    PS1+=$(__fontify '\w' bold blue)
    PS1+=$(__fontify "$(__git_ps1 '(%s)')" red)
    PS1+=$(__fontify '\$' bold white)
    PS1+=' '

    BUILDING_PS1=
}

__draw-rule ()
{
    rule=''
    for ((i=0; i<COLUMNS; i++))
    do
        rule+=—
    done
    __fontify ${rule} dim
}

__refresh-terminal ()
{
    local last_status=$?

    __set-title
    __set-prompt ${last_status}
    __draw-rule
}


. /usr/lib/git-core/git-sh-prompt
GIT_PS1_SHOWDIRTYSTATE=t
GIT_PS1_SHOWUPSTREAM=auto

export PROMPT_COMMAND=__refresh-terminal