gitprompt

findtag() {
    local ref=$1
    local gitdir=$2
    if [ -z "$gitdir" -o -z "$ref" ]; then
        echo "Bad arguments of '$ref' '$gitdir'"
        return 1
    fi
    for tag in `find $gitdir/refs/tags -type f`; do
        grep $ref $tag > /dev/null
        if [ $? == 0 ]; then
            striped="${tag#$gitdir/refs/tags}"
            echo $striped
            return 0
        fi
    done
}

maptag() {
    local head=$1
    local gitdir=$2
    local branch=""
    if [ -z "$head" -o -z "$gitdir" ]; then
        echo "Bad args to maptag"
        return 1
    fi
    # Revert to this if tag searching is too slow.
    #branch="d:${head:0:7}"
    #echo $branch
    #return 0

    local tag=`grep $head $gitdir/packed-refs`
    if [ ! -z "$tag" ]; then
        branch="tag:${tag##*refs/tags/}"
    else
        tag=`findtag "$head" "$gitdir"`
        if [ -z "$tag" ]; then
            branch="d:${head:0:7}"
        else
            branch="tag:$tag"
            fi
    fi
    echo $branch
}

mapref() {
    local head=$1
    local gitdir=$2
    local branch=""
    if [ -z "$head" -o -z "$gitdir" ]; then
        echo "Bad args to mapref"
        return 1
    fi

    case "$head" in
        ref:*)
            branch="${head##*/}"
            ;;
        "")
            branch=""
            ;;
        *)
            branch=`maptag "$head" "$gitdir"`
            ;;
    esac
    echo $branch
}

# Fast git branch from: https://gist.github.com/wolever/6525437
gitbranch() {
    export GITBRANCH=""
 
    local repo="${_GITBRANCH_LAST_REPO-}"
    local gitdir=""
#    [[ ! -z "$repo" ]] && gitdir="$repo/.git"

    # If we don't have a last seen git repo, or we are in a different directory
    if [[ -z "$repo" || "$PWD" != "$repo"* || ! -e "$gitdir" ]]; then
        local cur="$PWD"
        while [[ ! -z "$cur" ]]; do
            if [[ -e "$cur/.git" ]]; then
                repo="$cur"
                gitdir="$cur/.git"
                break
            fi
            cur="${cur%/*}"
        done
    fi
 
    if [[ -z "$gitdir" ]]; then
        unset _GITBRANCH_LAST_REPO
        return 0
    fi

    # Find the git directory for a submodule
    if [ -f $gitdir ]; then
        local gitdirLoc
        read gitdirLoc < "$gitdir"
        pattern="gitdir: (.*)"
        if [[ $gitdirLoc =~ $pattern ]]; then
            gitdirRelative="${BASH_REMATCH[1]}"
            local absolute="^/.*"
            if [[ $gitdirRelative =~ $absolute ]]; then
                gitdir="$gitdirRelative"
            else
                gitdir="$repo/$gitdirRelative"
            fi
        else
            echo "Failed to find git dir in $gitdirLoc"
            export GITBRANCH="Failed to find git dir in $gitdirLoc"
            return 0
        fi
    fi

    export _GITBRANCH_LAST_REPO="${repo}"
    local head=""
    local branch=""
    read head < "$gitdir/HEAD"

    branch=`mapref "$head" "$gitdir"`
    if [[ -z "$branch" ]]; then
        export GITBRANCH=""
        return 0
    fi
    export GITBRANCH="$branch"
}


COLOR_LIGHT_CYAN='\e[1;36m'
COLOR_NC='\e[0m' # No Color
export PS1="\A \u@\h:[\[${COLOR_LIGHT_CYAN}\]\$GITBRANCH\[${COLOR_NC}\]]\w$ "
_mk_prompt() {
    gitbranch
    export PS1="\A \u@\h:[\[${COLOR_LIGHT_CYAN}\]\$GITBRANCH\[${COLOR_NC}\]]\w$ "
}
export PROMPT_COMMAND=_mk_prompt