prompt.bash

#!/usr/bin/env bash

function __upwards {
    local h
    local t
    h="$1"
    t=""
    [ "${h}" != "/" ] || h=""
    while [ -n "${h}" ]; do
        "${@:2}" "${h}" "${t}" || return 0
        [ -z "${t}" ] || t="/${t}"
        t="${h##*/}${t}"
        h="${h%/*}"
    done
    "${@:2}" "${h}" "${t}" || return 1
    return 0
}

function __prompt {
    echo -n "$(__prompt_path "$1")"
}

function __prompt_path {
    local path
    local arc_path
    local res
    path="$1"
    arc_path="$(__upwards "$(pwd)" __up_arcadia_path)"
    path=${path%/}
    if [ -z "${arc_path}" ]; then
        echo -n "${path}"
    else
        res="${arc_path#/}"
        [ -n "${res}" ] || res="^"
        echo -n "${path%${arc_path}}/${res}"
    fi
}

function __prompt_vcs {
    __prompt_git=()
    __prompt_git_bare=false
    __prompt_arc=()
    __prompt_arcanum=()
    __upwards "$(pwd -P)" __up_vcs
    for entry in "${__prompt_git[@]}"; do
        echo -n " (${entry})"
    done
    for entry in "${__prompt_arc[@]}"; do
        echo -n " (${entry})"
    done
    for entry in "${__prompt_arcanum[@]}"; do
        echo -n " (${entry})"
    done
}

function __up_arcadia_path {
    if [ -f "$1/.arcadia.root" ]; then
        echo "/$2"
        return 1
    fi
    return 0
}

function __up_vcs {
    local name
    name="$1"
    name="${name##*/}"
    if [ -f "$1/HEAD" -a -d "$1/refs" -a -d "$1/objects" ]; then
        __prompt_git+=("!$(__git_info "$1")")
        __prompt_git_bare=true
    fi
    if ! ${__prompt_git_bare} && [ -d "$1/.git" ]; then
        __prompt_git+=("$(__git_info "$1/.git")")
    fi
    if [ -d "$1/.arc" -a -f "$1/.arc/HEAD" ]; then
        __prompt_arc+=("$(__arc_info "$1/.arc")")
    fi
    if [ -d "$1/.arcanum" -a -f "$1/.arcanum/pr" ]; then
        __prompt_arcanum+=("$(__arcanum_info "$1/.arcanum")")
    fi

    return 0
}

function __git_info {
    [ -f "$1/HEAD" ] || return 1
    local git_head
    local git_ref
    git_head="$(cat "$1/HEAD" 2>/dev/null)"
    if [ "${git_head:0:5}" = "ref: " ]; then
        git_ref="${git_head#ref: }"
        git_ref="${git_ref#refs/}"
        echo -n "${git_ref}"
    else
        echo -n "[${git_head:0:7}]"
    fi
}

function __arc_info {
    [ -f "$1/HEAD" ] || return 1
    local arc_remote
    local arc_id
    local arc_symbolic
    while read -r line; do
        if [ "${line:0:7}" == "Remote:" ]; then
            arc_remote="${line#Remote: }"
        elif [ "${line:0:3}" == "Id:" ]; then
            arc_id="${line#Id: }"
        elif [ "${line:0:9}" == "Symbolic:" ]; then
            arc_symbolic="${line#Symbolic: }"
        fi
    done <<< "$(cat "$1/HEAD" 2>/dev/null)"
    arc_remote="${arc_remote#\"}"
    arc_remote="${arc_remote%\"}"
    arc_id="${arc_id#\"}"
    arc_id="${arc_id%\"}"
    arc_symbolic="${arc_symbolic#\"}"
    arc_symbolic="${arc_symbolic%\"}"
    if [ -n "${arc_symbolic}" ]; then
        echo -n "${arc_symbolic}"
    elif [ -n "${arc_id}" ]; then
        echo -n "[${arc_id}]"
    fi
    if [ -n "${arc_remote}" ]; then
        echo -n ":${arc_remote}"
    fi
}

function __arcanum_info {
    [ -f "$1/pr" ] || return 1
    echo -n "$(cat "$1/pr")"
}

export PS1="${HOSTNAME} \$(__prompt \"\w\")\[\033[34m\$(__prompt_vcs) \[\033[32m\]\$\[\033[00m\] "