.bash_prompt

#!/usr/bin/env bash

__powerline() {
    # colorscheme
    readonly FG_BLACK="\[$(tput setaf 0)\]"
    readonly FG_RED="\[$(tput setaf 1)\]"
    readonly FG_GREEN="\[$(tput setaf 2)\]"
    readonly FG_YELLOW="\[$(tput setaf 3)\]"
    readonly FG_BLUE="\[$(tput setaf 4)\]"
    readonly FG_MAGENTA="\[$(tput setaf 5)\]"
    readonly FG_CYAN="\[$(tput setaf 6)\]"
    readonly FG_WHITE="\[$(tput setaf 7)\]"

    readonly BG_BLACK="\[$(tput setab 0)\]"
    readonly BG_RED="\[$(tput setab 1)\]"
    readonly BG_GREEN="\[$(tput setab 2)\]"
    readonly BG_YELLOW="\[$(tput setab 3)\]"
    readonly BG_BLUE="\[$(tput setab 4)\]"
    readonly BG_MAGENTA="\[$(tput setab 5)\]"
    readonly BG_CYAN="\[$(tput setab 6)\]"
    readonly BG_WHITE="\[$(tput setab 7)\]"

    readonly DIM="\[$(tput dim)\]"
    readonly REVERSE="\[$(tput rev)\]"
    readonly RESET="\[$(tput sgr0)\]"
    readonly BOLD="\[$(tput bold)\]"

    # Unicode symbols
    readonly GIT_PROMPT_SYMBOL_BRANCH='➦'
    readonly GIT_PROMPT_SYMBOL_ADD="${FG_WHITE}Ⓐ ${RESET}"
    readonly GIT_PROMPT_SYMBOL_DELETE="${FG_RED}Ⓓ ${RESET}"
    readonly GIT_PROMPT_SYMBOL_MODIFY="${FG_MAGENTA}Ⓜ ${RESET}"
    readonly GIT_PROMPT_SYMBOL_RENAME="${FG_CYAN}Ⓡ ${RESET}"
    readonly GIT_PROMPT_SYMBOL_COMMIT="${FG_YELLOW}Ⓒ ${RESET}"
    readonly GIT_PROMPT_SYMBOL_PUSH="⬆"
    readonly GIT_PROMPT_SYMBOL_PULL="⬇"

    readonly SYSTEM_PROMPT_SYMBOL_TRUE='✔'
    readonly SYSTEM_PROMPT_SYMBOL_FALSE='✘'
    readonly SYSTEM_PROMPT_SYMBOL_JOBS='⚙'
    readonly SYSTEM_PROMPT_SYMBOL_ROOT='⚡'
    readonly SYSTEM_PROMPT_SYMBOL_AT='@'
    readonly SYSTEM_PROMPT_SYMBOL_USER='➜'
    readonly SYSTEM_PROMPT_SYMBOL_SEPARATOR=''

    __git_info() {

        if [ ! -x "$(which git)" ]; then
            printf "${FG_BLUE}${SYSTEM_PROMPT_SYMBOL_SEPARATOR}${RESET}"
            return # git not found
        fi

        # get current branch name or short SHA1 hash for detached head
        local BRANCH="$(git symbolic-ref --short HEAD 2>/dev/null || git describe --tags --always 2>/dev/null)"
        if [ ! -n "$BRANCH" ]; then
            printf "${FG_BLUE}${SYSTEM_PROMPT_SYMBOL_SEPARATOR}${RESET}"
            return # git branch not found
        fi

        local INDEX=$(command git status --porcelain -b 2> /dev/null)
        local STATUS=""
        local GIT_PROMPT_SYMBOL

        local stat="$(echo $INDEX | grep '^##' | grep -o '\[.\+\]$')"
        local aheadN="$(echo $stat | grep -o 'ahead \d\+' | grep -o '\d\+')"
        local behindN="$(echo $stat | grep -o 'behind \d\+' | grep -o '\d\+')"

        if [ -n "$behindN" ]; then
             STATUS="$GIT_PROMPT_SYMBOL_PULL $behindN$STATUS"
        fi
        if [ -n "$aheadN" ]; then
             STATUS="$GIT_PROMPT_SYMBOL_PUSH $aheadN$STATUS"
        fi
        if $(echo "$INDEX" | grep '^A  ' &> /dev/null); then
            STATUS="$GIT_PROMPT_SYMBOL_COMMIT$STATUS"
        elif $(echo "$INDEX" | grep '^M  ' &> /dev/null); then
            STATUS="$GIT_PROMPT_SYMBOL_COMMIT$STATUS"
        fi
        if $(echo "$INDEX" | grep '^R  ' &> /dev/null); then
            STATUS="$GIT_PROMPT_SYMBOL_RENAME$STATUS"
        fi
        if $(echo "$INDEX" | grep '^ M ' &> /dev/null); then
            STATUS="$GIT_PROMPT_SYMBOL_MODIFY$STATUS"
        elif $(echo "$INDEX" | grep '^AM ' &> /dev/null); then
            STATUS="$GIT_PROMPT_SYMBOL_MODIFY$STATUS"
        elif $(echo "$INDEX" | grep '^ T ' &> /dev/null); then
            STATUS="$GIT_PROMPT_SYMBOL_MODIFY$STATUS"
        fi
        if $(echo "$INDEX" | grep '^ D ' &> /dev/null); then
            STATUS="$GIT_PROMPT_SYMBOL_DELETE$STATUS"
        elif $(echo "$INDEX" | grep '^D  ' &> /dev/null); then
            STATUS="$GIT_PROMPT_SYMBOL_DELETE$STATUS"
        elif $(echo "$INDEX" | grep '^AD ' &> /dev/null); then
            STATUS="$GIT_PROMPT_SYMBOL_DELETE$STATUS"
        fi
        if $(echo "$INDEX" | command grep -E '^\?\? ' &> /dev/null); then
            STATUS="$GIT_PROMPT_SYMBOL_ADD$STATUS"
        fi

        if [ -n "${STATUS}" ]; then
            GIT_PROMPT_SYMBOL="${BG_YELLOW}${FG_BLUE}${SYSTEM_PROMPT_SYMBOL_SEPARATOR} ${FG_BLACK}${GIT_PROMPT_SYMBOL_BRANCH}${BRANCH} ${STATUS} ${RESET}${FG_YELLOW}${SYSTEM_PROMPT_SYMBOL_SEPARATOR}${RESET}"
        else
            GIT_PROMPT_SYMBOL="${BG_GREEN}${FG_BLUE}${SYSTEM_PROMPT_SYMBOL_SEPARATOR} ${FG_BLACK}${GIT_PROMPT_SYMBOL_BRANCH}${BRANCH} ${RESET}${FG_GREEN}${SYSTEM_PROMPT_SYMBOL_SEPARATOR}${RESET}"
        fi
        printf "${GIT_PROMPT_SYMBOL}"
    }

    ps1() {
        local RETVAL=$?
        local PROMPT_SYMBOL
        local PROMPT_SYMBOL_DIR="${BG_BLUE}${FG_BLACK} \w ${RESET}"

        [[ $RETVAL -ne 0 ]] && PROMPT_SYMBOL+="${BG_BLACK}${FG_RED}${SYSTEM_PROMPT_SYMBOL_FALSE} ${RESET}"
        [[ $(jobs -l | wc -l) -gt 0 ]] && PROMPT_SYMBOL+="${BG_BLACK}${FG_CYAN}${SYSTEM_PROMPT_SYMBOL_JOBS} ${RESET}"
        [[ $UID -eq 0 ]] && PROMPT_SYMBOL+="${BG_BLACK}${FG_YELLOW}${SYSTEM_PROMPT_SYMBOL_ROOT} \u${SYSTEM_PROMPT_SYMBOL_AT}\h ${RESET}"
        [[ -n "${PROMPT_SYMBOL}" ]] && PROMPT_SYMBOL="${BG_BLACK} ${PROMPT_SYMBOL}${BG_BLUE}${FG_BLACK}${SYSTEM_PROMPT_SYMBOL_SEPARATOR}${RESET}"
        PS1="${PROMPT_SYMBOL}${PROMPT_SYMBOL_DIR}$(__git_info) "
    }

    PROMPT_COMMAND=ps1
}

__powerline
unset __powerline