bash_prompt

# Requirements:
#   1. A 24-bit-color-capable terminal (e.g., iTerm)
#   2. A font patched by Nerd Fonts (https://www.nerdfonts.com/)
#   3. The `__git_ps1` Bash function (macOS: `source /usr/local/etc/bash_completion.d/git-prompt.sh`)

if [ -z $PROMPT_SEPARATOR_CHARACTER ]; then
    __prompt_separator_character=">"
else
    __prompt_separator_character=$PROMPT_SEPARATOR_CHARACTER
fi

if [ -z $PROMPT_LOGO ]; then
    __prompt_logo="*"
else
    __prompt_logo=$PROMPT_LOGO
fi

if [ $(uname) == "Darwin" ]; then
    __prompt_hostname=$(scutil --get LocalHostName)
else
    __prompt_hostname=$(hostname -s)
fi

__prompt_blue="[38;2;97;175;239m"
__prompt_green="[38;2;140;197;111m"
__prompt_grey="[38;2;127;132;142m"
__prompt_orange="[38;2;209;154;102m"
__prompt_reset="\e[m"

__prompt_main_color () {
    if [ -z $PROMPT_MAIN_COLOR_CODE ]; then
        echo -e "\x1b$__prompt_green"
    else
        echo -e "\x1b$PROMPT_MAIN_COLOR_CODE"
    fi
}

__prompt_separator () {
    echo -e " \x1b[38;2;92;99;112m$__prompt_separator_character\x1b[m "
}

__prompt_git_status () {
    __git_status=$(git status --porcelain=v2 2>/dev/null)

    if [ -z "$__git_status" ]; then
        echo -e "\x1b${__prompt_grey}\x1b[m"
    else
        echo -e "\x1b${__prompt_green}\x1b[m"
    fi
}

# TODO: Check if an upstream exists
__prompt_git_ahead_behind () {
    __local_ref=$(git rev-parse @)
    __remote_ref=$(git rev-parse @{u} 2>/dev/null)
    __merge_base=$(git merge-base @ @{u} 2>/dev/null)

    if ([ -z "$__remote_ref" ] && [ -z "$__merge_base"]) || [ "$__local_ref" = "$__remote_ref" ]; then
        return
    fi

    if [ $__local_ref = $__merge_base ]; then
        echo -e " \x1b${__prompt_green}󰁆\x1b[m"
    elif [ $__remote_ref = $__merge_base ]; then
        echo -e " \x1b${__prompt_green}󰁞\x1b[m"
    else
        echo -e " \x1b${__prompt_orange}\x1b[m"
    fi
}

__prompt_git () {
    __git_branch=$(__git_ps1 "(%s)")

    if [ -n "$__git_branch" ]; then
        echo -e "$(__prompt_separator)$__git_branch $(__prompt_git_status)$(__prompt_git_ahead_behind)"
    fi
}

# Prompt parts:
#   username + $__prompt_logo + host...
#   then the current directory (\w)...
#   then Git status, if applicable...
#   then a newline followed by "$ " or "# "
export PS1="\n$(__prompt_main_color)[\u \e$__prompt_grey$__prompt_logo$(__prompt_main_color) $__prompt_hostname]$(__prompt_separator)\w\$(__prompt_git)\n\$ "

# One Dark theme colors
#   background: 39;44;53
#   grey: 127;132;142
#   grey1: 32;37;44
#   grey2: 43;49;61
#   grey3: 62;72;91
#   grey4: 92;99;112
#   grey5: 169;178;192
#   tan: 109;113;112
#   red: 244;71;71
#   coral: 224;108;117
#   orange: 209;154;102
#   yellow: 229;192;123
#   green: 140;197;111
#   green1: 152;195;121
#   bluegreen: 86;182;194
#   blue: 97;175;239
#   purple: 198;120;221