#!/bin/bash

# Show (a short piece of) information related to current location.
# Use a keyword to specify what info to show.

DIE() {
    echo "==> $progname: error: $1"
    exit 0
}

Options() {
    local opts
    local lopts="help,timeout:"
    local sopts="ht:"

    opts="$(/usr/bin/getopt -o=$sopts --longoptions $lopts --name "$progname" -- "$@")" || {
        Options -h
        return 1
    }

    eval set -- "$opts"

    while true ; do
        case "$1" in
            -t | --timeout)   timeout="$2" ; shift ;;
            -h | --help)
                cat <<EOF >&2
$progname - show info about your current location

Usage: $progname [options] [location-item]

Location-item: one of
   ${items[*]}
Location-item defaults to showing all available info.

Options:
  -h, --help       This help.
  -t, --timeout    Max number of seconds to wait for a response from
                   $infourl (default: $timeout_default).
EOF
                exit 0
                ;;
            
            --) shift ; break ;;
        esac
        shift
    done

    item="$1"

    local it
    for it in "${items[@]}" ; do
        [ "$item" = "$it" ] && break
    done
    
    [ "$item" = "$it" ] || DIE "item name must be one of: ${items[*]}"
    [ -n "$timeout" ]   || DIE "given timeout value cannot be empty"
}

Main() {
    local progname="$(basename "$0")"

    # default values
    local timeout_default=30
    local timeout=$timeout_default
    local item=""

    # supported values
    local items=(city country hostname ip loc org postal region timezone "")   # "" means: all

    # info source
    local infourl=https://ipinfo.io

    Options "$@"

    # show the wanted location info
    echo "$(LANG=C curl -Lsm $timeout $infourl/$item)"
}

Main "$@"