#!/bin/bash
# ------------------------------------------------------------------------------
# Copyright (c) 2013-2022 Geoffray Levasseur <fatalerrors@geoffray-levasseur.org>
# Protected by the BSD3 license. Please read bellow for details.
#
# * Redistribution and use in source and binary forms,
# * with or without modification, are permitted provided
# * that the following conditions are met:
# *
# *   Redistributions of source code must retain the above
# *   copyright notice, this list of conditions and the
# *   following disclaimer.
# *
# *   Redistributions in binary form must reproduce the above
# *   copyright notice, this list of conditions and the following
# *   disclaimer in the documentation and/or other materials
# *   provided with the distribution.
# *
# *   Neither the name of the copyright holder nor the names
# *   of any other contributors may be used to endorse or
# *   promote products derived from this software without
# *   specific prior written permission.
# *
# * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
# * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
# * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
# * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
# * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
# * OF SUCH DAMAGE.
# ------------------------------------------------------------------------------

# ------------------------------------------------------------------------------
# Determine if parameter is a valid IPv4 address
# Usage: isipv4 <ip_address>
isipv4()
{
    # Set up local variables
    local ip=$1
    [[ -z $ip ]] && return 1

    # Start with a regex format test
    if [[ $ip =~ ^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$ ]]; then
        local old_ifs=$IFS
        IFS="."
        ip=($ip)
        IFS=$old_ifs
        if [[ ${ip[0]} -le 255 && ${ip[1]} -le 255 &&
            ${ip[2]} -le 255 && ${ip[3]} -le 255 ]]; then
            if [[ -t 1 ]]; then
                disp "The given IPv4 is valid."
            fi
            return 0
        fi
    fi
    if [[ -t 1 ]]; then
        disp "The given parameter is NOT a valid IPv4."
    fi
    return 1
}
export -f isipv4
# ------------------------------------------------------------------------------


# ------------------------------------------------------------------------------
# Determine if parameter is a valid IPv4 address
# Usage: isipv6 <ip_address>
isipv6()
{
    local ip="$1"
    local regex='^([0-9a-fA-F]{0,4}:){1,7}[0-9a-fA-F]{0,4}$'
    if [[ $ip =~ $regex ]]; then
        if [[ -t 1 ]]; then
            disp "The given IPv6 is valid."
        fi
        return 0
    fi
    if [[ -t 1 ]]; then
        disp "The given parameter is not a valid IPv6."
    fi
    return 1
}
export -f isipv6
# ------------------------------------------------------------------------------


# ------------------------------------------------------------------------------
# Encode a string so it can be used as a URL parameter
# Usage: urlencode <string>
urlencode() {
    local LANG=C
    local str="$*"
    local length="${#str}"
    for (( i = 0; i < length; i++ )); do
        local c="${str:i:1}"
        case "$c" in
            [a-zA-Z0-9.~_-]) printf "$c" ;;
            ' ') printf '+' ;;
            *) printf '%%%02X' "'$c" #| cut -d' ' -f2 ;;
        esac
    done
}
export -f urlencode
# ------------------------------------------------------------------------------


# ------------------------------------------------------------------------------
# Fetch and display external IP information
# Usage: myextip [-i|--ip] [-s|--isp] [-l|--loc] [-c|--coord]
# If no option is provided, all information will be displayed.
# Options:
#   -i, --ip      Display only the external IP address
#   -s, --isp     Display only the ISP name
#   -l, --loc     Display only the location (city, region, country)
#   -c, --coord   Display only the coordinates (latitude, longitude)
myextip() {
    local show_ip=false show_isp=false show_loc=false
    local show_coord=false show_as=false
    local all=true

    # Parse arguments
    while [[ "$#" -gt 0 ]]; do
        case "$1" in
            -i|--ip)
                show_ip=true
                all=false
                ;;
            -s|--isp)
                show_isp=true
                all=false
                ;;
            -l|--loc)
                show_loc=true
                all=false
                ;;
            -c|--coord)
                show_coord=true
                all=false
                ;;
            -a|--as)
                show_as=true
                all=false
                ;;
            -h|--help)
                printf "Usage: myextip [-i|--ip] [-s|--isp] [-l|--loc] [-c|--coord] [-a|--as]\n"
                printf "Fetch and display external IP information.\n\n"
                printf "Options:\n"
                printf "  -i, --ip      Display only the external IP address\n"
                printf "  -s, --isp     Display only the ISP name\n"
                printf "  -l, --loc     Display only the location (city, region, country)\n"
                printf "  -c, --coord   Display only the coordinates (latitude, longitude)\n"
                printf "  -a, --as      Display only the Autonomous System (AS) information\n"
                return 0
                ;;
            --)
                shift
                break
                ;;
            *)
                disp E "Unknown option: $1"
                return 1
                ;;
        esac
        shift
    done

    # Fetch data
    local response
    response=$(curl -s http://ip-api.com/json/)

    # Parse with jq
    if command -v jq >/dev/null 2>&1; then
        echo "$response" | jq -r --argjson all "$all" --argjson ip "$show_ip" \
          --argjson isp "$show_isp" --argjson loc "$show_loc" \
          --argjson coord "$show_coord" --argjson as "$show_as" '
            [
                (if $all or $ip then "IP Address : \(.query)" else empty end),
                (if $all or $isp then "ISP        : \(.isp)" else empty end),
                (if $all or $loc then "Location   : \(.city), \(.regionName), \(.country)" else empty end),
                (if $all or $coord then "Coordinates: \(.lat), \(.lon)" else empty end),
                (if $all or $as then "AS         : \(.as)" else empty end)
            ] | .[]'
    else
        echo "$response"
    fi
}
export -f myextip
# ------------------------------------------------------------------------------


# ------------------------------------------------------------------------------
# EOF