#!/bin/bash

set -u

# $1: url
gettitle() {
    curl -Ls "$1" | grep -iPo '(?<=<title>)(.*)(?=</title>)'
}

main() {
    local infile
    infile="$1"

    while read line; do
        if [[ ! "$line" =~ ^\*.* ]]; then
            echo "$line"
            continue
        fi

        local url
        local title
        local rfc

        rfc=""
        url=""
        line="${line//\* /}"
        if [[ "$line" =~ ^rfc[0-9]+ ]]; then
            rfc="$line"
            url="https://tools.ietf.org/html/$rfc"
        else
            url="$(echo "${line//\* /}" | sed 's/\s+$//')"
        fi

        title="$(gettitle "$url")"

        if [[ "$rfc" != "" ]]; then
            echo "* $url[$(echo $rfc | awk '{ print toupper($0) }')] -- $(echo $title | sed 's/.*-\s//')"
        else
            echo "* $url[$title]"
        fi
    done < "$infile"
}

main "$@"