#!/usr/bin/env ruby

require "uri"
require "digest"

filename, *urls = ARGV

unless filename && urls.any?
  warn "Please supply a filename and url"
  exit 1
end

path = filename.sub(File.basename(filename), "")
content = File.read(filename)

urls.each do |url|
  link_id = content.scan(/\[(\d+)\]: #{url}/).first.first

  unless link_id
    warn "Link not found"
    exit 1
  end

  page_content = `curl -s #{url}`
  text_content = `w3m #{url}`

  begin
    title = page_content
      .scan(/<title[^>]*>(.*?)<\/title>/mi)
      .first
      .first
      .strip
  rescue => ex
    warn "Title error (#{ex}; #{url})"
    exit 1
  end

  hash = Digest::MD5.base64digest(url + text_content)
    .scan(/[a-z0-9]/i)
    .first(6)
    .join
    .downcase

  link_filename = "#{URI.parse(url).host.gsub(".", "-")}-#{hash}.txt"

  File.write("#{path}/#{link_filename}", text_content)

  content.gsub!(/\[#{link_id}\]([^:])/, "[#{link_id}][^#{link_id}-backup]\\1")
  content << "\n[^#{link_id}-backup]: \"<a href=\"#{url}\">#{title}</a>\"; <a href=\"#{link_filename}\">backed up #{Time.now.utc}</a>"
end

File.write(filename, content)