Simple web mail viewer

web_mail_viewer.rb

require 'base64'

class WebMailViewer < Sinatra::Base
  
  configure(:integration, :development, :test) do
    enable :logging
  end
  
  before do
    if ActionMailer::Base.delivery_method != :file
      halt "Sorry, but this feature works only for delivery_method == :file"
    end

    halt "Sorry, no local emails found" unless File.exists?(Rails.root.join('tmp/mails'))
  end

  helpers do
    def list_files
      Dir.glob(Rails.root.join('tmp/mails/*')).map do |file|
        {
          :updated_at => File.mtime(file),
          :name => File.basename(file),
          :file => file
        }
      end.sort_by{|i| i[:updated_at]}.reverse
    end
    
    def encode_address(str)
      Base64.encode64 str
    end
    
    def decode_address(str)
      Base64.decode64 str
    end
  end
  
  get "/" do
    mails = list_files
    return "Sorry, no local emails found" if mails.empty?
    
    mails.map do |file|
      "#{file[:updated_at].to_s(:db)} -- <a href='#{url('/view/' + encode_address(file[:name]))}'>#{file[:name]}</a>"
    end.join('<br />')
  end
  
  get "/view/:address" do
    address = decode_address(params[:address])

    mail = list_files.find {|file| file[:name] == address}
    if mail
      content_type 'text/plain', :charset => 'utf-8'
      File.open(mail[:file], "rb").read
    else
      "No such file!"
    end
  end
end