# Wayback Classic
# Copyright (C) 2024 Jessica Stokes
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

require 'open-uri'
require_relative 'error_reporting'
require_relative 'web_client/cache'

module WaybackClassic
  VERSION = "1.0.0"

  class WebClient
    class ForbiddenError < ErrorReporting::ForbiddenError; end

    class NotFoundError < ErrorReporting::NotFoundError; end

    private_class_method def self.user_agent
      http_host = ENV["SERVER_NAME"] || ENV["HTTP_HOST"]
      webmaster_email = ENV["WEBMASTER_EMAIL"]

      if !http_host or !webmaster_email
        raise ErrorReporting::ServerError.new("Server error: missing instance details (#{http_host}; #{webmaster_email})")
      end

      "WaybackClassic/#{WaybackClassic::VERSION} (#{http_host}; #{webmaster_email}) Ruby/#{RUBY_VERSION}"
    end

    def self.open(uri, options = {})
      options['User-Agent'] = user_agent
      Cache.get(uri) || Cache.put(uri, URI.open(uri, options))
    rescue OpenURI::HTTPError => error
      case error.io.status[0]
      when "403"
        raise ForbiddenError.new("Got a #{error.io.status.join(' ')} response while retrieving data. This may mean the URL has been excluded from the Wayback Machine.")
      when "404"
        raise NotFoundError.new("Got a #{error.io.status.join(' ')} response while retrieving data. This may mean the URL has not been archived by the Wayback Machine.")
      else
        raise error
      end
    end
  end
end