# frozen_string_literal: true

#
# Copyright (C) 2011 - present Instructure, Inc.
#
# This file is part of Canvas.
#
# Canvas 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, version 3 of the License.
#
# Canvas 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 <http://www.gnu.org/licenses/>.
#

class HostUrl
  class << self
    attr_accessor :outgoing_email_domain
    attr_writer :outgoing_email_address, :outgoing_email_default_name

    # See ActionDispatch::HostAuthorization; HostUrl is added as an object to config.hosts
    def ===(host)
      host == default_host || host == file_host(Account.default)
    end

    @@default_host = nil
    @@file_host = nil
    @@domain_config = nil
    @@protocol = nil

    def reset_cache!
      @@default_host = @@file_host = @@domain_config = @@protocol = nil
    end

    def domain_config
      unless @@domain_config
        @@domain_config = ConfigFile.load("domain")
        @@domain_config ||= {}
      end
      @@domain_config
    end

    # returns "http" or "https" depending on whether this instance of canvas runs over ssl
    def protocol
      unless @@protocol
        is_secure = if domain_config.key?("ssl")
                      domain_config["ssl"]
                    elsif Attachment.file_store_config.key?("secure")
                      Attachment.file_store_config["secure"]
                    else
                      Rails.env.production?
                    end

        @@protocol = is_secure ? "https" : "http"
      end

      @@protocol
    end

    def context_host(_context = nil, _current_host = nil)
      default_host
    end

    def context_hosts(context = nil, current_host = nil)
      Array(context_host(context, current_host))
    end

    def default_host
      if !@@default_host && domain_config.key?(:domain)
        @@default_host = domain_config[:domain]
      end
      res = @@default_host
      res ||= ENV["RAILS_HOST_WITH_PORT"]
      res
    end

    def file_host_with_shard(account, _current_host = nil)
      return [@@file_host, Shard.default] if @@file_host

      res = nil
      res = @@file_host = domain_config[:files_domain] if domain_config.key?(:files_domain)
      Rails.logger.warn("No separate files host specified for account id #{account.id}.  This is a potential security risk.") unless res || !Rails.env.production?
      res ||= @@file_host = default_host
      [res, Shard.default]
    end

    def file_host(account, current_host = nil)
      file_host_with_shard(account, current_host).first
    end

    def cdn_host
      # by default only set it for development. useful so that gravatar can
      # proxy our fallback urls
      host = ENV["CANVAS_CDN_HOST"]
      host ||= "canvas.instructure.com" if Rails.env.development?
      host
    end

    def outgoing_email_address(preferred_user = "notifications")
      @outgoing_email_address.presence || "#{preferred_user}@#{outgoing_email_domain}"
    end

    def outgoing_email_default_name
      @outgoing_email_default_name.presence || I18n.t("#email.default_from_name", "Instructure Canvas")
    end

    def file_host=(val)
      @@file_host = val
    end

    def default_host=(val)
      @@default_host = val
    end

    def is_file_host?(domain)
      safer_host = file_host(Account.default)
      safer_host != default_host && domain == safer_host
    end

    def has_file_host?
      default_host != file_host(Account.default)
    end
  end
end
