# Copyright (c) 2012 by Tracelytics, Inc.
# All rights reserved.

require 'digest/sha1'

module Oboe
  module Util
    module Base64URL
      module_function

      def encode(bin)
        c = [bin].pack('m0').gsub(/\=+\Z/, '').tr('+/', '-_').rstrip
        m = c.size % 4
        c += '=' * (4 - m) if m != 0
        c
      end

      def decode(bin)
        m = bin.size % 4
        bin += '=' * (4 - m) if m != 0
        bin.tr('-_', '+/').unpack('m0').first
      end
    end
  end

  module Loading
    def self.setup_logger
      if defined?(::Rails) and ::Rails.logger
        Oboe.logger = ::Rails.logger
      end
    end

    def self.load_access_key
      unless Oboe::Config.access_key
        config_file = '/etc/tracelytics.conf'
        return unless File.exists?(config_file)
        
        begin
          File.open(config_file).each do |line|
            if line =~ /^tracelyzer.access_key=/ or line =~ /^access_key/
              bits = line.split(/=/)
              Oboe::Config[:access_key] = bits[1].strip
              Oboe::Config[:rum_id] = Oboe::Util::Base64URL.encode(Digest::SHA1.digest("RUM" + Oboe::Config[:access_key]))
              break
            end
          end
        rescue
          Oboe.logger.error "Having trouble parsing #{config_file}..."
        end
      end
    end

    def self.require_api
      require 'oboe/version'

      pattern = File.join(File.dirname(__FILE__), 'api', '*.rb')
      Dir.glob(pattern) do |f|
        require f
      end
      require 'oboe/api'

      begin
        Oboe::API.extend_with_tracing
      rescue LoadError => e
        Oboe.logger.fatal "[oboe/error] Couldn't load oboe api."
      end
      
      require 'oboe/config'
    end

    def self.load_framework_instrumentation
      pattern = File.join(File.dirname(__FILE__), 'frameworks/*/', '*.rb')
      Dir.glob(pattern) do |f|
        begin
          require f
        rescue => e
          Oboe.logger.error "[oboe/loading] Error loading framework file '#{f}' : #{e}"
        end
      end
    end
  end
end

Oboe::Loading.require_api
Oboe::Loading.load_framework_instrumentation