#!/usr/bin/env ruby
require 'rubygems'
require 'optparse'
require 'json'
require 'hashlib'

def report(&block)
  Onering::Reporter.add(&block)
end

module Onering
  class Reporter
    DEFAULT_PLUGIN_GEMNAMES=[
      'onering-report-plugins'
    ]

    DEFAULT_PLUGIN_PATH = [
      '/var/lib/onering/reporter'
    ]

    DEFAULT_FACTER_PATH = [
      '/etc/facter'
    ]

    class<<self
      attr_reader :facter_path

      def setup(config={})
        @options = config
        @facter_path = DEFAULT_FACTER_PATH

        @path = [*@options[:plugin_path]]
        @path += DEFAULT_PLUGIN_PATH

      # add gem paths to the @path
        ([*@options[:plugin_gems]]+DEFAULT_PLUGIN_GEMNAMES).compact.each do |g|
          begin
            p = File.join(Gem::Specification.find_by_name(g).gem_dir, 'lib')
            @path << File.join(p, 'reporter')
            @facter_path << File.join(p, 'facter')
          rescue Gem::LoadError
            next
          end
        end

      # attempt to load things
        begin
          require 'rubygems'
        rescue
          nil
        end

        begin
          require 'ohai'
          Ohai::Config[:plugin_path] << '/etc/chef/ohai_plugins'
          @ohai = Ohai::System.new
          @ohai.all_plugins
        rescue LoadError
          @ohai = nil
        end

        begin
          ENV['FACTERLIB'] = @facter_path.join(':')
          require 'facter'
          @facter = Facter
        rescue LoadError
          @facter = nil
        end
      end


      def fact(name, default=nil)
        if @facter
          return (Facter.value(name) or default)
        end

        return nil
      end

      def load_plugins
      # load plugins from @path
        @path.compact.each do |root|
          begin
            Dir["#{root}/*"].each do |directory|

            # only process top-level directories
              if File.directory?(directory)
                d = File.basename(directory)

              # allow plugins to be conditionally loaded based on fact values:
              #   default - always load
              #   <fact>-<fact_value> - load if <fact> == <fact_value>
              #
                if d == 'default' or Facter.value(d.split('-',2).first).to_s.downcase.nil_empty == d.split('-',2).last.to_s.downcase.nil_empty
                  Dir[File.join(directory, '*.rb')].each do |e|
                    e = File.basename(e, '.rb')
                    require "#{directory}/#{e}"
                  end
                end
              end
            end
          rescue Exception => e
            STDERR.puts e.message
            next
          end
        end
      end

      def add(&block)
        if block_given?
          instance_eval(&block)
        end
      end

      def property(name, value=nil)
        @_report[:properties].set(name, value) if value
      end

      def stat(name, value=nil)
        @_report[:properties][:metrics] ||= {}
        @_report[:properties][:metrics].set(name, value) if value
      end

      def report
        @id = (@options[:id] || (IO.read('/etc/hardware.id').to_s.nil_empty rescue nil))

        if not @id.nil?
          hostname = (Facter.value('fqdn') rescue %x{hostname -f}.strip.chomp)

          @_report = {
            :id           => @id,
            :name         => hostname,
            :aliases      => @options[:aliases],
            :tags         => @options[:tags],
            :status       => (@options[:status] || 'online'),
            :inventory    => true,
            :properties   => {}
          }

        # loads plugins and populates @_report
          load_plugins

          return @_report.compact()
        else
          raise "Cannot generate report without a hardware ID"
        end

        nil
      end
    end
  end
end