class EScleaner

# File lib/elasticsearch-data-cleaner.rb, line 14
def initialize(options)
  @connection = ::Faraday.new options.url, { :request => { :timeout => options.timeout } }
  @options = options
  info()
end

# File lib/elasticsearch-data-cleaner.rb, line 38
def acknowledged_test(response, answer)
  # Testing ES response for errors
  r = parse_response response.body
  if r.has_key? answer and r[answer] == true
  else
    raise 'request failed'
  end
end

# File lib/elasticsearch-data-cleaner.rb, line 85
def delete(object)
  # Deleting indices or types
  $logger.info("deleting #{object}#{@options.dry_run ? ' (dry_run)': ''}")
  if !@options.dry_run
    resp = @connection.delete "#{object}"
    acknowledged_test resp, 'acknowledged'
  end
end

# File lib/elasticsearch-data-cleaner.rb, line 71
def docs(index)
  # Returns number of documents for index
  resp = @connection.get "#{index}/_stats/docs"
  r = (parse_response resp.body)['_all']['primaries']['docs']['count']
  if r
    if r < 10
      $logger.warn("index #{index} has #{r} docs")
    end
    return r
  else
    raise "could not get count of docs for index #{index}"
  end
end

# File lib/elasticsearch-data-cleaner.rb, line 54
def exists(index, type)
  #checks if type exists
  if @es_version['major'] >= 5
    url = "#{index}/_mapping/#{type}"
  else
    url = "#{index}/#{type}"
  end
  resp = @connection.head url
  if resp.status == 200
    return true
  elsif resp.status == 404
    return false
  else
    raise "could not check if type #{index}/#{type} exists. got response code #{resp.status}"
  end
end

# File lib/elasticsearch-data-cleaner.rb, line 20
def info
  #get ES information
  resp = @connection.get
  @es_info = parse_response resp.body
  @es_version = {}
  @es_version['major'], @es_version['minor'], @es_version['patch'] = @es_info['version']['number'].split('.').map { |i| i.to_i }
  $logger.debug("detected Elasticsearch #{@es_version['major']}.#{@es_version['minor']}")
end

# File lib/elasticsearch-data-cleaner.rb, line 47
def list
  # Get list of indices
  resp = @connection.get "_aliases"
  r = parse_response resp.body
  r.keys
end

# File lib/elasticsearch-data-cleaner.rb, line 94
def optimize(index)
  # Run _forcemerge or _optimize
  if @es_version['major'] > 2 or (@es_version['major'] == 2 and @es_version['minor'] >= 1)
    api = '_forcemerge'
  else
    api = '_optimize'
  end
  $logger.info("starting optimize for index #{index}#{@options.dry_run ? ' (dry_run)': ''}")
  if !@options.dry_run
    resp = @connection.post "#{index}/#{api}?only_expunge_deletes=true"
    failed = (parse_response resp.body)['_shards']['failed']
    if failed > 0
      $logger.warn("optimizing of index #{index} returns #{failed} failed shards")
    end
  end
end

# File lib/elasticsearch-data-cleaner.rb, line 29
def parse_response(response)
  j = ::JSON.parse response
  if j.has_key?('error')
    raise j['error']
  else
    j
  end
end

# File lib/elasticsearch-data-cleaner.rb, line 111
def run(config)
  # Run rotate of ES data
  config.each do |pattern, settings|
    a = []
    list().each do |index|
      # check if empty just delete it
      if !@options.empty and docs(index) == 0
        delete(index)
      else
        begin
          a << DateTime.strptime(index, pattern)
        rescue
        end
      end
    end
    today = Date.today
    sorted = a.sort
    while sorted.length > 0
      need_to_optimize = false
      date = sorted.pop
      d = date.to_date
      index = date.strftime(pattern)
      if d > today
        if settings['future'] == false
          $logger.debug("going to delete index #{index}. It is future")
          delete(index)
        end
      else
        if settings['number']
          if settings['number'] <= 0
            delete(index)
          else
            if settings['types']
              # Checking types settings
              settings['types'].each do |type, type_settings|
                if exists(index, type)
                  if type_settings['number']
                    if type_settings['number'] <= 0
                      delete("#{index}/#{type}")
                      if type_settings['optimize'] and need_to_optimize == false
                        need_to_optimize = true
                      end
                    else
                      type_settings['number'] -= 1
                    end
                  end
                end
              end
            end
          end
          settings['number'] -= 1
        end
      end
      a.delete(date)
      # do optimize if needed
      if need_to_optimize
        optimize(index)
      end
    end
  end
end