require "fileutils"

class MultiSolr::TimelineCoreHandler

  attr_reader :simple_core_handler_class
  attr_reader :core_group_name
  attr_reader :solr_url


  def initialize solr_url, core_group_name, simple_core_handler_class
    @simple_core_handler_class = simple_core_handler_class
    @core_group_name = core_group_name
    @solr_url = solr_url || raise("No solr-url given!")
  end


  def create_single_core_handler core_name=nil, options=nil
    core_name ||= last_core_name
    @simple_core_handler_class.new @solr_url, core_name, options
  end



  # Liefert Array mit den Namen der verfügbaren Cores, die mit dem Core-Namen (see core_name) beginnen
  # Diese Liste wird gecached
  def list_cores include_empties=false
    return @cores if @cores
    status = self.core_status
    @cores = []
    matcher = Regexp.new "^#{@core_group_name}"
    status.each do |core_name, data|
      next unless matcher.match(core_name)
      next if data['index']['numDocs'] < 3 && !include_empties
      @cores << core_name
    end
    @cores.sort!
    MultiSolr.logger.info "MultiSolr::TimelineCoreHandler.list_cores: #{@cores.join(',')}"
    @cores
  end

  # Rücksetzen Cache der core-liste (see list_cores)
  def reset_cores
    @cores = @last_core_name = nil
  end

  # Liefert Name des letzte Cores der laut alphabetischer Liste (see list_cores) existiert
  def last_core_name
    @last_core_name ||= list_cores.last
  end

  def base_connection
    @_connection ||= RSolr.connect :url => @solr_url
  end


  def core_connection core_name=nil
    core_name ||= last_core_name
    RSolr.connect :url => "#{@solr_url}/#{core_name}"
  end


  def create_core suffix=nil
    suffix = Time.now.strftime('%Y%m%d-%H%M') if suffix.nil?
    new_core_name = "#{@core_group_name}-#{suffix}"
    status = self.core_status last_core_name
    old_name = status['name']
    instance_dir_old = status['instanceDir']
    instance_dir = instance_dir_old.sub(/^solr\//, '') # führendes solr im instanceDir ist zuviel, also entfernen
    data_dir = status['dataDir'].sub(/#{old_name}\/$/, new_core_name)
    data_dir.sub!(/^#{instance_dir_old}/, '')# führendes instanceDir im dataDir ist zuviel, also entfernen
    res = self.base_connection.get 'admin/cores', :params => {:action => 'CREATE',
                                                  :name => new_core_name,
                                                  :instanceDir => instance_dir,
                                                  :dataDir => data_dir}
    reset_cores
    MultiSolr.logger.info "MultiSolr::TimelineCoreHandler.create_core: Core '#{new_core_name}' created. dataDir=#{data_dir}, instanceDir=#{instance_dir}"
    new_core_name
  end


  def dataimport import_handler_name, command='full-import', core_name=nil
    core_name ||= last_core_name
    con = core_connection core_name
    res = con.get import_handler_name, :params => {:command => command}
    MultiSolr.logger.info "MultiSolr::TimelineCoreHandler.dataimport: core=#{core_name}, command=#{command}, handler=#{import_handler_name}"
    res
  end

  # Entfernen angegebenen Core aus der Core-Liste inkl. unload-Befehl an den Solr
  # Achtung! Diese Methode löscht kann nur dann die physischen Daten des Cores löschen,
  # wenn dieser mit einer absoluten Pfad-Angabe im solr konfiguriert ist!
  # Parameter:
  #   core_name:    Name des zu löschenden Cores
  #   with_data:    optionaler Angabe ob Daten mit gelöscht werden sollen (Standardmäßig aus)
  def remove_core core_name, with_data=false
    status = self.core_status core_name
    raise "no core '#{core_name}'!" if status.nil? || status['name'].nil?
    base_connection.get 'admin/cores', :params => {:action => 'unload', :core => core_name}
    MultiSolr.logger.info "MultiSolr::TimelineCoreHandler.remove_core: Core '#{core_name}' unloaded"
    if with_data
      data_dir = status['dataDir']
      raise "No absolute DataDir-Path! Only Core was unloaded!" unless data_dir.start_with?('/')
      FileUtils.rm_rf data_dir
    end
    reset_cores
    nil
  end


  # Liefert Core-Status evtl. aller Cores oder wenn Core-Name angegeben des einzelnen Cores
  # returns Hash mit den Statusdaten
  #   Beispiel für alle Cores:
  #      {'core-01'=>{'name'=>'core-01',
  #                   'instanceDir'=>'solr/cobra-stock/',
  #                   'dataDir'=>'solr/cobra-stock/../../data/cobra-stock/',
  #                   'startTime'=>'2012-04-11T09:49:07.93Z',
  #                   'uptime'=>7796905,
  #                   'index'=>{'numDocs'=>1369046,'maxDoc'=>1369046,'version'=>1334134600492,'optimized'=>true,'current'=>true,'hasDeletions'=>false,'directory'=>'org.apache.lucene.store.NIOFSDirectory:org.apache.lucene.store.NIOFSDirectory@/home/bledig/Projects/lava/multi-solr/data/cobra-stock-20120411-1123/index lockFactory=org.apache.lucene.store.NativeFSLockFactory@1896a4c','lastModified'=>'2012-04-11T09:43:32Z'}},
  #                  },...
  #      }
  def core_status core_name=nil
    params = {:action => 'STATUS' }
    params[:core] = core_name if core_name
    res = base_connection.get 'admin/cores', :params => params
    status = res && res['status']
    raise 'No status for cores available' if status.nil?
    return status[core_name] if core_name
    status
  end

end