module RequestLogAnalyzer::FileFormat
  class Haproxy < RequestLogAnalyzer::FileFormat::Base
    extend CommonRegularExpressions

    # substitute version specific parts of the haproxy entry regexp.
    def self.compose_regexp(millisecs, backends, counters, connections, queues)
      %r{
        (#{ip_address}):\d+\s # client_ip ':' client_port
        \[(#{timestamp('%d/%b/%Y:%H:%M:%S')})#{millisecs}\]\s # '[' accept_date ']'
        (\S+)\s # frontend_name
        #{backends}
        #{counters}
        (\d+)\s # status_code
        \+?(\d+)\s # bytes_read
        (\S+)\s # captured_request_cookie
        (\S+)\s # captured_response_cookie
        (\w|-)(\w|-)(\w|-)(\w|-)\s # termination_state
        #{connections}
        #{queues}
        (\S*)\s? # captured_request_headers
        (\S*)\s? # captured_response_headers
        "([^"]*)" # '"' http_request '"'
      }x
    end

    # Define line types

    # line definition for haproxy 1.3 and higher
    line_definition :haproxy13 do |line|
      line.header = true
      line.footer = true
      line.teaser = /\.\d{3}\] \S+ \S+\/\S+ / # .millisecs] frontend_name backend_name/server_name

      line.regexp = compose_regexp(
        '\.\d{3}', # millisecs
        '(\S+)\/(\S+)\s', # backend_name '/' server_name
        '(\d+|-1)\/(\d+|-1)\/(\d+|-1)\/(\d+|-1)\/\+?(\d+)\s', # Tq '/' Tw '/' Tc '/' Tr '/' Tt
        '(\d+)\/(\d+)\/(\d+)\/(\d+)\/\+?(\d+)\s', # actconn '/' feconn '/' beconn '/' srv_conn '/' retries
        '(\d+)\/(\d+)\s' # srv_queue '/' backend_queue
      )

      line.capture(:client_ip).as(:string)
      line.capture(:timestamp).as(:timestamp)
      line.capture(:frontend_name).as(:string)
      line.capture(:backend_name).as(:string)
      line.capture(:server_name).as(:string)
      line.capture(:tq).as(:nillable_duration, unit: :msec)
      line.capture(:tw).as(:nillable_duration, unit: :msec)
      line.capture(:tc).as(:nillable_duration, unit: :msec)
      line.capture(:tr).as(:nillable_duration, unit: :msec)
      line.capture(:tt).as(:duration, unit: :msec)
      line.capture(:status_code).as(:integer)
      line.capture(:bytes_read).as(:traffic, unit: :byte)
      line.capture(:captured_request_cookie).as(:nillable_string)
      line.capture(:captured_response_cookie).as(:nillable_string)
      line.capture(:termination_event_code).as(:nillable_string)
      line.capture(:terminated_session_state).as(:nillable_string)
      line.capture(:clientside_persistence_cookie).as(:nillable_string)
      line.capture(:serverside_persistence_cookie).as(:nillable_string)
      line.capture(:actconn).as(:integer)
      line.capture(:feconn).as(:integer)
      line.capture(:beconn).as(:integer)
      line.capture(:srv_conn).as(:integer)
      line.capture(:retries).as(:integer)
      line.capture(:srv_queue).as(:integer)
      line.capture(:backend_queue).as(:integer)
      line.capture(:captured_request_headers).as(:nillable_string)
      line.capture(:captured_response_headers).as(:nillable_string)
      line.capture(:http_request).as(:nillable_string)
    end

    # haproxy 1.2 has a few fields less than 1.3+
    line_definition :haproxy12 do |line|
      line.header = true
      line.footer = true
      line.teaser = /\.\d{3}\] \S+ \S+ / # .millisecs] frontend_name server_name

      line.regexp = compose_regexp(
        '\.\d{3}', # millisecs
        '(\S+)\s', # server_name
        '(\d+|-1)\/(\d+|-1)\/(\d+|-1)\/(\d+|-1)\/\+?(\d+)\s', # Tq '/' Tw '/' Tc '/' Tr '/' Tt
        '(\d+)\/(\d+)\/(\d+)\s', # srv_conn '/' listener_conn '/' process_conn
        '(\d+)\/(\d+)\s' # srv_queue '/' backend_queue
      )

      line.capture(:client_ip).as(:string)
      line.capture(:timestamp).as(:timestamp)
      line.capture(:frontend_name).as(:string)
      line.capture(:server_name).as(:string)
      line.capture(:tq).as(:nillable_duration, unit: :msec)
      line.capture(:tw).as(:nillable_duration, unit: :msec)
      line.capture(:tc).as(:nillable_duration, unit: :msec)
      line.capture(:tr).as(:nillable_duration, unit: :msec)
      line.capture(:tt).as(:duration, unit: :msec)
      line.capture(:status_code).as(:integer)
      line.capture(:bytes_read).as(:traffic, unit: :byte)
      line.capture(:captured_request_cookie).as(:nillable_string)
      line.capture(:captured_response_cookie).as(:nillable_string)
      line.capture(:termination_event_code).as(:nillable_string)
      line.capture(:terminated_session_state).as(:nillable_string)
      line.capture(:clientside_persistence_cookie).as(:nillable_string)
      line.capture(:serverside_persistence_cookie).as(:nillable_string)
      line.capture(:srv_conn).as(:integer)
      line.capture(:listener_conn).as(:integer)
      line.capture(:process_conn).as(:integer)
      line.capture(:srv_queue).as(:integer)
      line.capture(:backend_queue).as(:integer)
      line.capture(:captured_request_headers).as(:nillable_string)
      line.capture(:captured_response_headers).as(:nillable_string)
      line.capture(:http_request).as(:nillable_string)
    end

    # and haproxy 1.1 has even less fields
    line_definition :haproxy11 do |line|
      line.header = true
      line.footer = true
      line.teaser = /:\d{2}\] \S+ \S+ / # :secs] frontend_name server_name

      line.regexp = compose_regexp(
        '', # no millisec precision in this version of haproxy
        '(\S+)\s', # server_name
        '(\d+|-1)\/(\d+|-1)\/(\d+|-1)\/\+?(\d+)\s', # Tq '/' Tc '/' Tr '/' Tt
        '(\d+)\/(\d+)\s', # listener_conn '/' process_conn
        '' # no queues in this version of haproxy
      )

      line.capture(:client_ip).as(:string)
      line.capture(:timestamp).as(:timestamp)
      line.capture(:frontend_name).as(:string)
      line.capture(:server_name).as(:string)
      line.capture(:tq).as(:nillable_duration, unit: :msec)
      line.capture(:tc).as(:nillable_duration, unit: :msec)
      line.capture(:tr).as(:nillable_duration, unit: :msec)
      line.capture(:tt).as(:duration, unit: :msec)
      line.capture(:status_code).as(:integer)
      line.capture(:bytes_read).as(:traffic, unit: :byte)
      line.capture(:captured_request_cookie).as(:nillable_string)
      line.capture(:captured_response_cookie).as(:nillable_string)
      line.capture(:termination_event_code).as(:nillable_string)
      line.capture(:terminated_session_state).as(:nillable_string)
      line.capture(:clientside_persistence_cookie).as(:nillable_string)
      line.capture(:serverside_persistence_cookie).as(:nillable_string)
      line.capture(:listener_conn).as(:integer)
      line.capture(:process_conn).as(:integer)
      line.capture(:srv_queue).as(:integer)
      line.capture(:backend_queue).as(:integer)
      line.capture(:captured_request_headers).as(:nillable_string)
      line.capture(:captured_response_headers).as(:nillable_string)
      line.capture(:http_request).as(:nillable_string)
    end

    # Define the summary report
    report do |analyze|
      analyze.hourly_spread field: :timestamp

      analyze.frequency :client_ip,
                        title: 'Hits per IP'

      analyze.frequency :frontend_name,
                        title: 'Hits per frontend service'

      analyze.frequency :backend_name,
                        title: 'Hits per backend service'

      analyze.frequency :server_name,
                        title: 'Hits per backend server'

      analyze.frequency :status_code,
                        title: 'HTTP response code frequency'

      analyze.frequency :http_request,
                        title: 'Most popular requests'

      analyze.frequency :http_request,
                        title: 'Most frequent HTTP 40x errors',
                        category: lambda { |r| "#{r[:http_request]}" },
                        if: lambda { |r| r[:status_code] >= 400 && r[:status_code] <= 417 }

      analyze.frequency :http_request,
                        title: 'Most frequent HTTP 50x errors',
                        category: lambda { |r| "#{r[:http_request]}" },
                        if: lambda { |r| r[:status_code] >= 500 && r[:status_code] <= 505 }

      analyze.traffic :bytes_read,
                      title: 'Traffic per frontend service',
                      category: lambda { |r| "#{r[:frontend_name]}" }

      analyze.traffic :bytes_read,
                      title: 'Traffic per backend service',
                      category: lambda { |r| "#{r[:backend_name]}" }

      analyze.traffic :bytes_read,
                      title: 'Traffic per backend server',
                      category: lambda { |r| "#{r[:server_name]}" }

      analyze.duration :tr,
                       title: 'Time waiting for backend response',
                       category: lambda { |r| "#{r[:http_request]}" }

      analyze.duration :tt,
                       title: 'Total time spent on request',
                       category: lambda { |r| "#{r[:http_request]}" }
    end

    # Define a custom Request class for the HAProxy file format to speed up
    # timestamp handling. Shamelessly copied from apache.rb
    class Request < RequestLogAnalyzer::Request
      MONTHS = { 'Jan' => '01', 'Feb' => '02', 'Mar' => '03', 'Apr' => '04', 'May' => '05', 'Jun' => '06',
                'Jul' => '07', 'Aug' => '08', 'Sep' => '09', 'Oct' => '10', 'Nov' => '11', 'Dec' => '12' }

      # Do not use DateTime.parse, but parse the timestamp ourselves to return
      # a integer to speed up parsing.
      def convert_timestamp(value, _definition)
        "#{value[7, 4]}#{MONTHS[value[3, 3]]}#{value[0, 2]}#{value[12, 2]}#{value[15, 2]}#{value[18, 2]}".to_i
      end

      # Make sure that the strings '-' or '{}' or '' are parsed as a nil value.
      def convert_nillable_string(value, _definition)
        value =~ /-|\{\}|^$/ ? nil : value
      end

      # Make sure that -1 is parsed as a nil value.
      def convert_nillable_duration(value, definition)
        value == '-1' ? nil : convert_duration(value, definition)
      end
    end
  end
end