require 'net/http'

require 'rubygems'
require 'rainbow'

module NginxTail
  class LogLine

    def self.component_to_module_name(component)
      # this mimicks the ActiveSupport::Inflector.camelize() method in Rails...
      component.to_s.gsub(/\/(.?)/) { "::#{$1.upcase}" }.gsub(/(?:^|_)(.)/) { $1.upcase }
    end
    
    def self.component_to_ntail_module(component)
      # this mimicks the ActiveSupport::Inflector.constantize() method in Rails...
      NginxTail.const_get(self.component_to_module_name(component))
    end

    attr_reader :raw_line
    attr_reader :parsable

    COMPONENTS = [
      :remote_addr,
      :remote_user,
      :time_local,
      :request,
      :status,
      :body_bytes_sent,
      :http_referer,
      :http_user_agent,
      :proxy_addresses,
    ]
    
    COMPONENTS.each do |symbol|
      attr_reader symbol
      include component_to_ntail_module(symbol)
    end

    include KnownIpAddresses # module to identify known IP addresses
    include LocalIpAddresses # module to identify local IP addresses

    SUBCOMPONENTS = [
      :http_method,
      :uri,
      :http_version,
    ]
    
    SUBCOMPONENTS.each do |symbol|
      attr_reader symbol
      include component_to_ntail_module(symbol)
    end

    #
    # http://wiki.nginx.org/NginxHttpLogModule#log_format - we currently only support the default "combined" log format...
    #

    NGINX_LOG_PATTERN = Regexp.compile(/\A(\S+) - (\S+) \[([^\]]+)\] "([^"]+)" (\S+) (\S+) "([^"]*?)" "([^"]*?)"( "([^"]*?)")?\Z/)
    NGINX_REQUEST_PATTERN = Regexp.compile(/\A(\S+) (.*?) (\S+)\Z/)
    NGINX_PROXY_PATTERN = Regexp.compile(/\A "([^"]*)"\Z/)

    def initialize(line)
      @parsable = if NGINX_LOG_PATTERN.match(@raw_line = line)
        @remote_addr, @remote_user, @time_local, @request, @status, @body_bytes_sent, @http_referer, @http_user_agent, @proxy_addresses = $~.captures
        if NGINX_REQUEST_PATTERN.match(@request)
          # counter example (ie. HTTP request that cannot by parsed)
          # 91.203.96.51 - - [21/Dec/2010:05:26:53 +0000] "-" 400 0 "-" "-"
          @http_method, @uri, @http_version = $~.captures
        end
        if @proxy_addresses and NGINX_PROXY_PATTERN.match(@proxy_addresses)
          @proxy_addresses = $~.captures.first.split(/, /)
        end
        true
      else
        false
      end
    end
    
    alias_method :remote_address, :remote_addr # a non-abbreviated alias, for convenience and readability...
    
    # for now, until we make it fancier...
    def method_missing(method, *params)
      raw_line.send method, *params
    end
    
    @@parser = FormattingParser.new
    
    def to_s()
      # simple but boring:
      # raw_line.to_s
      color = if redirect_status?
        :yellow
      elsif !success_status?
        :red
      else
        :default
      end
      unless result = @@parser.parse("%d - %a - %s - %r - %u - %f")
        raise @@parser.terminal_failures.join("\n")
      else
        def result.value(log_line, color)
          elements.map { |element| element.value(log_line, color) }.join
        end
      end
      result.value(self, color) 
    end
  
  end # class LogLine
end # module NginxTail