require 'open4'

# add additional fields to Exception class to format errors according to OT-API
module OpenToxError
  attr_accessor :http_code, :uri
  def initialize message, uri=nil
    super message
    #unless self.is_a? Errno::EAGAIN # avoid "Resource temporarily unavailable" errors
      @uri = uri.to_s.sub(%r{//.*:.*@},'//') # remove credentials from uri
      @http_code ||= 500
      @rdf = RDF::Graph.new
      subject = RDF::Node.new
      @rdf << [subject, RDF.type, RDF::OT.ErrorReport]
      @rdf << [subject, RDF::OT.actor, @uri]
      @rdf << [subject, RDF::OT.message, message.sub(/^"/,'').sub(/"$/,'')]
      @rdf << [subject, RDF::OT.statusCode, @http_code]
      @rdf << [subject, RDF::OT.errorCode, self.class.to_s]
      @rdf << [subject, RDF::OT.errorCause, short_backtrace]
      $logger.error("\n"+self.to_turtle)
    #end
  end

  def short_backtrace
    backtrace = caller.collect{|line| line unless line =~ /#{File.dirname(__FILE__)}/}.compact
    cut_index = backtrace.find_index{|line| line.match /sinatra|minitest/}
    cut_index ||= backtrace.size
    cut_index -= 1
    cut_index = backtrace.size-1 if cut_index < 0
    backtrace[0..cut_index].join("\n")
  end

  RDF_FORMATS.each do |format|
    # rdf serialization methods for all formats e.g. to_rdfxml
    send :define_method, "to_#{format}".to_sym do
      RDF::Writer.for(format).buffer do |writer|
        @rdf.each{|statement| writer << statement} if @rdf
      end
    end
  end

  def to_turtle # redefine to use prefixes (not supported by RDF::Writer)
    prefixes = {:rdf => "http://www.w3.org/1999/02/22-rdf-syntax-ns#"}
    ['OT', 'DC', 'XSD', 'OLO'].each{|p| prefixes[p.downcase.to_sym] = eval("RDF::#{p}.to_s") }
    RDF::Turtle::Writer.for(:turtle).buffer(:prefixes => prefixes)  do |writer|
      @rdf.each{|statement| writer << statement} if @rdf
    end
  end

end

class RuntimeError
#class StandardError
  include OpenToxError
end

# clutters log file with library errors
#class NoMethodError
  #include OpenToxError
#end

module OpenTox

  class Error < RuntimeError
    include OpenToxError
    
    def initialize code, message, uri=nil
      @http_code = code
      super message, uri
    end
  end

  # OpenTox errors
  RestClientWrapper.known_errors.each do |error|
    # create error classes 
    c = Class.new Error do
      define_method :initialize do |message, uri=nil|
        super error[:code], message, uri
      end
    end
    OpenTox.const_set error[:class],c
    
    # define global methods for raising errors, eg. bad_request_error
    Object.send(:define_method, error[:method]) do |message,uri=nil|
      raise c.new(message.inspect, uri)
    end
  end
  
end