class Fedora::Repository

def self.flush
  Thread.current[:repo]=nil
end

def self.instance
  raise "did you register a repo?" unless Thread.current[:repo]
  Thread.current[:repo]
end

def self.register(url, surrogate=nil)
  url = url.to_s.chop if url.to_s =~ /\/\Z/
  Thread.current[:repo]= Fedora::Repository.new(url, surrogate)
  begin
    repo = Thread.current[:repo]
    attributes = repo.describe_repository
    repo.repository_name = attributes["repositoryName"].first
    repo.base_url = attributes["repositoryBaseURL"].first
    repo.fedora_version = attributes["repositoryVersion"].first
    repo.pid_namespace = attributes["repositoryPID"].first["PID-namespaceIdentifier"].first
    repo.pid_delimiter = attributes["repositoryPID"].first["PID-delimiter"].first
  rescue
  end
  Thread.current[:repo]
end

def connection(refresh = false)
  if refresh || @connection.nil?
    @connection = Fedora::Connection.new(@fedora_url, Fedora::XmlFormat, @surrogate)
  end
  @connection
end

def convert_xml(response)
  results = FedoraObjects.new
  return results unless response && response['resultList']
  results.session_token = response['listSession']['token'] if response['listSession']
  objectFields = response['resultList']['objectFields']
  case objectFields
    when Array
      objectFields.each { |attrs| results << FedoraObject.new(attrs.rekey!) }
    when Hash
      results << FedoraObject.new(objectFields.rekey!)
  end
  results.each {|result| result.new_object = false}
  results
end

def create(object)
  case object
    when Fedora::FedoraObject
      pid = (object.pid ? object : 'new')
      response = connection.post("#{url_for(pid)}?" + object.attributes.to_fedora_query, object.blob)
      if response.code == '201'
        object.pid = extract_pid(response) 
        object.new_object = false
        true
      else
        false
      end
    when Fedora::Datastream
      raise ArgumentError, "Missing dsID attribute" if object.dsid.nil?
      extra_headers = {}
      extra_headers['Content-Type'] = object.attributes[:mimeType] if object.attributes[:mimeType]
      response = connection.post("#{url_for(object)}?" + object.attributes.to_fedora_query, 
        object.blob, extra_headers)
      if response.code == '201'
        object.new_object = false
        true
      else
        false
      end
    else
      raise ArgumentError, "Unknown object type"
  end
  
end

def delete(object)
  raise ArgumentError, "Object must not be nil" if object.nil?
  response = connection.delete("#{url_for(object)}")
  response.code == '200' or response.code == '204'  # Temporary hack around error in Fedora 3.0 Final's REST API
end

def describe_repository
  result_body = connection.raw_get("#{fedora_url.path}/describe?xml=true").body
  XmlSimple.xml_in(result_body)
end

def export(object, extra_params={})
  extra_params = {:format=>:foxml, :context=>:archive}.merge!(extra_params)
  if extra_params[:format].kind_of?(String)
    format = extra_params[:format]
  else
    format = case extra_params[:format]
      when :atom then "info:fedora/fedora-system:ATOM-1.1"
      when :atom_zip then "info:fedora/fedora-system:ATOMZip-1.1"
      when :mets then "info:fedora/fedora-system:METSFedoraExt-1.1"
      when :foxml then "info:fedora/fedora-system:FOXML-1.1"
      else "info:fedora/fedora-system:FOXML-1.1"
    end
  end
  fetch_custom(object, "export", :format=>format, :context=>extra_params[:context].to_s)
end

def extract_pid(response)
  CGI.unescape(response['Location'].split('/').last)
end

def fetch_content(object_uri)
  response = connection.raw_get("#{url_for(object_uri)}?format=xml")
  StringResponse.new(response.body, response.content_type)
end

def fetch_custom(object, method, extra_params = { :format => 'xml' })
  path = case method
    when :profile then ""
    else "/#{method}"
  end
  
  extra_params.delete(:format) if method == :export
  connection.raw_get("#{url_for(object)}#{path}?#{extra_params.to_fedora_query}").body
end

def find_model(pid, klazz)
  obj = self.find_objects("pid=#{pid}").first
  doc = REXML::Document.new(obj.object_xml, :ignore_whitespace_nodes=>:all)
  klazz.deserialize(doc)
end

def find_objects(*args)
  raise ArgumentError, "Missing query string" unless args.length >= 1
  options = args.last.is_a?(Hash) ? args.pop : {}
  
  fields = options[:select]
  fields = (fields.nil? || (fields == :all)) ? ALL_FIELDS : ([:pid] + ([fields].flatten! - [:pid]))
  
  query = args.join(' ')
  params = { :resultFormat => 'xml', :query => query }
  params[:maxResults] = options[:limit] if options[:limit]
  params[:sessionToken] = options[:sessionToken] if options[:sessionToken]
  includes = fields.inject("") { |s, f| s += "&#{f}=true"; s }
  
  convert_xml(connection.get("#{fedora_url.path}/objects?#{params.to_fedora_query}#{includes}"))
end

def ingest(content_to_ingest, extra_params={})
  if extra_params[:pid]
    url = url_for(extra_params[:pid])
  else
    url = url_for("new")
  end
  
  if content_to_ingest.kind_of?(File) 
    content_to_ingest = content_to_ingest.read
  end
    
  connection.post(url,content_to_ingest)
end

def initialize(fedora_url, surrogate=nil)
  @fedora_url = fedora_url.is_a?(URI) ? fedora_url : URI.parse(fedora_url)
  @surrogate = surrogate
  @connection = nil
end

def nextid
  d = REXML::Document.new(connection.post(fedora_url.path+"/management/getNextPID?xml=true").body)
  d.elements['//pid'].text
end

def save(object)
  object.new_object? ? create(object) : update(object)
end

def update(object)
  raise ArgumentError, "Missing pid attribute" if object.nil? || object.pid.nil?
  case object
  when Fedora::FedoraObject
    response = connection.put("#{url_for(object)}?" + object.attributes.to_fedora_query)
    response.code == '200' || '307'
  when Fedora::Datastream
    raise ArgumentError, "Missing dsID attribute" if object.dsid.nil?
    response = connection.put("#{url_for(object)}?" + object.attributes.to_fedora_query, object.blob)
    response.code == '200' || '201'
    return response.code
  else
    raise ArgumentError, "Unknown object type"
  end
end

def url_for(object)
  uri = object.respond_to?(:uri) ? object.uri : object.to_s
  uri = (uri[0..NAMESPACE.length-1] == NAMESPACE ? uri[NAMESPACE.length..-1] : uri) # strip of fedora:info namespace
  "#{fedora_url.path}/objects/#{uri}"
end