# Requests to the Resolve controller are OpenURLs.
# There is one exception: Instead of an OpenURL, you can include the
# parameter umlaut.request_id=[some id] to hook up to a pre-existing
# umlaut request (that presumably was an OpenURL). 

class ResolveController < UmlautController
  
  
  
  
  before_filter :init_processing
  # Init processing will look at this list, and for actions mentioned,
  # will not create a @user_request if an existing one can't be found.
  # Used for actions meant only to deal with existing requests. 
  @@no_create_request_actions = ['background_update']
  after_filter :save_request
  
  layout :layout_name,  
         :except => [:partial_html_sections]
  
  	
  def index
    self.service_dispatch()

    # check for menu skipping configuration. link is a ServiceResponse
    link = should_skip_menu
    if ( ! link.nil? )                   
      
      redirect_to url_for(:controller => "link_router",
                   :action => "index",
                   :id => link.id )            
    else
      # Render configed view, if configed, or default view if not.             
      render umlaut_config.resolve_view
    end

  end

  # inputs an OpenURL request into the system and stores it, but does
  # NOT actually dispatch services to provide a response. Will usually 
  # be called by software, not a human browser. Sometimes
  # it's useful to do this as a first step before redirecting the user
  # to the actual resolve action for the supplied request--for instance,
  # when the OpenURL metadata comes in a POST and can't be redirected. 
  def register_request
    # init before filter already took care of setting up the request.
    @user_request.save!

    # Return data in headers allowing client to redirect user
    # to view actual response. 
    headers["x-umlaut-request_id"] = @user_request.id
    headers["x-umlaut-resolve_url"] = url_for( :controller => 'resolve', 'umlaut.request_id'.to_sym => @user_request.id )
    headers["x-umlaut-permalink_url"] = current_permalink_url()

    # Return empty body. Once we have the xml response done,
    # this really ought to return an xml response, but with
    # no service responses yet available.
    render(:nothing => true)
  end

  # Useful for developers, generate a coins. Start from
  # search/journals?umlaut.display_coins=true
  # or search/books?umlaut.display_coins=true
  def display_coins

  end

  # Display a non-javascript background service status page--or
  # redirect back to index if we're done.
  def background_status

    unless ( @user_request.any_services_in_progress? )
      
      # Just redirect to ordinary index, no need to show progress status.
      # Include request.id, but also context object kev. 
      
      params_hash = 
         {:controller=>"resolve",
          :action=>'index', 
          'umlaut.skip_resolve_menu'.to_sym => params['umlaut.skip_resolve_menu'],
          'umlaut.request_id'.to_sym => @user_request.id }
      
      url = url_for_with_co( params_hash, @user_request.to_context_object )
      
      redirect_to( url )
    else
      # If we fall through, we'll show the background_status view, a non-js
      # meta-refresh update on progress of background services.
      # Your layout should respect this instance var--it will if it uses
      # the resolve_head_content partial, which it should.
      @meta_refresh_self = umlaut_config.lookup!("poll_wait_seconds", 4)
    end
  end

  # This action is for external callers. An external caller _could_ get
  # data as xml or json or whatever. But Umlaut already knows how to render
  # it. What if the external caller wants the rendered content, but in
  # discrete letter packets, a packet of HTML for each ServiceTypeValue?
  # This does that, and also let's the caller know if background
  # services are still running and should be refreshed, and gives
  # the caller a URL to refresh from if neccesary.   
  
  def partial_html_sections
    # Tell our application_helper#url_for to generate urls with hostname
    @generate_urls_with_host = true

    # Force background status to be the spinner--default js way of putting
    # spinner in does not generally work through ajax techniques.
    @force_bg_progress_spinner = true

    # Mark that we're doing a partial generation, because it might
    # matter later. 
    @generating_embed_partials = true
        
    # Run the request if neccesary. 
    self.service_dispatch()
    @user_request.save!

    self.api_render()
    
  end
  
  def api

    # Run the request if neccesary. 
    self.service_dispatch()
    @user_request.save!

    api_render()
    
  end  


    
  def rescue_action_in_public(exception)  
    render(:template => "error/resolve_error", :status => 500 ) 
  end  

  protected
  
  
  # We intentionally use a method calculated at request-time for layout,
  # so it can be changed in config at request-time. 
  def layout_name
    umlaut_config.resolve_layout
  end

    
  # Retrives or sets up the relevant Umlaut Request, and returns it. 
  def init_processing
    # intentionally trigger creation of session if it didn't already exist
    # because we need to track session ID for caching. Can't find any
    # way to force session creation without setting a value in session,
    # so we do this weird one. 
    session[nil] = nil
    
    # We have to clean the params of bad char encoding bytes, or it causes
    # no end of problems later. We can't just refuse to process, sources
    # do send us bad bytes, I'm afraid. 
    params.values.each do |v|
      EnsureValidEncoding.ensure_valid_encoding!(v, :invalid => :replace)
    end
    
    # Create an UmlautRequest object. 
    options = {}
    if (  @@no_create_request_actions.include?(params[:action])  )
      options[:allow_create] = false
    end
    @user_request ||= Request.find_or_create(params, session, request, options )

    # If we chose not to create a request and still don't have one, bale out.
    return unless @user_request
    
    @user_request.save!
     
    @collection = create_collection      
  end

  def save_request
    @user_request.save!
  end
 	

  # Based on app config and context, should we skip the resolve
  # menu and deliver a 'direct' link? Returns nil if menu
  # should be displayed, or the ServiceType join object
  # that should be directly linked to. 
  def should_skip_menu
    # From usabilty test, do NOT skip if coming from A-Z list/journal lookup.
    # First, is it over-ridden in url?
    if ( params['umlaut.skip_resolve_menu'] == 'false')
      return nil
    elsif ( params['umlaut.skip_resolve_menu_for_type'] )      
      skip = {:service_types => params['umlaut.skip_resolve_menu_for_type'].split(",") }
    end
    
    # Otherwise if not from url, load from app config
    skip  ||= umlaut_config.skip_resolve_menu  if skip.nil?    

    if (skip.kind_of?( FalseClass ))
      # nope
      return nil
    end

    return_value = nil
    if (skip.kind_of?(Hash) )
      # excluded rfr_ids?
      exclude_rfr_ids = skip[:excluded_rfr_ids]
      rfr_id = @user_request.referrer_id  
      return nil if exclude_rfr_ids != nil && exclude_rfr_ids.find {|i| i == rfr_id}

      # Services to skip for?
      skip[:service_types].each do | service |
        service = ServiceTypeValue[service] unless service.kind_of?(ServiceTypeValue)  

        candidates = 
        @user_request.service_responses.find(:all, 
          :conditions => ["service_type_value_name = ?", service.name])
        
        return_value = candidates.first 
        
      end

      # But wait, make sure it's included in :services if present.
      if (return_value && skip[:services] )
        return_value = nil unless skip[:services].include?( return_value.service_id )
      end
    elsif (skip.kind_of?(Proc ))
      return_value = skip.call( :request => @user_request )
      
    else
      logger.error( "Unexpected value in config 'skip_resolve_menu'; assuming false." )
    end
    
    return return_value;    
  end

  


  # Uses an "umlaut.response_format" param to return either
  # XML or JSON(p).  Is called from an action that has a standardly rendered
  # Rails template that delivers XML.  Will convert that standardly rendered
  # template output to json using built in converters if needed.  
  def api_render    
    # Format?
    request.format = "xml" if request.format.html? # weird hack to support legacy behavior, with xml as default
    if params["umlaut.response_format"] == "jsonp"
      request.format = "json"
      params["umlaut.jsonp"] ||= "umlautLoaded" 
    elsif params["umlaut.response_format"]
      request.format = params["umlaut.response_format"]
    end
        
    
    respond_to do |format|
      format.xml do         
        render(:layout => false)
      end
      
      format.json do        
        # get the xml in a string
        xml_str = 
          with_format(:xml) do
            render_to_string(:layout=>false)
          end
        # convert to hash. For some reason the ActionView::OutputBuffer
        # we actually have (which looks like a String but isn't exactly)
        # can't be converted to a hash, we need to really force String
        # with #to_str
        data_as_hash = Hash.from_xml( xml_str.to_str )
        # And conver to json. Ta-da!
        json_str = data_as_hash.to_json
  
        # Handle jsonp, deliver JSON inside a javascript function call,
        # with function name specified in parameters. 
        render(:json => json_str, :callback => params["umlaut.jsonp"] )      
      end    
    end
  end

  def service_dispatch()
    @collection.dispatch_services!
  end


  
end