require 'noumenon'
require 'sinatra'
require 'rack/mime'

# The core Noumenon web application, responsible for loading content from the repository,
# and then either rendering it with the appropriate template, or passing it to the specified
# application.
#
# @api public
class Noumenon::Core < Sinatra::Base
  def default_options
    {}
  end
  
  def initialize(options = {})
    @options = default_options.merge(options.symbolize_keys)
    @options[:mount_point] ||= "/"
    
    super nil
  end
  
  # Renders a content item within it's template and layout.
  #
  # If the template or layout is not specified then it will be set to "default".
  #
  # @param [ Hash ] page The content item to render.
  # @option page [ String ] :template The template to use when rendering the item.
  # @option page [ String ] :layout The layout to put the template within.
  # @return [ String ] The rendered page, or an error message if any templates could not be rendered.
  # @api public
  def render_page(page)
    page[:template] ||= "default"
    page[:layout] ||= "default"

    begin
      template = Noumenon.theme.template("#{page[:template]}.nou.html")
      content = template.render(page)
      
      wrap_with_layout(content, page)
    rescue Noumenon::Template::NotFoundError => e
      halt 500, "<h1>Missing Template</h1><p>The template '#{page[:template]}' does not exist within the current theme.</p>"
    rescue Noumenon::Template::MissingContentError => e
      halt 500, "<h1>Missing Fields</h1><p>#{e}</p>"
    end
  end
  

  # Convenience method to access the current content repository.
  #
  # @api public
  # @return [ Noumenon::Repository ] the current content repository
  def content
    Noumenon.content_repository
  end
  
  # The default assets handler is incredibly naive, loading the entire asset into memory, and then
  # sending it back out again. In the future asset repositories will be able to implement more sensible
  # methods of sending content, such as redirecting to an S3 URL.
  #
  # TODO: Abstract /assets/ out to an application which can be implemented by repositories which
  #       can't just provide a URL straight up (such as MongoDB).
  get "/assets/*" do |path|
    asset = Noumenon.asset_repository.get_asset_path(path)
    halt 404, "Asset not found" unless asset
    
    send_file asset
  end

  def route_missing
    if content && page = content.get(File.join(@options[:mount_point], @request.path_info))
      render_page(page)
    else
      halt 404, "<h1>Page Not Found</h1>"
    end 
  end

  private
    def wrap_with_layout(content, page)
      begin
        layout = Noumenon.theme.layout("#{page[:layout]}.nou.html")
        return layout.render( page.merge(content: content) )
      rescue Noumenon::Template::NotFoundError => e
        if page[:layout] == "default"
          return content
        else
          halt 500, "<h1>Missing Layout</h1><p>The layout '#{page[:layout]}' does not exist within the current theme.</p>"
        end
      end
    end
end