require 'noumenon'
require 'sinatra'

# 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
  # 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
  
  get "/assets/*" do |path|
    asset = Noumenon.asset_repository.get_asset("/#{path}")
    halt 404, "Asset not found" unless asset
    
    asset
  end

  get "*" do |path|
    page = content.get(path)
    
    unless page
      # Search up the tree until we either hit the top, and 404, or find a mounted application.
      path = path.split("/")
      while path.size > 0
        path.pop
        page = content.get(path.join("/"))
        break if page && page[:type] == "application"
      end
      
      halt 404, "<h1>Page Not Found</h1>" unless page
      path = path.join("/")
    end
    
    case page[:type]
    when "application"
      app = page[:application].constantize
      
      # Rewrite PATH_INFO so that the child application can listen to URLs assuming it's at the root.
      env["PATH_INFO"].gsub!("#{path}", "")
      env["PATH_INFO"] = "/" if env["PATH_INFO"] == ""
      app.new(page).call(env)
    else
      render_page(page)
    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