module Merb
  
  class Dispatcher
    class << self
      
      attr_accessor :path_prefix
      
      def use_mutex=(val)
        @@use_mutex = val
      end
      
      @@mutex = Mutex.new
      @@use_mutex = ::Merb::Server.use_mutex
      # This is where we grab the incoming request REQUEST_URI and use that in
      # the merb RouteMatcher to determine which controller and method to run.
      # Returns a 2 element tuple of: [controller, action]
      def handle(request, response)
        start = Time.now
        
        request_uri = request.params[Merb::Const::REQUEST_URI]
        request_uri.sub!(path_prefix, '') if path_prefix
        route = route_path(request_uri)
      
        allowed = route.delete(:allowed)
        rest = route.delete(:rest)
        namespace = route.delete(:namespace)
        
        cont = namespace ? "#{namespace}/#{route[:controller]}" : route[:controller]
        
        klass = resolve_controller(cont)
        controller = klass.build(request.body, request.params, route, response)
      
        if rest
          method = controller.request.method
          if allowed.keys.include?(method) && action = allowed[method]
            controller.params[:action] = action
          else
            raise Merb::HTTPMethodNotAllowed.new(method, allowed)
          end  
        else  
          action = route[:action]
        end
        controller._benchmarks[:setup_time] = Time.now - start
        if @@use_mutex
          @@mutex.synchronize {
            controller.dispatch(action)
          }
        else
          controller.dispatch(action)
        end
        [controller, action]
      end
      
      def route_path(path)
        path = path.sub(/\/+/, '/').sub(/\?.*$/, '')
        path = path[0..-2] if (path[-1] == ?/) && path.size > 1
        Merb::Router.match(path)
      end
      
      # Take a controller class name string and reload or require the right
      # controller file then CamelCase it and return the class object.
      def resolve_controller(controller_name)
        segments = controller_name.split('/').map{|s| s.snake_case}
        path = "#{DIST_ROOT}/app/controllers/#{controller_name}.rb"
        cnt = segments.map{|s| s.camel_case }.join('::')
        
        if !File.exist?(path)
          raise "Bad controller! #{cnt}"
        end unless $TESTING
        
        begin
          if MERB_ENV == 'development'
            Object.send(:remove_const, cnt) rescue nil
            load(path)
          end
          return Object.full_const_get(cnt)
        rescue RuntimeError
          warn "Error getting instance of '#{controller_name.camel_case}': #{$!}"
          raise $!
        end
      end

    end # end class << self
      
  end
  
end