require 'test/unit'
require 'test/unit/assertions'
require 'rexml/document'

module Test #:nodoc:
  module Unit #:nodoc:
    # In addition to these specific assertions, you also have easy access to various collections that the regular test/unit assertions
    # can be used against. These collections are:
    #
    # * assigns: Instance variables assigned in the action that's available for the view.
    # * session: Objects being saved in the session.
    # * flash: The flash objects being currently in the session.
    # * cookies: Cookies being sent to the user on this request.
    # 
    # These collections can be used just like any other hash:
    #
    #   assert_not_nil assigns(:person) # makes sure that a @person instance variable was set
    #   assert_equal "Dave", cookies[:name] # makes sure that a cookie called :name was set as "Dave"
    #   assert flash.empty? # makes sure that there's nothing in the flash
    #
    # For historic reasons, the assigns hash uses string-based keys. So assigns[:person] won't work, but assigns["person"] will. To
    # appease our yearning for symbols, though, an alternative accessor has been deviced using a method call instead of index referencing.
    # So assigns(:person) will work just like assigns["person"], but again, assigns[:person] will not work.
    #
    # On top of the collections, you have the complete url that a given action redirected to available in redirect_to_url.
    #
    # For redirects within the same controller, you can even call follow_redirect and the redirect will be follow triggering another
    # action call which can then be asserted against.
    module Assertions
      # Asserts that the response is one of the following types:
      # 
      # * <tt>:success</tt>: Status code was 200
      # * <tt>:redirect</tt>: Status code was in the 300-399 range
      # * <tt>:missing</tt>: Status code was 404
      # * <tt>:error</tt>:  Status code was in the 500-599 range
      #
      # You can also pass an explicit status code number as the type, like assert_response(501)
      def assert_response(type, message = nil)
        if [ :success, :missing, :redirect, :error ].include?(type) && @response.send("#{type}?")
          assert_block("") { true } # to count the assertion
        elsif type.is_a?(Fixnum) && @response.response_code == type
          assert_block("") { true } # to count the assertion
        else
          assert_block(build_message(message, "Expected response to be a <?>, but was <?>", type, @response.response_code)) { false }
        end
      end

      # Assert that the redirection options passed in match those of the redirect called in the latest action. This match can be partial,
      # such at assert_redirected_to(:controller => "weblog") will also match the redirection of 
      # redirect_to(:controller => "weblog", :action => "show") and so on.
      def assert_redirected_to(options = {}, message=nil)
        assert_redirect(message)

        if options.is_a?(String)
          msg = build_message(message, "expected a redirect to <?>, found one to <?>", options, @response.redirect_url)
          
          url_regexp = %r{^(\w+://.*?(/|$|\?))(.*)$}
          eurl, epath, url, path = [options, @response.redirect_url].collect do |url|
            u, p = (url_regexp =~ url) ? [$1, $3] : [nil, url]
            [u, (p[0..0] == '/') ? p : '/' + p]
          end.flatten

          if eurl && url then assert_equal(eurl, url, msg)
          else assert_equal(epath, path, msg)
          end
        else
          msg = build_message(message, "response is not a redirection to all of the options supplied (redirection is <?>)",
                              @response.redirected_to || @response.redirect_url)

          assert_block(msg) do
            if options.is_a?(Symbol)
              @response.redirected_to == options
            else
              options.keys.all? do |k| 
                options[k] == (@response.redirected_to[k].respond_to?(:to_param) ? @response.redirected_to[k].to_param : @response.redirected_to[k] unless @response.redirected_to[k].nil?)
              end
            end
          end
        end
      end

      # Asserts that the request was rendered with the appropriate template file.
      def assert_template(expected = nil, message=nil)
        rendered = expected ? @response.rendered_file(!expected.include?('/')) : @response.rendered_file
        msg = build_message(message, "expecting <?> but rendering with <?>", expected, rendered)
        assert_block(msg) do
          if expected.nil?
            @response.rendered_with_file?
          else
            expected == rendered
          end
        end
      end

      # Asserts that the routing of the given path is handled correctly and that the parsed options match.
      def assert_recognizes(expected_options, path, extras={}, message=nil)
        # Load routes.rb if it hasn't been loaded.
        ActionController::Routing::Routes.reload if ActionController::Routing::Routes.empty? 
      
        # Assume given controller
        request = ActionController::TestRequest.new({}, {}, nil)
        request.path = path
        ActionController::Routing::Routes.recognize!(request)
      
        expected_options = expected_options.clone
        extras.each_key { |key| expected_options.delete key } unless extras.nil?
      
        msg = build_message(message, "The recognized options <?> did not match <?>", 
            request.path_parameters, expected_options)
        assert_block(msg) { request.path_parameters == expected_options }
      end

      # Asserts that the provided options can be used to generate the provided path.
      def assert_generates(expected_path, options, defaults={}, extras = {}, message=nil)
        # Load routes.rb if it hasn't been loaded.
        ActionController::Routing::Routes.reload if ActionController::Routing::Routes.empty? 
      
        # Assume given controller
        request = ActionController::TestRequest.new({}, {}, nil)
        request.path_parameters = (defaults or {}).clone
        request.path_parameters[:controller] ||= options[:controller]
      
        generated_path, found_extras = ActionController::Routing::Routes.generate(options, request)
        generated_path = generated_path.join('/')
        msg = build_message(message, "found extras <?>, not <?>", found_extras, extras)
        assert_block(msg) { found_extras == extras }
      
        msg = build_message(message, "The generated path <?> did not match <?>", generated_path, 
            expected_path)
        assert_block(msg) { expected_path == generated_path }
      end

      # asserts that path and options match both ways, in other words, the URL generated from 
      # options is same as path, and also that the options recognized from path are same as options
      def assert_routing(path, options, defaults={}, extras={}, message=nil)
        assert_recognizes(options, path, extras, message)
        assert_generates(path, options, defaults, extras, message)
      end

      # Asserts that there is a tag/node/element in the body of the response
      # that meets all of the given conditions. The +conditions+ parameter must
      # be a hash of any of the following keys (all are optional):
      #
      # * <tt>:tag</tt>: the node type must match the corresponding value
      # * <tt>:attributes</tt>: a hash. The node's attributes must match the
      #   corresponding values in the hash.
      # * <tt>:parent</tt>: a hash. The node's parent must match the
      #   corresponding hash.
      # * <tt>:child</tt>: a hash. At least one of the node's immediate children
      #   must meet the criteria described by the hash.
      # * <tt>:ancestor</tt>: a hash. At least one of the node's ancestors must
      #   meet the criteria described by the hash.
      # * <tt>:descendant</tt>: a hash. At least one of the node's descendants
      #   must meet the criteria described by the hash.
      # * <tt>:sibling</tt>: a hash. At least one of the node's siblings must
      #   meet the criteria described by the hash.
      # * <tt>:after</tt>: a hash. The node must be after any sibling meeting
      #   the criteria described by the hash, and at least one sibling must match.
      # * <tt>:before</tt>: a hash. The node must be before any sibling meeting
      #   the criteria described by the hash, and at least one sibling must match.
      # * <tt>:children</tt>: a hash, for counting children of a node. Accepts
      #   the keys:
      #   * <tt>:count</tt>: either a number or a range which must equal (or
      #     include) the number of children that match.
      #   * <tt>:less_than</tt>: the number of matching children must be less
      #     than this number.
      #   * <tt>:greater_than</tt>: the number of matching children must be
      #     greater than this number.
      #   * <tt>:only</tt>: another hash consisting of the keys to use
      #     to match on the children, and only matching children will be
      #     counted.
      # * <tt>:content</tt>: (text nodes only). The content of the node must
      #   match the given value.
      #
      # Conditions are matched using the following algorithm:
      #
      # * if the condition is a string, it must be a substring of the value.
      # * if the condition is a regexp, it must match the value.
      # * if the condition is a number, the value must match number.to_s.
      # * if the condition is +true+, the value must not be +nil+.
      # * if the condition is +false+ or +nil+, the value must be +nil+.
      #
      # Usage:
      #
      #   # assert that there is a "span" tag
      #   assert_tag :tag => "span"
      #
      #   # assert that there is a "span" inside of a "div"
      #   assert_tag :tag => "span", :parent => { :tag => "div" }
      #
      #   # assert that there is a "span" somewhere inside a table
      #   assert_tag :tag => "span", :ancestor => { :tag => "table" }
      #
      #   # assert that there is a "span" with at least one "em" child
      #   assert_tag :tag => "span", :child => { :tag => "em" }
      #
      #   # assert that there is a "span" containing a (possibly nested)
      #   # "strong" tag.
      #   assert_tag :tag => "span", :descendant => { :tag => "strong" }
      #
      #   # assert that there is a "span" containing between 2 and 4 "em" tags
      #   # as immediate children
      #   assert_tag :tag => "span",
      #              :children => { :count => 2..4, :only => { :tag => "em" } } 
      #
      #   # get funky: assert that there is a "div", with an "ul" ancestor
      #   # and an "li" parent (with "class" = "enum"), and containing a 
      #   # "span" descendant that contains text matching /hello world/
      #   assert_tag :tag => "div",
      #              :ancestor => { :tag => "ul" },
      #              :parent => { :tag => "li",
      #                           :attributes => { :class => "enum" } },
      #              :descendant => { :tag => "span",
      #                               :child => /hello world/ }
      def assert_tag(opts)
        tag = find_tag(opts)
        assert tag, "expected tag, but no tag found matching #{opts.inspect} in:\n#{@response.body.inspect}"
      end
      
      # Identical to #assert_tag, but asserts that a matching tag does _not_
      # exist. (See #assert_tag for a full discussion of the syntax.)
      def assert_no_tag(opts)
        tag = find_tag(opts)
        assert !tag, "expected no tag, but found tag matching #{opts.inspect} in:\n#{@response.body.inspect}"
      end
    
    end
  end
end