require "rack/session/abstract/id"
require "active_support/core_ext/hash/conversions"
require "active_support/core_ext/object/to_query"
require "active_support/core_ext/module/anonymous"
require "active_support/core_ext/hash/keys"
require "active_support/testing/constant_lookup"
require "action_controller/template_assertions"
require "rails-dom-testing"

module ActionController
  class Metal
    include Testing::Functional
  end

  module Live
    # Disable controller / rendering threads in tests. User tests can access
    # the database on the main thread, so they could open a txn, then the
    # controller thread will open a new connection and try to access data
    # that's only visible to the main thread's txn. This is the problem in #23483.
    remove_method :new_controller_thread
    def new_controller_thread # :nodoc:
      yield
    end
  end

  # ActionController::TestCase will be deprecated and moved to a gem in Rails 5.1.
  # Please use ActionDispatch::IntegrationTest going forward.
  class TestRequest < ActionDispatch::TestRequest #:nodoc:
    DEFAULT_ENV = ActionDispatch::TestRequest::DEFAULT_ENV.dup
    DEFAULT_ENV.delete "PATH_INFO"

    def self.new_session
      TestSession.new
    end

    attr_reader :controller_class

    # Create a new test request with default `env` values.
    def self.create(controller_class)
      env = {}
      env = Rails.application.env_config.merge(env) if defined?(Rails.application) && Rails.application
      env["rack.request.cookie_hash"] = {}.with_indifferent_access
      new(default_env.merge(env), new_session, controller_class)
    end

    def self.default_env
      DEFAULT_ENV
    end
    private_class_method :default_env

    def initialize(env, session, controller_class)
      super(env)

      self.session = session
      self.session_options = TestSession::DEFAULT_OPTIONS.dup
      @controller_class = controller_class
      @custom_param_parsers = {
        xml: lambda { |raw_post| Hash.from_xml(raw_post)["hash"] }
      }
    end

    def query_string=(string)
      set_header Rack::QUERY_STRING, string
    end

    def content_type=(type)
      set_header "CONTENT_TYPE", type
    end

    def assign_parameters(routes, controller_path, action, parameters, generated_path, query_string_keys)
      non_path_parameters = {}
      path_parameters = {}

      parameters.each do |key, value|
        if query_string_keys.include?(key)
          non_path_parameters[key] = value
        else
          if value.is_a?(Array)
            value = value.map(&:to_param)
          else
            value = value.to_param
          end

          path_parameters[key] = value
        end
      end

      if get?
        if query_string.blank?
          self.query_string = non_path_parameters.to_query
        end
      else
        if ENCODER.should_multipart?(non_path_parameters)
          self.content_type = ENCODER.content_type
          data = ENCODER.build_multipart non_path_parameters
        else
          fetch_header("CONTENT_TYPE") do |k|
            set_header k, "application/x-www-form-urlencoded"
          end

          case content_mime_type.to_sym
          when nil
            raise "Unknown Content-Type: #{content_type}"
          when :json
            data = ActiveSupport::JSON.encode(non_path_parameters)
          when :xml
            data = non_path_parameters.to_xml
          when :url_encoded_form
            data = non_path_parameters.to_query
          else
            @custom_param_parsers[content_mime_type.symbol] = ->(_) { non_path_parameters }
            data = non_path_parameters.to_query
          end
        end

        data_stream = StringIO.new(data)
        set_header "CONTENT_LENGTH", data_stream.length.to_s
        set_header "rack.input", data_stream
      end

      fetch_header("PATH_INFO") do |k|
        set_header k, generated_path
      end
      path_parameters[:controller] = controller_path
      path_parameters[:action] = action

      self.path_parameters = path_parameters
    end

    ENCODER = Class.new do
      include Rack::Test::Utils

      def should_multipart?(params)
        # FIXME: lifted from Rack-Test. We should push this separation upstream.
        multipart = false
        query = lambda { |value|
          case value
          when Array
            value.each(&query)
          when Hash
            value.values.each(&query)
          when Rack::Test::UploadedFile
            multipart = true
          end
        }
        params.values.each(&query)
        multipart
      end

      public :build_multipart

      def content_type
        "multipart/form-data; boundary=#{Rack::Test::MULTIPART_BOUNDARY}"
      end
    end.new

    private

      def params_parsers
        super.merge @custom_param_parsers
      end
  end

  class LiveTestResponse < Live::Response
    # Was the response successful?
    alias_method :success?, :successful?

    # Was the URL not found?
    alias_method :missing?, :not_found?

    # Was there a server-side error?
    alias_method :error?, :server_error?
  end

  # Methods #destroy and #load! are overridden to avoid calling methods on the
  # @store object, which does not exist for the TestSession class.
  class TestSession < Rack::Session::Abstract::SessionHash #:nodoc:
    DEFAULT_OPTIONS = Rack::Session::Abstract::Persisted::DEFAULT_OPTIONS

    def initialize(session = {})
      super(nil, nil)
      @id = SecureRandom.hex(16)
      @data = stringify_keys(session)
      @loaded = true
    end

    def exists?
      true
    end

    def keys
      @data.keys
    end

    def values
      @data.values
    end

    def destroy
      clear
    end

    def fetch(key, *args, &block)
      @data.fetch(key.to_s, *args, &block)
    end

    private

      def load!
        @id
      end
  end

  # Superclass for ActionController functional tests. Functional tests allow you to
  # test a single controller action per test method.
  #
  # == Use integration style controller tests over functional style controller tests.
  #
  # Rails discourages the use of functional tests in favor of integration tests
  # (use ActionDispatch::IntegrationTest).
  #
  # New Rails applications no longer generate functional style controller tests and they should
  # only be used for backward compatibility. Integration style controller tests perform actual
  # requests, whereas functional style controller tests merely simulate a request. Besides,
  # integration tests are as fast as functional tests and provide lot of helpers such as +as+,
  # +parsed_body+ for effective testing of controller actions including even API endpoints.
  #
  # == Basic example
  #
  # Functional tests are written as follows:
  # 1. First, one uses the +get+, +post+, +patch+, +put+, +delete+ or +head+ method to simulate
  #    an HTTP request.
  # 2. Then, one asserts whether the current state is as expected. "State" can be anything:
  #    the controller's HTTP response, the database contents, etc.
  #
  # For example:
  #
  #   class BooksControllerTest < ActionController::TestCase
  #     def test_create
  #       # Simulate a POST response with the given HTTP parameters.
  #       post(:create, params: { book: { title: "Love Hina" }})
  #
  #       # Asserts that the controller tried to redirect us to
  #       # the created book's URI.
  #       assert_response :found
  #
  #       # Asserts that the controller really put the book in the database.
  #       assert_not_nil Book.find_by(title: "Love Hina")
  #     end
  #   end
  #
  # You can also send a real document in the simulated HTTP request.
  #
  #   def test_create
  #     json = {book: { title: "Love Hina" }}.to_json
  #     post :create, json
  #   end
  #
  # == Special instance variables
  #
  # ActionController::TestCase will also automatically provide the following instance
  # variables for use in the tests:
  #
  # <b>@controller</b>::
  #      The controller instance that will be tested.
  # <b>@request</b>::
  #      An ActionController::TestRequest, representing the current HTTP
  #      request. You can modify this object before sending the HTTP request. For example,
  #      you might want to set some session properties before sending a GET request.
  # <b>@response</b>::
  #      An ActionDispatch::TestResponse object, representing the response
  #      of the last HTTP response. In the above example, <tt>@response</tt> becomes valid
  #      after calling +post+. If the various assert methods are not sufficient, then you
  #      may use this object to inspect the HTTP response in detail.
  #
  # (Earlier versions of \Rails required each functional test to subclass
  # Test::Unit::TestCase and define @controller, @request, @response in +setup+.)
  #
  # == Controller is automatically inferred
  #
  # ActionController::TestCase will automatically infer the controller under test
  # from the test class name. If the controller cannot be inferred from the test
  # class name, you can explicitly set it with +tests+.
  #
  #   class SpecialEdgeCaseWidgetsControllerTest < ActionController::TestCase
  #     tests WidgetController
  #   end
  #
  # == \Testing controller internals
  #
  # 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:
  #
  # * session: Objects being saved in the session.
  # * flash: The flash objects 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_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
  #
  # On top of the collections, you have the complete URL that a given action redirected to available in <tt>redirect_to_url</tt>.
  #
  # For redirects within the same controller, you can even call follow_redirect and the redirect will be followed, triggering another
  # action call which can then be asserted against.
  #
  # == Manipulating session and cookie variables
  #
  # Sometimes you need to set up the session and cookie variables for a test.
  # To do this just assign a value to the session or cookie collection:
  #
  #   session[:key] = "value"
  #   cookies[:key] = "value"
  #
  # To clear the cookies for a test just clear the cookie collection:
  #
  #   cookies.clear
  #
  # == \Testing named routes
  #
  # If you're using named routes, they can be easily tested using the original named routes' methods straight in the test case.
  #
  #  assert_redirected_to page_url(title: 'foo')
  class TestCase < ActiveSupport::TestCase
    module Behavior
      extend ActiveSupport::Concern
      include ActionDispatch::TestProcess
      include ActiveSupport::Testing::ConstantLookup
      include Rails::Dom::Testing::Assertions

      attr_reader :response, :request

      module ClassMethods
        # Sets the controller class name. Useful if the name can't be inferred from test class.
        # Normalizes +controller_class+ before using.
        #
        #   tests WidgetController
        #   tests :widget
        #   tests 'widget'
        def tests(controller_class)
          case controller_class
          when String, Symbol
            self.controller_class = "#{controller_class.to_s.camelize}Controller".constantize
          when Class
            self.controller_class = controller_class
          else
            raise ArgumentError, "controller class must be a String, Symbol, or Class"
          end
        end

        def controller_class=(new_class)
          self._controller_class = new_class
        end

        def controller_class
          if current_controller_class = _controller_class
            current_controller_class
          else
            self.controller_class = determine_default_controller_class(name)
          end
        end

        def determine_default_controller_class(name)
          determine_constant_from_test_name(name) do |constant|
            Class === constant && constant < ActionController::Metal
          end
        end
      end

      # Simulate a GET request with the given parameters.
      #
      # - +action+: The controller action to call.
      # - +params+: The hash with HTTP parameters that you want to pass. This may be +nil+.
      # - +body+: The request body with a string that is appropriately encoded
      #   (<tt>application/x-www-form-urlencoded</tt> or <tt>multipart/form-data</tt>).
      # - +session+: A hash of parameters to store in the session. This may be +nil+.
      # - +flash+: A hash of parameters to store in the flash. This may be +nil+.
      #
      # You can also simulate POST, PATCH, PUT, DELETE, and HEAD requests with
      # +post+, +patch+, +put+, +delete+, and +head+.
      # Example sending parameters, session and setting a flash message:
      #
      #   get :show,
      #     params: { id: 7 },
      #     session: { user_id: 1 },
      #     flash: { notice: 'This is flash message' }
      #
      # Note that the request method is not verified. The different methods are
      # available to make the tests more expressive.
      def get(action, **args)
        res = process(action, method: "GET", **args)
        cookies.update res.cookies
        res
      end

      # Simulate a POST request with the given parameters and set/volley the response.
      # See +get+ for more details.
      def post(action, **args)
        process(action, method: "POST", **args)
      end

      # Simulate a PATCH request with the given parameters and set/volley the response.
      # See +get+ for more details.
      def patch(action, **args)
        process(action, method: "PATCH", **args)
      end

      # Simulate a PUT request with the given parameters and set/volley the response.
      # See +get+ for more details.
      def put(action, **args)
        process(action, method: "PUT", **args)
      end

      # Simulate a DELETE request with the given parameters and set/volley the response.
      # See +get+ for more details.
      def delete(action, **args)
        process(action, method: "DELETE", **args)
      end

      # Simulate a HEAD request with the given parameters and set/volley the response.
      # See +get+ for more details.
      def head(action, **args)
        process(action, method: "HEAD", **args)
      end

      # Simulate an HTTP request to +action+ by specifying request method,
      # parameters and set/volley the response.
      #
      # - +action+: The controller action to call.
      # - +method+: Request method used to send the HTTP request. Possible values
      #   are +GET+, +POST+, +PATCH+, +PUT+, +DELETE+, +HEAD+. Defaults to +GET+. Can be a symbol.
      # - +params+: The hash with HTTP parameters that you want to pass. This may be +nil+.
      # - +body+: The request body with a string that is appropriately encoded
      #   (<tt>application/x-www-form-urlencoded</tt> or <tt>multipart/form-data</tt>).
      # - +session+: A hash of parameters to store in the session. This may be +nil+.
      # - +flash+: A hash of parameters to store in the flash. This may be +nil+.
      # - +format+: Request format. Defaults to +nil+. Can be string or symbol.
      # - +as+: Content type. Defaults to +nil+. Must be a symbol that corresponds
      #   to a mime type.
      #
      # Example calling +create+ action and sending two params:
      #
      #   process :create,
      #     method: 'POST',
      #     params: {
      #       user: { name: 'Gaurish Sharma', email: 'user@example.com' }
      #     },
      #     session: { user_id: 1 },
      #     flash: { notice: 'This is flash message' }
      #
      # To simulate +GET+, +POST+, +PATCH+, +PUT+, +DELETE+ and +HEAD+ requests
      # prefer using #get, #post, #patch, #put, #delete and #head methods
      # respectively which will make tests more expressive.
      #
      # Note that the request method is not verified.
      def process(action, method: "GET", params: {}, session: nil, body: nil, flash: {}, format: nil, xhr: false, as: nil)
        check_required_ivars

        if body
          @request.set_header "RAW_POST_DATA", body
        end

        http_method = method.to_s.upcase

        @html_document = nil

        cookies.update(@request.cookies)
        cookies.update_cookies_from_jar
        @request.set_header "HTTP_COOKIE", cookies.to_header
        @request.delete_header "action_dispatch.cookies"

        @request          = TestRequest.new scrub_env!(@request.env), @request.session, @controller.class
        @response         = build_response @response_klass
        @response.request = @request
        @controller.recycle!

        @request.set_header "REQUEST_METHOD", http_method

        if as
          @request.content_type = Mime[as].to_s
          format ||= as
        end

        parameters = params.symbolize_keys

        if format
          parameters[:format] = format
        end

        generated_extras = @routes.generate_extras(parameters.merge(controller: controller_class_name, action: action.to_s))
        generated_path = generated_path(generated_extras)
        query_string_keys = query_parameter_names(generated_extras)

        @request.assign_parameters(@routes, controller_class_name, action.to_s, parameters, generated_path, query_string_keys)

        @request.session.update(session) if session
        @request.flash.update(flash || {})

        if xhr
          @request.set_header "HTTP_X_REQUESTED_WITH", "XMLHttpRequest"
          @request.fetch_header("HTTP_ACCEPT") do |k|
            @request.set_header k, [Mime[:js], Mime[:html], Mime[:xml], "text/xml", "*/*"].join(", ")
          end
        end

        @request.fetch_header("SCRIPT_NAME") do |k|
          @request.set_header k, @controller.config.relative_url_root
        end

        begin
          @controller.recycle!
          @controller.dispatch(action, @request, @response)
        ensure
          @request = @controller.request
          @response = @controller.response

          if @request.have_cookie_jar?
            unless @request.cookie_jar.committed?
              @request.cookie_jar.write(@response)
              cookies.update(@request.cookie_jar.instance_variable_get(:@cookies))
            end
          end
          @response.prepare!

          if flash_value = @request.flash.to_session_value
            @request.session["flash"] = flash_value
          else
            @request.session.delete("flash")
          end

          if xhr
            @request.delete_header "HTTP_X_REQUESTED_WITH"
            @request.delete_header "HTTP_ACCEPT"
          end
          @request.query_string = ""

          @response.sent!
        end

        @response
      end

      def controller_class_name
        @controller.class.anonymous? ? "anonymous" : @controller.class.controller_path
      end

      def generated_path(generated_extras)
        generated_extras[0]
      end

      def query_parameter_names(generated_extras)
        generated_extras[1] + [:controller, :action]
      end

      def setup_controller_request_and_response
        @controller = nil unless defined? @controller

        @response_klass = ActionDispatch::TestResponse

        if klass = self.class.controller_class
          if klass < ActionController::Live
            @response_klass = LiveTestResponse
          end
          unless @controller
            begin
              @controller = klass.new
            rescue
              warn "could not construct controller #{klass}" if $VERBOSE
            end
          end
        end

        @request          = TestRequest.create(@controller.class)
        @response         = build_response @response_klass
        @response.request = @request

        if @controller
          @controller.request = @request
          @controller.params = {}
        end
      end

      def build_response(klass)
        klass.create
      end

      included do
        include ActionController::TemplateAssertions
        include ActionDispatch::Assertions
        class_attribute :_controller_class
        setup :setup_controller_request_and_response
        ActiveSupport.run_load_hooks(:action_controller_test_case, self)
      end

      private

        def scrub_env!(env)
          env.delete_if { |k, v| k =~ /^(action_dispatch|rack)\.request/ }
          env.delete_if { |k, v| k =~ /^action_dispatch\.rescue/ }
          env.delete "action_dispatch.request.query_parameters"
          env.delete "action_dispatch.request.request_parameters"
          env["rack.input"] = StringIO.new
          env
        end

        def document_root_element
          html_document.root
        end

        def check_required_ivars
          # Sanity check for required instance variables so we can give an
          # understandable error message.
          [:@routes, :@controller, :@request, :@response].each do |iv_name|
            if !instance_variable_defined?(iv_name) || instance_variable_get(iv_name).nil?
              raise "#{iv_name} is nil: make sure you set it in your test's setup method."
            end
          end
        end
    end

    include Behavior
  end
end