require "forwardable"
require "ostruct"

require "webrat/core/mime"
require "webrat/core/save_and_open_page"

module Webrat
  # A page load or form submission returned an unsuccessful response code (500-599)
  class PageLoadError < WebratError
  end
  
  def self.session_class
    case Webrat.configuration.mode
    when :rails
      RailsSession
    when :merb
      MerbSession
    when :selenium
      SeleniumSession
    when :rack
      RackSession
    when :sinatra
      SinatraSession
    when :mechanize
      MechanizeSession
    else
      raise WebratError.new(<<-STR)
Unknown Webrat mode: #{Webrat.configuration.mode.inspect}

Please ensure you have a Webrat configuration block that specifies a mode
in your test_helper.rb, spec_helper.rb, or env.rb (for Cucumber).
For example:

  Webrat.configure do |config|
    config.mode = :rails
  end
      STR
    end
  end
  
  class Session
    extend Forwardable
    include Logging
    include SaveAndOpenPage
    
    attr_reader :current_url
    attr_reader :elements
    
    def initialize(context = nil) #:nodoc:
      @http_method     = :get
      @data            = {}
      @default_headers = {}
      @custom_headers  = {}
      @context         = context
      
      reset
    end
    
    def current_dom #:nodoc:
      current_scope.dom
    end
    
    # For backwards compatibility -- removing in 1.0
    def current_page #:nodoc:
      page = OpenStruct.new
      page.url = @current_url
      page.http_method = @http_method
      page.data = @data
      page
    end
    
    def doc_root #:nodoc:
      nil
    end
    
    def header(key, value)
      @custom_headers[key] = value
    end

    def http_accept(mime_type)
      header('Accept', Webrat::MIME.mime_type(mime_type))
    end
    
    def basic_auth(user, pass)
      encoded_login = ["#{user}:#{pass}"].pack("m*")
      header('HTTP_AUTHORIZATION', "Basic #{encoded_login}")
    end

    def headers #:nodoc:
      @default_headers.dup.merge(@custom_headers.dup)
    end

    def request_page(url, http_method, data) #:nodoc:
      h = headers
      h['HTTP_REFERER'] = @current_url if @current_url

      debug_log "REQUESTING PAGE: #{http_method.to_s.upcase} #{url} with #{data.inspect} and HTTP headers #{h.inspect}"
      if h.empty?
        send "#{http_method}", url, data || {}
      else
        send "#{http_method}", url, data || {}, h
      end

      save_and_open_page if exception_caught? && Webrat.configuration.open_error_files?
      raise PageLoadError.new("Page load was not successful (Code: #{response_code.inspect}):\n#{formatted_error}") unless success_code?
      
      reset
      
      @current_url  = url
      @http_method  = http_method
      @data         = data
      
      return response
    end
    
    def success_code? #:nodoc:
      (200..499).include?(response_code)
    end
    
    def exception_caught? #:nodoc:
      response_body =~ /Exception caught/
    end
    
    def current_scope #:nodoc:
      scopes.last || page_scope
    end
    
    # Reloads the last page requested. Note that this will resubmit forms
    # and their data.
    def reloads
      request_page(@current_url, @http_method, @data)
    end

    webrat_deprecate :reload, :reloads
      
    
    # Works like click_link, but only looks for the link text within a given selector
    # 
    # Example:
    #   click_link_within "#user_12", "Vote"
    def click_link_within(selector, link_text)
      within(selector) do
        click_link(link_text)
      end
    end

    webrat_deprecate :clicks_link_within, :click_link_within
    
    def within(selector)
      scopes.push(Scope.from_scope(self, current_scope, selector))
      ret = yield(current_scope)
      scopes.pop
      return ret
    end
    
    # Issues a GET request for a page, follows any redirects, and verifies the final page
    # load was successful.
    #
    # Example:
    #   visit "/"
    def visit(url = nil, http_method = :get, data = {})
      request_page(url, http_method, data)
    end
    
    webrat_deprecate :visits, :visit

    # Subclasses can override this to show error messages without html
    def formatted_error #:nodoc:
      response_body
    end

    def scopes #:nodoc:
      @_scopes ||= []
    end

    def page_scope #:nodoc:
      @_page_scope ||= Scope.from_page(self, response, response_body)
    end
    
    def dom
      page_scope.dom
    end
    
    def xml_content_type?
      false
    end
    
    def simulate
      return if Webrat.configuration.mode == :selenium
      yield
    end
    
    def automate
      return unless Webrat.configuration.mode == :selenium
      yield
    end
    
    def_delegators :current_scope, :fill_in,            :fills_in
    def_delegators :current_scope, :set_hidden_field
    def_delegators :current_scope, :submit_form
    def_delegators :current_scope, :check,              :checks
    def_delegators :current_scope, :uncheck,            :unchecks
    def_delegators :current_scope, :choose,             :chooses
    def_delegators :current_scope, :select,             :selects
    def_delegators :current_scope, :select_datetime,    :selects_datetime
    def_delegators :current_scope, :select_date,        :selects_date
    def_delegators :current_scope, :select_time,        :selects_time
    def_delegators :current_scope, :attach_file,        :attaches_file
    def_delegators :current_scope, :click_area,         :clicks_area
    def_delegators :current_scope, :click_link,         :clicks_link
    def_delegators :current_scope, :click_button,       :clicks_button
    def_delegators :current_scope, :field_labeled
    def_delegators :current_scope, :field_by_xpath
    def_delegators :current_scope, :field_with_id
    def_delegators :current_scope, :select_option
    
  private
    
    def reset
      @elements     = {}
      @_scopes      = nil
      @_page_scope  = nil
    end
    
  end
end