module Wovnrb

  class Headers
    attr_reader :unmasked_url
    attr_reader :url
    attr_reader :protocol
    attr_reader :unmasked_host
    attr_reader :host
    attr_reader :unmasked_pathname
    attr_reader :pathname
    attr_reader :redis_url

    # Generates new instance of Wovnrb::Headers.
    # Its parameters are set by parsing env variable.
    #
    def initialize(env, settings)
      @env = env
      @settings = settings
      @protocol = @env['rack.url_scheme']
      if settings['use_proxy'] && @env.has_key?('HTTP_X_FORWARDED_HOST')
        @unmasked_host = @env['HTTP_X_FORWARDED_HOST']
      else
        @unmasked_host = @env['HTTP_HOST']
      end
      unless @env.has_key?('REQUEST_URI')
        # Add '/' to PATH_INFO as a possible fix for pow server
        @env['REQUEST_URI'] = (@env['PATH_INFO'] =~ /^[^\/]/ ? '/' : '') + @env['PATH_INFO'] + (@env['QUERY_STRING'].size == 0 ? '' : "?#{@env['QUERY_STRING']}")
      end
      # REQUEST_URI is expected to not contain the server name
      # heroku contains http://...
      if @env['REQUEST_URI'] =~ /:\/\//
        @env['REQUEST_URI'] = @env['REQUEST_URI'].sub(/^.*:\/\/[^\/]+/, '')
      end
      @unmasked_pathname = @env['REQUEST_URI'].split('?')[0]
      @unmasked_pathname += '/' unless @unmasked_pathname =~ /\/$/ || @unmasked_pathname =~ /\/[^\/.]+\.[^\/.]+$/
      @unmasked_url = "#{@protocol}://#{@unmasked_host}#{@unmasked_pathname}"
      if settings['use_proxy'] && @env.has_key?('HTTP_X_FORWARDED_HOST')
        @host = @env['HTTP_X_FORWARDED_HOST']
      else
        @host = @env['HTTP_HOST']
      end
      @env['wovnrb.target_lang'] = self.lang_code
      @host = settings['url_pattern'] == 'subdomain' ? remove_lang(@host, self.lang_code) : @host
      @pathname, @query = @env['REQUEST_URI'].split('?')
      @pathname = settings['url_pattern'] == 'path' ? remove_lang(@pathname, self.lang_code) : @pathname
      @query = @query || ''
      @url = "#{@host}#{@pathname}#{(@query.length > 0 ? '?' : '') + remove_lang(@query, self.lang_code)}"
      if settings['query'].length > 0
        query_vals = []
        settings['query'].each do |qv|
          rx = Regexp.new("(^|&)(?<query_val>#{qv}[^&]+)(&|$)")
          m = @query.match(rx)
          if m && m[:query_val]
            query_vals.push(m[:query_val])
          end
        end
        if query_vals.length > 0
          @query = "?#{query_vals.sort.join('&')}"
        else
          @query = ''
        end
      else
        @query = ''
      end
      @query = remove_lang(@query, self.lang_code)
      @pathname = @pathname.gsub(/\/$/, '')
      @redis_url = "#{@host}#{@pathname}#{@query}"
    end

    # Get the language code of the current request
    #
    # @return [String] The lang code of the current page
    def lang_code
      (self.path_lang && self.path_lang.length > 0) ? self.path_lang : @settings['default_lang']
    end

    # picks up language code from requested URL by using url_pattern_reg setting.
    # when language code is invalid, this method returns empty string.
    # if you want examples, please see test/lib/headers_test.rb.
    #
    # @return [String] language code in requrested URL.
    def path_lang
      if @path_lang.nil?
        rp = Regexp.new(@settings['url_pattern_reg'])
        if @settings['use_proxy'] && @env.has_key?('HTTP_X_FORWARDED_HOST')
          match = "#{@env['HTTP_X_FORWARDED_HOST']}#{@env['REQUEST_URI']}".match(rp)
        else
          match = "#{@env['SERVER_NAME']}#{@env['REQUEST_URI']}".match(rp)
        end
        if match && match[:lang] && Lang.get_lang(match[:lang])
          @path_lang = Lang.get_code(match[:lang])
        else
          @path_lang = ''
        end
      end
      return @path_lang
    end

    def browser_lang
      if @browser_lang.nil?
        match = (@env['HTTP_COOKIE'] || '').match(/wovn_selected_lang\s*=\s*(?<lang>[^;\s]+)/)
        if match && match[:lang] && Lang.get_lang(match[:lang])
          @browser_lang = match[:lang]
        else
# IS THIS RIGHT?
          @browser_lang = ''
          accept_langs = (@env['HTTP_ACCEPT_LANGUAGE'] || '').split(/[,;]/)
          accept_langs.each do |l|
            if Lang.get_lang(l)
              @browser_lang = l
              break
            end
          end
        end
      end
      return @browser_lang
    end

    def redirect(lang=self.browser_lang)
      redirect_headers = {}
      redirect_headers['location'] = self.redirect_location(lang)
      redirect_headers['content-length'] = '0'
      return redirect_headers
    end

    def redirect_location(lang)
      if lang == @settings['default_lang']
# IS THIS RIGHT??
        return "#{self.protocol}://#{self.url}"
        #return remove_lang("#{@env['HTTP_HOST']}#{@env['REQUEST_URI']}", lang)
      else
        # TODO test
        lang_code = Store.instance.settings['custom_lang_aliases'][lang] || lang
        location = self.url
        case @settings['url_pattern']
        when 'query'
          if location !~ /\?/
            location = "#{location}?wovn=#{lang_code}"
          else @env['REQUEST_URI'] !~ /(\?|&)wovn=/
            location = "#{location}&wovn=#{lang_code}"
          end
        when 'subdomain'
          location = "#{lang_code.downcase}.#{location}"
       #when 'path'
        else
          location = location.sub(/(\/|$)/, "/#{lang_code}/");
        end
        return "#{self.protocol}://#{location}"
      end
    end

    def request_out(def_lang=@settings['default_lang'])
      case @settings['url_pattern']
      when 'query'
        @env['REQUEST_URI'] = remove_lang(@env['REQUEST_URI']) if @env.has_key?('REQUEST_URI')
        @env['QUERY_STRING'] = remove_lang(@env['QUERY_STRING']) if @env.has_key?('QUERY_STRING')
        @env['ORIGINAL_FULLPATH'] = remove_lang(@env['ORIGINAL_FULLPATH']) if @env.has_key?('ORIGINAL_FULLPATH')
      when 'subdomain'
        if @settings['use_proxy'] && @env.has_key?('HTTP_X_FORWARDED_HOST')
          @env['HTTP_X_FORWARDED_HOST'] = remove_lang(@env['HTTP_X_FORWARDED_HOST'])
        else
          @env["HTTP_HOST"] = remove_lang(@env["HTTP_HOST"])
          @env["SERVER_NAME"] = remove_lang(@env["SERVER_NAME"])
        end
        if @env.has_key?('HTTP_REFERER')
          @env["HTTP_REFERER"] = remove_lang(@env["HTTP_REFERER"])
        end
     #when 'path'
      else
        @env['REQUEST_URI'] = remove_lang(@env['REQUEST_URI'])
        if @env.has_key?('REQUEST_PATH')
          @env['REQUEST_PATH'] = remove_lang(@env['REQUEST_PATH'])
        end
        @env['PATH_INFO'] = remove_lang(@env['PATH_INFO'])
        if @env.has_key?('ORIGINAL_FULLPATH')
          @env['ORIGINAL_FULLPATH'] = remove_lang(@env['ORIGINAL_FULLPATH'])
        end
        if @env.has_key?('HTTP_REFERER')
          @env["HTTP_REFERER"] = remove_lang(@env["HTTP_REFERER"])
        end
      end
      @env
    end

    # Remove language code from the URI.
    #
    # @param uri  [String] original URI
    # @param lang_code [String] language code
    # @return     [String] removed URI
    def remove_lang(uri, lang=self.path_lang)
      lang_code = Store.instance.settings['custom_lang_aliases'][lang] || lang

      # Do nothing if lang is empty.
      if lang_code.nil? || lang_code.empty?
        return uri
      end

      case @settings['url_pattern']
      when 'query'
        return uri.sub(/(^|\?|&)wovn=#{lang_code}(&|$)/, '\1').gsub(/(\?|&)$/, '')
      when 'subdomain'
        rp = Regexp.new('(^|(//))' + lang_code + '\.', 'i')
        return uri.sub(rp, '\1')
     #when 'path'
      else
        return uri.sub(/\/#{lang_code}(\/|$)/, '/')
      end
    end

    def out(headers)
      r = Regexp.new("//" + @host)
      lang_code = Store.instance.settings['custom_lang_aliases'][self.lang_code] || self.lang_code
      if lang_code != @settings['default_lang'] && headers.has_key?("Location") && headers["Location"] =~ r
        case @settings['url_pattern']
        when 'query'
          if headers['Location'] =~ /\?/
            headers['Location'] += "&"
          else
            headers['Location'] += "?"
          end
          headers['Location'] += "wovn=#{lang_code}"
        when 'subdomain'
          headers['Location'] = headers["Location"].sub(/\/\/([^.]+)/, '//' + lang_code + '.\1')
       #when 'path'
        else
          headers['Location'] = headers['Location'].sub(/(\/\/[^\/]+)/, '\1/' + lang_code)
        end
      end
      headers
    end

  end

end