module ScaffoldLogic
  module FormHelper
    SELECT_PROMPT_OPTION = '<option>Select...</option>'

    # Returns a check mark.
    #
    # Usage:
    #
    #   <%= checkmark -%>
    def checkmark
      %{<div class="checkmark"></div>}.html_safe
    end

    def countdown_field(field_id,update_id,max,options = {})
      function = "$('#{update_id}').innerHTML = (#{max} - $F('#{field_id}').length);"
      count_field_tag(field_id,function,options)
    end

    def count_field(field_id,update_id,options = {})
      function = "$('#{update_id}').innerHTML = $F('#{field_id}').length;"
      count_field_tag(field_id,function,options)
    end

    def count_field_tag(field_id,function,options = {})
      %{
        <script type="text/javascript">
          Event.observe($('#{field_id}'), 'keydown', function (){ #{function} });
        </script>
      }.html_safe
    end

    # Returns a simulated text-field for read-only versions of a form.
    #
    # Usage:
    #
    #   <%= faux_field 'Name', @user.name -%>
    def faux_field(label, content, options={:field_id => nil, :help => nil})
      if options[:help]
        options[:field_id] ||= "field_#{Time.zone.now.to_i}#{rand(10000)}"
        %{#{tag_for_label_with_inline_help label, options[:field_id], options[:help]}<div class="faux_field">#{content}</div>}.html_safe
      else
        %{<label>#{label}</label><div class="faux_field">#{content}</div>}.html_safe
      end
    end

    # Returns a legend tag that renders correctly in all browsers.
    #
    # Usage:
    #
    #   <%= legend_tag "Report Criteria" -%>
    #
    # With help text:
    #
    #   <%= legend_tag "Report Criteria", :help => "Some descriptive copy here." -%>
    #     <span id="hide_or_show_backlinks" class="show_link" style="background-color: #999999;
    #     border: 1px solid #999999;" onclick="javascript:hide_or_show('backlinks');"></span>Backlinks (<%=
    #     @google_results.size -%>)
    #   <%- end -%>
    #
    # Recommended CSS to support display of help icon and text:
    #
    #   .help_icon {
    #     display: block;
    #     float: left;
    #     margin-top: -16px;
    #     margin-left: 290px;
    #     border-left: 1px solid #444444;
    #     padding: 3px 6px;
    #     cursor: pointer;
    #   }
    #
    #   div.popup_help {
    #     color: #666666;
    #     width: 98%;
    #     background: #ffffff;
    #     padding: 1em;
    #     border: 1px solid #999999;
    #     margin: 1em 0em;
    #   }
    def legend_tag(text, options={})
      options[:id] ||= "#{text.downcase.gsub(' ', '-')}-legend"
      if options[:help]
        _html = %{<div id="#{options[:id]}" class="faux_legend">#{text}<span class="help_icon" onclick="$('#{options[:id]}-help').toggle();">?</span></div>\r}
        _html << %{<div id="#{options[:id]}-help" class="popup_help" style="display: none;">#{options[:help]}<br /></div>\r}
      else
        _html = %{<div id="#{options[:id]}" class="faux_legend">#{text}</div>\r}
      end
      _html.gsub!(/ id=""/,'')
      _html.gsub!(/ class=""/,'')
      _html.html_safe
    end

    # Create a set of tags for displaying a field label with inline help.
    # Field label text is appended with a ? icon, which responds to a click
    # by showing or hiding the provided help text.
    #
    # Sample usage:
    #
    #   <%= tag_for_label_with_inline_help 'Relative Frequency', 'rel_frequency', 'Relative frequency of search traffic for this keyword across multiple search engines, as measured by WordTracker.' %>
    #
    # Yields:
    #
    #   <label for="rel_frequency">Relative Frequency: <%= image_tag "/images/help_icon.png", :onclick => "$('rel_frequency_help').toggle();", :class => 'inline_icon' %></label>
    #   <div class="inline_help" id="rel_frequency_help" style="display: none;">
    #     <p>Relative frequency of search traffic for this keyword across multiple search engines, as measured by WordTracker.</p>
    #   </div>
    def tag_for_label_with_inline_help( label_text, field_id, help_text )
      _html = ""
      _html << %{<label for="#{field_id}">#{label_text}}
      _html << %{<img alt="Help Icon" class="inline_icon" src="/images/icons/help_icon.png" width="14" height="12" onclick="$('#{field_id}_help').toggle();" />}
      _html << %{</label>}
      _html << %{<div class="inline_help" id="#{field_id}_help" style="display: none;">}
      _html << %{<p>#{help_text}</p>}
      _html << %{</div>}
      _html
    end

    # Create a set of tags for displaying a field label followed by instructions.
    # The instructions are displayed on a new line following the field label.
    #
    # Usage:
    #
    #   <%= tag_for_label_with_instructions 'Status', 'is_active', 'Only active widgets will be visible to the public.' %>
    #
    # Yields:
    #
    #   <label for="is_active">
    #     Status
    #     <span class="instructions">Only active widgets will be visible to the public.</span>
    #   </label>
    def tag_for_label_with_instructions( label_text, field_id, instructions )
      _html = ""
      _html << %{<label for="#{field_id}">#{label_text}}
      _html << %{<span class="instructions">#{instructions}</span>}
      _html << %{</label>}
      _html
    end

    # Returns a string of HTML option tags for the given array of option values. Specify the selected value for stickiness.
    #
    # Usage:
    #
    #   <%= select_tag :user, tags_for_option_values(User.all.map{ |c| [c.name, c.id] }, params[:user]) -%>
    def tags_for_option_values( a, selected = nil, prompt_option = SELECT_PROMPT_OPTION )
      "#{prompt_option}#{a.map{ |_e| _flag = _e[1].to_s == selected ? 'selected="1"' : ''; _e.is_a?(Array) ? "<option value=\"#{_e[1]}\" #{_flag}>#{_e[0]}</option>" : "<option>#{_e}</option>" }}".html_safe
    end
  end
end