Add search summary panel and full filter support

Why these changes are being introduced:

It would be helpful if users could see what filters they've
applied to a search directly below the search bar, which would
also provide another path to remove filters.

Relevant ticket(s):

https://mitlibraries.atlassian.net/browse/GDT-142
https://mitlibraries.atlassian.net/browse/GDT-196

How this addresses that need:

This provides the requested panel. We had been calling this a
"filter removal" panel, but I ended up naming the partial
`search_summary` to avoid any confusion with the filter
sidebar. However, the currently displayed data has the
`filter-removal` class, because it's possible we will want to
show advanced search terms here, too.

While working on this, it occurred to me that the existing TIMDEX
UI filter implementation is incomplete. It pulls in the aggregation
names and uses those as the internal filter names. This works fine
for the existing `contentType` and `source` filters, but it will
cause a name collision for filters that also exist as regular
search inputs (e.g. `contributors` vs. `contributorsFilter`). Since
we will be adding more aggregations and filters soon, it makes sense
to fix this problem now.

Because this only lists filters at present, we've changed the
label from 'You searched for' to 'Applied filters'. This is
subject to change.

Side effects of these changes:

* The "You searched for" list has been removed, as this feature
replaces it. As mentioned above, we will likely want to provide
that information in some manner in the search summary, but that
will require some discussion with Darcy, who is out-of-office at
the moment.
* Filter keys are now cast as symbols throughout the application.
Previously, they would be strings in some places and symbols in
others. I found that confusing, but if this change is even more
confusing, I'm happy to revert it.
* A few tests have been skipped due to the removal of the "You
searched for list". I chose not to delete them in case we
reintroduce that feature in the near future.
* Most of the cassettes have been regenerated, due to changes to
the `TimdexSearch` model.

Address code review feedback

Author: jazairi

app/assets/stylesheets/partials/_panels.scss

@@ -99,3 +99,36 @@
     }
   }
 }
+
+.filter-summary {
+  color: $black;
+  background-color: $gray-l3;
+  margin-top: 0;
+  border: 0;
+  padding: 2rem;
+  padding-top: 1.5rem;
+  display: flex;
+  .hd-filter-summary {
+    margin-right: 2rem;
+    padding-top: 0.3rem;
+  }
+  a {
+    font-size: $fs-small;
+    text-decoration: none;
+    padding: .5rem;
+    &::before {
+      font-family: FontAwesome;
+      content: '\f00d';
+      padding-right: .25rem;
+    }
+    &:hover,
+    &:focus {
+      color: $white;
+      background-color: $black;
+    }
+    margin-right: 2rem;
+  }
+  @media (max-width: $bp-screen-md) {
+    display: block;
+  }
+}

app/assets/stylesheets/partials/_search.scss

@@ -5,7 +5,7 @@
 /* basic search bar */
 .basic-search {
   background-color: #989898;
-  margin-bottom: 1rem;
+  margin-bottom: 0rem;
   padding: 1.6rem 2rem;
 
   details {

app/controllers/search_controller.rb

@@ -33,7 +33,11 @@ def extract_filters(response)
     aggs = response&.data&.search&.to_h&.dig('aggregations')
     return if aggs.blank?
 
-    aggs.select { |_, agg_values| agg_values.present? }
+    # We use aggregations to determine which terms can be filtered. However, agg names do not include 'filter', whereas
+    # our filter fields do (e.g., 'source' vs 'sourceFilter'). Because of this mismatch, we need to modify the
+    # aggregation key names before collecting them as filters, so that when a filter is applied, it searches the
+    # correct field name.
+    aggs.select { |_, agg_values| agg_values.present? }.transform_keys { |key| (key.dup << 'Filter').to_sym }
   end
 
   def extract_results(response)

app/helpers/filter_helper.rb

@@ -9,7 +9,7 @@ def add_filter(query, filter, term)
     # seems like the best solution as each record only has a single source
     # in the data so there will never be a case to apply multiple in an AND
     # which is all we support in filter application.
-    if new_query[filter].present? && filter != 'source'
+    if new_query[filter].present? && filter != :sourceFilter
       new_query[filter] << term
       new_query[filter].uniq!
     else
@@ -21,8 +21,8 @@ def add_filter(query, filter, term)
 
   def nice_labels
     {
-      'contentType' => 'Content types',
-      'source' => 'Sources'
+      contentTypeFilter: 'Content type',
+      sourceFilter: 'Source'
     }
   end
 
@@ -44,4 +44,14 @@ def filter_applied?(terms, term)
 
     terms.include?(term)
   end
+
+  def applied_filters
+    filters = []
+    @enhanced_query.map do |param, values|
+      next unless param.to_s.include? 'Filter'
+
+      values.each { |value| filters << { param => value } }
+    end
+    filters
+  end
 end

app/helpers/form_helper.rb

@@ -2,9 +2,8 @@ module FormHelper
   def source_checkbox(source, params)
     "<div class='field-subitem'>
       <label class='field-checkbox'>
-        <input type='checkbox' value='#{source.downcase}' name='source[]' class='source'#{if params[:source]&.include?(source.downcase)
-                                                                                            ' checked'
-                                                                                          end}>
+        <input type='checkbox' value='#{source.downcase}' name='sourceFilter[]'
+               class='source'#{' checked' if params[:sourceFilter]&.include?(source.downcase) }>
         #{source}
       </label>
     </div>".html_safe

app/models/enhancer.rb

@@ -2,7 +2,7 @@ class Enhancer
   attr_accessor :enhanced_query
 
   QUERY_PARAMS = %i[q citation contentType contributors fundingInformation identifiers locations subjects title].freeze
-  FILTER_PARAMS = [:source].freeze
+  FILTER_PARAMS = %i[sourceFilter contentTypeFilter].freeze
   # accepts all params as each enhancer may require different data
   def initialize(params)
     @enhanced_query = {}

app/models/query_builder.rb

@@ -3,7 +3,7 @@ class QueryBuilder
 
   RESULTS_PER_PAGE = 20
   QUERY_PARAMS = %w[q citation contributors fundingInformation identifiers locations subjects title].freeze
-  FILTER_PARAMS = %i[source contentType].freeze
+  FILTER_PARAMS = %i[sourceFilter contentTypeFilter].freeze
 
   def initialize(enhanced_query)
     @query = {}
@@ -29,8 +29,8 @@ def extract_query(enhanced_query)
   end
 
   def extract_filters(enhanced_query)
-    # NOTE: ui and backend naming are not aligned so we can't loop here. we should fix in UI
-    @query['sourceFilter'] = enhanced_query[:source]
-    @query['contentType'] = enhanced_query[:contentType]
+    FILTER_PARAMS.each do |qp|
+      @query[qp] = enhanced_query[qp]
+    end
   end
 end

app/models/timdex_search.rb

@@ -15,7 +15,7 @@ class TimdexSearch < TimdexBase
       $sourceFilter: [String!]
       $index: String
       $from: String
-      $contentType: [String!]
+      $contentTypeFilter: [String!]
     ) {
       search(
         searchterm: $q
@@ -29,7 +29,7 @@ class TimdexSearch < TimdexBase
         sourceFilter: $sourceFilter
         index: $index
         from: $from
-        contentTypeFilter: $contentType
+        contentTypeFilter: $contentTypeFilter
       ) {
         hits
         records {

app/views/search/_filter.html.erb

@@ -1,4 +1,4 @@
-<% return if values.empty? %>
+<% return if values.blank? %>
 
 <div class="category">
   <button class="filter-label <%= 'expanded' if @enhanced_query[category.to_sym].present? || first == true %>"

app/views/search/_search_summary.html.erb

@@ -0,0 +1,15 @@
+<% return unless applied_filters.any? %>
+
+<div class="filter-summary">
+  <h2 class="hd-filter-summary hd-5">Applied filters: </h2>
+  <ul class="list-filter-summary list-inline">
+  <% applied_filters.each do |filter| %>
+    <li>
+      <a href="<%= results_path(remove_filter(@enhanced_query, filter.keys[0], filter.values[0])) %>">
+        <%= "#{nice_labels[filter.keys[0]] || filter.keys[0]}: #{filter.values[0]}" %>
+        <span class="sr">Remove applied filter?</span>
+      </a>
+    </li>
+  <% end %>
+  </ul>
+</div>