Add featured hashtags to profiles (#9755)

* Add hashtag filter to profiles

GET /@:username/tagged/:hashtag
GET /api/v1/accounts/:id/statuses?tagged=:hashtag

* Display featured hashtags on public profile

* Use separate model for featured tags

* Update featured hashtag counters on-write

* Limit featured tags to 10

1 files changed, 46 insertions, 0 deletions

diff --git a/app/models/featured_tag.rb b/app/models/featured_tag.rb
new file mode 100644
index 000000000..b5a10ad2d
--- /dev/null
+++ b/app/models/featured_tag.rb
@@ -0,0 +1,46 @@
+# frozen_string_literal: true
+# == Schema Information
+#
+# Table name: featured_tags
+#
+#  id             :bigint(8)        not null, primary key
+#  account_id     :bigint(8)
+#  tag_id         :bigint(8)
+#  statuses_count :bigint(8)        default(0), not null
+#  last_status_at :datetime
+#  created_at     :datetime         not null
+#  updated_at     :datetime         not null
+#
+
+class FeaturedTag < ApplicationRecord
+  belongs_to :account, inverse_of: :featured_tags, required: true
+  belongs_to :tag, inverse_of: :featured_tags, required: true
+
+  delegate :name, to: :tag, allow_nil: true
+
+  validates :name, presence: true
+  validate :validate_featured_tags_limit, on: :create
+
+  def name=(str)
+    self.tag = Tag.find_or_initialize_by(name: str.delete('#').mb_chars.downcase.to_s)
+  end
+
+  def increment(timestamp)
+    update(statuses_count: statuses_count + 1, last_status_at: timestamp)
+  end
+
+  def decrement(deleted_status_id)
+    update(statuses_count: [0, statuses_count - 1].max, last_status_at: account.statuses.where(visibility: %i(public unlisted)).tagged_with(tag).where.not(id: deleted_status_id).select(:created_at).first&.created_at)
+  end
+
+  def reset_data
+    self.statuses_count = account.statuses.where(visibility: %i(public unlisted)).tagged_with(tag).count
+    self.last_status_at = account.statuses.where(visibility: %i(public unlisted)).tagged_with(tag).select(:created_at).first&.created_at
+  end
+
+  private
+
+  def validate_featured_tags_limit
+    errors.add(:base, I18n.t('featured_tags.errors.limit')) if account.featured_tags.count >= 10
+  end
+end