Add tag alias undo support

app/jobs/tag_alias_undo_job.rb

@@ -0,0 +1,8 @@
+class TagAliasJob < ApplicationJob
+  queue_as :tags
+
+  def perform(*args)
+    ta = TagAlias.find(args[0])
+    ta.process_undo!(update_topic: args[1])
+  end
+end

app/jobs/tag_alias_update_posts_job.rb

@@ -1,9 +0,0 @@
-class TagAliasUpdatePostsJob < ApplicationJob
-  queue_as :tags
-
-  def perform(*args)
-    ta = TagAlias.find(args[0])
-
-    ta.update_posts
-  end
-end

app/models/tag_alias.rb

@@ -1,4 +1,6 @@
 class TagAlias < TagRelationship
+  has_many :tag_rel_undos, as: :tag_rel
+
   after_save :create_mod_action
   validates :antecedent_name, uniqueness: true
   validate :absence_of_transitive_relation
@@ -9,9 +11,16 @@ class TagAlias < TagRelationship
     def approve!(update_topic: true, approver: CurrentUser.user)
       CurrentUser.scoped(approver) do
         update(status: "queued", approver_id: approver.id)
+        create_undo_information
         TagAliasJob.perform_later(id, update_topic)
       end
     end
+
+    def undo!(approver: CurrentUser.user)
+      CurrentUser.scoped(approver) do
+        TagAliaseUndoJob.perform_later(id, true)
+      end
+    end
   end
 
   module ForumMethods
@@ -54,7 +63,7 @@ class TagAlias < TagRelationship
     TagAlias.to_aliased_with_originals(names).values
   end
 
-  def self.to_aliased_query(query)
+  def self.to_aliased_query(query, overrides: nil)
     # Remove tag types (newline syntax)
     query.gsub!(/(^| )(-)?(#{TagCategory.mapping.keys.sort_by { |x| -x.size }.join("|")}):([\S])/i, '\1\2\4')
     # Remove tag types (comma syntax)
@@ -66,11 +75,85 @@ class TagAlias < TagRelationship
         [negated ? x[1..-1] : x, negated]
       end
       aliased = to_aliased_with_originals(tags.map { |t| t[0] })
+      aliased.merge!(overrides) if overrides
       tags.map { |t| "#{t[1] ? '-' : ''}#{aliased[t[0]]}" }.join(" ")
     end
     lines.uniq.join("\n")
   end
 
+  def process_undo!(update_topic: true)
+    unless valid?
+      raise errors.full_messages.join("; ")
+    end
+
+    CurrentUser.scoped(approver) do
+      update(status: "pending")
+      update_posts_locked_tags_undo
+      update_blacklists_undo
+      update_posts_undo
+      forum_updater.update(retirement_message, "UNDONE") if update_topic
+      rename_wiki_and_artist_undo
+    end
+    tag_rel_undos.update_all(applied: true)
+  end
+
+  def update_posts_locked_tags_undo
+    Post.without_timeout do
+      Post.where_ilike(:locked_tags, "*#{consequent_name}*").find_each(batch_size: 50) do |post|
+        fixed_tags = TagAlias.to_aliased_query(post.locked_tags, overrides: {consequent_name => antecedent_name})
+        CurrentUser.scoped(creator, creator_ip_addr) do
+          post.update_column(:locked_tags, fixed_tags)
+        end
+      end
+    end
+  end
+
+  def update_blacklists_undo
+    User.without_timeout do
+      User.where_ilike(:blacklisted_tags, "*#{consequent_name}*").find_each(batch_size: 50) do |user|
+        fixed_blacklist = TagAlias.to_aliased_query(user.blacklisted_tags, overrides: {consequent_name => antecedent_name})
+        user.update_column(:blacklisted_tags, fixed_blacklist)
+      end
+    end
+  end
+
+  def update_posts_undo
+    Post.without_timeout do
+      tag_rel_undos.where(applied: false).each do |tu|
+        Post.where(id: tu.undo_data).find_each do |post|
+          post.do_not_version_changes = true
+          post.tag_string_diff = "-#{consequent_name} #{antecedent_name}"
+          post.save
+        end
+      end
+
+      # TODO: Race condition with indexing jobs here.
+      antecedent_tag.fix_post_count if antecedent_tag
+      consequent_tag.fix_post_count if consequent_tag
+    end
+  end
+
+  def rename_wiki_and_artist_undo
+    consequent_wiki = WikiPage.titled(consequent_name).first
+    if consequent_wiki.present?
+      if WikiPage.titled(antecedent_name).blank?
+        CurrentUser.scoped(creator, creator_ip_addr) do
+          consequent_wiki.update(title: antecedent_name, skip_secondary_validations: true)
+        end
+      else
+        forum_updater.update(conflict_message)
+      end
+    end
+
+    if consequent_tag.category == Tag.categories.artist
+      if consequent_tag.artist.present? && antecedent_tag.artist.blank?
+        CurrentUser.scoped(creator, creator_ip_addr) do
+          consequent_tag.artist.update!(name: antecedent_name)
+        end
+      end
+    end
+  end
+
   def process!(update_topic: true)
     unless valid?
       raise errors.full_messages.join("; ")
@@ -82,14 +165,13 @@ class TagAlias < TagRelationship
       CurrentUser.scoped(approver) do
         update(status: "processing")
         move_aliases_and_implications
-        move_saved_searches
         ensure_category_consistency
         update_posts_locked_tags
         update_blacklists
         update_posts
         forum_updater.update(approval_message(approver), "APPROVED") if update_topic
         rename_wiki_and_artist
-        update(status: "active", post_count: consequent_tag.post_count)
+        update(status: 'active', post_count: consequent_tag.post_count)
       end
     rescue Exception => e
       Rails.logger.error("[TA] #{e.message}\n#{e.backtrace}")
@@ -116,17 +198,6 @@ class TagAlias < TagRelationship
     end
   end
 
-  def move_saved_searches
-    escaped = Regexp.escape(antecedent_name)
-
-    if SavedSearch.enabled?
-      SavedSearch.where("query like ?", "%#{antecedent_name}%").find_each do |ss|
-        ss.query = ss.query.sub(/(?:^| )#{escaped}(?:$| )/, " #{consequent_name} ").strip.gsub(/  /, " ")
-        ss.save
-      end
-    end
-  end
-
   def move_aliases_and_implications
     aliases = TagAlias.where(["consequent_name = ?", antecedent_name])
     aliases.each do |ta|
@@ -182,6 +253,18 @@ class TagAlias < TagRelationship
     end
   end
 
+  def create_undo_information
+    post_ids = []
+    Post.transaction do
+      Post.without_timeout do
+        Post.sql_raw_tag_match(antecedent_name).find_each do |post|
+          post_ids << post.id
+        end
+        tag_rel_undos.create!(undo_data: post_ids)
+      end
+    end
+  end
+
   def update_posts
     Post.without_timeout do
       Post.sql_raw_tag_match(antecedent_name).find_each do |post|

app/models/tag_implication.rb

@@ -1,6 +1,8 @@
 class TagImplication < TagRelationship
   extend Memoist
 
+  has_many :tag_rel_undos, as: :tag_rel
+
   array_attribute :descendant_names
 
   before_save :update_descendant_names
@@ -150,6 +152,19 @@ class TagImplication < TagRelationship
       end
     end
 
+    def create_undo_information
+      Post.without_timeout do
+        Post.sql_raw_tag_match(antecedent_name).find_in_batches do |posts|
+          post_info = Hash.new
+          posts.each do |p|
+            post_info[p.id] = p.tag_string
+          end
+          tag_rel_undos.create!(undo_data: post_info)
+        end
+      end
+
+    end
+
     def update_posts
       Post.without_timeout do
         Post.sql_raw_tag_match(antecedent_name).find_each do |post|
@@ -165,6 +180,7 @@ class TagImplication < TagRelationship
 
     def approve!(approver: CurrentUser.user, update_topic: true)
       update(status: "queued", approver_id: approver.id)
+      create_undo_information
       TagImplicationJob.perform_later(id, update_topic)
     end
 

app/models/tag_rel_undo.rb

@@ -0,0 +1,3 @@
+class TagRelUndo < ApplicationRecord
+  belongs_to :tag_rel, polymorphic: true
+end

db/migrate/20191003070653_create_tag_relationship_undos.rb

@@ -0,0 +1,10 @@
+class CreateTagRelationshipUndos < ActiveRecord::Migration[6.0]
+  def change
+    create_table :tag_rel_undos do |t|
+      t.references :tag_rel, polymorphic: true
+      t.json :undo_data
+      t.boolean :applied, default: false
+      t.timestamps
+    end
+  end
+end

db/structure.sql

@@ -2185,6 +2185,40 @@ CREATE SEQUENCE public.tag_implications_id_seq
 ALTER SEQUENCE public.tag_implications_id_seq OWNED BY public.tag_implications.id;
 
 
+--
+-- Name: tag_rel_undos; Type: TABLE; Schema: public; Owner: -
+--
+
+CREATE TABLE public.tag_rel_undos (
+    id bigint NOT NULL,
+    tag_rel_type character varying,
+    tag_rel_id bigint,
+    undo_data json,
+    applied boolean DEFAULT false,
+    created_at timestamp(6) without time zone NOT NULL,
+    updated_at timestamp(6) without time zone NOT NULL
+);
+
+
+--
+-- Name: tag_rel_undos_id_seq; Type: SEQUENCE; Schema: public; Owner: -
+--
+
+CREATE SEQUENCE public.tag_rel_undos_id_seq
+    START WITH 1
+    INCREMENT BY 1
+    NO MINVALUE
+    NO MAXVALUE
+    CACHE 1;
+
+
+--
+-- Name: tag_rel_undos_id_seq; Type: SEQUENCE OWNED BY; Schema: public; Owner: -
+--
+
+ALTER SEQUENCE public.tag_rel_undos_id_seq OWNED BY public.tag_rel_undos.id;
+
+
 --
 -- Name: tag_subscriptions; Type: TABLE; Schema: public; Owner: -
 --
@@ -3162,6 +3196,13 @@ ALTER TABLE ONLY public.tag_aliases ALTER COLUMN id SET DEFAULT nextval('public.
 ALTER TABLE ONLY public.tag_implications ALTER COLUMN id SET DEFAULT nextval('public.tag_implications_id_seq'::regclass);
 
 
+--
+-- Name: tag_rel_undos id; Type: DEFAULT; Schema: public; Owner: -
+--
+
+ALTER TABLE ONLY public.tag_rel_undos ALTER COLUMN id SET DEFAULT nextval('public.tag_rel_undos_id_seq'::regclass);
+
+
 --
 -- Name: tag_subscriptions id; Type: DEFAULT; Schema: public; Owner: -
 --
@@ -3708,6 +3749,14 @@ ALTER TABLE ONLY public.tag_implications
     ADD CONSTRAINT tag_implications_pkey PRIMARY KEY (id);
 
 
+--
+-- Name: tag_rel_undos tag_rel_undos_pkey; Type: CONSTRAINT; Schema: public; Owner: -
+--
+
+ALTER TABLE ONLY public.tag_rel_undos
+    ADD CONSTRAINT tag_rel_undos_pkey PRIMARY KEY (id);
+
+
 --
 -- Name: tag_subscriptions tag_subscriptions_pkey; Type: CONSTRAINT; Schema: public; Owner: -
 --
@@ -4744,6 +4793,13 @@ CREATE INDEX index_tag_implications_on_consequent_name ON public.tag_implication
 CREATE INDEX index_tag_implications_on_forum_post_id ON public.tag_implications USING btree (forum_post_id);
 
 
+--
+-- Name: index_tag_rel_undos_on_tag_rel_type_and_tag_rel_id; Type: INDEX; Schema: public; Owner: -
+--
+
+CREATE INDEX index_tag_rel_undos_on_tag_rel_type_and_tag_rel_id ON public.tag_rel_undos USING btree (tag_rel_type, tag_rel_id);
+
+
 --
 -- Name: index_tag_subscriptions_on_creator_id; Type: INDEX; Schema: public; Owner: -
 --
@@ -5268,6 +5324,7 @@ INSERT INTO "schema_migrations" (version) VALUES
 ('20190905111159'),
 ('20190916204908'),
 ('20190919213915'),
-('20190924233432');
+('20190924233432'),
+('20191003070653');