keep track of post approvals to prevent approval cycles

app/logical/daily_maintenance.rb

@@ -15,6 +15,7 @@ class DailyMaintenance
     TagAlias.update_cached_post_counts_for_all
     PostDisapproval.dmail_messages!
     Tag.clean_up_negative_post_counts!
+    PostApproval.prune!
     SuperVoter.init!
     AntiVoter.init!
   end

app/models/post.rb

@@ -274,7 +274,7 @@ class Post < ActiveRecord::Base
 
   module ApprovalMethods
     def is_approvable?
-      !is_status_locked? && (is_pending? || is_flagged? || is_deleted?) && approver_id != CurrentUser.id
+      !is_status_locked? && (is_pending? || is_flagged? || is_deleted?) && !PostApproval.approved?(CurrentUser.id, id)
     end
 
     def flag!(reason, options = {})
@@ -314,7 +314,7 @@ class Post < ActiveRecord::Base
         raise ApprovalError.new("You cannot approve a post you uploaded")
       end
 
-      if approver_id == CurrentUser.id
+      if approver_id == CurrentUser.id || PostApproval.approved?(CurrentUser.id, id)
         errors.add(:approver, "have already approved this post")
         raise ApprovalError.new("You have previously approved this post and cannot approve it again")
       end
@@ -324,6 +324,9 @@ class Post < ActiveRecord::Base
       self.is_pending = false
       self.is_deleted = false
       self.approver_id = CurrentUser.id
+
+      PostApproval.create(user_id: CurrentUser.id, post_id: id)
+
       save!
     end
 
@@ -1362,7 +1365,7 @@ class Post < ActiveRecord::Base
       end
 
       if !CurrentUser.is_admin? 
-        if approver_id == CurrentUser.id
+        if approver_id == CurrentUser.id || PostApproval.approved?(CurrentUser.id, id)
           raise ApprovalError.new("You have previously approved this post and cannot undelete it")
         elsif uploader_id == CurrentUser.id
           raise ApprovalError.new("You cannot undelete a post you uploaded")

app/models/post_approval.rb

@@ -0,0 +1,12 @@
+class PostApproval < ActiveRecord::Base
+	belongs_to :user
+	belongs_to :post
+
+	def self.prune!
+		where("created_at < ?", 1.month.ago).delete_all
+	end
+
+	def self.approved?(user_id, post_id)
+		where(user_id: user_id, post_id: post_id).exists?
+	end
+end

app/views/posts/show.html.erb

@@ -148,7 +148,9 @@
   <meta name="favorites" content="<%= @post.fav_string %>">
   <meta name="pools" content="<%= @post.pool_string %>">
   <meta name="post-id" content="<%= @post.id %>">
-  <meta name="post-is-approvable" content="<%= @post.is_approvable? %>">
+  <% if CurrentUser.can_approve_posts? %>
+    <meta name="post-is-approvable" content="<%= @post.is_approvable? %>">
+  <% end %>
   <meta name="post-is-deleted" content="<%= @post.is_deleted? %>">
   <meta name="post-is-flagged" content="<%= @post.is_flagged? %>">
   <meta name="config-large-width" content="<%= Danbooru.config.large_image_width %>">

db/migrate/20161101003139_create_post_approvals.rb

@@ -0,0 +1,12 @@
+class CreatePostApprovals < ActiveRecord::Migration
+  def change
+    create_table :post_approvals do |t|
+    	t.integer :user_id, null: false
+    	t.integer :post_id, null: false
+      t.timestamps null: false
+    end
+
+    add_index :post_approvals, :user_id
+    add_index :post_approvals, :post_id
+  end
+end

db/structure.sql

@@ -2617,6 +2617,38 @@ CREATE SEQUENCE post_appeals_id_seq
 ALTER SEQUENCE post_appeals_id_seq OWNED BY post_appeals.id;
 
 
+--
+-- Name: post_approvals; Type: TABLE; Schema: public; Owner: -
+--
+
+CREATE TABLE post_approvals (
+    id integer NOT NULL,
+    user_id integer NOT NULL,
+    post_id integer NOT NULL,
+    created_at timestamp without time zone NOT NULL,
+    updated_at timestamp without time zone NOT NULL
+);
+
+
+--
+-- Name: post_approvals_id_seq; Type: SEQUENCE; Schema: public; Owner: -
+--
+
+CREATE SEQUENCE post_approvals_id_seq
+    START WITH 1
+    INCREMENT BY 1
+    NO MINVALUE
+    NO MAXVALUE
+    CACHE 1;
+
+
+--
+-- Name: post_approvals_id_seq; Type: SEQUENCE OWNED BY; Schema: public; Owner: -
+--
+
+ALTER SEQUENCE post_approvals_id_seq OWNED BY post_approvals.id;
+
+
 --
 -- Name: post_disapprovals; Type: TABLE; Schema: public; Owner: -
 --
@@ -4307,6 +4339,13 @@ ALTER TABLE ONLY pools ALTER COLUMN id SET DEFAULT nextval('pools_id_seq'::regcl
 ALTER TABLE ONLY post_appeals ALTER COLUMN id SET DEFAULT nextval('post_appeals_id_seq'::regclass);
 
 
+--
+-- Name: id; Type: DEFAULT; Schema: public; Owner: -
+--
+
+ALTER TABLE ONLY post_approvals ALTER COLUMN id SET DEFAULT nextval('post_approvals_id_seq'::regclass);
+
+
 --
 -- Name: id; Type: DEFAULT; Schema: public; Owner: -
 --
@@ -4712,6 +4751,14 @@ ALTER TABLE ONLY post_appeals
     ADD CONSTRAINT post_appeals_pkey PRIMARY KEY (id);
 
 
+--
+-- Name: post_approvals_pkey; Type: CONSTRAINT; Schema: public; Owner: -
+--
+
+ALTER TABLE ONLY post_approvals
+    ADD CONSTRAINT post_approvals_pkey PRIMARY KEY (id);
+
+
 --
 -- Name: post_disapprovals_pkey; Type: CONSTRAINT; Schema: public; Owner: -
 --
@@ -6768,6 +6815,20 @@ CREATE INDEX index_post_appeals_on_creator_ip_addr ON post_appeals USING btree (
 CREATE INDEX index_post_appeals_on_post_id ON post_appeals USING btree (post_id);
 
 
+--
+-- Name: index_post_approvals_on_post_id; Type: INDEX; Schema: public; Owner: -
+--
+
+CREATE INDEX index_post_approvals_on_post_id ON post_approvals USING btree (post_id);
+
+
+--
+-- Name: index_post_approvals_on_user_id; Type: INDEX; Schema: public; Owner: -
+--
+
+CREATE INDEX index_post_approvals_on_user_id ON post_approvals USING btree (user_id);
+
+
 --
 -- Name: index_post_disapprovals_on_post_id; Type: INDEX; Schema: public; Owner: -
 --
@@ -7459,3 +7520,5 @@ INSERT INTO schema_migrations (version) VALUES ('20161018221128');
 
 INSERT INTO schema_migrations (version) VALUES ('20161024220345');
 
+INSERT INTO schema_migrations (version) VALUES ('20161101003139');
+

test/models/post_approval_test.rb

@@ -0,0 +1,62 @@
+require 'test_helper'
+
+class PostApprovalTest < ActiveSupport::TestCase
+	context "a pending post" do
+		setup do
+			@user = FactoryGirl.create(:user)
+			CurrentUser.user = @user
+			CurrentUser.ip_addr = "127.0.0.1"
+
+			@post = FactoryGirl.create(:post, uploader_id: @user.id, is_pending: true)
+
+			@approver = FactoryGirl.create(:user)
+			@approver.can_approve_posts = true
+			@approver.save
+			CurrentUser.user = @approver
+
+			CurrentUser.stubs(:can_approve_posts?).returns(true)
+		end
+
+		teardown do
+			CurrentUser.user = nil
+		end
+
+		should "allow approval" do
+			assert_equal(false, PostApproval.approved?(@approver.id, @post.id))
+		end
+
+		context "That is approved" do
+			should "create a postapproval record" do
+				assert_difference("PostApproval.count") do
+					@post.approve!
+				end
+			end
+
+			context "that is then flagged" do
+				setup do
+					@user2 = FactoryGirl.create(:user)
+					@user3 = FactoryGirl.create(:user)
+					@approver2 = FactoryGirl.create(:user)
+					@approver2.can_approve_posts = true
+					@approver2.save
+				end
+
+				should "prevent the first approver from approving again" do
+					@post.approve!
+					CurrentUser.user = @user2
+					@post.flag!("blah")
+					CurrentUser.user = @approver2
+					@post.approve!
+					assert_not_equal(@approver.id, @post.approver_id)
+					CurrentUser.user = @user3
+					@post.flag!("blah blah")
+					CurrentUser.user = @approver
+
+					assert_raises(Post::ApprovalError) do
+						@post.approve!
+					end
+				end
+			end
+		end
+	end
+end