favorites: show favlist when hovering over favcount.

Changes:

* Make it so you can click or hover over a post's favorite count to see
  the list of public favorites.
* Remove the "Show »" button next to the favorite count.
* Make the favorites list visible to all users. Before favorites were
  only visible to Gold users.
* Make the /favorites page show the list of all public favorites,
  instead of redirecting to the current user's favorites.
* Add /posts/:id/favorites endpoint.
* Add /users/:id/favorites endpoint.

This is for several reasons:

* To make viewing favorites work the same way as viewing upvotes.
* To make posts load faster for Gold users. Before, we loaded all the
  favorites when viewing a post, even when the user didn't look at them.
  This made pageloads slower for posts that had hundreds or thousands of
  favorites. Now we only load the favlist if the user hovers over the favcount.
* To make the favorite list visible to all users. Before, it wasn't
  visible to non-Gold users, because of the performance issue listed above.
* To make it more obvious that favorites are public by default. Before,
  since regular users could only see the favcount, they may have
  mistakenly believed other users couldn't see their favorites.

app/components/favorites_tooltip_component.rb

@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+# This component represents the tooltip that displays when you hover over a post's favorite count.
+class FavoritesTooltipComponent < ApplicationComponent
+  attr_reader :post, :current_user
+
+  def initialize(post:, current_user:)
+    super
+    @post = post
+    @current_user = current_user
+  end
+
+  def favorites
+    post.favorites.includes(:user).order(id: :desc)
+  end
+
+  def favoriter_name(favorite)
+    if policy(favorite).can_see_favoriter?
+      link_to_user(favorite.user)
+    else
+      tag.i("hidden")
+    end
+  end
+end

app/components/favorites_tooltip_component/favorites_tooltip_component.html.erb

@@ -0,0 +1,9 @@
+<div class="favorites-tooltip thin-scrollbar">
+  <div class="post-favoriters">
+    <% favorites.each do |favorite| %>
+      <div class="post-favoriter truncate">
+        <%= favoriter_name(favorite) %>
+      </div>
+    <% end %>
+  </div>
+</div>

app/components/favorites_tooltip_component/favorites_tooltip_component.js

@@ -0,0 +1,65 @@
+import Utility from "../../javascript/src/javascripts/utility.js";
+import { delegate, hideAll } from 'tippy.js';
+import 'tippy.js/dist/tippy.css';
+
+class FavoritesTooltipComponent {
+  // Trigger on the post favcount link.
+  static TARGET_SELECTOR = "span.post-favcount a";
+  static SHOW_DELAY = 125;
+  static HIDE_DELAY = 125;
+  static DURATION = 250;
+  static instance = null;
+
+  static initialize() {
+    if ($(FavoritesTooltipComponent.TARGET_SELECTOR).length === 0) {
+      return;
+    }
+
+    FavoritesTooltipComponent.instance = delegate("body", {
+      allowHTML: true,
+      appendTo: document.querySelector("#post-favorites-tooltips"),
+      delay: [FavoritesTooltipComponent.SHOW_DELAY, FavoritesTooltipComponent.HIDE_DELAY],
+      duration: FavoritesTooltipComponent.DURATION,
+      interactive: true,
+      maxWidth: "none",
+      target: FavoritesTooltipComponent.TARGET_SELECTOR,
+      theme: "common-tooltip",
+      touch: false,
+
+      onShow: FavoritesTooltipComponent.onShow,
+      onHide: FavoritesTooltipComponent.onHide,
+    });
+  }
+
+  static async onShow(instance) {
+    let $target = $(instance.reference);
+    let $tooltip = $(instance.popper);
+    let postId = $target.parents("[data-id]").data("id");
+
+    hideAll({ exclude: instance });
+
+    try {
+      $tooltip.addClass("tooltip-loading");
+
+      instance._request = $.get(`/posts/${postId}/favorites?variant=tooltip`);
+      let html = await instance._request;
+      instance.setContent(html);
+
+      $tooltip.removeClass("tooltip-loading");
+    } catch (error) {
+      if (error.status !== 0 && error.statusText !== "abort") {
+        Utility.error(`Error displaying favorites for post #${postId} (error: ${error.status} ${error.statusText})`);
+      }
+    }
+  }
+
+  static async onHide(instance) {
+    if (instance._request?.state() === "pending") {
+      instance._request.abort();
+    }
+  }
+}
+
+$(document).ready(FavoritesTooltipComponent.initialize);
+
+export default FavoritesTooltipComponent;

app/components/favorites_tooltip_component/favorites_tooltip_component.scss

@@ -0,0 +1,13 @@
+.favorites-tooltip {
+  font-size: var(--text-xs);
+  max-height: 240px;
+
+  .post-favoriter {
+    max-width: 160px;
+  }
+}
+
+span.post-favcount a {
+  color: var(--text-color);
+  &:hover { text-decoration: underline; }
+}

app/controllers/favorites_controller.rb

@@ -1,19 +1,16 @@
 class FavoritesController < ApplicationController
-  respond_to :html, :xml, :json, :js
+  respond_to :js, :json, :html, :xml
 
   def index
-    authorize Favorite
-    if !request.format.html?
-      @favorites = Favorite.visible(CurrentUser.user).paginated_search(params)
-      respond_with(@favorites)
-    elsif params[:user_id].present?
-      user = User.find(params[:user_id])
-      redirect_to posts_path(tags: "ordfav:#{user.name}", format: request.format.symbol)
-    elsif !CurrentUser.is_anonymous?
-      redirect_to posts_path(tags: "ordfav:#{CurrentUser.user.name}", format: request.format.symbol)
-    else
-      redirect_to posts_path(format: request.format.symbol)
-    end
+    post_id = params[:post_id] || params[:search][:post_id]
+    user_id = params[:user_id] || params[:search][:user_id]
+    user_name = params[:search][:user_name]
+    @post = Post.find(post_id) if post_id
+    @user = User.find(user_id) if user_id
+    @user = User.find_by_name(user_name) if user_name
+
+    @favorites = authorize Favorite.visible(CurrentUser.user).paginated_search(params, defaults: { post_id: @post&.id, user_id: @user&.id })
+    respond_with(@favorites)
   end
 
   def create

app/helpers/components_helper.rb

@@ -24,6 +24,10 @@ module ComponentsHelper
     render PostVotesTooltipComponent.new(post: post, **options)
   end
 
+  def render_favorites_tooltip(post, **options)
+    render FavoritesTooltipComponent.new(post: post, **options)
+  end
+
   def render_post_navbar(post, **options)
     render PostNavbarComponent.new(post: post, **options)
   end

app/javascript/packs/application.js

@@ -37,6 +37,7 @@ import Blacklist from "../src/javascripts/blacklists.js";
 import CommentComponent from "../../components/comment_component/comment_component.js";
 import CurrentUser from "../src/javascripts/current_user.js";
 import Dtext from "../src/javascripts/dtext.js";
+import FavoritesTooltipComponent from "../../components/favorites_tooltip_component/favorites_tooltip_component.js";
 import IqdbQuery from "../src/javascripts/iqdb_queries.js";
 import Note from "../src/javascripts/notes.js";
 import PopupMenuComponent from "../../components/popup_menu_component/popup_menu_component.js";
@@ -59,6 +60,7 @@ Danbooru.Blacklist = Blacklist;
 Danbooru.CommentComponent = CommentComponent;
 Danbooru.CurrentUser = CurrentUser;
 Danbooru.Dtext = Dtext;
+Danbooru.FavoritesTooltipComponent = FavoritesTooltipComponent;
 Danbooru.IqdbQuery = IqdbQuery;
 Danbooru.Note = Note;
 Danbooru.PopupMenuComponent = PopupMenuComponent;

app/javascript/src/javascripts/posts.js

@@ -30,7 +30,6 @@ Post.initialize_all = function() {
   if ($("#c-posts").length && $("#a-show").length) {
     this.initialize_links();
     this.initialize_post_relationship_previews();
-    this.initialize_favlist();
     this.initialize_post_sections();
     this.initialize_post_image_resize_links();
     this.initialize_recommended();
@@ -242,13 +241,6 @@ Post.toggle_relationship_preview = function(preview, preview_link) {
   }
 }
 
-Post.initialize_favlist = function() {
-  $("#show-favlist-link, #hide-favlist-link").on("click.danbooru", function(e) {
-    $("#favlist, #show-favlist-link, #hide-favlist-link").toggle();
-    e.preventDefault();
-  });
-}
-
 Post.view_original = function(e = null) {
   if (Utility.test_max_width(660)) {
     // Do the default behavior (navigate to image)

app/javascript/src/styles/specific/posts.scss

@@ -170,10 +170,6 @@ div#c-posts {
       }
     }
 
-    #favlist {
-      word-wrap: break-word;
-    }
-
     #recommended.loading-recommended-posts {
       pointer-events: none;
       opacity: 0.5;

app/models/favorite.rb

@@ -6,10 +6,16 @@ class Favorite < ApplicationRecord
   after_create :upvote_post_on_create
   after_destroy :unvote_post_on_destroy
 
-  scope :public_favorites, -> { where(user: User.bit_prefs_match(:enable_private_favorites, false)) }
+  scope :public_favorites, -> { where(user: User.has_public_favorites) }
 
   def self.visible(user)
-    user.is_admin? ? all : where(user: user).or(public_favorites)
+    if user.is_admin?
+      all
+    elsif user.is_anonymous?
+      public_favorites
+    else
+      where(user: user).or(public_favorites)
+    end
   end
 
   def self.search(params)

app/models/post.rb

@@ -50,7 +50,6 @@ class Post < ApplicationRecord
   has_many :approvals, :class_name => "PostApproval", :dependent => :destroy
   has_many :disapprovals, :class_name => "PostDisapproval", :dependent => :destroy
   has_many :favorites, dependent: :destroy
-  has_many :favorited_users, through: :favorites, source: :user
   has_many :replacements, class_name: "PostReplacement", :dependent => :destroy
 
   attr_accessor :old_tag_string, :old_parent_id, :old_source, :old_rating, :has_constraints, :disable_versioning
@@ -667,13 +666,6 @@ class Post < ApplicationRecord
       Favorite.exists?(post: self, user: user)
     end
 
-    # Users who publicly favorited this post, ordered by time of favorite.
-    def visible_favorited_users(viewer)
-      favorited_users.order("favorites.id DESC").select do |fav_user|
-        Pundit.policy!(viewer, fav_user).can_see_favorites?
-      end
-    end
-
     def favorite_groups
       FavoriteGroup.for_post(id)
     end

app/policies/favorite_policy.rb

@@ -6,4 +6,8 @@ class FavoritePolicy < ApplicationPolicy
   def destroy?
     record.user_id == user.id
   end
+
+  def can_see_favoriter?
+    user.is_admin? || record.user == user || !record.user.enable_private_favorites?
+  end
 end

app/policies/post_policy.rb

@@ -59,10 +59,6 @@ class PostPolicy < ApplicationPolicy
     user.is_gold?
   end
 
-  def can_view_favlist?
-    user.is_gold?
-  end
-
   # whether to show the + - links in the tag list.
   def show_extra_links?
     user.is_gold?

app/views/favorites/_search.html.erb

@@ -0,0 +1,6 @@
+<%= search_form_for(favorites_path) do |f| %>
+  <%= f.input :user_name, label: "Favoriter", input_html: { value: @user&.name, "data-autocomplete": "user" } %>
+  <%= f.input :post_id, label: "Post", input_html: { value: @post&.id } %>
+  <%= f.input :post_tags_match, label: "Tags", input_html: { value: params[:search][:post_tags_match], "data-autocomplete": "tag-query" } %>
+  <%= f.submit "Search" %>
+<% end %>

app/views/favorites/_update.js.erb

@@ -4,19 +4,8 @@
   $("#add-to-favorites, #add-fav-button, #remove-from-favorites, #remove-fav-button").toggle();
   $("#remove-fav-button").addClass("animate");
   $("span.post-votes[data-id=<%= @post.id %>]").replaceWith("<%= j render_post_votes @post, current_user: CurrentUser.user %>");
-  $("#favcount-for-post-<%= @post.id %>").text(<%= @post.fav_count %>);
+  $("span.post-favcount[data-id=<%= @post.id %>]").html("<%= j link_to @post.fav_count, favorites_path(post_id: @post.id, variant: :compact) %>");
   $(".fav-buttons").toggleClass("fav-buttons-false").toggleClass("fav-buttons-true");
 
-  <% if policy(@post).can_view_favlist? %>
-    var fav_count = <%= @post.fav_count %>;
-    $("#favlist").html("<%= j render "posts/partials/show/favorite_list", post: @post %>");
-
-    if (fav_count === 0) {
-      $("#show-favlist-link, #hide-favlist-link, #favlist").hide();
-    } else if (!$("#favlist").is(":visible")) {
-      $("#show-favlist-link").show();
-    }
-  <% end %>
-
   Danbooru.Utility.notice("<%= j flash[:notice] %>");
 <% end %>

app/views/favorites/index.html+tooltip.erb

@@ -0,0 +1,3 @@
+<% if @post.present? %>
+  <%= render_favorites_tooltip(@post, current_user: CurrentUser.user) %>
+<% end %>

app/views/favorites/index.html.erb

@@ -0,0 +1,44 @@
+<div id="c-favorites">
+  <div id="a-index">
+    <% if @post %>
+      <h1><%= link_to "Favorites", favorites_path %>/<%= link_to @post.dtext_shortlink, @post %></h1>
+    <% elsif @user %>
+      <h1><%= link_to "Favorites", favorites_path %>/<%= link_to_user @user %></h1>
+    <% else %>
+      <h1><%= link_to "Favorites", favorites_path %></h1>
+    <% end %>
+
+    <%= render "search" %>
+
+    <%= table_for @favorites.includes(:user, post: [:uploader, :media_asset]), class: "striped autofit" do |t| %>
+      <% if @post.nil? %>
+        <% t.column "Post" do |favorite| %>
+          <%= post_preview(favorite.post, show_deleted: true) %>
+        <% end %>
+
+        <% t.column "Tags", td: {class: "col-expand"} do |favorite| %>
+          <%= render_inline_tag_list(favorite.post) %>
+        <% end %>
+
+        <% t.column "Uploader" do |favorite| %>
+          <%= link_to_user favorite.post.uploader %>
+          <%= link_to "»", favorites_path(search: { post_tags_match: "user:#{favorite.post.uploader.name}" }) %>
+          <div><%= time_ago_in_words_tagged(favorite.post.created_at) %></div>
+        <% end %>
+      <% end %>
+
+      <% if @user.nil? %>
+        <% t.column "Favoriter" do |favorite| %>
+          <% if policy(favorite).can_see_favoriter? %>
+            <%= link_to_user favorite.user %>
+            <%= link_to "»", favorites_path(search: { user_name: favorite.user.name }) %>
+          <% else %>
+            <i>hidden</i>
+          <% end %>
+        <% end %>
+      <% end %>
+    <% end %>
+
+    <%= numbered_paginator(@favorites) %>
+  </div>
+</div>

app/views/layouts/default.html.erb

@@ -102,6 +102,7 @@
     <div id="post-tooltips"></div>
     <div id="user-tooltips"></div>
     <div id="post-votes-tooltips"></div>
+    <div id="post-favorites-tooltips"></div>
     <div id="popup-menus"></div>
   </div>
 

app/views/posts/partials/show/_favorite_list.html.erb

@@ -1,2 +0,0 @@
-<%# post %>
-<%= safe_join(post.visible_favorited_users(CurrentUser.user).map { |user| link_to_user(user) }, ", ") %>

app/views/posts/partials/show/_information.html.erb

@@ -23,14 +23,12 @@
   <li id="post-info-score">
     Score: <%= render_post_votes post, current_user: CurrentUser.user %>
   </li>
-  <li id="post-info-favorites">Favorites: <span id="favcount-for-post-<%= post.id %>"><%= post.fav_count %></span>
-    <% if policy(post).can_view_favlist? %>
-    <%= link_to "Show »", "#", id: "show-favlist-link", style: ("display: none;" if post.fav_count == 0) %>
-    <%= link_to "« Hide", "#", id: "hide-favlist-link", style: "display: none;" %>
-    <div id="favlist" style="display: none;" class="ml-4">
-      <%= render "posts/partials/show/favorite_list", post: post %>
-    </div>
-  <% end %></li>
+  <li id="post-info-favorites">
+    Favorites:
+    <%= tag.span class: "post-favcount", "data-id": post.id do %>
+      <%= link_to post.fav_count, post_favorites_path(post) %>
+    <% end %>
+  </li>
   <li id="post-info-status">
     Status:
     <% if post.is_pending? %>