From bc628db4177727ff9a59dffe7e89393b03e5d029 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ren=C3=A9=20F=C3=B6hring?= <rene.foehring@5minds.de>
Date: Sun, 8 Apr 2018 11:53:36 +0200
Subject: [PATCH] Add moderation tools

---
 .gitignore                                    |  1 +
 config/prod.secret.example.exs                |  7 ++
 lib/elixir_status/publisher.ex                | 71 ++++++++++++++++---
 lib/elixir_status/publisher/guard.ex          | 12 ++++
 lib/elixir_status_moderation_sample.ex        |  7 ++
 ...80408074127_add_moderation_to_postings.exs | 11 +++
 web/controllers/posting_controller.ex         | 34 +++++++++
 web/models/posting.ex                         |  5 +-
 web/persistence/posting.ex                    | 41 +++++++++++
 web/router.ex                                 |  4 ++
 web/static/css/app/component.post.scss        | 29 ++++++++
 web/templates/posting/moderate.html.eex       | 28 ++++++++
 web/templates/posting/posting.html.eex        | 32 ++++++++-
 web/views/view_helper.ex                      |  9 ++-
 14 files changed, 279 insertions(+), 12 deletions(-)
 create mode 100644 lib/elixir_status_moderation_sample.ex
 create mode 100644 priv/repo/migrations/20180408074127_add_moderation_to_postings.exs
 create mode 100644 web/templates/posting/moderate.html.eex

diff --git a/.gitignore b/.gitignore
index 687c0d6..3ccf7bd 100644
--- a/.gitignore
+++ b/.gitignore
@@ -28,3 +28,4 @@ erl_crash.dump
 /config/logger.extension.exs
 .envrc
 .tool-versions-e
+lib/elixir_status_moderation.ex
diff --git a/config/prod.secret.example.exs b/config/prod.secret.example.exs
index 0e82be0..e7eef1f 100644
--- a/config/prod.secret.example.exs
+++ b/config/prod.secret.example.exs
@@ -31,3 +31,10 @@ config :appsignal, :config,
   push_api_key: "your-hex-appsignal-key",
   env: :prod,
   revision: Mix.Project.config()[:version]
+
+# This function receives the posting and author as arguments and determines
+# reasons why it requires moderation
+# Return an empty list if no moderation is necessary
+config :elixir_status,
+       :publisher_moderation_reasons,
+       &ElixirStatusModerationSample.moderation_reasons/2
diff --git a/lib/elixir_status/publisher.ex b/lib/elixir_status/publisher.ex
index c7cf7dd..8e97612 100644
--- a/lib/elixir_status/publisher.ex
+++ b/lib/elixir_status/publisher.ex
@@ -23,7 +23,11 @@ defmodule ElixirStatus.Publisher do
     if Guard.blocked?(new_posting, author) do
       after_create_blocked(new_posting, author)
     else
-      after_create_valid(new_posting, author)
+      if Guard.moderation_required?(new_posting, author) do
+        after_create_moderation_required(new_posting, author)
+      else
+        after_create_valid(new_posting, author)
+      end
     end
   end
 
@@ -35,26 +39,43 @@ defmodule ElixirStatus.Publisher do
     Posting.unpublish(new_posting)
   end
 
+  defp after_create_moderation_required(new_posting, author) do
+    new_posting
+    |> create_all_short_links
+    |> send_direct_message_moderation_required
+
+    reasons = Guard.moderation_reasons(new_posting, author)
+
+    Posting.require_moderation(new_posting, reasons)
+  end
+
   defp after_create_valid(new_posting, author) do
     new_posting
     |> create_all_short_links
     |> send_direct_message_valid
 
-    tweet_uid = post_to_twitter(new_posting, author.twitter_handle)
-    Posting.update_published_tweet_uid(new_posting, tweet_uid)
+    tweet_about_posting!(new_posting, author)
+  end
+
+  @doc """
+    Called when a posting is published during moderation by PostingController.
+  """
+  def after_publish_moderated(posting, author) do
+    tweet_about_posting!(posting, author)
   end
 
   @doc """
     Called when a posting is unpublished by PostingController.
   """
   def after_unpublish(posting) do
-    if posting.published_tweet_uid do
-      spawn(fn ->
-        ExTwitter.destroy_status(posting.published_tweet_uid)
-      end)
+    remove_tweet!(posting)
+  end
 
-      Posting.update_published_tweet_uid(posting, nil)
-    end
+  @doc """
+    Called when a posting is marked as spam during moderation by PostingController.
+  """
+  def after_mark_as_spam(posting) do
+    remove_tweet!(posting)
   end
 
   @doc """
@@ -89,6 +110,21 @@ defmodule ElixirStatus.Publisher do
     "#{uid}-#{permatitle}"
   end
 
+  def tweet_about_posting!(posting, author) do
+    tweet_uid = post_to_twitter(posting, author.twitter_handle)
+    Posting.update_published_tweet_uid(posting, tweet_uid)
+  end
+
+  defp remove_tweet!(posting) do
+    if posting.published_tweet_uid do
+      spawn(fn ->
+        ExTwitter.destroy_status(posting.published_tweet_uid)
+      end)
+
+      Posting.update_published_tweet_uid(posting, nil)
+    end
+  end
+
   defp create_all_short_links(posting) do
     posting
     |> SharedUrls.for_posting()
@@ -104,6 +140,18 @@ defmodule ElixirStatus.Publisher do
     send_on_twitter(text, Mix.env())
   end
 
+  def send_direct_message_moderation_required(posting) do
+    text = """
+    ***MODERATE***
+
+    #{short_title(posting.title)}
+
+    #{moderation_url(posting)}
+    """
+
+    send_on_twitter(text, Mix.env())
+  end
+
   defp send_direct_message_valid(%ElixirStatus.Posting{title: title, permalink: permalink}) do
     text = "#{short_title(title)} #{short_url(permalink)}"
 
@@ -214,4 +262,9 @@ defmodule ElixirStatus.Publisher do
 
     ElixirStatus.URL.from_path("/=#{uid}")
   end
+
+  defp moderation_url(posting) do
+    "/moderate/#{posting.moderation_key}"
+    |> ElixirStatus.URL.from_path()
+  end
 end
diff --git a/lib/elixir_status/publisher/guard.ex b/lib/elixir_status/publisher/guard.ex
index 81f9232..90e138c 100644
--- a/lib/elixir_status/publisher/guard.ex
+++ b/lib/elixir_status/publisher/guard.ex
@@ -1,6 +1,7 @@
 defmodule ElixirStatus.Publisher.Guard do
   @publisher_blocked_urls Application.get_env(:elixir_status, :publisher_blocked_urls)
   @publisher_blocked_user_names Application.get_env(:elixir_status, :publisher_blocked_user_names)
+  @publisher_moderation_reasons Application.get_env(:elixir_status, :publisher_moderation_reasons)
 
   alias ElixirStatus.Publisher.SharedUrls
 
@@ -8,6 +9,17 @@ defmodule ElixirStatus.Publisher.Guard do
     blocked_author?(author) or blocked_posting?(posting)
   end
 
+  def moderation_required?(posting, author) do
+    moderation_reasons(posting, author)
+    |> List.wrap()
+    |> Enum.any?()
+  end
+
+  def moderation_reasons(posting, author) do
+    @publisher_moderation_reasons.(posting, author)
+    |> Enum.reject(&is_nil/1)
+  end
+
   def blocked_author?(author) do
     blocked_user_names = all_blocked_user_names()
 
diff --git a/lib/elixir_status_moderation_sample.ex b/lib/elixir_status_moderation_sample.ex
new file mode 100644
index 0000000..26565b8
--- /dev/null
+++ b/lib/elixir_status_moderation_sample.ex
@@ -0,0 +1,7 @@
+defmodule ElixirStatusModerationSample do
+  def moderation_reasons(posting, author) do
+    [
+      String.starts_with?(posting.title, "!!! ") && "Title starts with three exclamation marks"
+    ]
+  end
+end
diff --git a/priv/repo/migrations/20180408074127_add_moderation_to_postings.exs b/priv/repo/migrations/20180408074127_add_moderation_to_postings.exs
new file mode 100644
index 0000000..1fbf071
--- /dev/null
+++ b/priv/repo/migrations/20180408074127_add_moderation_to_postings.exs
@@ -0,0 +1,11 @@
+defmodule ElixirStatus.Repo.Migrations.AddModerationToPostings do
+  use Ecto.Migration
+
+  def change do
+    alter table(:postings) do
+      add(:moderation_key, :string)
+      add(:awaiting_moderation, :boolean, default: false)
+      add(:metadata, :map)
+    end
+  end
+end
diff --git a/web/controllers/posting_controller.ex b/web/controllers/posting_controller.ex
index 8a434bc..6d989cb 100644
--- a/web/controllers/posting_controller.ex
+++ b/web/controllers/posting_controller.ex
@@ -192,6 +192,37 @@ defmodule ElixirStatus.PostingController do
     |> redirect(to: posting_path(conn, :index))
   end
 
+  def moderate(conn, %{"moderation_key" => moderation_key}) do
+    assigns = [
+      moderation_key: moderation_key,
+      posting: ElixirStatus.Persistence.Posting.find_by_moderation_key(moderation_key)
+    ]
+
+    render(conn, "moderate.html", assigns)
+  end
+
+  def moderate_mark_as_spam(conn, %{"moderation_key" => moderation_key}) do
+    posting = ElixirStatus.Persistence.Posting.find_by_moderation_key(moderation_key)
+
+    ElixirStatus.Persistence.Posting.mark_as_spam(posting)
+    Publisher.after_mark_as_spam(posting)
+
+    conn
+    |> put_flash(:info, "Posting was not published.")
+    |> redirect(to: posting_path(conn, :index))
+  end
+
+  def moderate_publish(conn, %{"moderation_key" => moderation_key}) do
+    posting = ElixirStatus.Persistence.Posting.find_by_moderation_key(moderation_key)
+
+    ElixirStatus.Persistence.Posting.publish_moderated(posting)
+    Publisher.after_publish_moderated(posting, posting.user)
+
+    conn
+    |> put_flash(:info, "Posting was successfully published.")
+    |> redirect(to: posting_path(conn, :index))
+  end
+
   defp load_posting(conn, _) do
     posting =
       case conn do
@@ -301,7 +332,10 @@ defmodule ElixirStatus.PostingController do
       title: params["title"],
       scheduled_at: params["scheduled_at"],
       published_at: Ecto.DateTime.utc(),
+      metadata: %{},
+      awaiting_moderation: false,
       public: true,
+      moderation_key: Ecto.UUID.generate(),
       type: PostingTypifier.run(tmp_post)["choice"] |> to_string,
       referenced_urls: PostingUrlFinder.run(tmp_post) |> Poison.encode!()
     }
diff --git a/web/models/posting.ex b/web/models/posting.ex
index e7998b6..9dfe640 100644
--- a/web/models/posting.ex
+++ b/web/models/posting.ex
@@ -10,6 +10,9 @@ defmodule ElixirStatus.Posting do
     field(:published_at, Ecto.DateTime)
     field(:published_tweet_uid, :string)
     field(:public, :boolean, default: false)
+    field(:moderation_key, :string)
+    field(:awaiting_moderation, :boolean, default: false)
+    field(:metadata, :map)
 
     field(:type, :string)
     field(:referenced_urls, :string)
@@ -20,7 +23,7 @@ defmodule ElixirStatus.Posting do
   end
 
   @required_fields ~w(user_id uid permalink title text published_at public)
-  @optional_fields ~w(published_tweet_uid scheduled_at type referenced_urls)
+  @optional_fields ~w(published_tweet_uid scheduled_at type referenced_urls moderation_key awaiting_moderation metadata)
 
   @doc """
   Creates a changeset based on the `model` and `params`.
diff --git a/web/persistence/posting.ex b/web/persistence/posting.ex
index 63406b4..05abc11 100644
--- a/web/persistence/posting.ex
+++ b/web/persistence/posting.ex
@@ -14,6 +14,14 @@ defmodule ElixirStatus.Persistence.Posting do
     |> Repo.one()
   end
 
+  def find_by_moderation_key(moderation_key) do
+    query = from(p in Posting, where: p.moderation_key == ^moderation_key)
+
+    query
+    |> Ecto.Query.preload(:user)
+    |> Repo.one()
+  end
+
   def find_by_permalink(permalink) do
     String.split(permalink, "-") |> Enum.at(0) |> find_by_uid
   end
@@ -115,9 +123,42 @@ defmodule ElixirStatus.Persistence.Posting do
     |> Repo.update!()
   end
 
+  def mark_as_spam(posting) do
+    metadata = posting.metadata || %{}
+    metadata = Map.put(metadata, "marked_as_spam_at", Ecto.DateTime.utc())
+
+    attributes = %{public: false, awaiting_moderation: false, metadata: metadata}
+
+    posting
+    |> ElixirStatus.Posting.changeset(attributes)
+    |> Repo.update!()
+  end
+
   def republish(posting) do
     posting
     |> ElixirStatus.Posting.changeset(%{public: true})
     |> Repo.update!()
   end
+
+  def publish_moderated(posting) do
+    metadata = posting.metadata || %{}
+    metadata = Map.put(metadata, "moderated_at", Ecto.DateTime.utc())
+
+    attributes = %{public: true, awaiting_moderation: false, metadata: metadata}
+
+    posting
+    |> ElixirStatus.Posting.changeset(attributes)
+    |> Repo.update!()
+  end
+
+  def require_moderation(posting, reasons) do
+    metadata = posting.metadata || %{}
+    metadata = Map.put(metadata, "moderation_reasons", reasons)
+
+    attributes = %{public: false, awaiting_moderation: true, metadata: metadata}
+
+    posting
+    |> ElixirStatus.Posting.changeset(attributes)
+    |> Repo.update!()
+  end
 end
diff --git a/web/router.ex b/web/router.ex
index ecb7294..307573b 100644
--- a/web/router.ex
+++ b/web/router.ex
@@ -54,6 +54,10 @@ defmodule ElixirStatus.Router do
     get("/p/:permalink", PostingController, :show, as: :permalink_posting)
     get("/p/edit/:permalink", PostingController, :edit)
 
+    get("/moderate/:moderation_key", PostingController, :moderate)
+    post("/moderate/:moderation_key/publish", PostingController, :moderate_publish)
+    post("/moderate/:moderation_key/mark_as_spam", PostingController, :moderate_mark_as_spam)
+
     get("/edit_profile", UserController, :edit, as: :edit_user)
     put("/reset_twitter_handle", UserController, :reset_twitter_handle, as: :reset_twitter_handle)
 
diff --git a/web/static/css/app/component.post.scss b/web/static/css/app/component.post.scss
index f116708..e47404d 100644
--- a/web/static/css/app/component.post.scss
+++ b/web/static/css/app/component.post.scss
@@ -23,6 +23,9 @@
 .post--unpublished {
   opacity: 0.4;
 }
+.post--awaiting-moderation {
+  border: 1px solid #b066ff;
+}
 
 .post--preview {
   margin-bottom: -2rem;
@@ -187,6 +190,32 @@ select.posting-type-selector {
   @include clearAfter
 }
 
+.post__moderation-hint {
+  color: #b066ff;
+  border: 1px solid #b066ff;
+  padding: 1rem 1rem 0 1rem;
+  margin-bottom: 1rem;
+
+  h3 {
+    color: #fff;
+    background-color: #b066ff;
+    padding: 1rem;
+    margin: -1rem -1rem 1rem -1rem;
+  }
+}
+
+.post__not-public-hint {
+  color: #e62117;
+  border: 1px solid #e62117;
+  padding: 1rem 1rem 0 1rem;
+
+  h3 {
+    color: #fff;
+    background-color: #e62117;
+    padding: 1rem;
+    margin: -1rem -1rem 1rem -1rem;
+  }
+}
 
 .post__body {
   a {
diff --git a/web/templates/posting/moderate.html.eex b/web/templates/posting/moderate.html.eex
new file mode 100644
index 0000000..3291e30
--- /dev/null
+++ b/web/templates/posting/moderate.html.eex
@@ -0,0 +1,28 @@
+<%= if @posting.metadata["moderated_at"] do %>
+  <p>
+    This post has already been moderated at <%= @posting.metadata["moderated_at"] |> human_readable_date(false) %>.
+  </p>
+<% end %>
+<%= if @posting.metadata["marked_as_spam_at"] do %>
+  <p>
+    This post has been marked as spam and unpublished at <%= @posting.metadata["marked_as_spam_at"] |> human_readable_date(false) %>.
+  </p>
+<% end %>
+
+<p>
+  <%= link "Publish", to: posting_path(@conn, :moderate_publish, @posting.moderation_key), class: "btn", method: :post %>
+</p>
+<p>
+  <%= link "Do not publish", to: posting_path(@conn, :moderate_mark_as_spam, @posting.moderation_key), class: "btn btn--danger", method: :post %>
+</p>
+
+<pre><%= inspect @posting.metadata["moderation_reasons"], pretty: true %></pre>
+
+
+<%= render ElixirStatus.PostingView, "posting.html", conn: @conn,
+            posting: @posting,
+            belongs_to_me?: false,
+            just_created_by_me?: false
+            %>
+
+<pre><%= inspect @posting, pretty: true %></pre>
diff --git a/web/templates/posting/posting.html.eex b/web/templates/posting/posting.html.eex
index 6b0a529..6287f7b 100644
--- a/web/templates/posting/posting.html.eex
+++ b/web/templates/posting/posting.html.eex
@@ -1,4 +1,4 @@
-<div class="post<%= if admin?(@conn) && !@posting.public, do: " post--unpublished" %>" data-posting-uid="<%= raw @posting.uid %>">
+<div class="post <%= if admin?(@conn) && !@posting.public && !@posting.awaiting_moderation, do: "post--unpublished" %> <%= if @posting.awaiting_moderation, do: "post--awaiting-moderation" %>" data-posting-uid="<%= raw @posting.uid %>">
   <div class="post__inner">
     <div class="post__avatar">
       <div class="image" style="background-image: url(<%= raw avatar_path(@posting.user) %>)"></div>
@@ -49,6 +49,36 @@
       </span>
     </span>
 
+    <%= if admin?(@conn) && !@posting.public do %>
+      <div class="post__not-public-hint">
+        <h3>This post is not public.</h3>
+
+        <p>
+          <%= link "Re-Publish", to: posting_path(@conn, :republish, @posting), method: :post %>
+        </p>
+      </div>
+    <% end %>
+    <%= if @posting.awaiting_moderation do %>
+      <div class="post__moderation-hint">
+        <h3>This post awaits moderation.</h3>
+
+        <p>
+          There is a growing number of posts plugging services not related to Elixir.
+          To keep the quality of this community, some posts have to moderatored.
+        </p>
+        <p>
+          Sorry for this inconvenience!
+        </p>
+
+        <%= if admin?(@conn) do %>
+          <p>
+            <%= link "Moderate", to: posting_path(@conn, :moderate, @posting.moderation_key) %>
+          </p>
+        <% end %>
+
+      </div>
+    <% end %>
+
     <div class="post__body">
       <%= sanitized_markdown @posting.text %>
     </div>
diff --git a/web/views/view_helper.ex b/web/views/view_helper.ex
index 487df17..4e94c6a 100644
--- a/web/views/view_helper.ex
+++ b/web/views/view_helper.ex
@@ -37,7 +37,14 @@ defmodule ViewHelper do
   def admin?(conn), do: ElixirStatus.Auth.admin?(conn)
 
   @doc "Returns a date formatted for humans."
-  def human_readable_date(date, use_abbrevs? \\ true) do
+  def human_readable_date(date, use_abbrevs? \\ true)
+
+  def human_readable_date(date, use_abbrevs?) when is_binary(date) do
+    Ecto.DateTime.cast!(date)
+    |> human_readable_date(use_abbrevs?)
+  end
+
+  def human_readable_date(date, use_abbrevs?) do
     if use_abbrevs? && this_year?(date) do
       cond do
         today?(date) ->