forum posting

lib/philomena/posts.ex

@@ -4,22 +4,12 @@ defmodule Philomena.Posts do
   """
 
   import Ecto.Query, warn: false
+  alias Ecto.Multi
   alias Philomena.Repo
 
+  alias Philomena.Topics.Topic
   alias Philomena.Posts.Post
-
-  @doc """
-  Returns the list of posts.
-
-  ## Examples
-
-      iex> list_posts()
-      [%Post{}, ...]
-
-  """
-  def list_posts do
-    Repo.all(Post)
-  end
+  alias Philomena.Notifications
 
   @doc """
   Gets a single post.
@@ -49,10 +39,60 @@ defmodule Philomena.Posts do
       {:error, %Ecto.Changeset{}}
 
   """
-  def create_post(attrs \\ %{}) do
-    %Post{}
-    |> Post.changeset(attrs)
-    |> Repo.insert()
+  def create_post(topic, user, attributes, params \\ %{}) do
+    topic_query =
+      Topic
+      |> where(id: ^topic.id)
+
+    Multi.new
+    |> Multi.run(:post, fn repo, _ ->
+      last_position =
+        Post
+        |> where(topic_id: ^topic.id)
+        |> order_by(desc: :topic_position)
+        |> select([p], p.topic_position)
+        |> limit(1)
+        |> repo.one()
+
+      Ecto.build_assoc(topic, :posts, [topic_position: (last_position || -1) + 1] ++ attributes)
+      |> Post.creation_changeset(user, params)
+      |> repo.insert()
+    end)
+    |> Multi.run(:update_topic, fn repo, %{post: %{id: post_id}} ->
+      {count, nil} =
+        repo.update_all(topic_query, inc: [post_count: 1], set: [last_post_id: post_id])
+
+      {:ok, count}
+    end)
+    |> Repo.isolated_transaction(:serializable)
+  end
+
+  def notify_post(post) do
+    spawn fn ->
+      topic =
+        post
+        |> Repo.preload(:topic)
+        |> Map.fetch!(:topic)
+
+      subscriptions =
+        topic
+        |> Repo.preload(:subscriptions)
+        |> Map.fetch!(:subscriptions)
+
+      Notifications.notify(
+        post,
+        subscriptions,
+        %{
+          actor_id: topic.id,
+          actor_type: "Topic",
+          actor_child_id: post.id,
+          actor_child_type: "Post",
+          action: "posted a new reply in"
+        }
+      )
+    end
+
+    post
   end
 
   @doc """
@@ -101,4 +141,20 @@ defmodule Philomena.Posts do
   def change_post(%Post{} = post) do
     Post.changeset(post, %{})
   end
+
+  def reindex_post(%Post{} = post) do
+    spawn fn ->
+      Post
+      |> preload(^indexing_preloads())
+      |> where(id: ^post.id)
+      |> Repo.one()
+      |> Post.index_document()
+    end
+
+    post
+  end
+
+  def indexing_preloads do
+    [:user, topic: :forum]
+  end
 end

lib/philomena/posts/post.ex

@@ -38,4 +38,18 @@ defmodule Philomena.Posts.Post do
     |> cast(attrs, [])
     |> validate_required([])
   end
+
+  @doc false
+  def creation_changeset(post, user, attrs) do
+    post
+    |> cast(attrs, [:body, :anonymous])
+    |> set_name_at_post_time(user)
+    |> validate_required([:body])
+    |> validate_length(:body, min: 1, max: 300_000, count: :bytes)
+  end
+
+  def set_name_at_post_time(changeset, nil), do: changeset
+  def set_name_at_post_time(changeset, %{name: name}) do
+    change(changeset, name_at_post_time: name)
+  end
 end

lib/philomena/repo.ex

@@ -4,4 +4,24 @@ defmodule Philomena.Repo do
     adapter: Ecto.Adapters.Postgres
 
   use Scrivener, page_size: 250
+
+  @levels %{
+    read_committed: "READ COMMITTED",
+    repeatable_read: "REPEATABLE READ",
+    serializable: "SERIALIZABLE"
+  }
+
+  def isolated_transaction(f, level) do
+    Philomena.Repo.transaction(fn ->
+      Philomena.Repo.query!("SET TRANSACTION ISOLATION LEVEL #{@levels[level]}")
+      Philomena.Repo.transaction(f)
+    end)
+    |> case do
+      {:ok, value} ->
+        value
+
+      error ->
+        error
+    end
+  end
 end

lib/philomena/topics/topic.ex

@@ -6,6 +6,7 @@ defmodule Philomena.Topics.Topic do
   alias Philomena.Users.User
   alias Philomena.Polls.Poll
   alias Philomena.Posts.Post
+  alias Philomena.Topics.Subscription
 
   @derive {Phoenix.Param, key: :slug}
   schema "topics" do
@@ -15,6 +16,8 @@ defmodule Philomena.Topics.Topic do
     belongs_to :last_post, Post
     belongs_to :forum, Forum
     has_one :poll, Poll
+    has_many :posts, Post
+    has_many :subscriptions, Subscription
 
     field :title, :string
     field :post_count, :integer, default: 0

lib/philomena_web/controllers/topic/post_controller.ex

@@ -1,10 +1,51 @@
 defmodule PhilomenaWeb.Topic.PostController do
   use PhilomenaWeb, :controller
 
-  #alias Philomena.{Forums.Forum}
-  #alias Philomena.Posts
+  alias Philomena.{Forums.Forum, Topics.Topic, Posts}
+  alias Philomena.Repo
 
   plug PhilomenaWeb.FilterBannedUsersPlug
+  plug PhilomenaWeb.UserAttributionPlug
   plug PhilomenaWeb.CanaryMapPlug, create: :show, edit: :show, update: :show
   plug :load_and_authorize_resource, model: Forum, id_field: "short_name", id_name: "forum_id", persisted: true
+  plug :load_topic
+
+  def create(conn, %{"post" => post_params}) do
+    attributes = conn.assigns.attributes
+    forum = conn.assigns.forum
+    topic = conn.assigns.topic
+    user = conn.assigns.current_user
+
+    case Posts.create_post(topic, user, attributes, post_params) do
+      {:ok, %{post: post}} ->
+        Posts.notify_post(post)
+        Posts.reindex_post(post)
+
+        conn
+        |> put_flash(:info, "Post created successfully.")
+        |> redirect(to: Routes.forum_topic_path(conn, :show, forum, topic, post_id: post.id) <> "#post_#{post.id}")
+
+      _error ->
+        conn
+        |> put_flash(:error, "There was an error creating the post")
+        |> redirect(external: conn.assigns.referrer)
+    end
+  end
+
+  defp load_topic(%{params: %{"topic_id" => slug}} = conn, _args) do
+    forum = conn.assigns.forum
+    user = conn.assigns.current_user
+
+    with topic when not is_nil(topic) <- Repo.get_by(Topic, slug: slug, forum_id: forum.id),
+         true <- Canada.Can.can?(user, :show, topic)
+    do
+      conn
+      |> assign(:topic, topic)
+    else
+      _ ->
+        conn
+        |> put_flash(:error, "Couldn't access that topic")
+        |> redirect(external: conn.assigns.referrer)
+    end
+  end
 end

lib/philomena_web/controllers/topic_controller.ex

@@ -1,7 +1,7 @@
 defmodule PhilomenaWeb.TopicController do
   use PhilomenaWeb, :controller
 
-  alias Philomena.{Forums.Forum, Topics, Topics.Topic, Posts.Post, Textile.Renderer}
+  alias Philomena.{Forums.Forum, Topics, Topics.Topic, Posts, Posts.Post, Textile.Renderer}
   alias Philomena.Repo
   import Ecto.Query
 
@@ -54,6 +54,10 @@ defmodule PhilomenaWeb.TopicController do
     watching =
       Topics.subscribed?(topic, conn.assigns.current_user)
 
-    render(conn, "show.html", posts: posts, watching: watching)
+    changeset =
+      %Post{}
+      |> Posts.change_post()
+
+    render(conn, "show.html", posts: posts, changeset: changeset, watching: watching)
   end
 end

lib/philomena_web/router.ex

@@ -86,7 +86,9 @@ defmodule PhilomenaWeb.Router do
     resources "/tags", TagController, only: [:index, :show]
     resources "/search", SearchController, only: [:index]
     resources "/forums", ForumController, only: [:index, :show] do
-      resources "/topics", TopicController, only: [:show]
+      resources "/topics", TopicController, only: [:show] do
+        resources "/posts", Topic.PostController, only: [:create], singleton: true
+      end
     end
     resources "/comments", CommentController, only: [:index]
 

lib/philomena_web/templates/topic/post/_form.html.slime

@@ -0,0 +1,25 @@
+= form_for @changeset, Routes.forum_topic_post_path(@conn, :create, @forum, @topic), fn f ->
+  = if @changeset.action do
+    .alert.alert-danger
+      p Oops, something went wrong! Please check the errors below.
+
+  .block
+    .block__header.block__header--js-tabbed
+      a.selected href="#" data-click-tab="write"
+        i.fa.fa-pencil>
+        ' Edit
+
+      a href="#" data-click-tab="preview"
+        i.fa.fa-eye>
+        ' Preview
+
+    .block__tab.communication-edit__tab.selected data-tab="write"
+      .field
+        = textarea f, :body, class: "input input--wide input--text js-preview-input js-toolbar-input", placeholder: "Please read the site rules before posting and use [spoiler][/spoiler] for NSFW stuff in SFW forums.", required: true
+        = error_tag f, :body
+
+    .block__tab.communication-edit__tab.hidden data-tab="preview"
+      ' [Loading preview...]
+
+    .block__content.communication-edit__actions
+      = submit "Post", class: "button"

lib/philomena_web/templates/topic/show.html.slime

@@ -47,7 +47,7 @@ h1 = @topic.title
 
   / Post form
   = if @topic.post_count < 200_000 do
-    /= render partial: 'topics/posts/form'
+    = render PhilomenaWeb.Topic.PostView, "_form.html", conn: @conn, forum: @forum, topic: @topic, changeset: @changeset
   - else
     /h3 Okay, we're impressed
     /p You're looking at a thread with over 200,000 posts in it!

lib/philomena_web/views/topic/post_view.ex

@@ -0,0 +1,3 @@
+defmodule PhilomenaWeb.Topic.PostView do
+  use PhilomenaWeb, :view
+end