Move conversation controller functionality into context

lib/philomena/conversations.ex

@@ -9,45 +9,7 @@ defmodule Philomena.Conversations do
   alias Philomena.Conversations.Conversation
   alias Philomena.Conversations.Message
   alias Philomena.Reports
-
+  alias Philomena.Users
-  @doc """
-  Creates a conversation.
-
-  ## Examples
-
-      iex> create_conversation(%{field: value})
-      {:ok, %Conversation{}}
-
-      iex> create_conversation(%{field: bad_value})
-      {:error, %Ecto.Changeset{}}
-
-  """
-  def create_conversation(from, attrs \\ %{}) do
-    %Conversation{}
-    |> Conversation.creation_changeset(from, attrs)
-    |> Repo.insert()
-    |> case do
-      {:ok, conversation} ->
-        report_non_approved_message(hd(conversation.messages))
-        {:ok, conversation}
-
-      error ->
-        error
-    end
-  end
-
-  @doc """
-  Returns an `%Ecto.Changeset{}` for tracking conversation changes.
-
-  ## Examples
-
-      iex> change_conversation(conversation)
-      %Ecto.Changeset{source: %Conversation{}}
-
-  """
-  def change_conversation(%Conversation{} = conversation) do
-    Conversation.changeset(conversation, %{})
-  end
 
   @doc """
   Returns the number of unread conversations for the given user.
@@ -75,6 +37,96 @@ defmodule Philomena.Conversations do
     |> Repo.aggregate(:count)
   end
 
+  @doc """
+  Returns a `m:Scrivener.Page` of conversations between the partner and the user.
+
+  ## Examples
+
+      iex> list_conversations_with("123", %User{}, page_size: 10)
+      %Scrivener.Page{}
+
+  """
+  def list_conversations_with(partner_id, user, pagination) do
+    query =
+      from c in Conversation,
+        where:
+          (c.from_id == ^partner_id and c.to_id == ^user.id) or
+            (c.to_id == ^partner_id and c.from_id == ^user.id)
+
+    list_conversations(query, user, pagination)
+  end
+
+  @doc """
+  Returns a `m:Scrivener.Page` of conversations sent by or received from the user.
+
+  ## Examples
+
+      iex> list_conversations_with("123", %User{}, page_size: 10)
+      %Scrivener.Page{}
+
+  """
+  def list_conversations(queryable \\ Conversation, user, pagination) do
+    query =
+      from c in queryable,
+        as: :conversations,
+        where:
+          (c.from_id == ^user.id and not c.from_hidden) or
+            (c.to_id == ^user.id and not c.to_hidden),
+        inner_lateral_join:
+          cnt in subquery(
+            from m in Message,
+              where: m.conversation_id == parent_as(:conversations).id,
+              select: %{count: count()}
+          ),
+        on: true,
+        order_by: [desc: :last_message_at],
+        preload: [:to, :from],
+        select: %{c | message_count: cnt.count}
+
+    Repo.paginate(query, pagination)
+  end
+
+  @doc """
+  Creates a conversation.
+
+  ## Examples
+
+      iex> create_conversation(from, to, %{field: value})
+      {:ok, %Conversation{}}
+
+      iex> create_conversation(from, to, %{field: bad_value})
+      {:error, %Ecto.Changeset{}}
+
+  """
+  def create_conversation(from, attrs \\ %{}) do
+    to = Users.get_user_by_name(attrs["recipient"])
+
+    %Conversation{}
+    |> Conversation.creation_changeset(from, to, attrs)
+    |> Repo.insert()
+    |> case do
+      {:ok, conversation} ->
+        report_non_approved_message(hd(conversation.messages))
+        {:ok, conversation}
+
+      error ->
+        error
+    end
+  end
+
+  @doc """
+  Returns an `%Ecto.Changeset{}` for tracking conversation changes.
+
+  ## Examples
+
+      iex> change_conversation(conversation)
+      %Ecto.Changeset{source: %Conversation{}}
+
+  """
+  def change_conversation(%Conversation{} = conversation) do
+    Conversation.changeset(conversation, %{})
+  end
+
   @doc """
   Marks a conversation as read or unread from the perspective of the given user.
 
@@ -138,6 +190,59 @@ defmodule Philomena.Conversations do
     end
   end
 
+  @doc """
+  Returns the number of messages in the given conversation.
+
+  ## Example
+
+      iex> count_messages(%Conversation{})
+      3
+
+  """
+  def count_messages(conversation) do
+    Message
+    |> where(conversation_id: ^conversation.id)
+    |> Repo.aggregate(:count)
+  end
+
+  @doc """
+  Returns a `m:Scrivener.Page` of 2-tuples of messages and rendered output
+  within a conversation.
+
+  Messages are ordered by user message preference (`messages_newest_first`).
+
+  When coerced to a list and rendered as Markdown, the result may look like:
+
+      [
+        {%Message{body: "hello *world*"}, "hello <strong>world</strong>"}
+      ]
+
+  ## Example
+
+      iex> list_messages(%Conversation{}, %User{}, & &1.body, page_size: 10)
+      %Scrivener.Page{}
+
+  """
+  def list_messages(conversation, user, collection_renderer, pagination) do
+    direction =
+      if user.messages_newest_first do
+        :desc
+      else
+        :asc
+      end
+
+    query =
+      from m in Message,
+        where: m.conversation_id == ^conversation.id,
+        order_by: [{^direction, :created_at}],
+        preload: :from
+
+    messages = Repo.paginate(query, pagination)
+    rendered = collection_renderer.(messages)
+
+    put_in(messages.entries, Enum.zip(messages.entries, rendered))
+  end
+
   @doc """
   Creates a message within a conversation.
 

lib/philomena/conversations/conversation.ex

@@ -4,7 +4,6 @@ defmodule Philomena.Conversations.Conversation do
 
   alias Philomena.Users.User
   alias Philomena.Conversations.Message
-  alias Philomena.Repo
 
   @derive {Phoenix.Param, key: :slug}
 
@@ -20,6 +19,8 @@ defmodule Philomena.Conversations.Conversation do
     field :from_hidden, :boolean, default: false
     field :slug, :string
     field :last_message_at, :utc_datetime
+
+    field :message_count, :integer, virtual: true
     field :recipient, :string, virtual: true
 
     timestamps(inserted_at: :created_at, type: :utc_datetime)
@@ -43,17 +44,17 @@ defmodule Philomena.Conversations.Conversation do
   end
 
   @doc false
-  def creation_changeset(conversation, from, attrs) do
+  def creation_changeset(conversation, from, to, attrs) do
     conversation
-    |> cast(attrs, [:title, :recipient])
+    |> cast(attrs, [:title])
-    |> validate_required([:title, :recipient])
-    |> validate_length(:title, max: 300, count: :bytes)
     |> put_assoc(:from, from)
-    |> put_recipient()
+    |> put_assoc(:to, to)
-    |> set_slug()
+    |> put_change(:slug, Ecto.UUID.generate())
-    |> set_last_message()
     |> cast_assoc(:messages, with: &Message.creation_changeset(&1, &2, from))
+    |> set_last_message()
     |> validate_length(:messages, is: 1)
+    |> validate_length(:title, max: 300, count: :bytes)
+    |> validate_required([:title, :from, :to])
   end
 
   @doc false
@@ -64,21 +65,7 @@ defmodule Philomena.Conversations.Conversation do
     |> set_last_message()
   end
 
-  defp set_slug(changeset) do
-    changeset
-    |> change(slug: Ecto.UUID.generate())
-  end
-
   defp set_last_message(changeset) do
     change(changeset, last_message_at: DateTime.utc_now(:second))
   end
-
-  defp put_recipient(changeset) do
-    recipient = changeset |> get_field(:recipient)
-    user = Repo.get_by(User, name: recipient)
-
-    changeset
-    |> put_change(:to, user)
-    |> validate_required(:to)
-  end
 end

lib/philomena/users.ex

@@ -55,6 +55,22 @@ defmodule Philomena.Users do
     Repo.get_by(User, email: email)
   end
 
+  @doc """
+  Gets a user by name.
+
+  ## Examples
+
+      iex> get_user_by_name("Administrator")
+      %User{}
+
+      iex> get_user_by_name("nonexistent")
+      nil
+
+  """
+  def get_user_by_name(name) when is_binary(name) do
+    Repo.get_by(User, name: name)
+  end
+
   @doc """
   Gets a user by email and password.
 

lib/philomena_web/controllers/conversation/message_controller.ex

@@ -1,10 +1,8 @@
 defmodule PhilomenaWeb.Conversation.MessageController do
   use PhilomenaWeb, :controller
 
-  alias Philomena.Conversations.{Conversation, Message}
+  alias Philomena.Conversations.Conversation
   alias Philomena.Conversations
-  alias Philomena.Repo
-  import Ecto.Query
 
   plug PhilomenaWeb.FilterBannedUsersPlug
   plug PhilomenaWeb.CanaryMapPlug, create: :show
@@ -15,20 +13,16 @@ defmodule PhilomenaWeb.Conversation.MessageController do
     id_field: "slug",
     persisted: true
 
+  @page_size 25
+
   def create(conn, %{"message" => message_params}) do
     conversation = conn.assigns.conversation
     user = conn.assigns.current_user
 
     case Conversations.create_message(conversation, user, message_params) do
       {:ok, _message} ->
-        count =
+        count = Conversations.count_messages(conversation)
-          Message
+        page = div(count + @page_size - 1, @page_size)
-          |> where(conversation_id: ^conversation.id)
-          |> Repo.aggregate(:count, :id)
-
-        page =
-          Float.ceil(count / 25)
-          |> round()
 
         conn
         |> put_flash(:info, "Message successfully sent.")

lib/philomena_web/controllers/conversation_controller.ex

@@ -4,8 +4,6 @@ defmodule PhilomenaWeb.ConversationController do
   alias PhilomenaWeb.NotificationCountPlug
   alias Philomena.{Conversations, Conversations.Conversation, Conversations.Message}
   alias PhilomenaWeb.MarkdownRenderer
-  alias Philomena.Repo
-  import Ecto.Query
 
   plug PhilomenaWeb.FilterBannedUsersPlug when action in [:new, :create]
 
@@ -19,42 +17,17 @@ defmodule PhilomenaWeb.ConversationController do
     only: :show,
     preload: [:to, :from]
 
-  def index(conn, %{"with" => partner}) do
+  def index(conn, params) do
     user = conn.assigns.current_user
 
-    Conversation
-    |> where(
-      [c],
-      (c.from_id == ^user.id and c.to_id == ^partner and not c.from_hidden) or
-        (c.to_id == ^user.id and c.from_id == ^partner and not c.to_hidden)
-    )
-    |> load_conversations(conn)
-  end
-
-  def index(conn, _params) do
-    user = conn.assigns.current_user
-
-    Conversation
-    |> where(
-      [c],
-      (c.from_id == ^user.id and not c.from_hidden) or (c.to_id == ^user.id and not c.to_hidden)
-    )
-    |> load_conversations(conn)
-  end
-
-  defp load_conversations(queryable, conn) do
     conversations =
-      queryable
+      case params do
-      |> join(
+        %{"with" => partner_id} ->
-        :inner_lateral,
+          Conversations.list_conversations_with(partner_id, user, conn.assigns.scrivener)
-        [c],
+
-        _ in fragment("SELECT COUNT(*) FROM messages m WHERE m.conversation_id = ?", c.id),
+        _ ->
-        on: true
+          Conversations.list_conversations(user, conn.assigns.scrivener)
-      )
+      end
-      |> order_by(desc: :last_message_at)
-      |> preload([:to, :from])
-      |> select([c, cnt], {c, cnt.count})
-      |> Repo.paginate(conn.assigns.scrivener)
 
     render(conn, "index.html", title: "Conversations", conversations: conversations)
   end
@@ -62,27 +35,17 @@ defmodule PhilomenaWeb.ConversationController do
   def show(conn, _params) do
     conversation = conn.assigns.conversation
     user = conn.assigns.current_user
-    pref = load_direction(user)
 
     messages =
-      Message
+      Conversations.list_messages(
-      |> where(conversation_id: ^conversation.id)
+        conversation,
-      |> order_by([{^pref, :created_at}])
+        user,
-      |> preload([:from])
+        &MarkdownRenderer.render_collection(&1, conn),
-      |> Repo.paginate(conn.assigns.scrivener)
+        conn.assigns.scrivener
+      )
 
-    rendered =
+    changeset = Conversations.change_message(%Message{})
-      messages.entries
+    Conversations.mark_conversation_read(conversation, user)
-      |> MarkdownRenderer.render_collection(conn)
-
-    messages = %{messages | entries: Enum.zip(messages.entries, rendered)}
-
-    changeset =
-      %Message{}
-      |> Conversations.change_message()
-
-    conversation
-    |> Conversations.mark_conversation_read(user)
 
     # Update the conversation ticker in the header
     conn = NotificationCountPlug.call(conn)
@@ -96,9 +59,10 @@ defmodule PhilomenaWeb.ConversationController do
   end
 
   def new(conn, params) do
-    changeset =
+    conversation =
       %Conversation{recipient: params["recipient"], messages: [%Message{}]}
-      |> Conversations.change_conversation()
+
+    changeset = Conversations.change_conversation(conversation)
 
     render(conn, "new.html", title: "New Conversation", changeset: changeset)
   end
@@ -116,7 +80,4 @@ defmodule PhilomenaWeb.ConversationController do
         render(conn, "new.html", changeset: changeset)
     end
   end
-
-  defp load_direction(%{messages_newest_first: false}), do: :asc
-  defp load_direction(_user), do: :desc
 end

lib/philomena_web/templates/conversation/index.html.slime

@@ -20,14 +20,14 @@ h1 My Conversations
           th.table--communication-list__stats With
           th.table--communication-list__options Options
       tbody
-        = for {c, count} <- @conversations do
+        = for c <- @conversations do
           tr class=conversation_class(@conn.assigns.current_user, c)
             td.table--communication-list__name
               => link c.title, to: ~p"/conversations/#{c}"
 
               .small-text.hide-mobile
-                => count
+                => c.message_count
-                = pluralize("message", "messages", count)
+                = pluralize("message", "messages", c.message_count)
                 ' ; started
                 = pretty_time(c.created_at)
                 ' , last message
@@ -36,7 +36,7 @@ h1 My Conversations
             td.table--communication-list__stats
               = render PhilomenaWeb.UserAttributionView, "_user.html", object: %{user: other_party(@current_user, c)}, conn: @conn
             td.table--communication-list__options
-              => link "Last message", to: last_message_path(c, count)
+              => link "Last message", to: last_message_path(c, c.message_count)
               ' &bull;
               => link "Hide", to: ~p"/conversations/#{c}/hide", data: [method: "post"], data: [confirm: "Are you really, really sure?"]