Aggiedit/lib/aggiedit/rooms.ex

defmodule Aggiedit.Rooms do
  @moduledoc """
  The Rooms context.
  """

  import Ecto.Query, warn: false
  alias Aggiedit.Repo

  alias Aggiedit.Accounts.User
  alias Aggiedit.Rooms.Room

  alias Aggiedit.Post.{Vote, Comment}

  alias Phoenix.PubSub

  def list_rooms do
    Repo.all(Room)
  end

  def get_room!(id), do: Repo.get!(Room, id)

  def create_room(attrs \\ %{}) do
    %Room{}
    |> Room.changeset(attrs)
    |> Repo.insert()
  end

  def update_room(%Room{} = room, attrs) do
    room
    |> Room.changeset(attrs)
    |> Repo.update()
  end

  def delete_room(%Room{} = room) do
    Repo.delete(room)
  end

  def change_room(%Room{} = room, attrs \\ %{}) do
    Room.changeset(room, attrs)
  end

  def create_or_find_room_with_domain(domain) do
    case Repo.get_by(Room, domain: domain) do
      room=%Room{} -> {:ok, room}
      nil -> create_room(%{domain: domain})
    end
  end

  alias Aggiedit.Rooms.Post

  def list_posts do
    Repo.all(Post)
  end

  def posts_in_room(room_id) do
    Repo.all((from p in Post, where: p.room_id == ^room_id, order_by: [asc: :id], select: p))
  end

  def get_post!(id), do: Repo.get!(Post, id)

  def create_post(attrs, user, after_save \\ &{:ok, &1}) do
    user = Repo.preload(user, :room)

    %Post{}
    |> Repo.preload([:user, :room])
    |> Post.changeset(attrs)
    |> Ecto.Changeset.put_assoc(:user, user)
    |> Ecto.Changeset.put_assoc(:room, user.room)
    |> Repo.insert()
    |> broadcast_post_over_room(:post_created)
    |> post_saved(after_save)
  end

  def update_post(%Post{} = post, attrs, after_save \\ &{:ok, &1}) do
    post
    |> Post.changeset(attrs)
    |> Repo.update()
    |> broadcast_post_over_room(:post_updated)
    |> post_saved(after_save)
  end

  defp post_saved({:ok, post}, func) do
    {:ok, _post} = func.(post)
  end
  defp post_saved(error, _fun), do: error

  def delete_post(%Post{} = post) do
    Repo.delete(post)
    |> broadcast_post_over_room(:post_deleted)
  end

  def change_post(%Post{} = post, attrs \\ %{}) do
    Post.changeset(post, attrs)
  end

  def vote_count(post) do
    post
    |> Repo.preload(:votes)
    |> Map.get(:votes)
    |> Enum.map(fn vote -> if vote.is_up, do: 1, else: -1 end)
    |> Enum.sum()
  end

  def vote_post(%Post{} = post, %User{} = user, direction) do
    is_up = direction == "upvote"
    vote = %Vote{is_up: is_up, user: user, post: post}
    |> Repo.insert(on_conflict: [set: [is_up: is_up]], conflict_target: [:user_id, :post_id])
    
    post = change_post(post, %{score: vote_count(post)})
    |> Repo.update()

    broadcast_post_over_room(post, :post_voted)
  end

  def comment_post(%Post{} = post, %User{} = user, comment) do
    Repo.insert(%Comment{comment: comment, user: user, post: post})
  end

  defp broadcast_post_over_room({:error, _reason}=error, _event), do: error
  defp broadcast_post_over_room({:ok, post}, event) do 
    PubSub.broadcast(Aggiedit.PubSub, "room:#{post.room_id}:posts", {event, post})
    {:ok, post}
  end

  def subscribe(room) do
    PubSub.subscribe(Aggiedit.PubSub, "room:#{room.id}:posts")
  end
end