philomena/lib/philomena/images.ex

defmodule Philomena.Images do
  @moduledoc """
  The Images context.
  """

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

  alias Philomena.Images.Image

  @doc """
  Returns the list of images.

  ## Examples

      iex> list_images()
      [%Image{}, ...]

  """
  def list_images do
    Repo.all(Image |> where(hidden_from_users: false) |> order_by(desc: :created_at) |> limit(25))
  end

  @doc """
  Gets a single image.

  Raises `Ecto.NoResultsError` if the Image does not exist.

  ## Examples

      iex> get_image!(123)
      %Image{}

      iex> get_image!(456)
      ** (Ecto.NoResultsError)

  """
  def get_image!(id) do
    Repo.one!(Image |> where(id: ^id) |> preload(:tags))
  end

  @doc """
  Creates a image.

  ## Examples

      iex> create_image(%{field: value})
      {:ok, %Image{}}

      iex> create_image(%{field: bad_value})
      {:error, %Ecto.Changeset{}}

  """
  def create_image(attrs \\ %{}) do
    %Image{}
    |> Image.changeset(attrs)
    |> Repo.insert()
  end

  @doc """
  Updates a image.

  ## Examples

      iex> update_image(image, %{field: new_value})
      {:ok, %Image{}}

      iex> update_image(image, %{field: bad_value})
      {:error, %Ecto.Changeset{}}

  """
  def update_image(%Image{} = image, attrs) do
    image
    |> Image.changeset(attrs)
    |> Repo.update()
  end

  @doc """
  Deletes a Image.

  ## Examples

      iex> delete_image(image)
      {:ok, %Image{}}

      iex> delete_image(image)
      {:error, %Ecto.Changeset{}}

  """
  def delete_image(%Image{} = image) do
    Repo.delete(image)
  end

  @doc """
  Returns an `%Ecto.Changeset{}` for tracking image changes.

  ## Examples

      iex> change_image(image)
      %Ecto.Changeset{source: %Image{}}

  """
  def change_image(%Image{} = image) do
    Image.changeset(image, %{})
  end

  def reindex_image(%Image{} = image) do
    spawn fn ->
      Image
      |> preload(^indexing_preloads())
      |> where(id: ^image.id)
      |> Repo.one()
      |> Image.index_document()
    end

    image
  end

  def indexing_preloads do
    [:user, :favers, :downvoters, :upvoters, :hiders, :deleter, :gallery_interactions, tags: [:aliases, :aliased_tag]]
  end

  alias Philomena.Images.Subscription

  def subscribed?(_image, nil), do: false
  def subscribed?(image, user) do
    Subscription
    |> where(image_id: ^image.id, user_id: ^user.id)
    |> Repo.exists?()
  end

  @doc """
  Creates a subscription.

  ## Examples

      iex> create_subscription(%{field: value})
      {:ok, %Subscription{}}

      iex> create_subscription(%{field: bad_value})
      {:error, %Ecto.Changeset{}}

  """
  def create_subscription(_image, nil), do: {:ok, nil}
  def create_subscription(image, user) do
    %Subscription{image_id: image.id, user_id: user.id}
    |> Subscription.changeset(%{})
    |> Repo.insert(on_conflict: :nothing)
  end

  @doc """
  Deletes a Subscription.

  ## Examples

      iex> delete_subscription(subscription)
      {:ok, %Subscription{}}

      iex> delete_subscription(subscription)
      {:error, %Ecto.Changeset{}}

  """
  def delete_subscription(image, user) do
    %Subscription{image_id: image.id, user_id: user.id}
    |> Repo.delete()
  end
end