philomena/lib/philomena/users/ability.ex

defimpl Canada.Can, for: [Atom, Philomena.Users.User] do
  alias Philomena.Users.User
  alias Philomena.Comments.Comment
  alias Philomena.Commissions.Commission
  alias Philomena.Conversations.Conversation
  alias Philomena.DuplicateReports.DuplicateReport
  alias Philomena.DnpEntries.DnpEntry
  alias Philomena.Images.Image
  alias Philomena.Forums.Forum
  alias Philomena.Topics.Topic
  alias Philomena.Posts.Post
  alias Philomena.Filters.Filter
  alias Philomena.Galleries.Gallery
  alias Philomena.DnpEntries.DnpEntry
  alias Philomena.UserLinks.UserLink
  alias Philomena.Tags.Tag
  alias Philomena.Reports.Report

  alias Philomena.Bans.User, as: UserBan
  alias Philomena.Bans.Subnet, as: SubnetBan
  alias Philomena.Bans.Fingerprint, as: FingerprintBan

  # Admins can do anything
  def can?(%User{role: "admin"}, _action, _model), do: true

  #
  # Moderators can...
  #

  # View filters
  def can?(%User{role: "moderator"}, :show, %Filter{}), do: true

  # View images
  def can?(%User{role: "moderator"}, :show, %Image{}), do: true

  # View comments
  def can?(%User{role: "moderator"}, :show, %Comment{}), do: true

  # View forums
  def can?(%User{role: "moderator"}, :show, %Forum{access_level: level})
    when level in ["normal", "assistant", "staff"], do: true
  def can?(%User{role: "moderator"}, :show, %Topic{hidden_from_users: true}), do: true

  # View conversations
  def can?(%User{role: "moderator"}, :show, %Conversation{}), do: true

  # View IP addresses and fingerprints
  def can?(%User{role: "moderator"}, :show, :ip_address), do: true

  # Manage duplicate reports
  def can?(%User{role: "moderator"}, :index, DuplicateReport), do: true
  def can?(%User{role: "moderator"}, :edit, %DuplicateReport{}), do: true

  # Manage reports
  def can?(%User{role: "moderator"}, :index, Report), do: true
  def can?(%User{role: "moderator"}, :show, %Report{}), do: true
  def can?(%User{role: "moderator"}, :edit, %Report{}), do: true

  # Manage user links
  def can?(%User{role: "moderator"}, :create_links, %User{}), do: true
  def can?(%User{role: "moderator"}, :edit_links, %User{}), do: true
  def can?(%User{role: "moderator"}, :edit, %UserLink{}), do: true
  def can?(%User{role: "moderator"}, :index, UserLink), do: true

  # Reveal anon users
  def can?(%User{role: "moderator"}, :reveal_anon, _object), do: true

  # Show the DNP list
  def can?(%User{role: "moderator"}, :index, DnpEntry), do: true
  def can?(%User{role: "moderator"}, :edit, %DnpEntry{}), do: true
  def can?(%User{role: "moderator"}, :update, %DnpEntry{}), do: true
  def can?(%User{role: "moderator"}, :show_reason, %DnpEntry{}), do: true
  def can?(%User{role: "moderator"}, :show_feedback, %DnpEntry{}), do: true

  # Create bans
  def can?(%User{role: "moderator"}, _action, UserBan), do: true
  def can?(%User{role: "moderator"}, _action, SubnetBan), do: true
  def can?(%User{role: "moderator"}, _action, FingerprintBan), do: true

  # Hide topics
  def can?(%User{role: "moderator"}, :hide, %Topic{}), do: true

  #
  # Assistants can...
  #


  # Image assistant actions
  def can?(%User{role: "assistant", role_map: %{"Image" => "moderator"}}, :show, %Image{}), do: true
  def can?(%User{role: "assistant", role_map: %{"Image" => "moderator"}}, :hide, %Image{}), do: true
  def can?(%User{role: "assistant", role_map: %{"Image" => "moderator"}}, :edit, %Image{}), do: true

  # Dupe assistant actions
  def can?(%User{role: "assistant", role_map: %{"DuplicateReport" => "moderator"}}, :index, DuplicateReport), do: true
  def can?(%User{role: "assistant", role_map: %{"DuplicateReport" => "moderator"}}, :edit, %DuplicateReport{}), do: true
  def can?(%User{role: "assistant", role_map: %{"DuplicateReport" => "moderator"}}, :show, %Image{}), do: true
  def can?(%User{role: "assistant", role_map: %{"DuplicateReport" => "moderator"}}, :edit, %Image{}), do: true
  def can?(%User{role: "assistant", role_map: %{"DuplicateReport" => "moderator"}}, :hide, %Comment{}), do: true

  # Comment assistant actions
  def can?(%User{role: "assistant", role_map: %{"Comment" => "moderator"}}, :show, %Comment{}), do: true
  def can?(%User{role: "assistant", role_map: %{"Comment" => "moderator"}}, :edit, %Comment{}), do: true
  def can?(%User{role: "assistant", role_map: %{"Comment" => "moderator"}}, :hide, %Comment{}), do: true

  # Topic assistant actions
  def can?(%User{role: "assistant", role_map: %{"Topic" => "moderator"}}, :show, %Topic{}), do: true
  def can?(%User{role: "assistant", role_map: %{"Topic" => "moderator"}}, :edit, %Topic{}), do: true
  def can?(%User{role: "assistant", role_map: %{"Topic" => "moderator"}}, :hide, %Topic{}), do: true
  def can?(%User{role: "assistant", role_map: %{"Topic" => "moderator"}}, :show, %Post{}), do: true
  def can?(%User{role: "assistant", role_map: %{"Topic" => "moderator"}}, :edit, %Post{}), do: true
  def can?(%User{role: "assistant", role_map: %{"Topic" => "moderator"}}, :hide, %Post{}), do: true

  # Tag assistant actions
  def can?(%User{role: "assistant", role_map: %{"Tag" => "moderator"}}, :edit, %Tag{}), do: true

  # User link assistant actions
  def can?(%User{role: "assistant", role_map: %{"UserLink" => "moderator"}}, :show, %UserLink{}), do: true
  def can?(%User{role: "assistant", role_map: %{"UserLink" => "moderator"}}, :edit, %UserLink{}), do: true

  # View forums
  def can?(%User{role: "assistant"}, :show, %Forum{access_level: level})
    when level in ["normal", "assistant"], do: true
  def can?(%User{role: "assistant"}, :show, %Topic{hidden_from_users: true}), do: true

  #
  # Users and anonymous users can...
  #

  # Edit their description and personal title
  def can?(%User{id: id}, :edit_description, %User{id: id}), do: true
  def can?(%User{id: id}, :edit_title, %User{id: id}), do: true

  # View conversations they are involved in
  def can?(%User{id: id}, :show, %Conversation{to_id: id}), do: true
  def can?(%User{id: id}, :show, %Conversation{from_id: id}), do: true

  # View filters they own and system filters
  def can?(_user, :show, %Filter{system: true}), do: true
  def can?(%User{}, action, Filter) when action in [:index, :new, :create], do: true
  def can?(%User{id: id}, action, %Filter{user_id: id}) when action in [:show, :edit, :update], do: true

  # Edit filters they own
  def can?(%User{id: id}, action, %Filter{user_id: id}) when action in [:edit, :update], do: true

  # View user links they've created
  def can?(%User{id: id}, :create_links, %User{id: id}), do: true
  def can?(%User{id: id}, :show, %UserLink{user_id: id}), do: true

  # Edit their commissions
  def can?(%User{id: id}, action, %Commission{user_id: id}) when action in [:edit, :update, :delete], do: true

  # View non-deleted images
  def can?(_user, action, Image)
      when action in [:new, :create, :index],
      do: true

  def can?(_user, action, %Image{hidden_from_users: false})
      when action in [:show, :index],
      do: true

  # Comment on images where that is allowed
  def can?(_user, :create_comment, %Image{hidden_from_users: false, commenting_allowed: true}), do: true

  # Edit comments on images
  def can?(%User{id: id}, :edit, %Comment{hidden_from_users: false, user_id: id} = comment) do
    # comment must have been made no later than 15 minutes ago
    time_ago = NaiveDateTime.utc_now() |> NaiveDateTime.add(-15 * 60)

    NaiveDateTime.diff(comment.created_at, time_ago) > 0
  end

  # Edit metadata on images where that is allowed
  def can?(_user, :edit_metadata, %Image{hidden_from_users: false, tag_editing_allowed: true}), do: true
  def can?(%User{id: id}, :edit_description, %Image{user_id: id, hidden_from_users: false, description_editing_allowed: true}), do: true

  # Vote on images they can see
  def can?(user, :vote, image), do: can?(user, :show, image)

  # View non-deleted comments
  def can?(_user, :show, %Comment{hidden_from_users: false}), do: true

  # View forums
  def can?(_user, :index, Forum), do: true
  def can?(_user, :show, %Forum{access_level: "normal"}), do: true
  def can?(_user, :show, %Topic{hidden_from_users: false}), do: true
  def can?(_user, :show, %Post{hidden_from_users: false}), do: true
  
  # Create and edit posts
  def can?(_user, :create_post, %Topic{locked_at: nil, hidden_from_users: false}), do: true
  def can?(%User{id: id}, :edit, %Post{hidden_from_users: false, user_id: id}), do: true

  # View profile pages
  def can?(_user, :show, %User{}), do: true

  # View and create DNP entries
  def can?(%User{}, action, DnpEntry) when action in [:new, :create], do: true
  def can?(%User{id: id}, :show, %DnpEntry{requesting_user_id: id}), do: true
  def can?(%User{id: id}, :show_reason, %DnpEntry{requesting_user_id: id}), do: true
  def can?(%User{id: id}, :show_feedback, %DnpEntry{requesting_user_id: id}), do: true

  def can?(_user, :show, %DnpEntry{aasm_state: "listed"}), do: true
  def can?(_user, :show_reason, %DnpEntry{aasm_state: "listed", hide_reason: false}), do: true

  # Create and edit galleries
  def can?(_user, :show, %Gallery{}), do: true
  def can?(%User{}, action, Gallery) when action in [:new, :create], do: true
  def can?(%User{id: id}, action, %Gallery{creator_id: id}) when action in [:edit, :update, :delete], do: true

  # Otherwise...
  def can?(_user, _action, _model), do: false
end