box

defmodule Box do
  @moduledoc """
  Box file sharing API client.
  """
  alias Tesla.Multipart

  @box_api_url "https://api.box.com/2.0"
  @box_upload_url "https://upload.box.com/api/2.0"

  @doc """
  folder_items returns the items in a folder.
  """
  def folder_items(client, folder, fields \\ []) do
    {:ok, response} =
      Tesla.get(client, @box_api_url <> "/folders/#{folder}/items",
        query: [fields: Enum.join(fields, ",")]
      )

    {:ok, response.body}
  end

  @doc """
  folder_from_path returns the folder id for a path in Box
  """
  def folder_from_path(_client, path) do
    if path == "/" or path == "." do
      {:ok, %{id: "0"}}
    else
      # TODO: fetch id for other paths
      raise "not implemented: folder_from_path #{path}"
    end
  end

  @doc """
  file_from_path returns the file name and id for a path in Box
  """
  def file_from_path(client, path) do
    filename = Path.basename(path)
    {:ok, folder} = folder_from_path(client, Path.dirname(path))
    {:ok, files} = folder_items(client, folder.id, [:id, :name])

    case Enum.find(files.entries, fn f -> f.type == "file" and f.name == filename end) do
      nil -> {:error, "file not found"}
      f -> {:ok, f}
    end
  end

  @doc """
  create_shared_link from a file.
  """
  def create_shared_link(client, file_id) do
    # https://developer.box.com/reference#shared-link-object
    {:ok, response} =
      Tesla.put(client, @box_api_url <> "/files/#{file_id}", %{
        shared_link: %{
          access: "open",
          # TODO: password, unshared_at?
          permissions: %{
            can_download: true
          }
        }
      })

    {:ok, response.body}
  end

  def file_info(client, file_id) do
    fields = [
      :type,
      :id,
      :sequence_id,
      :etag,
      :name,
      :created_at,
      :modified_at,
      :description,
      :size,
      :path_collection,
      :created_by,
      :modified_by,
      :trashed_at,
      :purged_at,
      :content_created_at,
      :content_modified_at,
      :owned_by,
      :shared_link,
      :folder_upload_email,
      :parent,
      :item_status,
      :item_collection,
      :sync_state,
      :has_collaborations,
      :permissions,
      :tags,
      :sha1,
      :shared_link,
      :version_number,
      :comment_count,
      :lock,
      :extension,
      :is_package,
      :can_non_owners_invite
    ]

    {:ok, response} =
      Tesla.get(client, @box_api_url <> "/files/#{file_id}",
        query: [fields: Enum.join(fields, ",")]
      )

    {:ok, response.body}
  end

  def upload(client, path, folder_id, name) do
    attributes =
      Jason.encode!(%{
        name: name,
        parent: %{id: folder_id}
      })

    mp =
      Multipart.new()
      |> Multipart.add_field("attributes", attributes)
      |> Multipart.add_file(path)

    {:ok, response} = Tesla.post(client, @box_upload_url <> "/files/content", mp)

    case response.status do
      201 ->
        {:ok, response.body}

      _ ->
        {:error, response.status, response.body}
    end
  end
end