defmodule Mix.Tasks.Wiki.Upload do
  use Mix.Task
  alias Wiki.{Repo, Accounts, Accounts.User, Content.Upload}

  @shortdoc "Decrypts an upload into the given file"
  def run(["decrypt", id, output_file]) do
    email = IO.gets("Email: ") |> String.trim()
    password = IO.gets("Password: ") |> String.trim()

    Mix.Task.run("app.start")

    user = Repo.get_by!(User, email: email)
    upload = Repo.get!(Upload, String.to_integer(id)) |> Repo.preload(:page)

    if upload.page.user_id != user.id do
      raise "upload owner does not match provided user"
    else
      key = Accounts.generate_content_encryption_key(user, %{"password" => password})
      key = Base.decode16!(key, case: :lower)
      Upload.decrypt_to_file(upload, key, output_file)
    end
  end
end