daily-tracker

accounts.ex (8096B)

---

 defmodule DailyTracker.Accounts do
   @moduledoc """
   The Accounts context.
   """
 
   import Ecto.Query, warn: false
   alias DailyTracker.Repo
 
   alias DailyTracker.Accounts.{User, UserToken, UserNotifier}
 
   ## Database getters
 
   @doc """
   Gets a user by email.
 
   ## Examples
 
       iex> get_user_by_email("foo@example.com")
       %User{}
 
       iex> get_user_by_email("unknown@example.com")
       nil
 
   """
   def get_user_by_email(email) when is_binary(email) do
     Repo.get_by(User, email: email)
   end
 
   @doc """
   Gets a user by email and password.
 
   ## Examples
 
       iex> get_user_by_email_and_password("foo@example.com", "correct_password")
       %User{}
 
       iex> get_user_by_email_and_password("foo@example.com", "invalid_password")
       nil
 
   """
   def get_user_by_email_and_password(email, password)
       when is_binary(email) and is_binary(password) do
     user = Repo.get_by(User, email: email)
     if User.valid_password?(user, password), do: user
   end
 
   @doc """
   Gets a single user.
 
   Raises `Ecto.NoResultsError` if the User does not exist.
 
   ## Examples
 
       iex> get_user!(123)
       %User{}
 
       iex> get_user!(456)
       ** (Ecto.NoResultsError)
 
   """
   def get_user!(id), do: Repo.get!(User, id)
 
   ## User registration
 
   @doc """
   Registers a user.
 
   ## Examples
 
       iex> register_user(%{field: value})
       {:ok, %User{}}
 
       iex> register_user(%{field: bad_value})
       {:error, %Ecto.Changeset{}}
 
   """
   def register_user(attrs) do
     %User{}
     |> User.email_changeset(attrs)
     |> Repo.insert()
   end
 
   ## Settings
 
   @doc """
   Checks whether the user is in sudo mode.
 
   The user is in sudo mode when the last authentication was done no further
   than 20 minutes ago. The limit can be given as second argument in minutes.
   """
   def sudo_mode?(user, minutes \\ -20)
 
   def sudo_mode?(%User{authenticated_at: ts}, minutes) when is_struct(ts, DateTime) do
     DateTime.after?(ts, DateTime.utc_now() |> DateTime.add(minutes, :minute))
   end
 
   def sudo_mode?(_user, _minutes), do: false
 
   @doc """
   Returns an `%Ecto.Changeset{}` for changing the user email.
 
   See `DailyTracker.Accounts.User.email_changeset/3` for a list of supported options.
 
   ## Examples
 
       iex> change_user_email(user)
       %Ecto.Changeset{data: %User{}}
 
   """
   def change_user_email(user, attrs \\ %{}, opts \\ []) do
     User.email_changeset(user, attrs, opts)
   end
 
   @doc """
   Updates the user email using the given token.
 
   If the token matches, the user email is updated and the token is deleted.
   """
   def update_user_email(user, token) do
     context = "change:#{user.email}"
 
     Repo.transact(fn ->
       with {:ok, query} <- UserToken.verify_change_email_token_query(token, context),
            %UserToken{sent_to: email} <- Repo.one(query),
            {:ok, user} <- Repo.update(User.email_changeset(user, %{email: email})),
            {_count, _result} <-
              Repo.delete_all(from(UserToken, where: [user_id: ^user.id, context: ^context])) do
         {:ok, user}
       else
         _ -> {:error, :transaction_aborted}
       end
     end)
   end
 
   @doc """
   Returns an `%Ecto.Changeset{}` for changing the user password.
 
   See `DailyTracker.Accounts.User.password_changeset/3` for a list of supported options.
 
   ## Examples
 
       iex> change_user_password(user)
       %Ecto.Changeset{data: %User{}}
 
   """
   def change_user_password(user, attrs \\ %{}, opts \\ []) do
     User.password_changeset(user, attrs, opts)
   end
 
   @doc """
   Updates the user password.
 
   Returns a tuple with the updated user, as well as a list of expired tokens.
 
   ## Examples
 
       iex> update_user_password(user, %{password: ...})
       {:ok, {%User{}, [...]}}
 
       iex> update_user_password(user, %{password: "too short"})
       {:error, %Ecto.Changeset{}}
 
   """
   def update_user_password(user, attrs) do
     user
     |> User.password_changeset(attrs)
     |> update_user_and_delete_all_tokens()
   end
 
   ## Session
 
   @doc """
   Generates a session token.
   """
   def generate_user_session_token(user) do
     {token, user_token} = UserToken.build_session_token(user)
     Repo.insert!(user_token)
     token
   end
 
   @doc """
   Gets the user with the given signed token.
 
   If the token is valid `{user, token_inserted_at}` is returned, otherwise `nil` is returned.
   """
   def get_user_by_session_token(token) do
     {:ok, query} = UserToken.verify_session_token_query(token)
     Repo.one(query)
   end
 
   @doc """
   Gets the user with the given magic link token.
   """
   def get_user_by_magic_link_token(token) do
     with {:ok, query} <- UserToken.verify_magic_link_token_query(token),
          {user, _token} <- Repo.one(query) do
       user
     else
       _ -> nil
     end
   end
 
   @doc """
   Logs the user in by magic link.
 
   There are three cases to consider:
 
   1. The user has already confirmed their email. They are logged in
      and the magic link is expired.
 
   2. The user has not confirmed their email and no password is set.
      In this case, the user gets confirmed, logged in, and all tokens -
      including session ones - are expired. In theory, no other tokens
      exist but we delete all of them for best security practices.
 
   3. The user has not confirmed their email but a password is set.
      This cannot happen in the default implementation but may be the
      source of security pitfalls. See the "Mixing magic link and password registration" section of
      `mix help phx.gen.auth`.
   """
   def login_user_by_magic_link(token) do
     {:ok, query} = UserToken.verify_magic_link_token_query(token)
 
     case Repo.one(query) do
       # Prevent session fixation attacks by disallowing magic links for unconfirmed users with password
       {%User{confirmed_at: nil, hashed_password: hash}, _token} when not is_nil(hash) ->
         raise """
         magic link log in is not allowed for unconfirmed users with a password set!
 
         This cannot happen with the default implementation, which indicates that you
         might have adapted the code to a different use case. Please make sure to read the
         "Mixing magic link and password registration" section of `mix help phx.gen.auth`.
         """
 
       {%User{confirmed_at: nil} = user, _token} ->
         user
         |> User.confirm_changeset()
         |> update_user_and_delete_all_tokens()
 
       {user, token} ->
         Repo.delete!(token)
         {:ok, {user, []}}
 
       nil ->
         {:error, :not_found}
     end
   end
 
   @doc ~S"""
   Delivers the update email instructions to the given user.
 
   ## Examples
 
       iex> deliver_user_update_email_instructions(user, current_email, &url(~p"/users/settings/confirm-email/#{&1}"))
       {:ok, %{to: ..., body: ...}}
 
   """
   def deliver_user_update_email_instructions(%User{} = user, current_email, update_email_url_fun)
       when is_function(update_email_url_fun, 1) do
     {encoded_token, user_token} = UserToken.build_email_token(user, "change:#{current_email}")
 
     Repo.insert!(user_token)
     UserNotifier.deliver_update_email_instructions(user, update_email_url_fun.(encoded_token))
   end
 
   @doc """
   Delivers the magic link login instructions to the given user.
   """
   def deliver_login_instructions(%User{} = user, magic_link_url_fun)
       when is_function(magic_link_url_fun, 1) do
     {encoded_token, user_token} = UserToken.build_email_token(user, "login")
     Repo.insert!(user_token)
     UserNotifier.deliver_login_instructions(user, magic_link_url_fun.(encoded_token))
   end
 
   @doc """
   Deletes the signed token with the given context.
   """
   def delete_user_session_token(token) do
     Repo.delete_all(from(UserToken, where: [token: ^token, context: "session"]))
     :ok
   end
 
   ## Token helper
 
   defp update_user_and_delete_all_tokens(changeset) do
     Repo.transact(fn ->
       with {:ok, user} <- Repo.update(changeset) do
         tokens_to_expire = Repo.all_by(UserToken, user_id: user.id)
 
         Repo.delete_all(from(t in UserToken, where: t.id in ^Enum.map(tokens_to_expire, & &1.id)))
 
         {:ok, {user, tokens_to_expire}}
       end
     end)
   end
 end