NEW: user accounts (#3)

assets/css/app.scss

@@ -1,31 +0,0 @@
-/* This file is for your main application css. */
-@import "./phoenix.css";
-
-/* Alerts and form errors */
-.alert {
-  padding: 15px;
-  margin-bottom: 20px;
-  border: 1px solid transparent;
-  border-radius: 4px;
-}
-.alert-info {
-  color: #31708f;
-  background-color: #d9edf7;
-  border-color: #bce8f1;
-}
-.alert-warning {
-  color: #8a6d3b;
-  background-color: #fcf8e3;
-  border-color: #faebcc;
-}
-.alert-danger {
-  color: #a94442;
-  background-color: #f2dede;
-  border-color: #ebccd1;
-}
-.alert p {
-  margin-bottom: 0;
-}
-.alert:empty {
-  display: none;
-}

config/test.exs

@@ -1,5 +1,8 @@
 use Mix.Config
 
+# Only in tests, remove the complexity from the password hashing algorithm
+config :bcrypt_elixir, :log_rounds, 1
+
 # Configure your database
 #
 # The MIX_TEST_PARTITION environment variable can be used

lib/mix/tasks/planner.register.ex

@@ -0,0 +1,20 @@
+defmodule Mix.Tasks.Planner.Register do
+  use Mix.Task
+
+  alias Planner.Accounts
+
+  @shortdoc "Register a new Planner user"
+
+  def run([email, password]) do
+    Mix.Task.run("app.start")
+
+    case Accounts.register_user(%{email: email, password: password}) do
+      {:ok, _} ->
+        Mix.shell().info("User created successfully.")
+
+      {:error, %Ecto.Changeset{} = changeset} ->
+        IO.inspect(changeset)
+        Mix.shell().error("There was a problem.")
+    end
+  end
+end

lib/planner/accounts.ex

@@ -0,0 +1,292 @@
+defmodule Planner.Accounts do
+  @moduledoc """
+  The Accounts context.
+  """
+
+  import Ecto.Query, warn: false
+  alias Planner.Repo
+  alias Planner.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.registration_changeset(attrs)
+    # Inline the confirmation, for now (MRD)
+    |> User.confirm_changeset()
+    |> Repo.insert()
+  end
+
+  ## Settings
+
+  @doc """
+  Returns an `%Ecto.Changeset{}` for changing the user e-mail.
+
+  ## Examples
+
+      iex> change_user_email(user)
+      %Ecto.Changeset{data: %User{}}
+
+  """
+  def change_user_email(user, attrs \\ %{}) do
+    User.email_changeset(user, attrs)
+  end
+
+  @doc """
+  Emulates that the e-mail will change without actually changing
+  it in the database.
+
+  ## Examples
+
+      iex> apply_user_email(user, "valid password", %{email: ...})
+      {:ok, %User{}}
+
+      iex> apply_user_email(user, "invalid password", %{email: ...})
+      {:error, %Ecto.Changeset{}}
+
+  """
+  def apply_user_email(user, password, attrs) do
+    user
+    |> User.email_changeset(attrs)
+    |> User.validate_current_password(password)
+    |> Ecto.Changeset.apply_action(:update)
+  end
+
+  @doc """
+  Updates the user e-mail in token.
+
+  If the token matches, the user email is updated and the token is deleted.
+  The confirmed_at date is also updated to the current time.
+  """
+  def update_user_email(user, token) do
+    context = "change:#{user.email}"
+
+    with {:ok, query} <- UserToken.verify_change_email_token_query(token, context),
+         %UserToken{sent_to: email} <- Repo.one(query),
+         {:ok, _} <- Repo.transaction(user_email_multi(user, email, context)) do
+      :ok
+    else
+      _ -> :error
+    end
+  end
+
+  defp user_email_multi(user, email, context) do
+    changeset = user |> User.email_changeset(%{email: email}) |> User.confirm_changeset()
+
+    Ecto.Multi.new()
+    |> Ecto.Multi.update(:user, changeset)
+    |> Ecto.Multi.delete_all(:tokens, UserToken.user_and_contexts_query(user, [context]))
+  end
+
+  @doc """
+  Delivers the update e-mail instructions to the given user.
+
+  ## Examples
+
+      iex> deliver_update_email_instructions(user, current_email, &Routes.user_update_email_url(conn, :edit, &1))
+      {:ok, %{to: ..., body: ...}}
+
+  """
+  def deliver_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 """
+  Returns an `%Ecto.Changeset{}` for changing the user password.
+
+  ## Examples
+
+      iex> change_user_password(user)
+      %Ecto.Changeset{data: %User{}}
+
+  """
+  def change_user_password(user, attrs \\ %{}) do
+    User.password_changeset(user, attrs)
+  end
+
+  @doc """
+  Updates the user password.
+
+  ## Examples
+
+      iex> update_user_password(user, "valid password", %{password: ...})
+      {:ok, %User{}}
+
+      iex> update_user_password(user, "invalid password", %{password: ...})
+      {:error, %Ecto.Changeset{}}
+
+  """
+  def update_user_password(user, password, attrs) do
+    changeset =
+      user
+      |> User.password_changeset(attrs)
+      |> User.validate_current_password(password)
+
+    Ecto.Multi.new()
+    |> Ecto.Multi.update(:user, changeset)
+    |> Ecto.Multi.delete_all(:tokens, UserToken.user_and_contexts_query(user, :all))
+    |> Repo.transaction()
+    |> case do
+      {:ok, %{user: user}} -> {:ok, user}
+      {:error, :user, changeset, _} -> {:error, changeset}
+    end
+  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.
+  """
+  def get_user_by_session_token(token) do
+    {:ok, query} = UserToken.verify_session_token_query(token)
+    Repo.one(query)
+  end
+
+  @doc """
+  Deletes the signed token with the given context.
+  """
+  def delete_session_token(token) do
+    Repo.delete_all(UserToken.token_and_context_query(token, "session"))
+    :ok
+  end
+
+  ## Reset password
+
+  @doc """
+  Delivers the reset password e-mail to the given user.
+
+  ## Examples
+
+      iex> deliver_user_reset_password_instructions(user, &Routes.user_reset_password_url(conn, :edit, &1))
+      {:ok, %{to: ..., body: ...}}
+
+  """
+  def deliver_user_reset_password_instructions(%User{} = user, reset_password_url_fun)
+      when is_function(reset_password_url_fun, 1) do
+    {encoded_token, user_token} = UserToken.build_email_token(user, "reset_password")
+    Repo.insert!(user_token)
+    UserNotifier.deliver_reset_password_instructions(user, reset_password_url_fun.(encoded_token))
+  end
+
+  @doc """
+  Gets the user by reset password token.
+
+  ## Examples
+
+      iex> get_user_by_reset_password_token("validtoken")
+      %User{}
+
+      iex> get_user_by_reset_password_token("invalidtoken")
+      nil
+
+  """
+  def get_user_by_reset_password_token(token) do
+    with {:ok, query} <- UserToken.verify_email_token_query(token, "reset_password"),
+         %User{} = user <- Repo.one(query) do
+      user
+    else
+      _ -> nil
+    end
+  end
+
+  @doc """
+  Resets the user password.
+
+  ## Examples
+
+      iex> reset_user_password(user, %{password: "new long password", password_confirmation: "new long password"})
+      {:ok, %User{}}
+
+      iex> reset_user_password(user, %{password: "valid", password_confirmation: "not the same"})
+      {:error, %Ecto.Changeset{}}
+
+  """
+  def reset_user_password(user, attrs) do
+    Ecto.Multi.new()
+    |> Ecto.Multi.update(:user, User.password_changeset(user, attrs))
+    |> Ecto.Multi.delete_all(:tokens, UserToken.user_and_contexts_query(user, :all))
+    |> Repo.transaction()
+    |> case do
+      {:ok, %{user: user}} -> {:ok, user}
+      {:error, :user, changeset, _} -> {:error, changeset}
+    end
+  end
+end

lib/planner/accounts/user.ex

@@ -0,0 +1,113 @@
+defmodule Planner.Accounts.User do
+  use Ecto.Schema
+  import Ecto.Changeset
+
+  @derive {Inspect, except: [:password]}
+  schema "users" do
+    field(:email, :string)
+    field(:password, :string, virtual: true)
+    field(:hashed_password, :string)
+    field(:confirmed_at, :naive_datetime)
+
+    timestamps()
+  end
+
+  @doc """
+  A user changeset for registration.
+
+  It is important to validate the length of both e-mail and password.
+  Otherwise databases may truncate the e-mail without warnings, which
+  could lead to unpredictable or insecure behaviour. Long passwords may
+  also be very expensive to hash for certain algorithms.
+  """
+  def registration_changeset(user, attrs) do
+    user
+    |> cast(attrs, [:email, :password])
+    |> validate_email()
+    |> validate_password()
+  end
+
+  defp validate_email(changeset) do
+    changeset
+    |> validate_required([:email])
+    |> validate_format(:email, ~r/^[^\s]+@[^\s]+$/, message: "must have the @ sign and no spaces")
+    |> validate_length(:email, max: 160)
+    |> unsafe_validate_unique(:email, Planner.Repo)
+    |> unique_constraint(:email)
+  end
+
+  defp validate_password(changeset) do
+    changeset
+    |> validate_required([:password])
+    |> validate_length(:password, min: 8, max: 80)
+    |> prepare_changes(&hash_password/1)
+  end
+
+  defp hash_password(changeset) do
+    password = get_change(changeset, :password)
+
+    changeset
+    |> put_change(:hashed_password, Bcrypt.hash_pwd_salt(password))
+    |> delete_change(:password)
+  end
+
+  @doc """
+  A user changeset for changing the e-mail.
+
+  It requires the e-mail to change otherwise an error is added.
+  """
+  def email_changeset(user, attrs) do
+    user
+    |> cast(attrs, [:email])
+    |> validate_email()
+    |> case do
+      %{changes: %{email: _}} = changeset -> changeset
+      %{} = changeset -> add_error(changeset, :email, "did not change")
+    end
+  end
+
+  @doc """
+  A user changeset for changing the password.
+  """
+  def password_changeset(user, attrs) do
+    user
+    |> cast(attrs, [:password])
+    |> validate_confirmation(:password, message: "does not match password")
+    |> validate_password()
+  end
+
+  @doc """
+  Confirms the account by setting `confirmed_at`.
+  """
+  def confirm_changeset(user) do
+    now = NaiveDateTime.utc_now() |> NaiveDateTime.truncate(:second)
+    change(user, confirmed_at: now)
+  end
+
+  @doc """
+  Verifies the password.
+
+  If there is no user or the user doesn't have a password, we call
+  `Bcrypt.no_user_verify/0` to avoid timing attacks.
+  """
+  def valid_password?(%Planner.Accounts.User{hashed_password: hashed_password}, password)
+      when is_binary(hashed_password) and byte_size(password) > 0 do
+    Bcrypt.verify_pass(password, hashed_password)
+  end
+
+  def valid_password?(_, _) do
+    Bcrypt.no_user_verify()
+    false
+  end
+
+  @doc """
+  Validates the current password otherwise adds an error to the changeset.
+  """
+  def validate_current_password(changeset, password) do
+    if valid_password?(changeset.data, password) do
+      changeset
+    else
+      add_error(changeset, :current_password, "is not valid")
+    end
+  end
+end

lib/planner/accounts/user_notifier.ex

@@ -0,0 +1,73 @@
+defmodule Planner.Accounts.UserNotifier do
+  # For simplicity, this module simply logs messages to the terminal.
+  # You should replace it by a proper e-mail or notification tool, such as:
+  #
+  #   * Swoosh - https://hexdocs.pm/swoosh
+  #   * Bamboo - https://hexdocs.pm/bamboo
+  #
+  defp deliver(to, body) do
+    require Logger
+    Logger.debug(body)
+    {:ok, %{to: to, body: body}}
+  end
+
+  @doc """
+  Deliver instructions to confirm account.
+  """
+  def deliver_confirmation_instructions(user, url) do
+    deliver(user.email, """
+
+    ==============================
+
+    Hi #{user.email},
+
+    You can confirm your account by visiting the url below:
+
+    #{url}
+
+    If you didn't create an account with us, please ignore this.
+
+    ==============================
+    """)
+  end
+
+  @doc """
+  Deliver instructions to reset password account.
+  """
+  def deliver_reset_password_instructions(user, url) do
+    deliver(user.email, """
+
+    ==============================
+
+    Hi #{user.email},
+
+    You can reset your password by visiting the url below:
+
+    #{url}
+
+    If you didn't request this change, please ignore this.
+
+    ==============================
+    """)
+  end
+
+  @doc """
+  Deliver instructions to update your e-mail.
+  """
+  def deliver_update_email_instructions(user, url) do
+    deliver(user.email, """
+
+    ==============================
+
+    Hi #{user.email},
+
+    You can change your e-mail by visiting the url below:
+
+    #{url}
+
+    If you didn't request this change, please ignore this.
+
+    ==============================
+    """)
+  end
+end

lib/planner/accounts/user_token.ex

@@ -0,0 +1,139 @@
+defmodule Planner.Accounts.UserToken do
+  use Ecto.Schema
+  import Ecto.Query
+
+  @hash_algorithm :sha256
+  @rand_size 32
+
+  # It is very important to keep the reset password token expiry short,
+  # since someone with access to the e-mail may take over the account.
+  @reset_password_validity_in_days 1
+  @confirm_validity_in_days 7
+  @change_email_validity_in_days 7
+  @session_validity_in_days 60
+
+  schema "users_tokens" do
+    field :token, :binary
+    field :context, :string
+    field :sent_to, :string
+    belongs_to :user, Planner.Accounts.User
+
+    timestamps(updated_at: false)
+  end
+
+  @doc """
+  Generates a token that will be stored in a signed place,
+  such as session or cookie. As they are signed, those
+  tokens do not need to be hashed.
+  """
+  def build_session_token(user) do
+    token = :crypto.strong_rand_bytes(@rand_size)
+    {token, %Planner.Accounts.UserToken{token: token, context: "session", user_id: user.id}}
+  end
+
+  @doc """
+  Checks if the token is valid and returns its underlying lookup query.
+
+  The query returns the user found by the token.
+  """
+  def verify_session_token_query(token) do
+    query =
+      from token in token_and_context_query(token, "session"),
+        join: user in assoc(token, :user),
+        where: token.inserted_at > ago(@session_validity_in_days, "day"),
+        select: user
+
+    {:ok, query}
+  end
+
+  @doc """
+  Builds a token with a hashed counter part.
+
+  The non-hashed token is sent to the user e-mail while the
+  hashed part is stored in the database, to avoid reconstruction.
+  The token is valid for a week as long as users don't change
+  their email.
+  """
+  def build_email_token(user, context) do
+    build_hashed_token(user, context, user.email)
+  end
+
+  defp build_hashed_token(user, context, sent_to) do
+    token = :crypto.strong_rand_bytes(@rand_size)
+    hashed_token = :crypto.hash(@hash_algorithm, token)
+
+    {Base.url_encode64(token, padding: false),
+     %Planner.Accounts.UserToken{
+       token: hashed_token,
+       context: context,
+       sent_to: sent_to,
+       user_id: user.id
+     }}
+  end
+
+  @doc """
+  Checks if the token is valid and returns its underlying lookup query.
+
+  The query returns the user found by the token.
+  """
+  def verify_email_token_query(token, context) do
+    case Base.url_decode64(token, padding: false) do
+      {:ok, decoded_token} ->
+        hashed_token = :crypto.hash(@hash_algorithm, decoded_token)
+        days = days_for_context(context)
+
+        query =
+          from token in token_and_context_query(hashed_token, context),
+            join: user in assoc(token, :user),
+            where: token.inserted_at > ago(^days, "day") and token.sent_to == user.email,
+            select: user
+
+        {:ok, query}
+
+      :error ->
+        :error
+    end
+  end
+
+  defp days_for_context("confirm"), do: @confirm_validity_in_days
+  defp days_for_context("reset_password"), do: @reset_password_validity_in_days
+
+  @doc """
+  Checks if the token is valid and returns its underlying lookup query.
+
+  The query returns the user token record.
+  """
+  def verify_change_email_token_query(token, context) do
+    case Base.url_decode64(token, padding: false) do
+      {:ok, decoded_token} ->
+        hashed_token = :crypto.hash(@hash_algorithm, decoded_token)
+
+        query =
+          from token in token_and_context_query(hashed_token, context),
+            where: token.inserted_at > ago(@change_email_validity_in_days, "day")
+
+        {:ok, query}
+
+      :error ->
+        :error
+    end
+  end
+
+  @doc """
+  Returns the given token with the given context.
+  """
+  def token_and_context_query(token, context) do
+    from Planner.Accounts.UserToken, where: [token: ^token, context: ^context]
+  end
+
+  @doc """
+  Gets all tokens for the given user for the given contexts.
+  """
+  def user_and_contexts_query(user, :all) do
+    from t in Planner.Accounts.UserToken, where: t.user_id == ^user.id
+  end
+
+  def user_and_contexts_query(user, [_ | _] = contexts) do
+    from t in Planner.Accounts.UserToken, where: t.user_id == ^user.id and t.context in ^contexts
+  end
+end

lib/planner_web/controllers/user_auth.ex

@@ -0,0 +1,149 @@
+defmodule PlannerWeb.UserAuth do
+  import Plug.Conn
+  import Phoenix.Controller
+
+  alias Planner.Accounts
+  alias PlannerWeb.Router.Helpers, as: Routes
+
+  # Make the remember me cookie valid for 60 days.
+  # If you want bump or reduce this value, also change
+  # the token expiry itself in UserToken.
+  @max_age 60 * 60 * 24 * 60
+  @remember_me_cookie "user_remember_me"
+  @remember_me_options [sign: true, max_age: @max_age]
+
+  @doc """
+  Logs the user in.
+
+  It renews the session ID and clears the whole session
+  to avoid fixation attacks. See the renew_session
+  function to customize this behaviour.
+
+  It also sets a `:live_socket_id` key in the session,
+  so LiveView sessions are identified and automatically
+  disconnected on logout. The line can be safely removed
+  if you are not using LiveView.
+  """
+  def login_user(conn, user, params \\ %{}) do
+    token = Accounts.generate_user_session_token(user)
+    user_return_to = get_session(conn, :user_return_to)
+
+    conn
+    |> renew_session()
+    |> put_session(:user_token, token)
+    |> put_session(:live_socket_id, "users_sessions:#{Base.url_encode64(token)}")
+    |> maybe_write_remember_me_cookie(token, params)
+    |> redirect(to: user_return_to || signed_in_path(conn))
+  end
+
+  defp maybe_write_remember_me_cookie(conn, token, %{"remember_me" => "true"}) do
+    put_resp_cookie(conn, @remember_me_cookie, token, @remember_me_options)
+  end
+
+  defp maybe_write_remember_me_cookie(conn, _token, _params) do
+    conn
+  end
+
+  # This function renews the session ID and erases the whole
+  # session to avoid fixation attacks. If there is any data
+  # in the session you may want to preserve after login/logout,
+  # you must explicitly fetch the session data before clearing
+  # and then immediately set it after clearing, for example:
+  #
+  #     defp renew_session(conn) do
+  #       preferred_locale = get_session(conn, :preferred_locale)
+  #
+  #       conn
+  #       |> configure_session(renew: true)
+  #       |> clear_session()
+  #       |> put_session(:preferred_locale, preferred_locale)
+  #     end
+  #
+  defp renew_session(conn) do
+    conn
+    |> configure_session(renew: true)
+    |> clear_session()
+  end
+
+  @doc """
+  Logs the user out.
+
+  It clears all session data for safety. See renew_session.
+  """
+  def logout_user(conn) do
+    user_token = get_session(conn, :user_token)
+    user_token && Accounts.delete_session_token(user_token)
+
+    if live_socket_id = get_session(conn, :live_socket_id) do
+      PlannerWeb.Endpoint.broadcast(live_socket_id, "disconnect", %{})
+    end
+
+    conn
+    |> renew_session()
+    |> delete_resp_cookie(@remember_me_cookie)
+    |> redirect(to: "/")
+  end
+
+  @doc """
+  Authenticates the user by looking into the session
+  and remember me token.
+  """
+  def fetch_current_user(conn, _opts) do
+    {user_token, conn} = ensure_user_token(conn)
+    user = user_token && Accounts.get_user_by_session_token(user_token)
+    assign(conn, :current_user, user)
+  end
+
+  defp ensure_user_token(conn) do
+    if user_token = get_session(conn, :user_token) do
+      {user_token, conn}
+    else
+      conn = fetch_cookies(conn, signed: [@remember_me_cookie])
+
+      if user_token = conn.cookies[@remember_me_cookie] do
+        {user_token, put_session(conn, :user_token, user_token)}
+      else
+        {nil, conn}
+      end
+    end
+  end
+
+  @doc """
+  Used for routes that require the user to not be authenticated.
+  """
+  def redirect_if_user_is_authenticated(conn, _opts) do
+    if conn.assigns[:current_user] do
+      conn
+      |> redirect(to: signed_in_path(conn))
+      |> halt()
+    else
+      conn
+    end
+  end
+
+  @doc """
+  Used for routes that require the user to be authenticated.
+
+  If you want to enforce the user e-mail is confirmed before
+  they use the application at all, here would be a good place.
+  """
+  def require_authenticated_user(conn, _opts) do
+    if conn.assigns[:current_user] do
+      conn
+    else
+      conn
+      |> put_flash(:error, "You must login to access this page.")
+      |> maybe_store_return_to()
+      |> redirect(to: Routes.user_session_path(conn, :new))
+      |> halt()
+    end
+  end
+
+  defp maybe_store_return_to(%{method: "GET", request_path: request_path} = conn) do
+    put_session(conn, :user_return_to, request_path)
+  end
+
+  defp maybe_store_return_to(conn), do: conn
+
+  defp signed_in_path(_conn), do: "/"
+end

lib/planner_web/controllers/user_reset_password_controller.ex

@@ -0,0 +1,59 @@
+defmodule PlannerWeb.UserResetPasswordController do
+  use PlannerWeb, :controller
+
+  alias Planner.Accounts
+
+  plug :get_user_by_reset_password_token when action in [:edit, :update]
+
+  def new(conn, _params) do
+    render(conn, "new.html")
+  end
+
+  def create(conn, %{"user" => %{"email" => email}}) do
+    if user = Accounts.get_user_by_email(email) do
+      Accounts.deliver_user_reset_password_instructions(
+        user,
+        &Routes.user_reset_password_url(conn, :edit, &1)
+      )
+    end
+
+    # Regardless of the outcome, show an impartial success/error message.
+    conn
+    |> put_flash(
+      :info,
+      "If your e-mail is in our system, you will receive instructions to reset your password shortly."
+    )
+    |> redirect(to: "/")
+  end
+
+  def edit(conn, _params) do
+    render(conn, "edit.html", changeset: Accounts.change_user_password(conn.assigns.user))
+  end
+
+  # Do not login the user after reset password to avoid a
+  # leaked token giving the user access to the account.
+  def update(conn, %{"user" => user_params}) do
+    case Accounts.reset_user_password(conn.assigns.user, user_params) do
+      {:ok, _} ->
+        conn
+        |> put_flash(:info, "Password reset successfully.")
+        |> redirect(to: Routes.user_session_path(conn, :new))
+
+      {:error, changeset} ->
+        render(conn, "edit.html", changeset: changeset)
+    end
+  end
+
+  defp get_user_by_reset_password_token(conn, _opts) do
+    %{"token" => token} = conn.params
+
+    if user = Accounts.get_user_by_reset_password_token(token) do
+      conn |> assign(:user, user) |> assign(:token, token)
+    else
+      conn
+      |> put_flash(:error, "Reset password link is invalid or it has expired.")
+      |> redirect(to: "/")
+      |> halt()
+    end
+  end
+end

lib/planner_web/controllers/user_session_controller.ex

@@ -0,0 +1,26 @@
+defmodule PlannerWeb.UserSessionController do
+  use PlannerWeb, :controller
+
+  alias Planner.Accounts
+  alias PlannerWeb.UserAuth
+
+  def new(conn, _params) do
+    render(conn, "new.html", error_message: nil)
+  end
+
+  def create(conn, %{"user" => user_params}) do
+    %{"email" => email, "password" => password} = user_params
+
+    if user = Accounts.get_user_by_email_and_password(email, password) do
+      UserAuth.login_user(conn, user, user_params)
+    else
+      render(conn, "new.html", error_message: "Invalid e-mail or password")
+    end
+  end
+
+  def delete(conn, _params) do
+    conn
+    |> put_flash(:info, "Logged out successfully.")
+    |> UserAuth.logout_user()
+  end
+end

lib/planner_web/controllers/user_settings_controller.ex

@@ -0,0 +1,72 @@
+defmodule PlannerWeb.UserSettingsController do
+  use PlannerWeb, :controller
+
+  alias Planner.Accounts
+  alias PlannerWeb.UserAuth
+
+  plug :assign_email_and_password_changesets
+
+  def edit(conn, _params) do
+    render(conn, "edit.html")
+  end
+
+  def update_email(conn, %{"current_password" => password, "user" => user_params}) do
+    user = conn.assigns.current_user
+
+    case Accounts.apply_user_email(user, password, user_params) do
+      {:ok, applied_user} ->
+        Accounts.deliver_update_email_instructions(
+          applied_user,
+          user.email,
+          &Routes.user_settings_url(conn, :confirm_email, &1)
+        )
+
+        conn
+        |> put_flash(
+          :info,
+          "A link to confirm your e-mail change has been sent to the new address."
+        )
+        |> redirect(to: Routes.user_settings_path(conn, :edit))
+
+      {:error, changeset} ->
+        render(conn, "edit.html", email_changeset: changeset)
+    end
+  end
+
+  def confirm_email(conn, %{"token" => token}) do
+    case Accounts.update_user_email(conn.assigns.current_user, token) do
+      :ok ->
+        conn
+        |> put_flash(:info, "E-mail changed successfully.")
+        |> redirect(to: Routes.user_settings_path(conn, :edit))
+
+      :error ->
+        conn
+        |> put_flash(:error, "Email change link is invalid or it has expired.")
+        |> redirect(to: Routes.user_settings_path(conn, :edit))
+    end
+  end
+
+  def update_password(conn, %{"current_password" => password, "user" => user_params}) do
+    user = conn.assigns.current_user
+
+    case Accounts.update_user_password(user, password, user_params) do
+      {:ok, user} ->
+        conn
+        |> put_flash(:info, "Password updated successfully.")
+        |> put_session(:user_return_to, Routes.user_settings_path(conn, :edit))
+        |> UserAuth.login_user(user)
+
+      {:error, changeset} ->
+        render(conn, "edit.html", password_changeset: changeset)
+    end
+  end
+
+  defp assign_email_and_password_changesets(conn, _opts) do
+    user = conn.assigns.current_user
+
+    conn
+    |> assign(:email_changeset, Accounts.change_user_email(user))
+    |> assign(:password_changeset, Accounts.change_user_password(user))
+  end
+end

lib/planner_web/router.ex

@@ -1,22 +1,19 @@
 defmodule PlannerWeb.Router do
   use PlannerWeb, :router
 
+  import PlannerWeb.UserAuth
+
   pipeline :browser do
-    plug :accepts, ["html"]
+    plug(:accepts, ["html"])
-    plug :fetch_session
+    plug(:fetch_session)
-    plug :fetch_flash
+    plug(:fetch_flash)
-    plug :protect_from_forgery
+    plug(:protect_from_forgery)
-    plug :put_secure_browser_headers
+    plug(:put_secure_browser_headers)
+    plug(:fetch_current_user)
   end
 
   pipeline :api do
-    plug :accepts, ["json"]
+    plug(:accepts, ["json"])
-  end
-
-  scope "/", PlannerWeb do
-    pipe_through :browser
-
-    get "/", PageController, :index
   end
 
   # Other scopes may use custom stacks.
@@ -35,8 +32,36 @@ defmodule PlannerWeb.Router do
     import Phoenix.LiveDashboard.Router
 
     scope "/" do
-      pipe_through :browser
+      pipe_through(:browser)
-      live_dashboard "/dashboard", metrics: PlannerWeb.Telemetry
+      live_dashboard("/dashboard", metrics: PlannerWeb.Telemetry)
     end
   end
+
+  scope "/", PlannerWeb do
+    pipe_through([:browser, :redirect_if_user_is_authenticated])
+
+    get("/users/login", UserSessionController, :new)
+    post("/users/login", UserSessionController, :create)
+    get("/users/reset_password", UserResetPasswordController, :new)
+    post("/users/reset_password", UserResetPasswordController, :create)
+    get("/users/reset_password/:token", UserResetPasswordController, :edit)
+    put("/users/reset_password/:token", UserResetPasswordController, :update)
+  end
+
+  scope "/", PlannerWeb do
+    pipe_through([:browser, :require_authenticated_user])
+
+    get("/", PageController, :index)
+
+    get("/users/settings", UserSettingsController, :edit)
+    put("/users/settings/update_password", UserSettingsController, :update_password)
+    put("/users/settings/update_email", UserSettingsController, :update_email)
+    get("/users/settings/confirm_email/:token", UserSettingsController, :confirm_email)
+  end
+
+  scope "/", PlannerWeb do
+    pipe_through([:browser])
+
+    delete("/users/logout", UserSessionController, :delete)
+  end
 end

lib/planner_web/templates/layout/app.html.eex

@@ -9,21 +9,16 @@
     <script defer type="text/javascript" src="<%= Routes.static_path(@conn, "/js/app.js") %>"></script>
   </head>
   <body>
-    <header>
-      <section class="container">
-        <nav role="navigation">
     <ul>
-            <li><a href="https://hexdocs.pm/phoenix/overview.html">Get Started</a></li>
+    <%= if @current_user do %>
-            <%= if function_exported?(Routes, :live_dashboard_path, 2) do %>
+      <li><%= @current_user.email %></li>
-              <li><%= link "LiveDashboard", to: Routes.live_dashboard_path(@conn, :home) %></li>
+      <li><%= link "Settings", to: Routes.user_settings_path(@conn, :edit) %></li>
+      <li><%= link "Logout", to: Routes.user_session_path(@conn, :delete), method: :delete %></li>
+    <% else %>
+      <li><%= link "Login", to: Routes.user_session_path(@conn, :new) %></li>
     <% end %>
     </ul>
-        </nav>
+
-        <a href="https://phoenixframework.org/" class="phx-logo">
-          <img src="<%= Routes.static_path(@conn, "/images/phoenix.png") %>" alt="Phoenix Framework Logo"/>
-        </a>
-      </section>
-    </header>
     <main role="main" class="container">
       <p class="alert alert-info" role="alert"><%= get_flash(@conn, :info) %></p>
       <p class="alert alert-danger" role="alert"><%= get_flash(@conn, :error) %></p>

lib/planner_web/templates/page/index.html.eex

@@ -1,38 +1 @@
-<section class="phx-hero">
+<h1>Planner</h1>
-  <h1><%= gettext "Welcome to %{name}!", name: "Phoenix" %></h1>
-  <p>Peace-of-mind from prototype to production</p>
-</section>
-
-<section class="row">
-  <article class="column">
-    <h2>Resources</h2>
-    <ul>
-      <li>
-        <a href="https://hexdocs.pm/phoenix/overview.html">Guides &amp; Docs</a>
-      </li>
-      <li>
-        <a href="https://github.com/phoenixframework/phoenix">Source</a>
-      </li>
-      <li>
-        <a href="https://github.com/phoenixframework/phoenix/blob/v1.5/CHANGELOG.md">v1.5 Changelog</a>
-      </li>
-    </ul>
-  </article>
-  <article class="column">
-    <h2>Help</h2>
-    <ul>
-      <li>
-        <a href="https://elixirforum.com/c/phoenix-forum">Forum</a>
-      </li>
-      <li>
-        <a href="https://webchat.freenode.net/?channels=elixir-lang">#elixir-lang on Freenode IRC</a>
-      </li>
-      <li>
-        <a href="https://twitter.com/elixirphoenix">Twitter @elixirphoenix</a>
-      </li>
-      <li>
-        <a href="https://elixir-slackin.herokuapp.com/">Elixir on Slack</a>
-      </li>
-    </ul>
-  </article>
-</section>

lib/planner_web/templates/user_reset_password/edit.html.eex

@@ -0,0 +1,25 @@
+<h1>Reset password</h1>
+
+<%= form_for @changeset, Routes.user_reset_password_path(@conn, :update, @token), fn f -> %>
+  <%= if @changeset.action do %>
+    <div class="alert alert-danger">
+      <p>Oops, something went wrong! Please check the errors below.</p>
+    </div>
+  <% end %>
+
+  <%= label f, :password, "New password" %>
+  <%= password_input f, :password, required: true %>
+  <%= error_tag f, :password %>
+
+  <%= label f, :password_confirmation, "Confirm new password" %>
+  <%= password_input f, :password_confirmation, required: true %>
+  <%= error_tag f, :password_confirmation %>
+
+  <div>
+    <%= submit "Reset password" %>
+  </div>
+<% end %>
+
+<p>
+  <%= link "Login", to: Routes.user_session_path(@conn, :new) %>
+</p>

lib/planner_web/templates/user_reset_password/new.html.eex

@@ -0,0 +1,14 @@
+<h1>Forgot your password?</h1>
+
+<%= form_for :user, Routes.user_reset_password_path(@conn, :create), fn f -> %>
+  <%= label f, :email %>
+  <%= text_input f, :email, required: true %>
+
+  <div>
+    <%= submit "Send instructions to reset password" %>
+  </div>
+<% end %>
+
+<p>
+  <%= link "Login", to: Routes.user_session_path(@conn, :new) %>
+</p>

lib/planner_web/templates/user_session/new.html.eex

@@ -0,0 +1,26 @@
+<h1>Login</h1>
+
+<%= form_for @conn, Routes.user_session_path(@conn, :create), [as: :user], fn f -> %>
+  <%= if @error_message do %>
+    <div class="alert alert-danger">
+      <p><%= @error_message %></p>
+    </div>
+  <% end %>
+
+  <%= label f, :email %>
+  <%= text_input f, :email, required: true %>
+
+  <%= label f, :password %>
+  <%= password_input f, :password, required: true %>
+
+  <%= label f, :remember_me, "Keep me logged in for 60 days" %>
+  <%= checkbox f, :remember_me %>
+
+  <div>
+    <%= submit "Login" %>
+  </div>
+<% end %>
+
+<p>
+  <%= link "Forgot your password?", to: Routes.user_reset_password_path(@conn, :new) %>
+</p>

lib/planner_web/templates/user_settings/edit.html.eex

@@ -0,0 +1,49 @@
+<h1>Settings</h1>
+
+<h3>Change e-mail</h3>
+
+<%= form_for @email_changeset, Routes.user_settings_path(@conn, :update_email), fn f -> %>
+  <%= if @email_changeset.action do %>
+    <div class="alert alert-danger">
+      <p>Oops, something went wrong! Please check the errors below.</p>
+    </div>
+  <% end %>
+
+  <%= label f, :email %>
+  <%= text_input f, :email, required: true %>
+  <%= error_tag f, :email %>
+
+  <%= label f, :current_password, for: "current_password_for_email" %>
+  <%= password_input f, :current_password, required: true, name: "current_password", id: "current_password_for_email" %>
+  <%= error_tag f, :current_password %>
+
+  <div>
+    <%= submit "Change e-mail" %>
+  </div>
+<% end %>
+
+<h3>Change password</h3>
+
+<%= form_for @password_changeset, Routes.user_settings_path(@conn, :update_password), fn f -> %>
+  <%= if @password_changeset.action do %>
+    <div class="alert alert-danger">
+      <p>Oops, something went wrong! Please check the errors below.</p>
+    </div>
+  <% end %>
+
+  <%= label f, :password, "New password" %>
+  <%= password_input f, :password, required: true %>
+  <%= error_tag f, :password %>
+
+  <%= label f, :password_confirmation, "Confirm new password" %>
+  <%= password_input f, :password_confirmation, required: true %>
+  <%= error_tag f, :password_confirmation %>
+
+  <%= label f, :current_password, for: "current_password_for_password" %>
+  <%= password_input f, :current_password, required: true, name: "current_password", id: "current_password_for_password" %>
+  <%= error_tag f, :current_password %>
+
+  <div>
+    <%= submit "Change password" %>
+  </div>
+<% end %>

lib/planner_web/views/user_confirmation_view.ex

@@ -0,0 +1,3 @@
+defmodule PlannerWeb.UserConfirmationView do
+  use PlannerWeb, :view
+end

lib/planner_web/views/user_registration_view.ex

@@ -0,0 +1,3 @@
+defmodule PlannerWeb.UserRegistrationView do
+  use PlannerWeb, :view
+end

lib/planner_web/views/user_reset_password_view.ex

@@ -0,0 +1,3 @@
+defmodule PlannerWeb.UserResetPasswordView do
+  use PlannerWeb, :view
+end

lib/planner_web/views/user_session_view.ex

@@ -0,0 +1,3 @@
+defmodule PlannerWeb.UserSessionView do
+  use PlannerWeb, :view
+end

lib/planner_web/views/user_settings_view.ex

@@ -0,0 +1,3 @@
+defmodule PlannerWeb.UserSettingsView do
+  use PlannerWeb, :view
+end

mix.exs

@@ -33,6 +33,7 @@ defmodule Planner.MixProject do
   # Type `mix help deps` for examples and options.
   defp deps do
     [
+      {:bcrypt_elixir, "~> 2.0"},
       {:phoenix, "~> 1.5.1"},
       {:phoenix_ecto, "~> 4.1"},
       {:ecto_sql, "~> 3.4"},
@@ -40,6 +41,7 @@ defmodule Planner.MixProject do
       {:phoenix_html, "~> 2.11"},
       {:phoenix_live_reload, "~> 1.2", only: :dev},
       {:phoenix_live_dashboard, "~> 0.2.0"},
+      {:phx_gen_auth, "~> 0.3.0", only: [:dev], runtime: false},
       {:telemetry_metrics, "~> 0.4"},
       {:telemetry_poller, "~> 0.4"},
       {:gettext, "~> 0.11"},

mix.lock

@@ -1,4 +1,6 @@
 %{
+  "bcrypt_elixir": {:hex, :bcrypt_elixir, "2.2.0", "3df902b81ce7fa8867a2ae30d20a1da6877a2c056bfb116fd0bc8a5f0190cea4", [:make, :mix], [{:comeonin, "~> 5.3", [hex: :comeonin, repo: "hexpm", optional: false]}, {:elixir_make, "~> 0.6", [hex: :elixir_make, repo: "hexpm", optional: false]}], "hexpm", "762be3fcb779f08207531bc6612cca480a338e4b4357abb49f5ce00240a77d1e"},
+  "comeonin": {:hex, :comeonin, "5.3.1", "7fe612b739c78c9c1a75186ef2d322ce4d25032d119823269d0aa1e2f1e20025", [:mix], [], "hexpm", "d6222483060c17f0977fad1b7401ef0c5863c985a64352755f366aee3799c245"},
   "connection": {:hex, :connection, "1.0.4", "a1cae72211f0eef17705aaededacac3eb30e6625b04a6117c1b2db6ace7d5976", [:mix], [], "hexpm", "4a0850c9be22a43af9920a71ab17c051f5f7d45c209e40269a1938832510e4d9"},
   "cowboy": {:hex, :cowboy, "2.8.0", "f3dc62e35797ecd9ac1b50db74611193c29815401e53bac9a5c0577bd7bc667d", [:rebar3], [{:cowlib, "~> 2.9.1", [hex: :cowlib, repo: "hexpm", optional: false]}, {:ranch, "~> 1.7.1", [hex: :ranch, repo: "hexpm", optional: false]}], "hexpm", "4643e4fba74ac96d4d152c75803de6fad0b3fa5df354c71afdd6cbeeb15fac8a"},
   "cowlib": {:hex, :cowlib, "2.9.1", "61a6c7c50cf07fdd24b2f45b89500bb93b6686579b069a89f88cb211e1125c78", [:rebar3], [], "hexpm", "e4175dc240a70d996156160891e1c62238ede1729e45740bdd38064dad476170"},
@@ -6,6 +8,7 @@
   "decimal": {:hex, :decimal, "1.8.1", "a4ef3f5f3428bdbc0d35374029ffcf4ede8533536fa79896dd450168d9acdf3c", [:mix], [], "hexpm", "3cb154b00225ac687f6cbd4acc4b7960027c757a5152b369923ead9ddbca7aec"},
   "ecto": {:hex, :ecto, "3.4.4", "a2c881e80dc756d648197ae0d936216c0308370332c5e77a2325a10293eef845", [:mix], [{:decimal, "~> 1.6 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "cc4bd3ad62abc3b21fb629f0f7a3dab23a192fca837d257dd08449fba7373561"},
   "ecto_sql": {:hex, :ecto_sql, "3.4.4", "d28bac2d420f708993baed522054870086fd45016a9d09bb2cd521b9c48d32ea", [:mix], [{:db_connection, "~> 2.2", [hex: :db_connection, repo: "hexpm", optional: false]}, {:ecto, "~> 3.4.3", [hex: :ecto, repo: "hexpm", optional: false]}, {:myxql, "~> 0.3.0 or ~> 0.4.0", [hex: :myxql, repo: "hexpm", optional: true]}, {:postgrex, "~> 0.15.0", [hex: :postgrex, repo: "hexpm", optional: true]}, {:tds, "~> 2.1.0", [hex: :tds, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "edb49af715dd72f213b66adfd0f668a43c17ed510b5d9ac7528569b23af57fe8"},
+  "elixir_make": {:hex, :elixir_make, "0.6.0", "38349f3e29aff4864352084fc736fa7fa0f2995a819a737554f7ebd28b85aaab", [:mix], [], "hexpm", "d522695b93b7f0b4c0fcb2dfe73a6b905b1c301226a5a55cb42e5b14d509e050"},
   "file_system": {:hex, :file_system, "0.2.8", "f632bd287927a1eed2b718f22af727c5aeaccc9a98d8c2bd7bff709e851dc986", [:mix], [], "hexpm", "97a3b6f8d63ef53bd0113070102db2ce05352ecf0d25390eb8d747c2bde98bca"},
   "gettext": {:hex, :gettext, "0.18.0", "406d6b9e0e3278162c2ae1de0a60270452c553536772167e2d701f028116f870", [:mix], [], "hexpm", "c3f850be6367ebe1a08616c2158affe4a23231c70391050bf359d5f92f66a571"},
   "jason": {:hex, :jason, "1.2.1", "12b22825e22f468c02eb3e4b9985f3d0cb8dc40b9bd704730efa11abd2708c44", [:mix], [{:decimal, "~> 1.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "b659b8571deedf60f79c5a608e15414085fa141344e2716fbd6988a084b5f993"},
@@ -17,6 +20,7 @@
   "phoenix_live_reload": {:hex, :phoenix_live_reload, "1.2.4", "940c0344b1d66a2e46eef02af3a70e0c5bb45a4db0bf47917add271b76cd3914", [:mix], [{:file_system, "~> 0.2.1 or ~> 0.3", [hex: :file_system, repo: "hexpm", optional: false]}, {:phoenix, "~> 1.4", [hex: :phoenix, repo: "hexpm", optional: false]}], "hexpm", "38f9308357dea4cc77f247e216da99fcb0224e05ada1469167520bed4cb8cccd"},
   "phoenix_live_view": {:hex, :phoenix_live_view, "0.13.3", "2186c55cc7c54ca45b97c6f28cfd267d1c61b5f205f3c83533704cd991bdfdec", [:mix], [{:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:phoenix, "~> 1.4.17 or ~> 1.5.2", [hex: :phoenix, repo: "hexpm", optional: false]}, {:phoenix_html, "~> 2.14", [hex: :phoenix_html, repo: "hexpm", optional: false]}], "hexpm", "c6309a7da2e779cb9cdf2fb603d75f38f49ef324bedc7a81825998bd1744ff8a"},
   "phoenix_pubsub": {:hex, :phoenix_pubsub, "2.0.0", "a1ae76717bb168cdeb10ec9d92d1480fec99e3080f011402c0a2d68d47395ffb", [:mix], [], "hexpm", "c52d948c4f261577b9c6fa804be91884b381a7f8f18450c5045975435350f771"},
+  "phx_gen_auth": {:hex, :phx_gen_auth, "0.3.0", "3d1f1943d7f6ecccec9a540422eec2b764d89a866e77367bc100f07f625091ef", [:mix], [{:phoenix, "~> 1.5.2", [hex: :phoenix, repo: "hexpm", optional: false]}], "hexpm", "98d5a0a8fc34fed40c6ea9db4f57ebad6c1c50cdc0ba3aa8bc4716a5e8285990"},
   "plug": {:hex, :plug, "1.10.3", "c9cebe917637d8db0e759039cc106adca069874e1a9034fd6e3fdd427fd3c283", [:mix], [{:mime, "~> 1.0", [hex: :mime, repo: "hexpm", optional: false]}, {:plug_crypto, "~> 1.1.1 or ~> 1.2", [hex: :plug_crypto, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "01f9037a2a1de1d633b5a881101e6a444bcabb1d386ca1e00bb273a1f1d9d939"},
   "plug_cowboy": {:hex, :plug_cowboy, "2.3.0", "149a50e05cb73c12aad6506a371cd75750c0b19a32f81866e1a323dda9e0e99d", [:mix], [{:cowboy, "~> 2.7", [hex: :cowboy, repo: "hexpm", optional: false]}, {:plug, "~> 1.7", [hex: :plug, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "bc595a1870cef13f9c1e03df56d96804db7f702175e4ccacdb8fc75c02a7b97e"},
   "plug_crypto": {:hex, :plug_crypto, "1.1.2", "bdd187572cc26dbd95b87136290425f2b580a116d3fb1f564216918c9730d227", [:mix], [], "hexpm", "6b8b608f895b6ffcfad49c37c7883e8df98ae19c6a28113b02aa1e9c5b22d6b5"},

priv/repo/migrations/20200613231040_create_users_auth_tables.exs

@@ -0,0 +1,27 @@
+defmodule Planner.Repo.Migrations.CreateUsersAuthTables do
+  use Ecto.Migration
+
+  def change do
+    execute "CREATE EXTENSION IF NOT EXISTS citext", ""
+
+    create table(:users) do
+      add :email, :citext, null: false
+      add :hashed_password, :string, null: false
+      add :confirmed_at, :naive_datetime
+      timestamps()
+    end
+
+    create unique_index(:users, [:email])
+
+    create table(:users_tokens) do
+      add :user_id, references(:users, on_delete: :delete_all), null: false
+      add :token, :binary, null: false
+      add :context, :string, null: false
+      add :sent_to, :string
+      timestamps(updated_at: false)
+    end
+
+    create index(:users_tokens, [:user_id])
+    create unique_index(:users_tokens, [:context, :token])
+  end
+end

test/planner/accounts_test.exs

@@ -0,0 +1,429 @@
+defmodule Planner.AccountsTest do
+  use Planner.DataCase
+
+  alias Planner.Accounts
+  import Planner.AccountsFixtures
+  alias Planner.Accounts.{User, UserToken}
+
+  describe "get_user_by_email/1" do
+    test "does not return the user if the email does not exist" do
+      refute Accounts.get_user_by_email("unknown@example.com")
+    end
+
+    test "returns the user if the email exists" do
+      %{id: id} = user = user_fixture()
+      assert %User{id: ^id} = Accounts.get_user_by_email(user.email)
+    end
+  end
+
+  describe "get_user_by_email_and_password/1" do
+    test "does not return the user if the email does not exist" do
+      refute Accounts.get_user_by_email_and_password("unknown@example.com", "hello world!")
+    end
+
+    test "does not return the user if the password is not valid" do
+      user = user_fixture()
+      refute Accounts.get_user_by_email_and_password(user.email, "invalid")
+    end
+
+    test "returns the user if the email and password are valid" do
+      %{id: id} = user = user_fixture()
+
+      assert %User{id: ^id} =
+               Accounts.get_user_by_email_and_password(user.email, valid_user_password())
+    end
+  end
+
+  describe "get_user!/1" do
+    test "raises if id is invalid" do
+      assert_raise Ecto.NoResultsError, fn ->
+        Accounts.get_user!(-1)
+      end
+    end
+
+    test "returns the user with the given id" do
+      %{id: id} = user = user_fixture()
+      assert %User{id: ^id} = Accounts.get_user!(user.id)
+    end
+  end
+
+  describe "register_user/1" do
+    test "requires email and password to be set" do
+      {:error, changeset} = Accounts.register_user(%{})
+
+      assert %{
+               password: ["can't be blank"],
+               email: ["can't be blank"]
+             } = errors_on(changeset)
+    end
+
+    test "validates email and password when given" do
+      {:error, changeset} = Accounts.register_user(%{email: "not valid", password: "nt vld"})
+
+      assert %{
+               email: ["must have the @ sign and no spaces"],
+               password: ["should be at least 8 character(s)"]
+             } = errors_on(changeset)
+    end
+
+    test "validates maximum values for e-mail and password for security" do
+      too_long = String.duplicate("db", 100)
+      {:error, changeset} = Accounts.register_user(%{email: too_long, password: too_long})
+      assert "should be at most 160 character(s)" in errors_on(changeset).email
+      assert "should be at most 80 character(s)" in errors_on(changeset).password
+    end
+
+    test "validates e-mail uniqueness" do
+      %{email: email} = user_fixture()
+      {:error, changeset} = Accounts.register_user(%{email: email})
+      assert "has already been taken" in errors_on(changeset).email
+
+      # Now try with the upper cased e-mail too, to check that email case is ignored.
+      {:error, changeset} = Accounts.register_user(%{email: String.upcase(email)})
+      assert "has already been taken" in errors_on(changeset).email
+    end
+
+    test "registers users with a hashed password" do
+      email = unique_user_email()
+      {:ok, user} = Accounts.register_user(%{email: email, password: valid_user_password()})
+      assert user.email == email
+      assert is_binary(user.hashed_password)
+      # assert is_nil(user.confirmed_at)
+      assert is_nil(user.password)
+    end
+  end
+
+  describe "change_user_email/2" do
+    test "returns a user changeset" do
+      assert %Ecto.Changeset{} = changeset = Accounts.change_user_email(%User{})
+      assert changeset.required == [:email]
+    end
+  end
+
+  describe "apply_user_email/3" do
+    setup do
+      %{user: user_fixture()}
+    end
+
+    test "requires email to change", %{user: user} do
+      {:error, changeset} = Accounts.apply_user_email(user, valid_user_password(), %{})
+      assert %{email: ["did not change"]} = errors_on(changeset)
+    end
+
+    test "validates email", %{user: user} do
+      {:error, changeset} =
+        Accounts.apply_user_email(user, valid_user_password(), %{email: "not valid"})
+
+      assert %{email: ["must have the @ sign and no spaces"]} = errors_on(changeset)
+    end
+
+    test "validates maximum value for e-mail for security", %{user: user} do
+      too_long = String.duplicate("db", 100)
+
+      {:error, changeset} =
+        Accounts.apply_user_email(user, valid_user_password(), %{email: too_long})
+
+      assert "should be at most 160 character(s)" in errors_on(changeset).email
+    end
+
+    test "validates e-mail uniqueness", %{user: user} do
+      %{email: email} = user_fixture()
+
+      {:error, changeset} =
+        Accounts.apply_user_email(user, valid_user_password(), %{email: email})
+
+      assert "has already been taken" in errors_on(changeset).email
+    end
+
+    test "validates current password", %{user: user} do
+      {:error, changeset} =
+        Accounts.apply_user_email(user, "invalid", %{email: unique_user_email()})
+
+      assert %{current_password: ["is not valid"]} = errors_on(changeset)
+    end
+
+    test "applies the e-mail without persisting it", %{user: user} do
+      email = unique_user_email()
+      {:ok, user} = Accounts.apply_user_email(user, valid_user_password(), %{email: email})
+      assert user.email == email
+      assert Accounts.get_user!(user.id).email != email
+    end
+  end
+
+  describe "deliver_update_email_instructions/3" do
+    setup do
+      %{user: user_fixture()}
+    end
+
+    test "sends token through notification", %{user: user} do
+      token =
+        extract_user_token(fn url ->
+          Accounts.deliver_update_email_instructions(user, "current@example.com", url)
+        end)
+
+      {:ok, token} = Base.url_decode64(token, padding: false)
+      assert user_token = Repo.get_by(UserToken, token: :crypto.hash(:sha256, token))
+      assert user_token.user_id == user.id
+      assert user_token.sent_to == user.email
+      assert user_token.context == "change:current@example.com"
+    end
+  end
+
+  describe "update_user_email/2" do
+    setup do
+      user = user_fixture()
+      email = unique_user_email()
+
+      token =
+        extract_user_token(fn url ->
+          Accounts.deliver_update_email_instructions(%{user | email: email}, user.email, url)
+        end)
+
+      %{user: user, token: token, email: email}
+    end
+
+    test "does not update e-mail with invalid token", %{user: user} do
+      assert Accounts.update_user_email(user, "oops") == :error
+      assert Repo.get!(User, user.id).email == user.email
+      assert Repo.get_by(UserToken, user_id: user.id)
+    end
+
+    test "does not update e-mail if user e-mail changed", %{user: user, token: token} do
+      assert Accounts.update_user_email(%{user | email: "current@example.com"}, token) == :error
+      assert Repo.get!(User, user.id).email == user.email
+      assert Repo.get_by(UserToken, user_id: user.id)
+    end
+
+    test "does not update e-mail if token expired", %{user: user, token: token} do
+      {1, nil} = Repo.update_all(UserToken, set: [inserted_at: ~N[2020-01-01 00:00:00]])
+      assert Accounts.update_user_email(user, token) == :error
+      assert Repo.get!(User, user.id).email == user.email
+      assert Repo.get_by(UserToken, user_id: user.id)
+    end
+  end
+
+  describe "change_user_password/2" do
+    test "returns a user changeset" do
+      assert %Ecto.Changeset{} = changeset = Accounts.change_user_password(%User{})
+      assert changeset.required == [:password]
+    end
+  end
+
+  describe "update_user_password/3" do
+    setup do
+      %{user: user_fixture()}
+    end
+
+    test "validates password", %{user: user} do
+      {:error, changeset} =
+        Accounts.update_user_password(user, valid_user_password(), %{
+          password: "nt vld",
+          password_confirmation: "another"
+        })
+
+      assert %{
+               password: ["should be at least 8 character(s)"],
+               password_confirmation: ["does not match password"]
+             } = errors_on(changeset)
+    end
+
+    test "validates maximum values for password for security", %{user: user} do
+      too_long = String.duplicate("db", 100)
+
+      {:error, changeset} =
+        Accounts.update_user_password(user, valid_user_password(), %{password: too_long})
+
+      assert "should be at most 80 character(s)" in errors_on(changeset).password
+    end
+
+    test "validates current password", %{user: user} do
+      {:error, changeset} =
+        Accounts.update_user_password(user, "invalid", %{password: valid_user_password()})
+
+      assert %{current_password: ["is not valid"]} = errors_on(changeset)
+    end
+
+    test "updates the password", %{user: user} do
+      {:ok, user} =
+        Accounts.update_user_password(user, valid_user_password(), %{
+          password: "new valid password"
+        })
+
+      assert is_nil(user.password)
+      assert Accounts.get_user_by_email_and_password(user.email, "new valid password")
+    end
+
+    test "deletes all tokens for the given user", %{user: user} do
+      _ = Accounts.generate_user_session_token(user)
+
+      {:ok, _} =
+        Accounts.update_user_password(user, valid_user_password(), %{
+          password: "new valid password"
+        })
+
+      refute Repo.get_by(UserToken, user_id: user.id)
+    end
+  end
+
+  describe "generate_user_session_token/1" do
+    setup do
+      %{user: user_fixture()}
+    end
+
+    test "generates a token", %{user: user} do
+      token = Accounts.generate_user_session_token(user)
+      assert user_token = Repo.get_by(UserToken, token: token)
+      assert user_token.context == "session"
+
+      # Creating the same token for another user should fail
+      assert_raise Ecto.ConstraintError, fn ->
+        Repo.insert!(%UserToken{
+          token: user_token.token,
+          user_id: user_fixture().id,
+          context: "session"
+        })
+      end
+    end
+  end
+
+  describe "get_user_by_session_token/1" do
+    setup do
+      user = user_fixture()
+      token = Accounts.generate_user_session_token(user)
+      %{user: user, token: token}
+    end
+
+    test "returns user by token", %{user: user, token: token} do
+      assert session_user = Accounts.get_user_by_session_token(token)
+      assert session_user.id == user.id
+    end
+
+    test "does not return user for invalid token" do
+      refute Accounts.get_user_by_session_token("oops")
+    end
+
+    test "does not return user for expired token", %{token: token} do
+      {1, nil} = Repo.update_all(UserToken, set: [inserted_at: ~N[2020-01-01 00:00:00]])
+      refute Accounts.get_user_by_session_token(token)
+    end
+  end
+
+  describe "delete_session_token/1" do
+    test "deletes the token" do
+      user = user_fixture()
+      token = Accounts.generate_user_session_token(user)
+      assert Accounts.delete_session_token(token) == :ok
+      refute Accounts.get_user_by_session_token(token)
+    end
+  end
+
+  describe "deliver_user_confirmation_instructions/2" do
+    setup do
+      %{user: user_fixture()}
+    end
+  end
+
+  describe "confirm_user/2" do
+    setup do
+      user = user_fixture()
+
+      token =
+        extract_user_token(fn url ->
+          Accounts.deliver_user_confirmation_instructions(user, url)
+        end)
+
+      %{user: user, token: token}
+    end
+  end
+
+  describe "deliver_user_reset_password_instructions/2" do
+    setup do
+      %{user: user_fixture()}
+    end
+
+    test "sends token through notification", %{user: user} do
+      token =
+        extract_user_token(fn url ->
+          Accounts.deliver_user_reset_password_instructions(user, url)
+        end)
+
+      {:ok, token} = Base.url_decode64(token, padding: false)
+      assert user_token = Repo.get_by(UserToken, token: :crypto.hash(:sha256, token))
+      assert user_token.user_id == user.id
+      assert user_token.sent_to == user.email
+      assert user_token.context == "reset_password"
+    end
+  end
+
+  describe "get_user_by_reset_password_token/2" do
+    setup do
+      user = user_fixture()
+
+      token =
+        extract_user_token(fn url ->
+          Accounts.deliver_user_reset_password_instructions(user, url)
+        end)
+
+      %{user: user, token: token}
+    end
+
+    test "returns the user with valid token", %{user: %{id: id}, token: token} do
+      assert %User{id: ^id} = Accounts.get_user_by_reset_password_token(token)
+      assert Repo.get_by(UserToken, user_id: id)
+    end
+
+    test "does not return the user with invalid token", %{user: user} do
+      refute Accounts.get_user_by_reset_password_token("oops")
+      assert Repo.get_by(UserToken, user_id: user.id)
+    end
+
+    test "does not return the user if token expired", %{user: user, token: token} do
+      {1, nil} = Repo.update_all(UserToken, set: [inserted_at: ~N[2020-01-01 00:00:00]])
+      refute Accounts.get_user_by_reset_password_token(token)
+      assert Repo.get_by(UserToken, user_id: user.id)
+    end
+  end
+
+  describe "reset_user_password/3" do
+    setup do
+      %{user: user_fixture()}
+    end
+
+    test "validates password", %{user: user} do
+      {:error, changeset} =
+        Accounts.reset_user_password(user, %{
+          password: "nt vld",
+          password_confirmation: "another"
+        })
+
+      assert %{
+               password: ["should be at least 8 character(s)"],
+               password_confirmation: ["does not match password"]
+             } = errors_on(changeset)
+    end
+
+    test "validates maximum values for password for security", %{user: user} do
+      too_long = String.duplicate("db", 100)
+      {:error, changeset} = Accounts.reset_user_password(user, %{password: too_long})
+      assert "should be at most 80 character(s)" in errors_on(changeset).password
+    end
+
+    test "updates the password", %{user: user} do
+      {:ok, updated_user} = Accounts.reset_user_password(user, %{password: "new valid password"})
+      assert is_nil(updated_user.password)
+      assert Accounts.get_user_by_email_and_password(user.email, "new valid password")
+    end
+
+    test "deletes all tokens for the given user", %{user: user} do
+      _ = Accounts.generate_user_session_token(user)
+      {:ok, _} = Accounts.reset_user_password(user, %{password: "new valid password"})
+      refute Repo.get_by(UserToken, user_id: user.id)
+    end
+  end
+
+  describe "inspect/2" do
+    test "does not include password" do
+      refute inspect(%User{password: "123456"}) =~ "password: \"123456\""
+    end
+  end
+end

test/planner_web/controllers/page_controller_test.exs

@@ -1,8 +0,0 @@
-defmodule PlannerWeb.PageControllerTest do
-  use PlannerWeb.ConnCase
-
-  test "GET /", %{conn: conn} do
-    conn = get(conn, "/")
-    assert html_response(conn, 200) =~ "Welcome to Phoenix!"
-  end
-end

test/support/conn_case.ex

@@ -40,4 +40,30 @@ defmodule PlannerWeb.ConnCase do
 
     {:ok, conn: Phoenix.ConnTest.build_conn()}
   end
+
+  @doc """
+  Setup helper that registers and logs in users.
+
+      setup :register_and_login_user
+
+  It stores an updated connection and a registered user in the
+  test context.
+  """
+  def register_and_login_user(%{conn: conn}) do
+    user = Planner.AccountsFixtures.user_fixture()
+    %{conn: login_user(conn, user), user: user}
+  end
+
+  @doc """
+  Logs the given `user` into the `conn`.
+
+  It returns an updated `conn`.
+  """
+  def login_user(conn, user) do
+    token = Planner.Accounts.generate_user_session_token(user)
+
+    conn
+    |> Phoenix.ConnTest.init_test_session(%{})
+    |> Plug.Conn.put_session(:user_token, token)
+  end
 end

test/support/fixtures/accounts_fixtures.ex

@@ -0,0 +1,27 @@
+defmodule Planner.AccountsFixtures do
+  @moduledoc """
+  This module defines test helpers for creating
+  entities via the `Planner.Accounts` context.
+  """
+
+  def unique_user_email, do: "user#{System.unique_integer()}@example.com"
+  def valid_user_password, do: "hello world!"
+
+  def user_fixture(attrs \\ %{}) do
+    {:ok, user} =
+      attrs
+      |> Enum.into(%{
+        email: unique_user_email(),
+        password: valid_user_password()
+      })
+      |> Planner.Accounts.register_user()
+
+    user
+  end
+
+  def extract_user_token(fun) do
+    {:ok, captured} = fun.(&"[TOKEN]#{&1}[TOKEN]")
+    [_, token, _] = String.split(captured.body, "[TOKEN]")
+    token
+  end
+end