decentralised_book_index/lib/decentralised_book_index/accounts/user.ex

defmodule DecentralisedBookIndex.Accounts.User do
  use Ash.Resource,
    otp_app: :decentralised_book_index,
    domain: DecentralisedBookIndex.Accounts,
    authorizers: [Ash.Policy.Authorizer],
    extensions: [AshAuthentication],
    data_layer: AshPostgres.DataLayer

  authentication do
    add_ons do
      log_out_everywhere do
        apply_on_password_change?(true)
      end

      confirmation :confirm_new_user do
        monitor_fields [:email]
        confirm_on_create? true
        confirm_on_update? false
        auto_confirm_actions [:sign_in_with_magic_link, :reset_password_with_token]
        sender DecentralisedBookIndex.Accounts.User.Senders.SendNewUserConfirmationEmail
      end
    end

    tokens do
      enabled? true
      token_resource DecentralisedBookIndex.Accounts.Token
      signing_secret DecentralisedBookIndex.Secrets
      store_all_tokens? true
      require_token_presence_for_authentication? true
    end

    strategies do
      password :password do
        identity_field :email

        resettable do
          sender DecentralisedBookIndex.Accounts.User.Senders.SendPasswordResetEmail
          # these configurations will be the default in a future release
          password_reset_action_name :reset_password_with_token
          request_password_reset_action_name :request_password_reset_token
        end
      end
    end
  end

  postgres do
    table "users"
    repo DecentralisedBookIndex.Repo
  end

  code_interface do
    define :list_moderators
    define :search, action: :search, args: [:email]

    define :get_by_id, action: :read, get_by: [:id]
    define :get_by_email, args: [:email]

    define :set_role, args: [:role]
    define :make_moderator
    define :make_user
  end

  actions do
    defaults [:read]

    read :get_by_subject do
      description "Get a user by the subject claim in a JWT"
      argument :subject, :string, allow_nil?: false
      get? true
      prepare AshAuthentication.Preparations.FilterBySubject
    end

    update :change_password do
      # Use this action to allow users to change their password by providing
      # their current password and a new password.

      require_atomic? false
      accept []
      argument :current_password, :string, sensitive?: true, allow_nil?: false
      argument :password, :string, sensitive?: true, allow_nil?: false
      argument :password_confirmation, :string, sensitive?: true, allow_nil?: false

      validate confirm(:password, :password_confirmation)

      validate {AshAuthentication.Strategy.Password.PasswordValidation,
                strategy_name: :password, password_argument: :current_password}

      change {AshAuthentication.Strategy.Password.HashPasswordChange, strategy_name: :password}
    end

    read :sign_in_with_password do
      description "Attempt to sign in using a email and password."
      get? true

      argument :email, :ci_string do
        description "The email to use for retrieving the user."
        allow_nil? false
      end

      argument :password, :string do
        description "The password to check for the matching user."
        allow_nil? false
        sensitive? true
      end

      # validates the provided email and password and generates a token
      prepare AshAuthentication.Strategy.Password.SignInPreparation

      metadata :token, :string do
        description "A JWT that can be used to authenticate the user."
        allow_nil? false
      end
    end

    read :sign_in_with_token do
      # In the generated sign in components, we validate the
      # email and password directly in the LiveView
      # and generate a short-lived token that can be used to sign in over
      # a standard controller action, exchanging it for a standard token.
      # This action performs that exchange. If you do not use the generated
      # liveviews, you may remove this action, and set
      # `sign_in_tokens_enabled? false` in the password strategy.

      description "Attempt to sign in using a short-lived sign in token."
      get? true

      argument :token, :string do
        description "The short-lived sign in token."
        allow_nil? false
        sensitive? true
      end

      # validates the provided sign in token and generates a token
      prepare AshAuthentication.Strategy.Password.SignInWithTokenPreparation

      metadata :token, :string do
        description "A JWT that can be used to authenticate the user."
        allow_nil? false
      end
    end

    create :register_with_password do
      description "Register a new user with a email and password."

      argument :email, :ci_string do
        allow_nil? false
      end

      argument :password, :string do
        description "The proposed password for the user, in plain text."
        allow_nil? false
        constraints min_length: 8
        sensitive? true
      end

      argument :password_confirmation, :string do
        description "The proposed password for the user (again), in plain text."
        allow_nil? false
        sensitive? true
      end

      # Sets the email from the argument
      change set_attribute(:email, arg(:email))

      # Hashes the provided password
      change AshAuthentication.Strategy.Password.HashPasswordChange

      # Generates an authentication token for the user
      change AshAuthentication.GenerateTokenChange

      # validates that the password matches the confirmation
      validate AshAuthentication.Strategy.Password.PasswordConfirmationValidation

      metadata :token, :string do
        description "A JWT that can be used to authenticate the user."
        allow_nil? false
      end
    end

    action :request_password_reset_token do
      description "Send password reset instructions to a user if they exist."

      argument :email, :ci_string do
        allow_nil? false
      end

      # creates a reset token and invokes the relevant senders
      run {AshAuthentication.Strategy.Password.RequestPasswordReset, action: :get_by_email}
    end

    read :get_by_email do
      description "Looks up a user by their email"
      get? true

      argument :email, :ci_string do
        allow_nil? false
      end

      filter expr(email == ^arg(:email))
    end

    update :reset_password_with_token do
      argument :reset_token, :string do
        allow_nil? false
        sensitive? true
      end

      argument :password, :string do
        description "The proposed password for the user, in plain text."
        allow_nil? false
        constraints min_length: 8
        sensitive? true
      end

      argument :password_confirmation, :string do
        description "The proposed password for the user (again), in plain text."
        allow_nil? false
        sensitive? true
      end

      # validates the provided reset token
      validate AshAuthentication.Strategy.Password.ResetTokenValidation

      # validates that the password matches the confirmation
      validate AshAuthentication.Strategy.Password.PasswordConfirmationValidation

      # Hashes the provided password
      change AshAuthentication.Strategy.Password.HashPasswordChange

      # Generates an authentication token for the user
      change AshAuthentication.GenerateTokenChange
    end

    update :set_role do
      description "Sets user role"
      accept [:role]
    end

    update :make_moderator do
      description "Sets user role to moderator"
      change set_attribute(:role, :moderator)
    end

    update :make_user do
      description "Sets user role to user"
      change set_attribute(:role, :user)
    end

    read :list_moderators do
      description "Looks up users with the moderator role"

      filter expr(role == :moderator)
    end

    read :search do
      argument :email, :ci_string do
        constraints allow_empty?: true
        default ""
      end

      filter expr(contains(email, ^arg(:email)))

      pagination offset?: true, default_limit: 10
    end
  end

  policies do
    bypass AshAuthentication.Checks.AshAuthenticationInteraction do
      authorize_if always()
    end

    bypass actor_attribute_equals(:role, :admin) do
      authorize_if always()
    end

    policy always() do
      forbid_if always()
    end
  end

  attributes do
    uuid_primary_key :id

    attribute :email, :ci_string do
      allow_nil? false
      public? true
    end

    attribute :hashed_password, :string do
      allow_nil? false
      sensitive? true
    end

    attribute :role, DecentralisedBookIndex.Accounts.Role do
      allow_nil? false
      default :user
      public? true
    end
  end

  identities do
    identity :unique_email, [:email]
  end
end