alibi-plugins 0.4.1

//! Anonymous accounts and their cleanup when a proven account replaces them.

use super::helpers::{
    apply_default_role, completed_response_session, delete_session_cookie_headers, get_cookie,
    issue_user_session_record, record_completed_session_record, response_has_session_cookie,
};
use alibi_core::wire::{SessionView, UserView};
use alibi_core::{
    AuthContext, AuthInitContext, AuthPlugin, AuthRequest, AuthResponse, AuthResult, AuthRoute,
    AuthSchema, AuthSession, AuthUser, BeforeRequestAction, CreateUser, HttpMethod, RequestMeta,
};
use async_trait::async_trait;
use rand::distr::{Alphanumeric, SampleString};
use serde_json::json;
use std::sync::Arc;

/// Application-owned generation of anonymous display names and email addresses.
#[async_trait]
pub trait AnonymousIdentity: Send + Sync {
    async fn email(&self) -> AuthResult<Option<String>> {
        Ok(None)
    }
    async fn name(&self, _request: &AuthRequest) -> AuthResult<Option<String>> {
        Ok(None)
    }
}

/// Both authenticated accounts involved in an anonymous account upgrade.
pub struct AnonymousLink {
    pub anonymous_user: UserView,
    pub anonymous_session: SessionView,
    pub new_user: UserView,
    pub new_session: SessionView,
}

/// Transfer application-owned data before the anonymous account is deleted.
#[async_trait]
pub trait LinkAnonymousAccount: Send + Sync {
    async fn link(&self, accounts: &AnonymousLink, request: &AuthRequest) -> AuthResult<()>;
}

#[derive(Clone, Default)]
pub struct AnonymousConfig {
    pub email_domain_name: Option<String>,
    pub identity: Option<Arc<dyn AnonymousIdentity>>,
    pub on_link_account: Option<Arc<dyn LinkAnonymousAccount>>,
    pub disable_delete_anonymous_user: bool,
}

#[derive(Clone, Default)]
pub struct AnonymousPlugin {
    config: AnonymousConfig,
}

impl AnonymousPlugin {
    #[must_use]
    pub fn new() -> Self {
        Self::default()
    }
    #[must_use]
    pub const fn with_config(config: AnonymousConfig) -> Self {
        Self { config }
    }

    #[expect(
        clippy::too_many_lines,
        reason = "Keep anonymous session reuse, user creation, and session issuance in request order"
    )]
    async fn sign_in<S: AuthSchema>(
        &self,
        req: &AuthRequest,
        ctx: &AuthContext<S>,
    ) -> AuthResult<AuthResponse> {
        use alibi_core::utils::cookie_utils::{
            create_session_cookie_with_max_age, create_session_like_cookie, related_cookie_name,
            sign_cookie_value, verify_cookie_value,
        };

        if let Some((current, _)) = anonymous_session(req, ctx).await
            && current.is_anonymous() == Some(true)
        {
            return Ok(error(
                400,
                "ANONYMOUS_USERS_CANNOT_SIGN_IN_AGAIN_ANONYMOUSLY",
                "Anonymous users cannot sign in again anonymously",
            ));
        }
        let custom = match &self.config.identity {
            Some(identity) => identity.email().await.map_err(callback_error)?,
            None => None,
        };
        let email = if let Some(email) = custom.filter(|value| !value.is_empty()) {
            if !super::authentication_helpers::is_valid_email(&email) {
                return Ok(error(
                    400,
                    "INVALID_EMAIL_FORMAT",
                    "Email was not generated in a valid format",
                ));
            }
            email
        } else {
            let id = Alphanumeric.sample_string(&mut rand::rng(), 32);
            self.config
                .email_domain_name
                .as_ref()
                .filter(|domain| !domain.is_empty())
                .map_or_else(
                    || format!("{id}@anonymous.placeholder.invalid"),
                    |domain| format!("temp-{id}@{domain}"),
                )
        };
        let name = match &self.config.identity {
            Some(identity) => identity.name(req).await.map_err(callback_error)?,
            None => None,
        }
        .filter(|name| !name.is_empty())
        .unwrap_or_else(|| "Anonymous".to_owned());
        let mut create = CreateUser::new().with_email(email).with_name(name);
        create.is_anonymous = Some(true);
        create.email_verified = Some(false);
        apply_default_role(ctx, &mut create);
        let user = ctx
            .database
            .create_user_with_source_record(
                create,
                alibi_core::user_validation::UserValidationSource::creation("anonymous"),
            )
            .await
            .map_err(|error| match error {
                alibi_core::AuthError::UserCreationCancelled => alibi_core::AuthError::Upstream {
                    status: 500,
                    code: "FAILED_TO_CREATE_USER",
                    message: "Failed to create user",
                },
                error @ (alibi_core::AuthError::Api { .. }
                | alibi_core::AuthError::Upstream { .. }
                | alibi_core::AuthError::BadRequest(_)
                | alibi_core::AuthError::InvalidRequest(_)
                | alibi_core::AuthError::Validation(_)
                | alibi_core::AuthError::InvalidCredentials
                | alibi_core::AuthError::Unauthenticated
                | alibi_core::AuthError::AuthenticationFailed(_)
                | alibi_core::AuthError::SessionNotFound
                | alibi_core::AuthError::Forbidden(_)
                | alibi_core::AuthError::SessionCreationCancelled
                | alibi_core::AuthError::BannedUser(_)
                | alibi_core::AuthError::Unauthorized
                | alibi_core::AuthError::UserNotFound
                | alibi_core::AuthError::NotFound(_)
                | alibi_core::AuthError::Conflict(_)
                | alibi_core::AuthError::MethodNotAllowed(_)
                | alibi_core::AuthError::PayloadTooLarge(_)
                | alibi_core::AuthError::UnprocessableEntity(_)
                | alibi_core::AuthError::RateLimited { .. }
                | alibi_core::AuthError::NotImplemented(_)
                | alibi_core::AuthError::Config(_)
                | alibi_core::AuthError::Database(_)
                | alibi_core::AuthError::Serialization(_)
                | alibi_core::AuthError::Plugin { .. }
                | alibi_core::AuthError::CallbackFailure(_)
                | alibi_core::AuthError::Internal(_)
                | alibi_core::AuthError::Encryption(_)
                | alibi_core::AuthError::PasswordHash(_)
                | alibi_core::AuthError::Jwt(_)) => error,
            })?;
        let meta = RequestMeta::from_request(req);
        let issued =
            issue_user_session_record(ctx, user.id().as_ref(), meta.ip_address, meta.user_agent)
                .await
                .map_err(|cause| match cause.into_auth_error() {
                    alibi_core::AuthError::SessionCreationCancelled => {
                        alibi_core::AuthError::Upstream {
                            status: 400,
                            code: "COULD_NOT_CREATE_SESSION",
                            message: "Could not create session",
                        }
                    }
                    cause @ (alibi_core::AuthError::Api { .. }
                    | alibi_core::AuthError::Upstream { .. }
                    | alibi_core::AuthError::BadRequest(_)
                    | alibi_core::AuthError::InvalidRequest(_)
                    | alibi_core::AuthError::Validation(_)
                    | alibi_core::AuthError::InvalidCredentials
                    | alibi_core::AuthError::Unauthenticated
                    | alibi_core::AuthError::AuthenticationFailed(_)
                    | alibi_core::AuthError::SessionNotFound
                    | alibi_core::AuthError::Forbidden(_)
                    | alibi_core::AuthError::UserCreationCancelled
                    | alibi_core::AuthError::BannedUser(_)
                    | alibi_core::AuthError::Unauthorized
                    | alibi_core::AuthError::UserNotFound
                    | alibi_core::AuthError::NotFound(_)
                    | alibi_core::AuthError::Conflict(_)
                    | alibi_core::AuthError::MethodNotAllowed(_)
                    | alibi_core::AuthError::PayloadTooLarge(_)
                    | alibi_core::AuthError::UnprocessableEntity(_)
                    | alibi_core::AuthError::RateLimited { .. }
                    | alibi_core::AuthError::NotImplemented(_)
                    | alibi_core::AuthError::Config(_)
                    | alibi_core::AuthError::Database(_)
                    | alibi_core::AuthError::Serialization(_)
                    | alibi_core::AuthError::Plugin { .. }
                    | alibi_core::AuthError::CallbackFailure(_)
                    | alibi_core::AuthError::Internal(_)
                    | alibi_core::AuthError::Encryption(_)
                    | alibi_core::AuthError::PasswordHash(_)
                    | alibi_core::AuthError::Jwt(_)) => cause,
                })?;
        // The created row is Source's original new-user snapshot, even if a
        // lifecycle hook subsequently changes the database during session creation.
        record_completed_session_record::<S>(&user, &issued.session);
        let mut response = AuthResponse::json(
            200,
            &json!({"token":issued.session.token(),"user":ctx.user_view(&user)}),
        )?;

        let preference_name = related_cookie_name(&ctx.config, "dont_remember");
        let dont_remember = get_cookie(req, &preference_name)
            .and_then(|value| verify_cookie_value(&value, ctx.config.current_secret()))
            .is_some_and(|value| !value.is_empty());
        response.headers.append(
            "set-cookie",
            create_session_cookie_with_max_age(
                Some(issued.session.token()),
                if dont_remember {
                    None
                } else {
                    Some(ctx.config.session.expires_in.num_seconds())
                },
                &ctx.config,
            )?,
        );
        if dont_remember {
            response.headers.append(
                "set-cookie",
                create_session_like_cookie(
                    &preference_name,
                    &sign_cookie_value("true", ctx.config.current_secret()),
                    None,
                    &ctx.config,
                )?,
            );
        }
        Ok(response)
    }

    async fn delete(
        &self,
        req: &AuthRequest,
        ctx: &AuthContext<impl AuthSchema>,
    ) -> AuthResult<AuthResponse> {
        let (user, _) =
            ctx.require_authoritative_session(req)
                .await
                .map_err(|error| match error {
                    alibi_core::AuthError::Unauthenticated => alibi_core::AuthError::Upstream {
                        status: 401,
                        code: "UNAUTHORIZED",
                        message: "Unauthorized",
                    },
                    error @ (alibi_core::AuthError::Api { .. }
                    | alibi_core::AuthError::Upstream { .. }
                    | alibi_core::AuthError::BadRequest(_)
                    | alibi_core::AuthError::InvalidRequest(_)
                    | alibi_core::AuthError::Validation(_)
                    | alibi_core::AuthError::InvalidCredentials
                    | alibi_core::AuthError::AuthenticationFailed(_)
                    | alibi_core::AuthError::SessionNotFound
                    | alibi_core::AuthError::Forbidden(_)
                    | alibi_core::AuthError::SessionCreationCancelled
                    | alibi_core::AuthError::UserCreationCancelled
                    | alibi_core::AuthError::BannedUser(_)
                    | alibi_core::AuthError::Unauthorized
                    | alibi_core::AuthError::UserNotFound
                    | alibi_core::AuthError::NotFound(_)
                    | alibi_core::AuthError::Conflict(_)
                    | alibi_core::AuthError::MethodNotAllowed(_)
                    | alibi_core::AuthError::PayloadTooLarge(_)
                    | alibi_core::AuthError::UnprocessableEntity(_)
                    | alibi_core::AuthError::RateLimited { .. }
                    | alibi_core::AuthError::NotImplemented(_)
                    | alibi_core::AuthError::Config(_)
                    | alibi_core::AuthError::Database(_)
                    | alibi_core::AuthError::Serialization(_)
                    | alibi_core::AuthError::Plugin { .. }
                    | alibi_core::AuthError::CallbackFailure(_)
                    | alibi_core::AuthError::Internal(_)
                    | alibi_core::AuthError::Encryption(_)
                    | alibi_core::AuthError::PasswordHash(_)
                    | alibi_core::AuthError::Jwt(_)) => error,
                })?;
        if self.config.disable_delete_anonymous_user {
            return Ok(error(
                400,
                "DELETE_ANONYMOUS_USER_DISABLED",
                "Deleting anonymous users is disabled",
            ));
        }
        if user.is_anonymous() != Some(true) {
            return Ok(error(403, "USER_IS_NOT_ANONYMOUS", "User is not anonymous"));
        }
        if let Err(cause) = ctx.database.delete_user_sessions(user.id().as_ref()).await {
            tracing::error!(%cause, "Failed to delete anonymous user sessions");
            return Ok(error(
                500,
                "FAILED_TO_DELETE_ANONYMOUS_USER_SESSIONS",
                "Failed to delete anonymous user sessions",
            ));
        }
        if let Err(cause) = ctx.database.delete_user(user.id().as_ref()).await {
            tracing::error!(%cause, "Failed to delete anonymous user");
            return Ok(error(
                500,
                "FAILED_TO_DELETE_ANONYMOUS_USER",
                "Failed to delete anonymous user",
            ));
        }
        let mut response = AuthResponse::json(200, &json!({"success":true}))?;
        for cookie in delete_session_cookie_headers(&ctx.config)? {
            response.headers.append("set-cookie", cookie);
        }
        Ok(response)
    }
}

#[async_trait]
impl<S: AuthSchema> AuthPlugin<S> for AnonymousPlugin {
    route_openapi_metadata!(S);

    fn name(&self) -> &'static str {
        "anonymous"
    }
    fn routes(&self) -> Vec<AuthRoute> {
        vec![
            AuthRoute::post("/sign-in/anonymous", "sign_in_anonymous"),
            AuthRoute::post("/delete-anonymous-user", "delete_anonymous_user"),
        ]
    }
    async fn on_init(&self, ctx: &mut AuthInitContext<S>) -> AuthResult<()> {
        ctx.set_metadata("anonymous.enabled", json!(true));
        let default = |mut input: CreateUser| {
            if input.is_anonymous.is_none() {
                input.is_anonymous = Some(false);
            }
            Ok(input)
        };
        if ctx.config.user_validation.is_some() {
            ctx.register_user_creation_adapter_default(default);
        } else {
            ctx.register_user_create_transform(default);
        }
        Ok(())
    }
    async fn on_request(
        &self,
        req: &AuthRequest,
        ctx: &AuthContext<S>,
    ) -> AuthResult<Option<AuthResponse>> {
        match (req.method(), req.path()) {
            (HttpMethod::Post, "/sign-in/anonymous") => Ok(Some(self.sign_in(req, ctx).await?)),
            (HttpMethod::Post, "/delete-anonymous-user") => Ok(Some(self.delete(req, ctx).await?)),
            _ => Ok(None),
        }
    }
    async fn before_request(
        &self,
        req: &AuthRequest,
        ctx: &AuthContext<S>,
    ) -> AuthResult<Option<BeforeRequestAction>> {
        if req.path() == "/sign-in/social"
            && let Some((user, _)) = anonymous_session(req, ctx).await
            && user.is_anonymous() == Some(true)
        {
            req.extensions()
                .insert(super::oauth::CapturedOAuthServerContext(
                    super::oauth::OAuthServerContext {
                        anonymous_user_id: user.id().into_owned(),
                    },
                ));
        }
        Ok(None)
    }
    async fn after_request(
        &self,
        req: &AuthRequest,
        ctx: &AuthContext<S>,
        response: AuthResponse,
    ) -> AuthResult<AuthResponse> {
        let matches = [
            "/sign-in",
            "/sign-up",
            "/callback",
            "/magic-link/verify",
            "/email-otp/verify-email",
            "/one-tap/callback",
            "/passkey/verify-authentication",
            "/phone-number/verify",
            "/verify-email",
        ]
        .iter()
        .any(|prefix| req.path().starts_with(prefix));
        if !matches {
            return Ok(response);
        }
        if !response_has_session_cookie(ctx, &response) {
            return Ok(response);
        }
        let Some((old_user, old_session)) = resolve_anonymous_session(req, ctx).await? else {
            return Ok(response);
        };
        if old_user.is_anonymous != Some(true) {
            return Ok(response);
        }
        let Some(issued) = completed_response_session(req, ctx, &response) else {
            return Ok(response);
        };
        if let Some(linker) = &self.config.on_link_account {
            // The new-user callback receives the real newly issued session,
            // including adapter fields hidden from public session responses.
            let mut new_session = issued.callback_session(ctx);
            new_session.omitted_fields.clear();
            linker
                .link(
                    &AnonymousLink {
                        anonymous_user: old_user.clone(),
                        anonymous_session: ctx.session_view(&old_session),
                        new_user: issued.callback_user(ctx),
                        new_session,
                    },
                    req,
                )
                .await
                .map_err(callback_error)?;
        }
        if self.config.disable_delete_anonymous_user
            || old_user.id == issued.user.id().as_ref()
            || issued.user.is_anonymous() == Some(true)
        {
            return Ok(response);
        }
        if let Err(error) = ctx.database.delete_user(&old_user.id).await {
            tracing::error!(user_id=%old_user.id,error=%error,"Failed to clean up anonymous account");
        }
        Ok(response)
    }
}

impl std::fmt::Debug for AnonymousConfig {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.debug_struct("AnonymousConfig").finish_non_exhaustive()
    }
}

impl std::fmt::Debug for AnonymousLink {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.debug_struct("AnonymousLink").finish_non_exhaustive()
    }
}

impl std::fmt::Debug for AnonymousPlugin {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.debug_struct("AnonymousPlugin").finish_non_exhaustive()
    }
}

// Source's nested get-session disables refresh, catches failed resolution, and
// retains its real expiry cleanup/response-cookie effects on the request.
async fn anonymous_session<S: AuthSchema>(
    req: &AuthRequest,
    ctx: &AuthContext<S>,
) -> Option<(alibi_core::AuthenticatedUser<S>, SessionView)> {
    let mut read = req.clone();
    _ = read.query.insert("disableRefresh".into(), "true".into());
    ctx.require_cached_session(&read).await.ok()
}

async fn resolve_anonymous_session<S: AuthSchema>(
    req: &AuthRequest,
    ctx: &AuthContext<S>,
) -> AuthResult<Option<(UserView, SessionView)>> {
    if let Some((user, session)) = anonymous_session(req, ctx).await
        && user.is_anonymous() == Some(true)
    {
        let user = match user {
            alibi_core::AuthenticatedUser::Stored(user) => ctx.user_view(&user),
            alibi_core::AuthenticatedUser::Cached(user) => *user,
        };
        return Ok(Some((user, session)));
    }
    let Some(context) = req
        .extensions()
        .get::<super::oauth::RecoveredOAuthServerContext>()
    else {
        return Ok(None);
    };
    let Some(user) = ctx
        .database
        .get_user_by_id_record(&context.0.anonymous_user_id)
        .await?
    else {
        return Ok(None);
    };
    if user.is_anonymous() != Some(true) {
        return Ok(None);
    }
    let session = ctx
        .database
        .get_user_sessions(&context.0.anonymous_user_id)
        .await?
        .into_iter()
        .find(|session| session.expires_at() > chrono::Utc::now());
    Ok(session.map(|session| (ctx.trusted_user_view(&user), ctx.session_view(&session))))
}

// An ordinary application exception has an empty 500 wire. Explicit typed
// HTTP errors retain their status/body, including coded and uncoded API errors.
fn callback_error(error: alibi_core::AuthError) -> alibi_core::AuthError {
    match error {
        alibi_core::AuthError::Internal(_) => {
            alibi_core::AuthError::CallbackFailure(Box::new(error))
        }
        other => other,
    }
}

fn error(status: u16, code: &'static str, message: &'static str) -> AuthResponse {
    alibi_core::AuthError::Upstream {
        status,
        code,
        message,
    }
    .to_auth_response()
}