use super::*; #[derive(Debug)]pub struct CreateBillingPreferencesParams {    pub max_monthly_llm_usage_spending_in_cents: i32,} #[derive(Debug, Default)]pub struct UpdateBillingPreferencesParams {    pub max_monthly_llm_usage_spending_in_cents: ActiveValue<i32>,} impl Database {    /// Returns the billing preferences for the given user, if they exist.    pub async fn get_billing_preferences(        &self,        user_id: UserId,    ) -> Result<Option<billing_preference::Model>> {        self.transaction(|tx| async move {            Ok(billing_preference::Entity::find()                .filter(billing_preference::Column::UserId.eq(user_id))                .one(&*tx)                .await?)        })        .await    }     /// Creates new billing preferences for the given user.    pub async fn create_billing_preferences(        &self,        user_id: UserId,        params: &CreateBillingPreferencesParams,    ) -> Result<billing_preference::Model> {        self.transaction(|tx| async move {            let preferences = billing_preference::Entity::insert(billing_preference::ActiveModel {                user_id: ActiveValue::set(user_id),                max_monthly_llm_usage_spending_in_cents: ActiveValue::set(                    params.max_monthly_llm_usage_spending_in_cents,                ),                ..Default::default()            })            .exec_with_returning(&*tx)            .await?;             Ok(preferences)        })        .await    }     /// Updates the billing preferences for the given user.    pub async fn update_billing_preferences(        &self,        user_id: UserId,        params: &UpdateBillingPreferencesParams,    ) -> Result<billing_preference::Model> {        self.transaction(|tx| async move {            let preferences = billing_preference::Entity::update_many()                .set(billing_preference::ActiveModel {                    max_monthly_llm_usage_spending_in_cents: params                        .max_monthly_llm_usage_spending_in_cents                        .clone(),                    ..Default::default()                })                .filter(billing_preference::Column::UserId.eq(user_id))                .exec_with_returning(&*tx)                .await?;             Ok(preferences                .into_iter()                .next()                .ok_or_else(|| anyhow!("billing preferences not found"))?)        })        .await    }}