import * as Store from '../../../internal/Store.js'
import * as Ttl from '../../../internal/Ttl.js'

/** Address-screening result. */
export type Result = { allowed: boolean }

/** Address-screening provider. */
export type Provider = {
  /** Screens one normalized account address on a Tempo chain. */
  screen(options: { address: string; chainId: number }): Promise<Result>
}

/** Allows every address while the external screening provider is unconfigured. */
export const allowAll: Provider = {
  async screen() {
    return { allowed: true }
  },
}

/** Screens one address, caching the provider result by chain and normalized address. */
export async function screen(options: screen.Options): Promise<Result> {
  const { address, chainId, provider, store, ttl = defaultTtl } = options
  return Store.memoize(() => provider.screen({ address, chainId }), {
    key: `mpp:screen:v1:${chainId}:${address.toLowerCase()}`,
    store,
    ttl,
  })
}

export declare namespace screen {
  /** Dependencies used to screen an address. */
  type Options = {
    /** Normalized account address. */
    address: string
    /** Tempo chain identifier. */
    chainId: number
    /** Address-screening provider. */
    provider: Provider
    /** Cache used for provider results. */
    store: Store.Store
    /** Cache duration. @default `Ttl.days(1)` */
    ttl?: number | undefined
  }
}

/** Default address-screening cache lifetime (24 hours). */
export const defaultTtl = Ttl.days(1)