import * as Mppx from 'mppx'

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

/** Returns the normalized Tempo sender and recipients in a validated credential. */
export function addresses(result: Awaited<ReturnType<typeof Mppx.Method.validateCredential>>) {
  const details = result.details as {
    sender?: string
    transfers?: readonly { recipient: string }[]
  }
  return [details.sender, ...(details.transfers?.map(({ recipient }) => recipient) ?? [])]
    .filter((address): address is string => address !== undefined)
    .map((address) => address.toLowerCase())
    .filter((address, index, values) => values.indexOf(address) === index)
}

/** Adapts Tempo API durable state to MPPX's atomic Cloudflare store contract. */
export function mppxStore(state: Store.State): Mppx.Store.AtomicStore {
  return Mppx.Store.cloudflare({
    delete: (key) => state.delete(key),
    get: (key) => state.get(key),
    put: (key, value) => state.put(key, value),
    update: (key, change) =>
      Store.change(state, key, (current) => {
        const next = change(current)
        // MPPX's Cloudflare adapter represents a missing value with JSON null.
        return next.op === 'delete' ? { ...next, op: 'set', value: 'null' as const } : next
      }),
  })
}