import type { Event } from 'nostr-tools'
import { generateSponsoringHashId } from '../hashIdGenerator'
import type { ExtractedSponsoring } from './types'
import {
  readAmountSats,
  readPaymentHash,
  readPayerPubkeyFromZapReceipt,
  readTagValue,
  readZapReceiptKind,
  resolveSponsoringArticleId,
} from './utils'

export async function extractSponsoringFromEvent(event: Event): Promise<ExtractedSponsoring | null> {
  if (event.kind !== 9735 || readZapReceiptKind(event) !== 'sponsoring') {
    return null
  }

  const extracted = readSponsoringFields(event)
  if (!extracted) {
    return null
  }

  const id = await generateSponsoringHashId(extracted)
  return { type: 'sponsoring', id, ...extracted, eventId: event.id }
}

function readSponsoringFields(event: Event): Omit<ExtractedSponsoring, 'type' | 'id' | 'eventId'> | null {
  const payerPubkey = readPayerPubkeyFromZapReceipt(event)
  const authorPubkey = readTagValue(event, 'author') ?? readTagValue(event, 'p')
  const amount = readAmountSats(event)
  if (!payerPubkey || !authorPubkey || amount === undefined) {
    console.error('[metadataExtractor] Invalid sponsoring zap receipt: missing required fields', { eventId: event.id })
    return null
  }

  const paymentHash = readPaymentHash(event)
  const seriesId = readTagValue(event, 'series')
  const articleId = resolveSponsoringArticleId({ articleTag: readTagValue(event, 'article'), eTag: readTagValue(event, 'e') })

  return {
    payerPubkey,
    authorPubkey,
    amount,
    paymentHash,
    ...(seriesId ? { seriesId } : {}),
    ...(articleId ? { articleId } : {}),
  }
}