story-research-zapwall/lib/platformTracking.ts

import { Event, EventTemplate, getEventHash, signEvent } from 'nostr-tools'
import { nostrService } from './nostr'
import { PLATFORM_NPUB } from './platformConfig'
import type { SimplePoolWithSub } from '@/types/nostr-tools-extended'

const RELAY_URL = process.env.NEXT_PUBLIC_NOSTR_RELAY_URL ?? 'wss://relay.damus.io'

export interface ContentDeliveryTracking {
  articleId: string
  articlePubkey: string
  recipientPubkey: string
  messageEventId: string
  zapReceiptId?: string
  amount: number
  authorAmount?: number
  platformCommission?: number
  timestamp: number
  verified: boolean
}

/**
 * Platform tracking service
 * Publishes tracking events on Nostr for content delivery verification
 * These events are signed by the platform and can be queried for audit purposes
 */
export class PlatformTrackingService {
  private readonly platformPubkey: string = PLATFORM_NPUB
  private readonly trackingKind = 30078 // Custom kind for platform tracking

  /**
   * Publish a content delivery tracking event
   * This event is published by the author but tagged for platform tracking
   * The platform can query these events to track all content deliveries
   */
  async trackContentDelivery(
    tracking: ContentDeliveryTracking,
    authorPrivateKey: string
  ): Promise<string | null> {
    try {
      const pool = nostrService.getPool()
      if (!pool) {
        console.error('Pool not initialized for platform tracking')
        return null
      }

      const authorPubkey = nostrService.getPublicKey()
      if (!authorPubkey) {
        console.error('Author public key not available for tracking')
        return null
      }

      const eventTemplate: EventTemplate = {
        kind: this.trackingKind,
        created_at: Math.floor(Date.now() / 1000),
        tags: [
          ['p', this.platformPubkey], // Tag platform for querying
          ['article', tracking.articleId],
          ['author', tracking.articlePubkey],
          ['recipient', tracking.recipientPubkey],
          ['message', tracking.messageEventId],
          ['amount', tracking.amount.toString()],
          ...(tracking.authorAmount ? [['author_amount', tracking.authorAmount.toString()]] : []),
          ...(tracking.platformCommission ? [['platform_commission', tracking.platformCommission.toString()]] : []),
          ['verified', tracking.verified ? 'true' : 'false'],
          ['timestamp', tracking.timestamp.toString()],
          ...(tracking.zapReceiptId ? [['zap_receipt', tracking.zapReceiptId]] : []),
        ],
        content: JSON.stringify({
          articleId: tracking.articleId,
          articlePubkey: tracking.articlePubkey,
          recipientPubkey: tracking.recipientPubkey,
          messageEventId: tracking.messageEventId,
          amount: tracking.amount,
          authorAmount: tracking.authorAmount,
          platformCommission: tracking.platformCommission,
          verified: tracking.verified,
          timestamp: tracking.timestamp,
          zapReceiptId: tracking.zapReceiptId,
        }),
      }

      const unsignedEvent = {
        pubkey: authorPubkey,
        ...eventTemplate,
      }

      const event: Event = {
        ...unsignedEvent,
        id: getEventHash(unsignedEvent),
        sig: signEvent(unsignedEvent, authorPrivateKey),
      } as Event

      const poolWithSub = pool as SimplePoolWithSub
      const pubs = poolWithSub.publish([RELAY_URL], event)
      await Promise.all(pubs)

      console.log('Platform tracking event published', {
        eventId: event.id,
        articleId: tracking.articleId,
        recipientPubkey: tracking.recipientPubkey,
        messageEventId: tracking.messageEventId,
        authorAmount: tracking.authorAmount,
        platformCommission: tracking.platformCommission,
        timestamp: new Date().toISOString(),
      })

      return event.id
    } catch (error) {
      console.error('Error publishing platform tracking event', {
        articleId: tracking.articleId,
        recipientPubkey: tracking.recipientPubkey,
        error: error instanceof Error ? error.message : 'Unknown error',
        timestamp: new Date().toISOString(),
      })
      return null
    }
  }

  /**
   * Query tracking events for an article
   * Returns all delivery tracking events for a specific article
   */
  async getArticleDeliveries(articleId: string): Promise<ContentDeliveryTracking[]> {
    try {
      const pool = nostrService.getPool()
      if (!pool) {
        return []
      }

      const filters = [
        {
          kinds: [this.trackingKind],
          '#p': [this.platformPubkey],
          '#article': [articleId],
          limit: 100,
        },
      ]

      return new Promise((resolve) => {
        const deliveries: ContentDeliveryTracking[] = []
        let resolved = false
        const poolWithSub = pool as SimplePoolWithSub
        const sub = poolWithSub.sub([RELAY_URL], filters)

        const finalize = () => {
          if (resolved) {
            return
          }
          resolved = true
          sub.unsub()
          resolve(deliveries)
        }

        sub.on('event', (event: Event) => {
          try {
            const data = JSON.parse(event.content) as ContentDeliveryTracking
            const zapReceiptTag = event.tags.find((tag) => tag[0] === 'zap_receipt')?.[1]
            const authorAmountTag = event.tags.find((tag) => tag[0] === 'author_amount')?.[1]
            const platformCommissionTag = event.tags.find((tag) => tag[0] === 'platform_commission')?.[1]

            const delivery: ContentDeliveryTracking = {
              ...data,
            }

            if (authorAmountTag) {
              delivery.authorAmount = parseInt(authorAmountTag, 10)
            }

            if (platformCommissionTag) {
              delivery.platformCommission = parseInt(platformCommissionTag, 10)
            }

            if (zapReceiptTag) {
              delivery.zapReceiptId = zapReceiptTag
            }

            deliveries.push(delivery)
          } catch (error) {
            console.error('Error parsing tracking event', {
              eventId: event.id,
              error: error instanceof Error ? error.message : 'Unknown error',
            })
          }
        })

        sub.on('eose', finalize)
        setTimeout(finalize, 5000)
      })
    } catch (error) {
      console.error('Error querying article deliveries', {
        articleId,
        error: error instanceof Error ? error.message : 'Unknown error',
      })
      return []
    }
  }

  /**
   * Query all deliveries for a recipient
   */
  async getRecipientDeliveries(recipientPubkey: string): Promise<ContentDeliveryTracking[]> {
    try {
      const pool = nostrService.getPool()
      if (!pool) {
        return []
      }

      const filters = [
        {
          kinds: [this.trackingKind],
          '#p': [this.platformPubkey],
          '#recipient': [recipientPubkey],
          limit: 100,
        },
      ]

      return new Promise((resolve) => {
        const deliveries: ContentDeliveryTracking[] = []
        let resolved = false
        const poolWithSub = pool as SimplePoolWithSub
        const sub = poolWithSub.sub([RELAY_URL], filters)

        const finalize = () => {
          if (resolved) {
            return
          }
          resolved = true
          sub.unsub()
          resolve(deliveries)
        }

        sub.on('event', (event: Event) => {
          try {
            const data = JSON.parse(event.content) as ContentDeliveryTracking
            const zapReceiptTag = event.tags.find((tag) => tag[0] === 'zap_receipt')?.[1]

            const delivery: ContentDeliveryTracking = {
              ...data,
            }

            if (zapReceiptTag) {
              delivery.zapReceiptId = zapReceiptTag
            }

            deliveries.push(delivery)
          } catch (error) {
            console.error('Error parsing tracking event', {
              eventId: event.id,
              error: error instanceof Error ? error.message : 'Unknown error',
            })
          }
        })

        sub.on('eose', finalize)
        setTimeout(finalize, 5000)
      })
    } catch (error) {
      console.error('Error querying recipient deliveries', {
        recipientPubkey,
        error: error instanceof Error ? error.message : 'Unknown error',
      })
      return []
    }
  }
}

export const platformTracking = new PlatformTrackingService()