import { Event } from 'ai-database'

// Events are emitted automatically when verbs execute
await Approve(user, document)
// Emits: { type: 'Document.approved', actor: user, target: document, ... }

// Subscribe to events
Event.on('Document.approved', async (event) => {
  await notify(event.target.author, 'Your document was approved!')
})

interface Event {
  id: string           // Unique event ID
  type: string         // Event type (e.g., 'Order.shipped')
  timestamp: Date      // When it occurred

  actor?: Thing        // Who/what caused it
  target?: Thing       // What it affected

  data: object         // Event-specific data
  metadata: object     // Additional context
}

import { Event } from 'ai-database'

// Subscribe to specific event type
Event.on('Order.created', async (event) => {
  await sendConfirmation(event.target)
})

// Subscribe to all events for a noun
Event.on('Order.*', async (event) => {
  await updateAnalytics(event)
})

// Subscribe to all events
Event.on('*', async (event) => {
  await auditLog.append(event)
})

// Events are usually emitted by verbs, but can be manual
import { emit } from 'ai-database'

await emit({
  type: 'User.signedIn',
  actor: user,
  data: { method: 'oauth', provider: 'google' },
})

import { EventStore } from 'ai-database'

// Replay events to rebuild state
const account = await EventStore.replay('Account', accountId)

// Get event history
const history = await EventStore.history('Order', orderId)

// Time travel
const orderAtTime = await EventStore.at('Order', orderId, pastDate)

// Saga / Process Manager
Event.on('Order.paid', async (event) => {
  await Action(Ship, event.target).execute()
})

// Event notification
Event.on('*.created', async (event) => {
  await webhooks.notify(event)
})

// Materialized view
Event.on('Order.*', async (event) => {
  await views.orders.update(event)
})