Ephemeral item support (#570)

backend impl and some of the UI for ephemeral item support

more to come, this is just a WIP so far

Consolidate client-side ephemeral fee logic in FeeButton components for easier reuse

* update the update_item function to handle the case where an item was not
ephemeral, but now is, so we charge the user accordingly

* introduce `hasDeleteCommand` for a better logical abstraction for some use cases in the code

* introduce `EPHEMERAL_FEE_SATS` which is derived from `EPHEMERAL_FEE_MSATS`, so we don't
have to the same calculation over and over

Remove fees for ephemeral items

* remove unused markdownField prop in FeeButton

* remove empty migration

minor code cleanup

Centralize delete item by author code to reduce duplication

api/resolvers/item.js

@@ -16,7 +16,7 @@ import { parse } from 'tldts'
 import uu from 'url-unshort'
 import { advSchema, amountSchema, bountySchema, commentSchema, discussionSchema, jobSchema, linkSchema, pollSchema, ssValidate } from '../../lib/validate'
 import { sendUserNotification } from '../webPush'
-import { defaultCommentSort, isJob } from '../../lib/item'
+import { defaultCommentSort, isJob, deleteItemByAuthor, getDeleteCommand, hasDeleteCommand } from '../../lib/item'
 import { notifyItemParents, notifyUserSubscribers, notifyZapped } from '../../lib/push-notifications'
 import { datePivot } from '../../lib/time'
 
@@ -654,21 +654,7 @@ export default {
         throw new GraphQLError('item does not belong to you', { extensions: { code: 'FORBIDDEN' } })
       }
 
-      const data = { deletedAt: new Date() }
-      if (old.text) {
-        data.text = '*deleted by author*'
-      }
-      if (old.title) {
-        data.title = 'deleted by author'
-      }
-      if (old.url) {
-        data.url = null
-      }
-      if (old.pollCost) {
-        data.pollCost = null
-      }
-
-      return await models.item.update({ where: { id: Number(id) }, data })
+      return await deleteItemByAuthor({ models, id, item: old })
     },
     upsertLink: async (parent, { id, hash, hmac, ...item }, { me, models, lnd }) => {
       await ssValidate(linkSchema, item, { models, me })
@@ -1109,6 +1095,12 @@ export const updateItem = async (parent, { sub: subName, forward, options, ...it
 
   await createMentions(item, models)
 
+  if (hasDeleteCommand(old.text)) {
+    // delete any deletion jobs that were created from a prior version of the item
+    await clearDeletionJobs(item, models)
+  }
+  await enqueueDeletionJob(item, models)
+
   item.comments = []
   return item
 }
@@ -1138,12 +1130,27 @@ export const createItem = async (parent, { forward, options, ...item }, { me, mo
 
   await createMentions(item, models)
 
+  await enqueueDeletionJob(item, models)
+
   notifyUserSubscribers({ models, item })
 
   item.comments = []
   return item
 }
 
+const clearDeletionJobs = async (item, models) => {
+  await models.$queryRawUnsafe(`DELETE FROM pgboss.job WHERE name = 'deleteItem' AND data->>'id' = '${item.id}';`)
+}
+
+const enqueueDeletionJob = async (item, models) => {
+  const deleteCommand = getDeleteCommand(item.text)
+  if (deleteCommand) {
+    await models.$queryRawUnsafe(`
+      INSERT INTO pgboss.job (name, data, startafter)
+      VALUES ('deleteItem', jsonb_build_object('id', ${item.id}), now() + interval '${deleteCommand.number} ${deleteCommand.unit}s');`)
+  }
+}
+
 const getForwardUsers = async (models, forward) => {
   const fwdUsers = []
   if (forward) {

lib/item.js

@@ -11,3 +11,38 @@ export const defaultCommentSort = (pinned, bio, createdAt) => {
 }
 
 export const isJob = item => typeof item.maxBid !== 'undefined'
+
+const deletePattern = /\B@delete\s+in\s+(\d+)\s+(second|minute|hour|day|week|month|year)s?/gi
+
+export const getDeleteCommand = (text = '') => {
+  const matches = [...text.matchAll(deletePattern)]
+  const commands = matches?.map(match => ({ number: match[1], unit: match[2] }))
+  return commands.length ? commands[commands.length - 1] : undefined
+}
+
+export const hasDeleteCommand = (text) => !!getDeleteCommand(text)
+
+export const deleteItemByAuthor = async ({ models, id, item }) => {
+  if (!item) {
+    item = await models.item.findUnique({ where: { id: Number(id) } })
+  }
+  if (!item) {
+    console.log('attempted to delete an item that does not exist', id)
+    return
+  }
+  const updateData = { deletedAt: new Date() }
+  if (item.text) {
+    updateData.text = '*deleted by author*'
+  }
+  if (item.title) {
+    updateData.title = 'deleted by author'
+  }
+  if (item.url) {
+    updateData.url = null
+  }
+  if (item.pollCost) {
+    updateData.pollCost = null
+  }
+
+  return await models.item.update({ where: { id: Number(id) }, data: updateData })
+}

worker/ephemeralItems.js

@@ -0,0 +1,13 @@
+import { deleteItemByAuthor } from '../lib/item.js'
+
+export function deleteItem ({ models }) {
+  return async function ({ data: eventData }) {
+    console.log('deleteItem', eventData)
+    const { id } = eventData
+    try {
+      await deleteItemByAuthor({ models, id })
+    } catch (err) {
+      console.error('failed to delete item', err)
+    }
+  }
+}

worker/index.js

@@ -15,6 +15,7 @@ import fetch from 'cross-fetch'
 import { authenticatedLndGrpc } from 'ln-service'
 import { views, rankViews } from './views.js'
 import { imgproxy } from './imgproxy.js'
+import { deleteItem } from './ephemeralItems.js'
 
 const { loadEnvConfig } = nextEnv
 const { ApolloClient, HttpLink, InMemoryCache } = apolloClient
@@ -68,6 +69,7 @@ async function work () {
   await boss.work('views', views(args))
   await boss.work('rankViews', rankViews(args))
   await boss.work('imgproxy', imgproxy(args))
+  await boss.work('deleteItem', deleteItem(args))
 
   console.log('working jobs')
 }