market data cloud function

functions/src/index.ts

@@ -3,6 +3,7 @@ import * as admin from 'firebase-admin'
 admin.initializeApp()
 
 // export * from './keep-awake'
+export * from './markets'
 export * from './place-bet'
 export * from './resolve-market'
 export * from './stripe'

functions/src/markets.ts

@@ -0,0 +1,59 @@
+import * as functions from 'firebase-functions'
+import * as admin from 'firebase-admin'
+import * as _ from 'lodash'
+
+import { getValues } from './utils'
+import { Contract } from '../../common/contract'
+import { getProbability } from '../../common/calculate'
+
+const cache = { lastUpdated: 0, data: '' }
+
+export const markets = functions
+  .runWith({ minInstances: 1 })
+  .https.onRequest(async (req, res) => {
+    const contracts: Contract[] = await getValues(
+      firestore.collection('contracts').orderBy('volume24Hours', 'desc')
+    )
+
+    if (!cache.data || Date.now() - cache.lastUpdated > 120 * 1000) {
+      const contractsInfo = contracts.map(getContractInfo)
+      cache.data = JSON.stringify(contractsInfo)
+      cache.lastUpdated = Date.now()
+    }
+
+    res.status(200).send(cache.data)
+  })
+
+const getContractInfo = ({
+  creatorUsername,
+  creatorName,
+  createdTime,
+  closeTime,
+  question,
+  description,
+  slug,
+  pool,
+  startPool,
+  volume7Days,
+  volume24Hours,
+  isResolved,
+  resolution,
+}: Contract) => {
+  return {
+    creatorUsername,
+    creatorName,
+    createdTime,
+    closeTime,
+    question,
+    description,
+    url: `https://manifold.markets/${creatorUsername}/${slug}`,
+    pool: pool.YES + pool.NO - startPool.YES - startPool.NO,
+    probability: getProbability(pool),
+    volume7Days,
+    volume24Hours,
+    isResolved,
+    resolution,
+  }
+}
+
+const firestore = admin.firestore()