Set up a read API using Vercel serverless functions (#49)

* Set up read API using Vercel serverless functions

Featuring:
/api/v0/markets
/api/v0/market/[contractId]
/api/v0/slug/[contractSlug]

* Include tags in API

web/pages/api/hello.ts

@@ -1,13 +0,0 @@
-// Next.js API route support: https://nextjs.org/docs/api-routes/introduction
-import type { NextApiRequest, NextApiResponse } from 'next'
-
-type Data = {
-  name: string
-}
-
-export default function handler(
-  req: NextApiRequest,
-  res: NextApiResponse<Data>
-) {
-  res.status(200).json({ name: 'John Doe' })
-}

web/pages/api/v0/_types.ts

@@ -0,0 +1,67 @@
+import { Bet } from '../../../../common/bet'
+import { getProbability } from '../../../../common/calculate'
+import { Comment } from '../../../../common/comment'
+import { Contract } from '../../../../common/contract'
+
+export type LiteContract = {
+  id: string
+  creatorUsername: string
+  creatorName: string
+  createdTime: number
+  closeTime?: number
+  question: string
+  description: string
+  tags: string[]
+  url: string
+  pool: number
+  probability: number
+  volume7Days: number
+  volume24Hours: number
+  isResolved: boolean
+  resolution?: string
+}
+
+export type FullContract = LiteContract & {
+  bets: Bet[]
+  comments: Comment[]
+}
+
+export type ApiError = {
+  error: string
+}
+
+export function toLiteContract({
+  id,
+  creatorUsername,
+  creatorName,
+  createdTime,
+  closeTime,
+  question,
+  description,
+  tags,
+  slug,
+  pool,
+  totalShares,
+  volume7Days,
+  volume24Hours,
+  isResolved,
+  resolution,
+}: Contract): LiteContract {
+  return {
+    id,
+    creatorUsername,
+    creatorName,
+    createdTime,
+    closeTime,
+    question,
+    description,
+    tags,
+    url: `https://manifold.markets/${creatorUsername}/${slug}`,
+    pool: pool.YES + pool.NO,
+    probability: getProbability(totalShares),
+    volume7Days,
+    volume24Hours,
+    isResolved,
+    resolution,
+  }
+}

web/pages/api/v0/market/[id].ts

@@ -0,0 +1,32 @@
+import { NextApiRequest, NextApiResponse } from 'next'
+import { listAllBets } from '../../../../lib/firebase/bets'
+import { listAllComments } from '../../../../lib/firebase/comments'
+import { getContractFromId } from '../../../../lib/firebase/contracts'
+import { FullContract, ApiError, toLiteContract } from '../_types'
+
+export default async function handler(
+  req: NextApiRequest,
+  res: NextApiResponse<FullContract | ApiError>
+) {
+  const { id } = req.query
+  const contractId = id as string
+
+  const [contract, bets, comments] = await Promise.all([
+    getContractFromId(contractId),
+    listAllBets(contractId),
+    listAllComments(contractId),
+  ])
+
+  if (!contract) {
+    res.status(404).json({ error: 'Contract not found' })
+    return
+  }
+
+  // Cache on Vercel edge servers for 2min
+  res.setHeader('Cache-Control', 'max-age=0, s-maxage=120')
+  return res.status(200).json({
+    ...toLiteContract(contract),
+    bets,
+    comments,
+  })
+}

web/pages/api/v0/markets.ts

@@ -0,0 +1,16 @@
+// Next.js API route support: https://vercel.com/docs/concepts/functions/serverless-functions
+import type { NextApiRequest, NextApiResponse } from 'next'
+import { listAllContracts } from '../../../lib/firebase/contracts'
+import { toLiteContract } from './_types'
+
+type Data = any[]
+
+export default async function handler(
+  req: NextApiRequest,
+  res: NextApiResponse<Data>
+) {
+  const contracts = await listAllContracts()
+  // Serve from Vercel cache, then update. see https://vercel.com/docs/concepts/functions/edge-caching
+  res.setHeader('Cache-Control', 's-maxage=1, stale-while-revalidate')
+  res.status(200).json(contracts.map(toLiteContract))
+}

web/pages/api/v0/slug/[slug].ts

@@ -0,0 +1,32 @@
+import { NextApiRequest, NextApiResponse } from 'next'
+import { listAllBets } from '../../../../lib/firebase/bets'
+import { listAllComments } from '../../../../lib/firebase/comments'
+import { getContractFromSlug } from '../../../../lib/firebase/contracts'
+import { FullContract, ApiError, toLiteContract } from '../_types'
+
+export default async function handler(
+  req: NextApiRequest,
+  res: NextApiResponse<FullContract | ApiError>
+) {
+  const { slug } = req.query
+
+  const contract = await getContractFromSlug(slug as string)
+
+  if (!contract) {
+    res.status(404).json({ error: 'Contract not found' })
+    return
+  }
+
+  const [bets, comments] = await Promise.all([
+    listAllBets(contract.id),
+    listAllComments(contract.id),
+  ])
+
+  // Cache on Vercel edge servers for 2min
+  res.setHeader('Cache-Control', 'max-age=0, s-maxage=120')
+  return res.status(200).json({
+    ...toLiteContract(contract),
+    bets,
+    comments,
+  })
+}