From 12aceef4ca03a504bba3e46ef61d0f81fb7b6ac6 Mon Sep 17 00:00:00 2001
From: Austin Chen <akrolsmir@gmail.com>
Date: Wed, 4 May 2022 11:44:24 -0400
Subject: [PATCH] Allow clients to create manalinks

---
 common/manalink.ts            | 10 ++++-----
 firestore.rules               |  5 +++++
 web/lib/firebase/manalinks.ts | 40 +++++++++++++++++++++++++++++++++++
 web/package.json              |  1 +
 web/pages/send.tsx            | 35 ++++++++++++++++++++++++++++++
 yarn.lock                     |  5 +++++
 6 files changed, 91 insertions(+), 5 deletions(-)
 create mode 100644 web/lib/firebase/manalinks.ts
 create mode 100644 web/pages/send.tsx

diff --git a/common/manalink.ts b/common/manalink.ts
index c48bebe0..9aa2a73f 100644
--- a/common/manalink.ts
+++ b/common/manalink.ts
@@ -1,6 +1,6 @@
 export type Manalink = {
   // The link to send: https://manifold.markets/send/{slug}
-  // Also functions as the unique identifier for the link.
+  // Also functions as the unique id for the link.
   slug: string
 
   // Note: we assume both fromId and toId are of SourceType 'USER'
@@ -11,10 +11,10 @@ export type Manalink = {
   token: 'M$' // TODO: could send eg YES shares too??
 
   createdTime: number
-  // If not set, the link is valid forever
-  expiresTime?: number
-  // If not set, the link can be used infinitely
-  maxUses?: number
+  // If set to Infinity, the link is valid forever
+  expiresTime: number
+  // If set to Infinity, the link can be used infinitely
+  maxUses: number
 
   // Successful redemptions of the link
   successes: Claim[]
diff --git a/firestore.rules b/firestore.rules
index 28e03e64..a24d156a 100644
--- a/firestore.rules
+++ b/firestore.rules
@@ -85,5 +85,10 @@ service cloud.firestore {
     match /txns/{txnId} {
       allow read;
     }
+
+    match /manalinks/{slug} {
+      allow read;
+      allow create, update: if request.auth.uid == request.resource.data.fromId;
+    }
   }
 }
diff --git a/web/lib/firebase/manalinks.ts b/web/lib/firebase/manalinks.ts
new file mode 100644
index 00000000..bd795035
--- /dev/null
+++ b/web/lib/firebase/manalinks.ts
@@ -0,0 +1,40 @@
+import { setDoc } from 'firebase/firestore'
+import { doc } from 'firebase/firestore'
+import { Manalink } from '../../../common/manalink'
+import { db } from './init'
+import { customAlphabet } from 'nanoid'
+
+export async function createManalink(data: {
+  fromId: string
+  amount: number
+  expiresTime: number
+  maxUses: number
+}) {
+  const { fromId, amount, expiresTime, maxUses } = data
+
+  // At 100 IDs per hour, using this alphabet and 8 chars, there's a 1% chance of collision in 2 years
+  // See https://zelark.github.io/nano-id-cc/
+  const nanoid = customAlphabet(
+    '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ',
+    8
+  )
+  const slug = nanoid()
+
+  if (amount <= 0 || isNaN(amount) || !isFinite(amount))
+    return { status: 'error', message: 'Invalid amount' }
+
+  const manalink: Manalink = {
+    slug,
+    fromId,
+    amount,
+    token: 'M$',
+    createdTime: Date.now(),
+    expiresTime,
+    maxUses,
+    successes: [],
+    failures: [],
+  }
+
+  const ref = doc(db, 'manalinks', slug)
+  await setDoc(ref, manalink)
+}
diff --git a/web/package.json b/web/package.json
index d29a01b5..dbc5bfb7 100644
--- a/web/package.json
+++ b/web/package.json
@@ -29,6 +29,7 @@
     "gridjs": "5.0.2",
     "gridjs-react": "5.0.2",
     "lodash": "4.17.21",
+    "nanoid": "^3.3.4",
     "next": "12.1.2",
     "react": "17.0.2",
     "react-confetti": "^6.0.1",
diff --git a/web/pages/send.tsx b/web/pages/send.tsx
new file mode 100644
index 00000000..9408a4c3
--- /dev/null
+++ b/web/pages/send.tsx
@@ -0,0 +1,35 @@
+import { Page } from '../components/page'
+import { SEO } from '../components/SEO'
+import { useUser } from '../hooks/use-user'
+import { createManalink } from '../lib/firebase/manalinks'
+
+export default function SendPage() {
+  const user = useUser()
+
+  return (
+    <Page>
+      <SEO
+        title="Send Mana"
+        description="Send mana to anyone via link!"
+        url="/send"
+      />
+
+      <h1>Send Mana</h1>
+      {user && (
+        <button
+          className="btn"
+          onClick={async () => {
+            await createManalink({
+              fromId: user.id,
+              amount: 1234,
+              expiresTime: Date.now() + 1000 * 60 * 60 * 24 * 7,
+              maxUses: Infinity,
+            })
+          }}
+        >
+          Create a new Manalink
+        </button>
+      )}
+    </Page>
+  )
+}
diff --git a/yarn.lock b/yarn.lock
index dfcb2a69..fe279b5c 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3793,6 +3793,11 @@ nanoid@^3.1.30:
   resolved "https://registry.yarnpkg.com/nanoid/-/nanoid-3.3.2.tgz#c89622fafb4381cd221421c69ec58547a1eec557"
   integrity sha512-CuHBogktKwpm5g2sRgv83jEy2ijFzBwMoYA60orPDR7ynsLijJDqgsi4RDGj3OJpy3Ieb+LYwiRmIOGyytgITA==
 
+nanoid@^3.3.4:
+  version "3.3.4"
+  resolved "https://registry.yarnpkg.com/nanoid/-/nanoid-3.3.4.tgz#730b67e3cd09e2deacf03c027c81c9d9dbc5e8ab"
+  integrity sha512-MqBkQh/OHTS2egovRtLk45wEyNXwF+cokD+1YPf9u5VfJiRdAiRwB2froX5Co9Rh20xs4siNPm8naNotSD6RBw==
+
 natural-compare@^1.4.0:
   version "1.4.0"
   resolved "https://registry.yarnpkg.com/natural-compare/-/natural-compare-1.4.0.tgz#4abebfeed7541f2c27acfb29bdbbd15c8d5ba4f7"