From 27a544205f3f03077c27ea70527a35085c852405 Mon Sep 17 00:00:00 2001
From: Ian Philips <iansphilips@gmail.com>
Date: Thu, 14 Jul 2022 11:09:28 -0600
Subject: [PATCH] Optimistically join groups

---
 web/components/groups/groups-button.tsx | 31 ++++++++++++++++++-------
 web/lib/firebase/groups.ts              | 27 +++++++--------------
 web/pages/group/[...slugs]/index.tsx    | 10 ++++----
 3 files changed, 36 insertions(+), 32 deletions(-)

diff --git a/web/components/groups/groups-button.tsx b/web/components/groups/groups-button.tsx
index b81155d1..f3ae77a2 100644
--- a/web/components/groups/groups-button.tsx
+++ b/web/components/groups/groups-button.tsx
@@ -1,6 +1,6 @@
 import clsx from 'clsx'
 import { User } from 'common/user'
-import { useState } from 'react'
+import { useEffect, useState } from 'react'
 import { useUser } from 'web/hooks/use-user'
 import { withTracking } from 'web/lib/service/analytics'
 import { Row } from 'web/components/layout/row'
@@ -9,9 +9,10 @@ import { TextButton } from 'web/components/text-button'
 import { Group } from 'common/group'
 import { Modal } from 'web/components/layout/modal'
 import { Col } from 'web/components/layout/col'
-import { addUserToGroup, leaveGroup } from 'web/lib/firebase/groups'
+import { joinGroup, leaveGroup } from 'web/lib/firebase/groups'
 import { firebaseLogin } from 'web/lib/firebase/users'
 import { GroupLink } from 'web/pages/groups'
+import toast from 'react-hot-toast'
 
 export function GroupsButton(props: { user: User }) {
   const { user } = props
@@ -88,22 +89,34 @@ export function JoinOrLeaveGroupButton(props: {
 }) {
   const { group, small, className } = props
   const currentUser = useUser()
-  const isFollowing = currentUser
-    ? group.memberIds.includes(currentUser.id)
-    : false
+  const [isMember, setIsMember] = useState<boolean>(false)
+  useEffect(() => {
+    if (currentUser && group.memberIds.includes(currentUser.id)) {
+      setIsMember(group.memberIds.includes(currentUser.id))
+    }
+  }, [currentUser, group])
+
   const onJoinGroup = () => {
     if (!currentUser) return
-    addUserToGroup(group, currentUser.id)
+    setIsMember(true)
+    joinGroup(group, currentUser.id).catch(() => {
+      setIsMember(false)
+      toast.error('Failed to join group')
+    })
   }
   const onLeaveGroup = () => {
     if (!currentUser) return
-    leaveGroup(group, currentUser.id)
+    setIsMember(false)
+    leaveGroup(group, currentUser.id).catch(() => {
+      setIsMember(true)
+      toast.error('Failed to leave group')
+    })
   }
 
   const smallStyle =
     'btn !btn-xs border-2 border-gray-500 bg-white normal-case text-gray-500 hover:border-gray-500 hover:bg-white hover:text-gray-500'
 
-  if (!currentUser || isFollowing === undefined) {
+  if (!currentUser || isMember === undefined) {
     if (!group.anyoneCanJoin)
       return <div className={clsx(className, 'text-gray-500')}>Closed</div>
     return (
@@ -116,7 +129,7 @@ export function JoinOrLeaveGroupButton(props: {
     )
   }
 
-  if (isFollowing) {
+  if (isMember) {
     return (
       <button
         className={clsx(
diff --git a/web/lib/firebase/groups.ts b/web/lib/firebase/groups.ts
index 762bfab1..6d695b7f 100644
--- a/web/lib/firebase/groups.ts
+++ b/web/lib/firebase/groups.ts
@@ -87,32 +87,23 @@ export async function addUserToGroupViaSlug(groupSlug: string, userId: string) {
     console.error(`Group not found: ${groupSlug}`)
     return
   }
-  return await addUserToGroup(group, userId)
+  return await joinGroup(group, userId)
 }
 
-export async function addUserToGroup(
-  group: Group,
-  userId: string
-): Promise<Group> {
+export async function joinGroup(group: Group, userId: string): Promise<void> {
   const { memberIds } = group
-  if (memberIds.includes(userId)) {
-    return group
-  }
+  if (memberIds.includes(userId)) return // already a member
+
   const newMemberIds = [...memberIds, userId]
-  const newGroup = { ...group, memberIds: newMemberIds }
-  await updateGroup(newGroup, { memberIds: uniq(newMemberIds) })
-  return newGroup
+  return await updateGroup(group, { memberIds: uniq(newMemberIds) })
 }
 
-export async function leaveGroup(group: Group, userId: string): Promise<Group> {
+export async function leaveGroup(group: Group, userId: string): Promise<void> {
   const { memberIds } = group
-  if (!memberIds.includes(userId)) {
-    return group
-  }
+  if (!memberIds.includes(userId)) return // not a member
+
   const newMemberIds = memberIds.filter((id) => id !== userId)
-  const newGroup = { ...group, memberIds: newMemberIds }
-  await updateGroup(newGroup, { memberIds: uniq(newMemberIds) })
-  return newGroup
+  return await updateGroup(group, { memberIds: uniq(newMemberIds) })
 }
 
 export async function addContractToGroup(group: Group, contract: Contract) {
diff --git a/web/pages/group/[...slugs]/index.tsx b/web/pages/group/[...slugs]/index.tsx
index c00a8e29..a364de43 100644
--- a/web/pages/group/[...slugs]/index.tsx
+++ b/web/pages/group/[...slugs]/index.tsx
@@ -8,7 +8,7 @@ import {
   groupPath,
   getGroupBySlug,
   updateGroup,
-  addUserToGroup,
+  joinGroup,
   addContractToGroup,
 } from 'web/lib/firebase/groups'
 import { Row } from 'web/components/layout/row'
@@ -604,19 +604,19 @@ function JoinGroupButton(props: {
   user: User | null | undefined
 }) {
   const { group, user } = props
-  function joinGroup() {
+  function addUserToGroup() {
     if (user && !group.memberIds.includes(user.id)) {
-      toast.promise(addUserToGroup(group, user.id), {
+      toast.promise(joinGroup(group, user.id), {
         loading: 'Joining group...',
         success: 'Joined group!',
-        error: "Couldn't join group",
+        error: "Couldn't join group, try again?",
       })
     }
   }
   return (
     <div>
       <button
-        onClick={user ? joinGroup : firebaseLogin}
+        onClick={user ? addUserToGroup : firebaseLogin}
         className={'btn-md btn-outline btn whitespace-nowrap normal-case'}
       >
         {user ? 'Join group' : 'Login to join group'}