userbook.gno

 1// Package userbook demonstrates a small userbook system working with gnoweb
 2package userbook
 3
 4import (
 5	"chain"
 6	"chain/runtime"
 7	"time"
 8
 9	"gno.land/p/nt/avl"
10	"gno.land/p/nt/seqid"
11	"gno.land/p/nt/ufmt"
12)
13
14type Signup struct {
15	address_XXX address
16	ordinal     int
17	timestamp   time.Time
18}
19
20var (
21	signupsTree = avl.NewTree()
22	tracker     = avl.NewTree()
23	idCounter   seqid.ID
24)
25
26const signUpEvent = "SignUp"
27
28func init() {
29	SignUp(cross) // Sign up the deployer
30}
31
32func SignUp(cur realm) string {
33	// Get transaction caller
34	caller := runtime.PreviousRealm().Address()
35
36	// Check if the user is already signed up
37	if _, exists := tracker.Get(caller.String()); exists {
38		panic(caller.String() + " is already signed up!")
39	}
40
41	now := time.Now()
42
43	// Sign up the user
44	signupsTree.Set(idCounter.Next().String(), &Signup{
45		caller,
46		signupsTree.Size(),
47		now,
48	})
49
50	tracker.Set(caller.String(), struct{}{})
51
52	chain.Emit(signUpEvent, "account", caller.String())
53
54	return ufmt.Sprintf("%s added to userbook! Timestamp: %s", caller.String(), now.Format(time.RFC822Z))
55}