member_grouping.gno

 1package commondao
 2
 3import (
 4	"errors"
 5
 6	"gno.land/p/nt/avl"
 7)
 8
 9// MemberGrouping defines an interface for storing multiple member groups.
10// Member grouping can be used by implementations that require grouping users
11// by roles or by tiers for example.
12type MemberGrouping interface {
13	// Size returns the number of groups that grouping contains.
14	Size() int
15
16	// Has checks if a group exists.
17	Has(name string) bool
18
19	// Add adds an new member group if it doesn't exists.
20	Add(name string) (MemberGroup, error)
21
22	// Get returns a member group.
23	Get(name string) (_ MemberGroup, found bool)
24
25	// Delete deletes a member group.
26	Delete(name string) error
27
28	// IterateByOffset iterates all member groups.
29	IterateByOffset(offset, count int, fn func(MemberGroup) bool)
30}
31
32// NewMemberGrouping creates a new members grouping.
33func NewMemberGrouping(options ...MemberGroupingOption) MemberGrouping {
34	g := &memberGrouping{
35		createStorage: func(string) MemberStorage { return NewMemberStorage() },
36	}
37
38	for _, apply := range options {
39		apply(g)
40	}
41	return g
42}
43
44type memberGrouping struct {
45	groups        avl.Tree // string(name) -> MemberGroup
46	createStorage func(group string) MemberStorage
47}
48
49// Size returns the number of groups that grouping contains.
50func (g memberGrouping) Size() int {
51	return g.groups.Size()
52}
53
54// Has checks if a group exists.
55func (g memberGrouping) Has(name string) bool {
56	return g.groups.Has(name)
57}
58
59// Add adds an new member group if it doesn't exists.
60func (g *memberGrouping) Add(name string) (MemberGroup, error) {
61	if g.groups.Has(name) {
62		return nil, errors.New("member group already exists: " + name)
63	}
64
65	mg, err := NewMemberGroup(name, g.createStorage(name))
66	if err != nil {
67		return nil, err
68	}
69
70	g.groups.Set(name, mg)
71	return mg, nil
72}
73
74// Get returns a member group.
75func (g memberGrouping) Get(name string) (_ MemberGroup, found bool) {
76	v, found := g.groups.Get(name)
77	if !found {
78		return nil, false
79	}
80	return v.(MemberGroup), true
81}
82
83// Delete deletes a member group.
84func (g *memberGrouping) Delete(name string) error {
85	g.groups.Remove(name)
86	return nil
87}
88
89// IterateByOffset iterates all member groups.
90func (g memberGrouping) IterateByOffset(offset, count int, fn func(MemberGroup) bool) {
91	g.groups.IterateByOffset(offset, count, func(_ string, v any) bool {
92		return fn(v.(MemberGroup))
93	})
94}