-
Notifications
You must be signed in to change notification settings - Fork 0
/
main.go
240 lines (211 loc) · 5.63 KB
/
main.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
package main
import (
"context"
"fmt"
"github.com/phonero/lime"
"go.uber.org/multierr"
"log"
"math/rand"
"net"
"net/http"
"os"
"os/signal"
"strconv"
"strings"
"sync"
)
var channels = make(map[string]*lime.ServerChannel)
var nodesToID = make(map[string]string)
var mu sync.RWMutex
var nodeFriends = make(map[string][]string)
func main() {
server := lime.NewServerBuilder().
// Handler for registering new user sessions
Register(func(ctx context.Context, candidate lime.Node, c *lime.ServerChannel) (lime.Node, error) {
mu.Lock()
defer mu.Unlock()
// Detect and resolve name collisions
name := candidate.Name
for {
if _, ok := nodesToID[candidate.Name]; ok {
candidate.Name = name + strconv.Itoa(rand.Intn(len(nodesToID)*10))
} else {
break
}
}
// Register a new established user session
sessionID := c.ID()
channels[sessionID] = c
nodesToID[candidate.Name] = sessionID
return candidate, nil
}).
// Callback for finished sessions, useful for updating our online users map
Finished(func(sessionID string) {
mu.Lock()
defer mu.Unlock()
// Remove a finished session
if channel, ok := channels[sessionID]; ok {
delete(nodesToID, channel.RemoteNode().Name)
delete(channels, sessionID)
}
}).
// Handler for all messages received by the server
MessagesHandlerFunc(handleMessage).
// Handler for commands with the "/friends" resource
RequestCommandHandlerFunc(
func(cmd *lime.RequestCommand) bool {
uri := cmd.URI.URL()
return cmd.ID != "" && strings.HasPrefix(uri.Path, "/friends")
},
handleFriendsCommand).
// Listen using the websocket transport in the 8080 port
ListenWebsocket(
&net.TCPAddr{Port: 8080},
&lime.WebsocketConfig{
CheckOrigin: func(r *http.Request) bool {
return true
}}).
EnableGuestAuthentication().
Build()
sig := make(chan os.Signal)
go func() {
if err := server.ListenAndServe(); err != lime.ErrServerClosed {
log.Printf("server: listen: %v\n", err)
close(sig)
}
}()
signal.Notify(sig)
log.Println("Listening at ws:8080. Press Ctrl+C to stop.")
<-sig
if err := server.Close(); err != nil {
log.Printf("server: close: %v\n", err)
}
}
func handleMessage(ctx context.Context, msg *lime.Message, _ lime.Sender) error {
mu.RLock()
defer mu.RUnlock()
var err error
// Check if it is a direct message to another user
if msg.To.Name != "" {
if sessionID, ok := nodesToID[msg.To.Name]; ok {
if c, ok := channels[sessionID]; ok {
err = c.SendMessage(ctx, msg)
}
}
} else {
// Broadcast the message to all others sessions
senderSessionID, _ := lime.ContextSessionID(ctx)
for id, c := range channels {
if id != senderSessionID {
err = multierr.Append(err, c.SendMessage(ctx, msg))
}
}
}
return err
}
func handleFriendsCommand(ctx context.Context, cmd *lime.RequestCommand, s lime.Sender) error {
node, _ := lime.ContextSessionRemoteNode(ctx)
var respCmd *lime.ResponseCommand
switch cmd.Method {
case lime.CommandMethodGet:
respCmd = getFriends(node, cmd)
case lime.CommandMethodSet:
respCmd = addFriend(cmd, node)
case lime.CommandMethodDelete:
respCmd = removeFriend(cmd, node)
default:
respCmd = cmd.FailureResponse(&lime.Reason{
Code: 1,
Description: "Unsupported method",
})
}
return s.SendResponseCommand(ctx, respCmd)
}
func getFriends(node lime.Node, cmd *lime.RequestCommand) *lime.ResponseCommand {
var respCmd *lime.ResponseCommand
if friends, ok := nodeFriends[node.Name]; ok {
items := make([]lime.Document, len(friends))
for i, f := range friends {
_, online := nodesToID[f]
items[i] = &Friend{
Nickname: f,
Online: online,
}
}
respCmd = cmd.SuccessResponseWithResource(
&lime.DocumentCollection{
Total: len(friends),
ItemType: friendMediaType,
Items: items,
})
} else {
respCmd = cmd.FailureResponse(&lime.Reason{
Code: 1,
Description: "No friends found",
})
}
return respCmd
}
func addFriend(cmd *lime.RequestCommand, node lime.Node) *lime.ResponseCommand {
var respCmd *lime.ResponseCommand
if f, ok := cmd.Resource.(*Friend); ok {
friends := nodeFriends[node.Name]
friends = append(friends, f.Nickname)
nodeFriends[node.Name] = friends
respCmd = cmd.SuccessResponse()
} else {
respCmd = cmd.FailureResponse(&lime.Reason{
Code: 1,
Description: fmt.Sprintf("Unexpected resource type, should be '%v'", friendMediaType.String()),
})
}
return respCmd
}
func removeFriend(cmd *lime.RequestCommand, node lime.Node) *lime.ResponseCommand {
var respCmd *lime.ResponseCommand
url := cmd.URI.URL()
segments := strings.Split(url.Path, "/")
if len(segments) >= 2 {
friends := nodeFriends[node.Name]
toRemove := -1
for i, f := range friends {
if string(f) == segments[1] {
toRemove = i
break
}
}
if toRemove >= 0 {
friends = append(friends[:toRemove], friends[toRemove+1:]...)
nodeFriends[node.Name] = friends
respCmd = cmd.SuccessResponse()
} else {
respCmd = cmd.FailureResponse(&lime.Reason{
Code: 1,
Description: fmt.Sprintf("Friend '%v' not found", segments[1]),
})
}
} else {
respCmd = cmd.FailureResponse(&lime.Reason{
Code: 1,
Description: "Invalid URI, should be '/friends/<nickname>'",
})
}
return respCmd
}
type Friend struct {
Nickname string `json:"nickname"`
Online bool `json:"online,omitempty"`
}
var friendMediaType = lime.MediaType{
Type: "application",
Subtype: "x-chat-friend",
Suffix: "json",
}
func (f *Friend) MediaType() lime.MediaType {
return friendMediaType
}
func init() {
lime.RegisterDocumentFactory(func() lime.Document {
return &Friend{}
})
}