Proper go.work implementation

shiritori/clients/clients.go

@@ -0,0 +1,76 @@
+package clients
+
+import (
+	"fmt"
+
+	"git.elnu.com/ElnuDev/jichanorg/httputils"
+)
+
+type Client = chan []httputils.SseEvent
+
+const EventWord = "word"
+const EventPlayerCount = "players"
+const EventNavigate = "navigate"
+
+type ClientSet struct {
+	clients map[Client]bool
+}
+
+func NewClientSet() ClientSet {
+	return ClientSet{make(map[Client]bool)}
+}
+
+func (clients ClientSet) Broadcast(events ...httputils.SseEvent) {
+	for client := range clients.clients {
+		client <- events
+	}
+}
+
+func (clients ClientSet) PlayerCount() int {
+	return len(clients.clients)
+}
+
+func (clients ClientSet) PlayerCountEvent(offset int) httputils.SseEvent {
+	playerCount := clients.PlayerCount() + offset
+	var data string
+	if playerCount == 0 {
+		data = "No players online."
+	} else {
+		data = fmt.Sprintf("%d player%s online.", playerCount, map[bool]string{true: "", false: "s"}[playerCount == 1])
+	}
+	return httputils.SseEvent{EventName: EventPlayerCount, Data: data}
+}
+
+func (clients ClientSet) BroadcastPlayerCount(offset int) {
+	clients.Broadcast(clients.PlayerCountEvent(offset))
+}
+
+func (clients ClientSet) BroadcastWord(word string) {
+	clients.Broadcast(
+		httputils.SseEvent{
+			EventName: EventWord,
+			Data:      fmt.Sprintf("<div>%s</div>", word),
+		},
+		httputils.SseEvent{
+			EventName: EventNavigate,
+			Data:      fmt.Sprintf("https://jisho.org/search/%s", word),
+		},
+	)
+}
+
+func (clients ClientSet) Connect(client Client) {
+	// Channels are blocking.
+	// Client initialization is waiting for connect() to complete.
+	// If we try to braodcast to it before connect() is done,
+	// the channel handling logic wouldn't have started yet,
+	// and broadcast() would be freeze.
+	// Therefore, we must broadcast an offset player count first,
+	// then actually add the client.
+	clients.BroadcastPlayerCount(1)
+	clients.clients[client] = true
+}
+
+func (clients ClientSet) Disconnect(client Client) {
+	delete(clients.clients, client)
+	clients.BroadcastPlayerCount(0)
+}