Initial import.

conn/xmpp/config.go

@@ -0,0 +1,29 @@
+package xmpp
+
+import (
+	"fmt"
+	"strings"
+
+	"gosrc.io/xmpp"
+)
+
+type Config struct {
+	Account  string `yaml:"account"`
+	Password string `yaml:"password"`
+}
+
+func (c *Config) xmppConfig() (*xmpp.Config, error) {
+	parts := strings.SplitN(c.Account, "@", 2)
+	if len(parts) != 2 {
+		return nil, fmt.Errorf("xmpp: invalid account '%s'", c.Account)
+	}
+
+	server := parts[1] + ":5222"
+	return &xmpp.Config{
+		TransportConfiguration: xmpp.TransportConfiguration{
+			Address: server,
+		},
+		Jid:        c.Account,
+		Credential: xmpp.Password(c.Password),
+	}, nil
+}

conn/xmpp/xmpp.go

@@ -0,0 +1,78 @@
+package xmpp
+
+import (
+	"context"
+	"fmt"
+	"kas/cps"
+	"log"
+
+	"gosrc.io/xmpp"
+	"gosrc.io/xmpp/stanza"
+)
+
+func messageHandler(s xmpp.Sender, p stanza.Packet) {
+	msg, ok := p.(stanza.Message)
+	if !ok {
+		log.Print("xmpp: ignore packet %T", p)
+		return
+	}
+
+	response, err := cps.Handle(context.Background(), msg.Body)
+	if err != nil {
+		err = fmt.Errorf("xmpp message handler: %w", err)
+		log.Print(err)
+	}
+
+	reply := stanza.Message{
+		Attrs: stanza.Attrs{
+			To: msg.From,
+		},
+		Body: response.String(),
+	}
+
+	err = s.Send(reply)
+	if err != nil {
+		log.Printf("xmpp: failed to send reply to %s: %s",
+			msg.From, err)
+	}
+}
+
+func logError(err error) {
+	err = fmt.Errorf("xmpp: %w", err)
+	log.Print(err)
+}
+
+func Start(cfg *Config) error {
+	log.Printf("starting XMPP server for %s", cfg.Account)
+	config, err := cfg.xmppConfig()
+	if err != nil {
+		return err
+	}
+
+	go func() {
+		for {
+			// TODO: what happens if we ask the bot to stop?
+			// Best answer: systemd service.
+			runClient(config)
+		}
+	}()
+
+	return nil
+}
+
+func runClient(cfg *xmpp.Config) {
+	router := xmpp.NewRouter()
+	router.HandleFunc("message", messageHandler)
+
+	client, err := xmpp.NewClient(cfg, router, logError)
+	if err != nil {
+		logError(err)
+		return
+	}
+
+	// If you pass the client to a connection manager, it will handle the reconnect policy
+	// for you automatically.
+	cm := xmpp.NewStreamManager(client, nil)
+
+	log.Print(cm.Run())
+}