Fix chromecast support

go.mod

@@ -37,6 +37,7 @@ require (
 	github.com/charmbracelet/x/ansi v0.11.7 // indirect
 	github.com/charmbracelet/x/cellbuf v0.0.15 // indirect
 	github.com/charmbracelet/x/term v0.2.2 // indirect
+	github.com/cenkalti/backoff v2.2.1+incompatible // indirect
 	github.com/chromedp/sysutil v1.1.0 // indirect
 	github.com/clipperhouse/displaywidth v0.11.0 // indirect
 	github.com/clipperhouse/stringish v0.1.1 // indirect
@@ -53,13 +54,15 @@ require (
 	github.com/gobwas/pool v0.2.1 // indirect
 	github.com/gobwas/ws v1.4.0 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
+	github.com/grandcat/zeroconf v1.0.0 // indirect
 	github.com/h2non/filetype v1.1.3 // indirect
 	github.com/knadh/koanf/maps v0.1.2 // indirect
 	github.com/leodido/go-urn v1.4.0 // indirect
 	github.com/lucasb-eyer/go-colorful v1.4.0 // indirect
 	github.com/mattn/go-isatty v0.0.23 // indirect
 	github.com/mattn/go-localereader v0.0.1 // indirect
 	github.com/mattn/go-runewidth v0.0.24 // indirect
+	github.com/miekg/dns v1.1.62 // indirect
 	github.com/mitchellh/copystructure v1.2.0 // indirect
 	github.com/mitchellh/go-homedir v1.1.0 // indirect
 	github.com/mitchellh/reflectwalk v1.0.2 // indirect
@@ -75,6 +78,7 @@ require (
 	golang.org/x/crypto v0.54.0 // indirect
 	golang.org/x/exp v0.0.0-20260718201538-764159d718ef // indirect
 	golang.org/x/image v0.44.0 // indirect
+	golang.org/x/net v0.57.0 // indirect
 	golang.org/x/sys v0.47.0 // indirect
 	golang.org/x/text v0.40.0 // indirect
 	gopkg.in/ini.v1 v1.67.3 // indirect

internal/device/chromecast.go

@@ -3,9 +3,13 @@ package device
 import (
 	"context"
 	"fmt"
+	"log/slog"
+	"net"
 	"net/url"
+	"strconv"
 
 	"github.com/vishen/go-chromecast/application"
+	castdns "github.com/vishen/go-chromecast/dns"
 
 	"github.com/stupside/castor/internal/media"
 )
@@ -18,17 +22,80 @@ type chromecastDevice struct {
 
 // connectChromecast opens the cast application channel. The underlying
 // library's Start has no context support, so cancellation cannot interrupt
-// the dial.
+// the dial. Address may be a bare host (default port 8009) or host:port as
+// produced by discovery; cast groups advertise on non-default ports.
 func connectChromecast(info Info) (Device, error) {
+	host := info.Address
+	port := chromecastPort
+	if h, p, err := net.SplitHostPort(info.Address); err == nil {
+		if n, err := strconv.Atoi(p); err == nil {
+			host, port = h, n
+		}
+	}
+
 	app := application.NewApplication(
 		application.WithCacheDisabled(true),
 	)
-	if err := app.Start(info.Address, chromecastPort); err != nil {
+	if err := app.Start(host, port); err != nil {
 		return nil, fmt.Errorf("connecting to chromecast: %w", err)
 	}
 	return &chromecastDevice{app: app}, nil
 }
 
+// discoverChromecast browses mDNS (_googlecast._tcp) for cast devices until
+// ctx expires. The entries channel is closed by the library when ctx is done,
+// so ranging over it consumes the full discovery window.
+func discoverChromecast(ctx context.Context) []Info {
+	entries, err := castdns.DiscoverCastDNSEntries(ctx, nil)
+	if err != nil {
+		slog.WarnContext(ctx, "chromecast discovery error", "error", err)
+		return nil
+	}
+
+	var devices []Info
+	seen := make(map[string]struct{})
+	for entry := range entries {
+		var host string
+		switch {
+		case entry.AddrV4 != nil:
+			host = entry.AddrV4.String()
+		case entry.AddrV6 != nil:
+			host = entry.AddrV6.String()
+		default:
+			continue
+		}
+
+		key := entry.UUID
+		if key == "" {
+			key = host + ":" + strconv.Itoa(entry.Port)
+		}
+		if _, ok := seen[key]; ok {
+			continue
+		}
+		seen[key] = struct{}{}
+
+		name := entry.DeviceName
+		if name == "" {
+			name = entry.Name
+		}
+		if name == "" {
+			name = entry.Host
+		}
+
+		address := host
+		if entry.Port > 0 && entry.Port != chromecastPort {
+			address = net.JoinHostPort(host, strconv.Itoa(entry.Port))
+		}
+
+		devices = append(devices, Info{
+			Name:    name,
+			Type:    TypeChromecast,
+			Address: address,
+		})
+	}
+	return devices
+}
+
 func (c *chromecastDevice) Play(_ context.Context, streamURL *url.URL, contentType string) error {
 	if err := c.app.Load(streamURL.String(), 0, contentType, false, true, true); err != nil {
 		return fmt.Errorf("starting chromecast playback: %w", err)

internal/device/device.go

@@ -10,6 +10,7 @@ import (
 	"log/slog"
 	"net/url"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/huin/goupnp"
@@ -68,17 +69,44 @@ func FindInfo(ctx context.Context, timeout time.Duration, dtype Type, name strin
 	return Info{}, fmt.Errorf("device %q (type %s) not found", name, dtype)
 }
 
-// Discover scans the local network for DLNA renderers. (Chromecast discovery
-// requires mDNS which the current dependency set doesn't ship; callers
-// connect to known Chromecast addresses directly.)
+// Discover scans the local network for renderers: DLNA via SSDP and
+// Chromecast via mDNS (_googlecast._tcp). Both scans run in parallel and
+// share the same timeout window.
 func Discover(ctx context.Context, timeout time.Duration) ([]Info, error) {
 	ctx, cancel := context.WithTimeout(ctx, timeout)
 	defer cancel()
 
+	var (
+		wg      sync.WaitGroup
+		mu      sync.Mutex
+		devices []Info
+	)
+	collect := func(found []Info) {
+		mu.Lock()
+		devices = append(devices, found...)
+		mu.Unlock()
+	}
+
+	wg.Add(2)
+	go func() {
+		defer wg.Done()
+		collect(discoverDLNA(ctx))
+	}()
+	go func() {
+		defer wg.Done()
+		collect(discoverChromecast(ctx))
+	}()
+	wg.Wait()
+
+	return devices, nil
+}
+
+// discoverDLNA scans for UPnP MediaRenderer devices via SSDP.
+func discoverDLNA(ctx context.Context) []Info {
 	results, err := goupnp.DiscoverDevicesCtx(ctx, "urn:schemas-upnp-org:device:MediaRenderer:1")
 	if err != nil {
 		slog.WarnContext(ctx, "DLNA discovery error", "error", err)
-		return nil, nil
+		return nil
 	}
 
 	devices := make([]Info, 0, len(results))
@@ -92,5 +120,5 @@ func Discover(ctx context.Context, timeout time.Duration) ([]Info, error) {
 			Address: r.Location.String(),
 		})
 	}
-	return devices, nil
+	return devices
 }