basic upnp discovery and cc forwarding

README.md

@@ -7,16 +7,17 @@
 
 # gaspode
 
-`gaspode` is a Go-powered Chromecast toolbox for local playback, live screen sharing, and a compact embedded control UI.
+`gaspode` is a Go-powered Chromecast toolbox for local playback, UPnP-backed media handoff, live screen sharing, and a compact embedded control UI.
 
-It discovers available devices, can stream hosted or uploaded video files, shares full screens or single app windows through an on-the-fly media endpoint, and ships with a browser-based control plane embedded directly into the binary. In practice that means you can send a local or remote video to a TV, use your desktop or a single window as a live Chromecast source, browse host-side media without opening a terminal, and even hand control over to your phone by scanning the built-in QR code for the web UI.
+It discovers available devices, can stream hosted or uploaded video files, can browse a UPnP or DLNA media server and relay one of its videos to Chromecast, shares full screens or single app windows through an on-the-fly media endpoint, and ships with a browser-based control plane embedded directly into the binary. In practice that means you can send a local or remote video to a TV, pick a movie from a media server without leaving the UI, use your desktop or a single app window as a live Chromecast source, browse host-side media without opening a terminal, and even hand control over to your phone by scanning the built-in QR code for the web UI.
 
 ## Features
 
 - Chromecast discovery with mDNS plus network-scan fallback
 - CLI workflows for listing devices, sending media, and sharing screens
-- Embedded web UI for device selection, source picking, audio options, stream control, and QR-based phone handoff
+- Embedded web UI for device selection, source picking, audio options, UPnP browsing, stream control, and QR-based phone handoff
 - Web UI host-file browsing restricted to an explicit media base directory
+- UPnP or DLNA media-server browsing with direct Chromecast relay
 - Local file streaming from the host machine without duplicating large source files
 - Optional compatibility mode for Chromecast-friendlier MP4/H.264/AAC delivery
 - Optional seekable-index creation for local media when Chromecast scrubbing matters
@@ -104,6 +105,8 @@ Open `http://127.0.0.1:11999` after starting the web UI.
 
 If you want to scan the built-in QR code from your phone, bind the web UI to a LAN-reachable address and optionally override the advertised URL with `--web-ui-advertise`.
 
+Inside the web UI you can choose between host-file streaming, uploaded files, UPnP or DLNA media-server browsing, full-screen sharing, and single-window sharing.
+
 ## Example Commands
 
 ```powershell

docs/cli.md

@@ -82,6 +82,11 @@ Meaning:
 - `--web-ui` starts the embedded browser UI on the given listen address
 - `--media-base-path` defines the only directory tree the web UI file browser may access and is required when `--web-ui` is used
 
+Web UI note:
+
+- the embedded UI can also browse UPnP or DLNA media servers on the network and relay selected videos to Chromecast
+- `--media-base-path` does not restrict UPnP browsing because those files are not host-local
+
 ## Discovery Notes
 
 - mDNS discovery is attempted first

docs/web-ui.md

@@ -13,8 +13,9 @@ Then open `http://127.0.0.1:11999`.
 ## What It Can Do
 
 - Discover and select available Chromecasts
-- Switch between video, screen, and window streaming modes
+- Switch between video, UPnP, screen, and window streaming modes
 - Browse video files directly on the host machine
+- Browse videos exposed by a UPnP or DLNA media server
 - Upload a video file through the browser
 - Toggle compatibility mode and optional seekable transcoding
 - Choose latency and audio options for live capture
@@ -32,6 +33,17 @@ Browse files directly on the machine running `gaspode` and stream them without c
 
 Upload a file through the browser. This is useful when the UI is opened from another device and the selected media is not already present on the host.
 
+## UPnP / DLNA
+
+The `UPnP` mode discovers active media servers on the local network, lets you choose one, browse its folders, and relay a selected video to Chromecast.
+
+Important behavior:
+
+- this browser is remote and does not use `--media-base-path`
+- `--media-base-path` still only limits the host-file browser
+- compatibility mode is available here too and proxies the remote media through `gaspode` when Chromecast needs a safer stream
+- seekable-index creation is only available for host-local files, not for remote UPnP items
+
 ## Compatibility Mode
 
 Compatibility mode transcodes video on the fly to a more Chromecast-friendly MP4/H.264/AAC stream.

internal/cli/root.go

@@ -16,6 +16,7 @@ import (
 	"gaspode/internal/chromecast"
 	"gaspode/internal/controlplane"
 	"gaspode/internal/logging"
+	"gaspode/internal/upnp"
 	"gaspode/internal/windowlist"
 
 	"github.com/spf13/cobra"
@@ -45,6 +46,10 @@ type audioDevicesOptions struct {
 	toJSON bool
 }
 
+type upnpScanOptions struct {
+	toJSON bool
+}
+
 type sendOptions struct {
 	mediaURL      string
 	mediaType     string
@@ -139,6 +144,7 @@ func NewRootCmd() *cobra.Command {
 	cmd.PersistentFlags().StringVar(&rootOpts.webUIAdvertise, "web-ui-advertise", "", "Override the advertised web UI URL used by the QR code, for example http://192.168.2.123:11999")
 	cmd.PersistentFlags().StringVar(&rootOpts.mediaBasePath, "media-base-path", "", "Base directory the web UI file browser is allowed to access")
 	cmd.AddCommand(newListCmd(&rootOpts))
+	cmd.AddCommand(newUPNPScanCmd(&rootOpts))
 	cmd.AddCommand(newAudioDevicesCmd())
 	cmd.AddCommand(newSendCmd(&rootOpts))
 	cmd.AddCommand(newScreenCmd(&rootOpts))
@@ -221,6 +227,61 @@ func newAudioDevicesCmd() *cobra.Command {
 	return cmd
 }
 
+// newUPNPScanCmd creates a standalone UPnP or DLNA discovery command.
+func newUPNPScanCmd(rootOpts *rootOptions) *cobra.Command {
+	opts := upnpScanOptions{}
+
+	cmd := &cobra.Command{
+		Use:          "upnp-scan",
+		Short:        "List active UPnP or DLNA media servers on the local network",
+		SilenceUsage: true,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			ctx, cancel := context.WithTimeout(cmd.Context(), rootOpts.timeout)
+			defer cancel()
+
+			var debugWriter io.Writer
+			logger, loggerErr := newLogger(cmd.ErrOrStderr(), rootOpts)
+			if loggerErr == nil && (rootOpts.debugDiscovery || logger.Enabled(logging.LevelDebug)) {
+				debugWriter = cmd.ErrOrStderr()
+			}
+
+			services, err := upnp.DiscoverWithDebug(ctx, debugWriter)
+			if err != nil {
+				services = []upnp.Service{}
+			}
+
+			if opts.toJSON {
+				if services == nil {
+					services = []upnp.Service{}
+				}
+				encoder := json.NewEncoder(cmd.OutOrStdout())
+				encoder.SetIndent("", "  ")
+				return encoder.Encode(services)
+			}
+
+			for _, service := range services {
+				name := strings.TrimSpace(service.FriendlyName)
+				if name == "" {
+					name = strings.TrimSpace(service.ModelName)
+				}
+				if name == "" {
+					name = service.ID
+				}
+				meta := strings.TrimSpace(strings.Join(filterNonEmpty(service.Manufacturer, service.ModelName), " · "))
+				if meta != "" {
+					fmt.Fprintf(cmd.OutOrStdout(), "%s\t%s\t%s\n", name, meta, service.Location)
+					continue
+				}
+				fmt.Fprintf(cmd.OutOrStdout(), "%s\t%s\n", name, service.Location)
+			}
+			return nil
+		},
+	}
+
+	cmd.Flags().BoolVar(&opts.toJSON, "to-json", false, "Print UPnP services as JSON")
+	return cmd
+}
+
 // newSendCmd creates the one-shot media send command.
 func newSendCmd(rootOpts *rootOptions) *cobra.Command {
 	sendOpts := sendOptions{}
@@ -453,3 +514,14 @@ func newLogger(stderr io.Writer, opts *rootOptions) (*logging.Logger, error) {
 	}
 	return logging.New(stderr, level), nil
 }
+
+func filterNonEmpty(values ...string) []string {
+	var result []string
+	for _, value := range values {
+		value = strings.TrimSpace(value)
+		if value != "" {
+			result = append(result, value)
+		}
+	}
+	return result
+}