From effb5d9f2db2a5a9041ddf196d8c43ad9ab09372 Mon Sep 17 00:00:00 2001
From: Jan Svabenik <jan@svabi.ch>
Date: Wed, 18 Mar 2026 07:38:51 +0100
Subject: [PATCH] Add on-demand decode endpoint

---
 cmd/sdrd/main.go                      | 20 ++++++++++++++++++++
 internal/recorder/decode_on_demand.go | 14 ++++++++++++++
 internal/recorder/readmeta.go         | 18 ++++++++++++++++++
 3 files changed, 52 insertions(+)
 create mode 100644 internal/recorder/decode_on_demand.go
 create mode 100644 internal/recorder/readmeta.go

diff --git a/cmd/sdrd/main.go b/cmd/sdrd/main.go
index 31640e0..9f0ae22 100644
--- a/cmd/sdrd/main.go
+++ b/cmd/sdrd/main.go
@@ -524,6 +524,26 @@ func main() {
 			http.ServeFile(w, r, filepath.Join(base, "signal.cf32"))
 			return
 		}
+		if r.URL.Path == "/api/recordings/"+id+"/decode" {
+			mode := r.URL.Query().Get("mode")
+			cmd := buildDecoderMap(cfgManager.Snapshot())[mode]
+			if cmd == "" {
+				http.Error(w, "decoder not configured", http.StatusBadRequest)
+				return
+			}
+			meta, err := recorder.ReadMeta(filepath.Join(base, "meta.json"))
+			if err != nil {
+				http.Error(w, "meta read failed", http.StatusInternalServerError)
+				return
+			}
+			res, err := recorder.DecodeOnDemand(cmd, filepath.Join(base, "signal.cf32"), meta.SampleRate)
+			if err != nil {
+				http.Error(w, res.Stderr, http.StatusInternalServerError)
+				return
+			}
+			_ = json.NewEncoder(w).Encode(res)
+			return
+		}
 		// default: meta.json
 		http.ServeFile(w, r, filepath.Join(base, "meta.json"))
 	})
diff --git a/internal/recorder/decode_on_demand.go b/internal/recorder/decode_on_demand.go
new file mode 100644
index 0000000..96fdaa2
--- /dev/null
+++ b/internal/recorder/decode_on_demand.go
@@ -0,0 +1,14 @@
+package recorder
+
+import (
+	"errors"
+
+	"sdr-visual-suite/internal/decoder"
+)
+
+func DecodeOnDemand(cmd string, iqPath string, sampleRate int) (decoder.Result, error) {
+	if cmd == "" {
+		return decoder.Result{}, errors.New("decoder command empty")
+	}
+	return decoder.Run(cmd, iqPath, sampleRate)
+}
diff --git a/internal/recorder/readmeta.go b/internal/recorder/readmeta.go
new file mode 100644
index 0000000..e82c6fc
--- /dev/null
+++ b/internal/recorder/readmeta.go
@@ -0,0 +1,18 @@
+package recorder
+
+import (
+	"encoding/json"
+	"os"
+)
+
+func ReadMeta(path string) (Meta, error) {
+	b, err := os.ReadFile(path)
+	if err != nil {
+		return Meta{}, err
+	}
+	var m Meta
+	if err := json.Unmarshal(b, &m); err != nil {
+		return Meta{}, err
+	}
+	return m, nil
+}