From ce25751c5d3d5204443995186e4ff40efab3c06d Mon Sep 17 00:00:00 2001
From: Stan Grams <sjg@haxx.space>
Date: Sat, 28 Feb 2026 16:41:25 +0100
Subject: [PATCH] [feat](trx-rds,trx-frontend-http): add af tuning and dynamic
 page title

Co-authored-by: Codex <codex@openai.com>
Signed-off-by: Stan Grams <sjg@haxx.space>
---
 src/decoders/trx-rds/src/lib.rs               | 45 ++++++++++++
 .../trx-frontend-http/assets/web/app.js       | 71 ++++++++++++++++++-
 .../trx-frontend-http/assets/web/index.html   |  1 +
 .../trx-frontend-http/assets/web/style.css    | 15 ++++
 src/trx-core/src/rig/state.rs                 |  2 +
 5 files changed, 132 insertions(+), 2 deletions(-)

diff --git a/src/decoders/trx-rds/src/lib.rs b/src/decoders/trx-rds/src/lib.rs
index 3bc58a6..4830069 100644
--- a/src/decoders/trx-rds/src/lib.rs
+++ b/src/decoders/trx-rds/src/lib.rs
@@ -305,6 +305,12 @@ impl Candidate {
         let group_type = ((block_b >> 12) & 0x0f) as u8;
         let version_b = ((block_b >> 11) & 0x1) != 0;
         if group_type == 0 {
+            if !version_b && block_c_kind == BlockKind::C {
+                let [af0, af1] = block_c.to_be_bytes();
+                if self.process_af_pair(af0, af1) {
+                    changed = true;
+                }
+            }
             let ta = ((block_b >> 4) & 0x1) != 0;
             if self.state.traffic_announcement != Some(ta) {
                 self.state.traffic_announcement = Some(ta);
@@ -421,6 +427,45 @@ impl Candidate {
         self.score = self.score.saturating_add(1);
         changed.then(|| self.state.clone())
     }
+
+    fn process_af_pair(&mut self, af0: u8, af1: u8) -> bool {
+        let mut changed = false;
+        if !is_af_count_code(af0) {
+            changed |= self.record_af_code(af0);
+        }
+        if !is_af_count_code(af1) {
+            changed |= self.record_af_code(af1);
+        }
+        changed
+    }
+
+    fn record_af_code(&mut self, code: u8) -> bool {
+        let Some(hz) = af_code_to_hz(code) else {
+            return false;
+        };
+        let afs = self
+            .state
+            .alternative_frequencies_hz
+            .get_or_insert_with(Vec::new);
+        if afs.contains(&hz) {
+            return false;
+        }
+        afs.push(hz);
+        afs.sort_unstable();
+        true
+    }
+}
+
+fn is_af_count_code(code: u8) -> bool {
+    (224..=249).contains(&code)
+}
+
+fn af_code_to_hz(code: u8) -> Option<u32> {
+    if (1..=204).contains(&code) {
+        Some(87_500_000 + u32::from(code) * 100_000)
+    } else {
+        None
+    }
 }
 
 #[derive(Debug, Clone)]
diff --git a/src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js b/src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js
index 73cd950..54fc1f6 100644
--- a/src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js
+++ b/src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js
@@ -390,6 +390,20 @@ function currentTheme() {
   return document.documentElement.getAttribute("data-theme") === "light" ? "light" : "dark";
 }
 
+function updateDocumentTitle(rds = null) {
+  if (!Number.isFinite(lastFreqHz)) {
+    document.title = originalTitle;
+    return;
+  }
+  const parts = [formatFreq(lastFreqHz)];
+  const ps = rds?.program_service;
+  if (ps && ps.length > 0) {
+    parts.push(ps);
+  }
+  parts.push(originalTitle);
+  document.title = parts.join(" - ");
+}
+
 function setTheme(theme) {
   const next = theme === "light" ? "light" : "dark";
   document.documentElement.setAttribute("data-theme", next);
@@ -957,6 +971,7 @@ function applyLocalTunedFrequency(hz, forceDisplay = false) {
     resetRdsDisplay();
   }
   lastFreqHz = hz;
+  updateDocumentTitle(lastSpectrumData?.rds ?? null);
   refreshWavelengthDisplay(lastFreqHz);
   if (forceDisplay) {
     freqDirty = false;
@@ -1136,8 +1151,10 @@ function updateFooterBuildInfo() {
 
 function updateTitle() {
   const titleEl = document.getElementById("rig-title");
-  if (!titleEl) return;
-  titleEl.textContent = serverVersion ? `trx-rs v${serverVersion}` : "trx-rs";
+  if (titleEl) {
+    titleEl.textContent = serverVersion ? `trx-rs v${serverVersion}` : "trx-rs";
+  }
+  updateDocumentTitle(lastSpectrumData?.rds ?? null);
 }
 
 function render(update) {
@@ -3281,6 +3298,42 @@ function buildRdsRawPayload(rds) {
   };
 }
 
+function formatRdsAfMHz(hz) {
+  return `${(hz / 1_000_000).toFixed(1)} MHz`;
+}
+
+async function tuneRdsAlternativeFrequency(hz) {
+  if (!Number.isFinite(hz) || hz <= 0) return;
+  const targetHz = Math.round(hz);
+  try {
+    await postPath(`/set_freq?hz=${targetHz}`);
+    applyLocalTunedFrequency(targetHz);
+    showHint(`Tuned ${formatRdsAfMHz(targetHz)}`, 1200);
+  } catch (_) {
+    showHint("Set freq failed", 1500);
+  }
+}
+
+function renderRdsAlternativeFrequencies(list) {
+  const afEl = document.getElementById("rds-af-list");
+  if (!afEl) return;
+  if (!Array.isArray(list) || list.length === 0) {
+    afEl.textContent = "--";
+    return;
+  }
+  afEl.innerHTML = "";
+  for (const hz of list) {
+    if (!Number.isFinite(hz) || hz <= 0) continue;
+    const btn = document.createElement("button");
+    btn.type = "button";
+    btn.className = "rds-af-btn";
+    btn.dataset.hz = String(Math.round(hz));
+    btn.textContent = formatRdsAfMHz(hz);
+    afEl.appendChild(btn);
+  }
+  if (!afEl.childElementCount) afEl.textContent = "--";
+}
+
 async function copyRdsPsToClipboard() {
   const rds = lastSpectrumData?.rds;
   const ps = rds?.program_service;
@@ -3328,8 +3381,19 @@ const rdsRawCopyBtn = document.getElementById("rds-raw-copy-btn");
 if (rdsRawCopyBtn) {
   rdsRawCopyBtn.addEventListener("click", () => { copyRdsRawToClipboard(); });
 }
+const rdsAfListEl = document.getElementById("rds-af-list");
+if (rdsAfListEl) {
+  rdsAfListEl.addEventListener("click", (event) => {
+    const btn = event.target instanceof HTMLElement ? event.target.closest(".rds-af-btn") : null;
+    const hz = Number(btn?.dataset?.hz);
+    if (btn && Number.isFinite(hz)) {
+      tuneRdsAlternativeFrequency(hz);
+    }
+  });
+}
 
 function updateRdsPsOverlay(rds) {
+  updateDocumentTitle(rds);
   // Overview strip overlay
   if (rdsPsOverlay) {
     const ps = rds?.program_service;
@@ -3377,6 +3441,7 @@ function updateRdsPsOverlay(rds) {
   const compEl     = document.getElementById("rds-compressed");
   const headEl     = document.getElementById("rds-artificial-head");
   const dynPtyEl   = document.getElementById("rds-dynamic-pty");
+  const afEl       = document.getElementById("rds-af-list");
   const rtEl       = document.getElementById("rds-radio-text");
   const rawEl      = document.getElementById("rds-raw");
   if (!statusEl) return;
@@ -3401,6 +3466,7 @@ function updateRdsPsOverlay(rds) {
     if (compEl) compEl.textContent = "--";
     if (headEl) headEl.textContent = "--";
     if (dynPtyEl) dynPtyEl.textContent = "--";
+    if (afEl) afEl.textContent = "--";
     if (rtEl) rtEl.textContent = "--";
     if (rawEl && lastSpectrumData) {
       const { bins: _b, ...rest } = lastSpectrumData;
@@ -3427,6 +3493,7 @@ function updateRdsPsOverlay(rds) {
   if (compEl) compEl.textContent = formatRdsFlag(rds.compressed);
   if (headEl) headEl.textContent = formatRdsFlag(rds.artificial_head);
   if (dynPtyEl) dynPtyEl.textContent = formatRdsFlag(rds.dynamic_pty);
+  renderRdsAlternativeFrequencies(rds.alternative_frequencies_hz);
   if (rtEl) rtEl.textContent = rds.radio_text ?? "--";
   rawEl.textContent = JSON.stringify(buildRdsRawPayload(rds), null, 2);
 }
diff --git a/src/trx-client/trx-frontend/trx-frontend-http/assets/web/index.html b/src/trx-client/trx-frontend/trx-frontend-http/assets/web/index.html
index 8d3aef9..020a3a5 100644
--- a/src/trx-client/trx-frontend/trx-frontend-http/assets/web/index.html
+++ b/src/trx-client/trx-frontend/trx-frontend-http/assets/web/index.html
@@ -287,6 +287,7 @@
           <div class="rds-field"><span class="rds-label">Compressed</span><span id="rds-compressed" class="rds-value">--</span></div>
           <div class="rds-field"><span class="rds-label">Artificial Head</span><span id="rds-artificial-head" class="rds-value">--</span></div>
           <div class="rds-field"><span class="rds-label">Dynamic PTY</span><span id="rds-dynamic-pty" class="rds-value">--</span></div>
+          <div class="rds-field"><span class="rds-label">AF</span><span id="rds-af-list" class="rds-value rds-af-list">--</span></div>
           <div class="rds-field"><span class="rds-label">RadioText</span><span id="rds-radio-text" class="rds-value rds-text">--</span></div>
         </div>
         <div class="rds-raw-header">
diff --git a/src/trx-client/trx-frontend/trx-frontend-http/assets/web/style.css b/src/trx-client/trx-frontend/trx-frontend-http/assets/web/style.css
index 7fe7200..a18710f 100644
--- a/src/trx-client/trx-frontend/trx-frontend-http/assets/web/style.css
+++ b/src/trx-client/trx-frontend/trx-frontend-http/assets/web/style.css
@@ -812,6 +812,21 @@ small { color: var(--text-muted); }
 .rds-value { font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace; font-size: 0.95rem; color: var(--text); }
 .rds-ps { font-size: 1.1rem; font-weight: 600; letter-spacing: 0.08em; color: var(--accent-green); }
 .rds-text { white-space: normal; overflow-wrap: anywhere; line-height: 1.35; }
+.rds-af-list { display: flex; flex-wrap: wrap; gap: 0.35rem; align-items: center; }
+.rds-af-btn {
+  height: 1.7rem;
+  padding: 0 0.55rem;
+  border: 1px solid var(--border-light);
+  border-radius: 999px;
+  background: var(--input-bg);
+  color: var(--text);
+  font: inherit;
+  cursor: pointer;
+}
+.rds-af-btn:hover {
+  border-color: var(--accent);
+  color: var(--accent);
+}
 .rds-no-signal { color: var(--text-muted); }
 .rds-decoding { color: var(--accent-green); }
 .rds-raw-header { display: flex; align-items: center; justify-content: space-between; gap: 0.6rem; margin-bottom: 0.3rem; }
diff --git a/src/trx-core/src/rig/state.rs b/src/trx-core/src/rig/state.rs
index 8f92404..1082011 100644
--- a/src/trx-core/src/rig/state.rs
+++ b/src/trx-core/src/rig/state.rs
@@ -320,6 +320,8 @@ pub struct RdsData {
     pub compressed: Option<bool>,
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub dynamic_pty: Option<bool>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub alternative_frequencies_hz: Option<Vec<u32>>,
 }
 
 /// Read-only projection of state shared with clients.