feat: emit duration + per-station history in liquidsoap

config/liquidsoap.liq

@@ -15,18 +15,50 @@ def emit_now_playing(station, m) =
     payload.add("title", m["title"])
     payload.add("album", m["album"])
     payload.add("filename", filename)
+    payload.add("duration", m["duration"])
     payload.add("started_at", string(int_of_float(time())))
     file.write(data=payload.stringify(), atomic=true, temp_dir="/now-playing", "/now-playing/#{station}.json")
   end
 end
 
+def append_history(station, m) =
+  filename = m["filename"]
+  if filename != "" then
+    history_path = "/now-playing/#{station}.history.json"
+    existing =
+      if file.exists(history_path) then
+        file.contents(history_path)
+      else
+        "[]"
+      end
+    arr =
+      try
+        json.parse(default=([] : [json]), existing)
+      catch _ do
+        ([] : [json])
+      end
+    entry = json()
+    entry.add("title", m["title"])
+    entry.add("artist", m["artist"])
+    entry.add("album", m["album"])
+    entry.add("filename", filename)
+    entry.add("started_at", string(int_of_float(time())))
+    new_arr = list.add(entry, list.prefix(50, arr))
+    out_str = json.stringify(new_arr)
+    file.write(data=out_str, atomic=true, temp_dir="/now-playing", history_path)
+  end
+end
+
 # === station: minecraft ===
 minecraft = playlist(
   reload_mode="watch",
   mode="randomize",
   "/library/minecraft/tracks"
 )
-minecraft.on_track(fun (m) -> emit_now_playing("minecraft", m))
+minecraft.on_track(fun (m) -> begin
+  emit_now_playing("minecraft", m)
+  append_history("minecraft", m)
+end)
 minecraft = crossfade(minecraft)
 minecraft = mksafe(minecraft)