From 49f044ecde8119d03d78fe167f375e71eabf6150 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Kristan?= <blaz@kristan-sp.si>
Date: Sun, 13 Oct 2024 10:43:56 +0200
Subject: [PATCH] Better fix for #4154

---
 wled00/json.cpp    | 19 ++++++++++++-------
 wled00/presets.cpp |  4 ++--
 2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/wled00/json.cpp b/wled00/json.cpp
index c877d1f3b..06eb3015e 100644
--- a/wled00/json.cpp
+++ b/wled00/json.cpp
@@ -454,20 +454,25 @@ bool deserializeState(JsonObject root, byte callMode, byte presetId)
     handleSet(nullptr, apireq, false);    // may set stateChanged
   }
 
-  // applying preset (2 cases: a) API call includes all preset values ("pd"), b) API only specifies preset ID ("ps"))
+  // Applying preset from JSON API has 2 cases: a) "pd" AKA "preset direct" and b) "ps" AKA "preset select"
+  // a) "preset direct" can only be an integer value representing preset ID. "preset direct" assumes JSON API contains the rest of preset content (i.e. from UI call)
+  //    "preset direct" JSON can contain "ps" API (i.e. call from UI to cycle presets) in such case stateChanged has to be false (i.e. no "win" or "seg" API)
+  // b) "preset select" can be cycling ("1~5~""), random ("r" or "1~5r"), ID, etc. value allowed from JSON API. This type of call assumes no state changing content in API call
   byte presetToRestore = 0;
-  // a) already applied preset content (requires "seg" or "win" but will ignore the rest)
   if (!root[F("pd")].isNull() && stateChanged) {
+    // a) already applied preset content (requires "seg" or "win" but will ignore the rest)
     currentPreset = root[F("pd")] | currentPreset;
-    if (root["win"].isNull()) presetCycCurr = currentPreset; // otherwise it was set in handleSet() [set.cpp]
+    if (root["win"].isNull()) presetCycCurr = currentPreset; // otherwise presetCycCurr was set in handleSet() [set.cpp]
     presetToRestore = currentPreset; // stateUpdated() will clear the preset, so we need to restore it after
+    DEBUG_PRINTF_P(PSTR("Preset direct: %d\n"), currentPreset);
   } else if (!root["ps"].isNull()) {
-    ps = presetCycCurr;
-    if (root["win"].isNull() && getVal(root["ps"], &ps, 0, 0) && ps > 0 && ps < 251 && ps != currentPreset) {
+    // we have "ps" call (i.e. from button or external API call) or "pd" that includes "ps" (i.e. from UI call)
+    if (root["win"].isNull() && getVal(root["ps"], &presetCycCurr, 0, 0) && presetCycCurr > 0 && presetCycCurr < 251 && presetCycCurr != currentPreset) {
+      DEBUG_PRINTF_P(PSTR("Preset select: %d\n"), presetCycCurr);
       // b) preset ID only or preset that does not change state (use embedded cycling limits if they exist in getVal())
-      applyPreset(ps, callMode); // async load from file system (only preset ID was specified)
+      applyPreset(presetCycCurr, callMode); // async load from file system (only preset ID was specified)
       return stateResponse;
-    }
+    } else presetCycCurr = currentPreset; // restore presetCycCurr
   }
 
   JsonObject playlist = root[F("playlist")];
diff --git a/wled00/presets.cpp b/wled00/presets.cpp
index 2749d4677..20edfd91e 100644
--- a/wled00/presets.cpp
+++ b/wled00/presets.cpp
@@ -118,7 +118,7 @@ void initPresetsFile()
 bool applyPresetFromPlaylist(byte index)
 {
   DEBUG_PRINTF_P(PSTR("Request to apply preset: %d\n"), index);
-  presetToApply = presetCycCurr = index;
+  presetToApply = index;
   callModeToApply = CALL_MODE_DIRECT_CHANGE;
   return true;
 }
@@ -127,7 +127,7 @@ bool applyPreset(byte index, byte callMode)
 {
   unloadPlaylist(); // applying a preset unloads the playlist (#3827)
   DEBUG_PRINTF_P(PSTR("Request to apply preset: %u\n"), index);
-  presetToApply = presetCycCurr = index;
+  presetToApply = index;
   callModeToApply = callMode;
   return true;
 }