Improve Nostr Zap functionality, BitAxe integration bugfix

lib/btclock/nostrdisplay_handler.cpp

@@ -0,0 +1,24 @@
+#include "nostrdisplay_handler.hpp"
+
+std::array<std::string, NUM_SCREENS> parseZapNotify(std::uint16_t amount, bool withSatsSymbol)
+{
+    std::string text = std::to_string(amount);
+    std::size_t textLength = text.length();
+    std::size_t startIndex = NUM_SCREENS - textLength;
+
+    std::array<std::string, NUM_SCREENS> textEpdContent = {"ZAP", "mdi-lnbolt", "", "", "", "", ""};
+
+    // Insert the sats symbol just before the digits
+    if (startIndex > 0 && withSatsSymbol)
+    {
+        textEpdContent[startIndex - 1] = "STS";
+    }
+
+    // Place the digits
+    for (std::size_t i = 0; i < textLength; i++)
+    {
+        textEpdContent[startIndex + i] = text.substr(i, 1);
+    }
+
+    return textEpdContent;
+}

lib/btclock/nostrdisplay_handler.hpp

@@ -0,0 +1,5 @@
+#include <array>
+#include <string>
+#include "utils.hpp"
+
+std::array<std::string, NUM_SCREENS> parseZapNotify(std::uint16_t amount, bool withSatsSymbol);