feat(wallet) skip picking flags in the random emoji picker function

Also add a test to validate the knowledge of the emoji picker function
about flags position

Closes #13715

ui/StatusQ/src/StatusQ/Core/Utils/Emoji.qml

@@ -125,22 +125,28 @@ QtObject {
         return undefined
     }
 
-    function getRandomEmoji(size) {
-        var randomEmoji = EmojiJSON.emoji_json[Math.floor(Math.random() * EmojiJSON.emoji_json.length)]
+    // Used to exclude flags emojis from the random emoji picker
+    // Based on the knowledge that flags emojis are contiguous in the emoji list
+    readonly property int firstFlagIndex: 1003
+    readonly property int lastFlagIndex: 1259
+    readonly property int flagsCount: lastFlagIndex - firstFlagIndex + 1
 
-        const extenstionIndex = randomEmoji.unicode.lastIndexOf('.');
+    // Returns a random emoji excluding flags emojis
+    function getRandomEmoji(size) {
+        let whitelistedIndex = Math.floor(Math.random() * (EmojiJSON.emoji_json.length - flagsCount))
+        // Compensating for the missing flags emojis index
+        if (whitelistedIndex >= firstFlagIndex) {
+            whitelistedIndex += flagsCount
+        }
+        var randomEmoji = EmojiJSON.emoji_json[whitelistedIndex]
+
+        const extensionIndex = randomEmoji.unicode.lastIndexOf('.');
         let iconCodePoint = randomEmoji.unicode
-        if (extenstionIndex > -1) {
-            iconCodePoint = iconCodePoint.substring(0, extenstionIndex)
+        if (extensionIndex > -1) {
+            iconCodePoint = iconCodePoint.substring(0, extensionIndex)
         }
 
-        // Split the unicode to get all the parts and then encode them from hex to utf8
-        const splitCodePoint = iconCodePoint.split('-')
-        let codePointParts = []
-        splitCodePoint.forEach(function (codePoint) {
-            codePointParts.push(`0x${codePoint}`)
-        })
-        const encodedIcon = String.fromCodePoint(...codePointParts);
+        const encodedIcon = getEmojiCodepoint(iconCodePoint)
 
         // Adding a space because otherwise, some emojis would fuse since emoji is just a string
         return Emoji.parse(encodedIcon, size || undefined) + ' '

ui/StatusQ/tests/TestCore/TestUtils/tst_Emoji.qml

@@ -0,0 +1,28 @@
+import QtQuick 2.15
+import QtTest 1.0
+
+import StatusQ.Core.Utils 0.1
+
+TestCase {
+    id: testCase
+    name: "TestEmoji"
+
+    // Test if the knowledge of the first and last index of the flags is still valid or need to be updated
+    function test_flags_indexes_are_valid() {
+        let emojis = Emoji.emojiJSON.emoji_json
+        let firstIndex = emojis.findIndex(function(emoji) {
+            return (emoji.category === "flags")
+        })
+        compare(Emoji.firstFlagIndex, firstIndex, "First flag index is still valid")
+
+        let lastIndex = -1;
+        for (let i = emojis.length - 1; i >= 0; i--) {
+            if (emojis[i].category === "flags") {
+                lastIndex = i;
+                break; // Exit the loop once the last flag is found
+            }
+        }
+        compare(Emoji.lastFlagIndex, lastIndex, "Last flag index is still valid")
+    }
+}
+