Refactor and add KDoc to MyCallScreeningService

Author: adamff-dev

app/src/main/java/com/addev/listaspam/MyCallScreeningService.kt

@@ -10,44 +10,41 @@ import android.telephony.TelephonyManager
 import android.widget.Toast
 import androidx.annotation.RequiresApi
 
+/**
+ * Call screening service to identify and block spam calls.
+ * Requires Android Q (API level 29) or higher.
+ */
+@RequiresApi(Build.VERSION_CODES.Q)
 class MyCallScreeningService : CallScreeningService() {
 
-    val spamUtils = SpamUtils()
+    private val spamUtils = SpamUtils()
 
     companion object {
         private const val SPAM_PREFS = "SPAM_PREFS"
         private const val BLOCK_NUMBERS_KEY = "BLOCK_NUMBERS"
     }
 
-    @RequiresApi(Build.VERSION_CODES.Q)
+    /**
+     * Called when an incoming call is being screened.
+     * @param details Details of the incoming call.
+     */
     override fun onScreenCall(details: Call.Details) {
-        if (details.callDirection != Call.Details.DIRECTION_INCOMING)
-            return
+        // Only handle incoming calls
+        if (details.callDirection != Call.Details.DIRECTION_INCOMING) return
 
-        var rawNumber = ""
-        if (details.handle != null) {
-            rawNumber = details.handle.schemeSpecificPart
-        } else if (details.gatewayInfo?.originalAddress != null){
-            rawNumber = details.gatewayInfo?.originalAddress?.schemeSpecificPart!!
-        } else if (details.intentExtras != null) {
-            var uri = details.intentExtras.getParcelable<Uri>(TelecomManager.EXTRA_INCOMING_CALL_ADDRESS)
-            if (uri == null) {
-                uri = details.intentExtras.getParcelable<Uri>(TelephonyManager.EXTRA_INCOMING_NUMBER)
-            }
-            if (uri != null) {
-                rawNumber = uri.schemeSpecificPart
-            }
-        }
+        val rawNumber = getRawPhoneNumber(details)
 
         rawNumber?.let {
             val sharedPreferences = getSharedPreferences(SPAM_PREFS, Context.MODE_PRIVATE)
             val blockedNumbers = sharedPreferences.getStringSet(BLOCK_NUMBERS_KEY, null)
 
+            // End call if the number is already blocked
             if (blockedNumbers?.contains(rawNumber) == true) {
                 endCall(details)
                 return
             }
 
+            // Check if the number is spam
             spamUtils.checkSpamNumber(this, it) { isSpam ->
                 if (isSpam) {
                     endCall(details)
@@ -56,6 +53,30 @@ class MyCallScreeningService : CallScreeningService() {
         }
     }
 
+    /**
+     * Extracts the raw phone number from the call details.
+     * @param details Details of the incoming call.
+     * @return Raw phone number as a String.
+     */
+    private fun getRawPhoneNumber(details: Call.Details): String? {
+        return when {
+            details.handle != null -> details.handle.schemeSpecificPart
+            details.gatewayInfo?.originalAddress != null -> details.gatewayInfo.originalAddress.schemeSpecificPart
+            details.intentExtras != null -> {
+                var uri = details.intentExtras.getParcelable<Uri>(TelecomManager.EXTRA_INCOMING_CALL_ADDRESS)
+                if (uri == null) {
+                    uri = details.intentExtras.getParcelable<Uri>(TelephonyManager.EXTRA_INCOMING_NUMBER)
+                }
+                uri?.schemeSpecificPart
+            }
+            else -> null
+        }
+    }
+
+    /**
+     * Ends the incoming call by responding to the call with disallow and reject options.
+     * @param details Details of the incoming call.
+     */
     private fun endCall(details: Call.Details) {
         respondToCall(
             details, CallResponse.Builder()