add random value for testing the graph if isTesting is set to true before compilation

app/src/main/java/ovh/smayzy/i2d_project_15_app/MainActivity.kt

@@ -26,6 +26,9 @@ import java.util.*
 import android.graphics.Color
 import androidx.core.content.ContextCompat
 import android.widget.TextView
+import java.io.InputStream
+import java.io.PipedInputStream
+import java.io.PipedOutputStream
 
 class MainActivity : AppCompatActivity() {
 
@@ -48,6 +51,8 @@ class MainActivity : AppCompatActivity() {
     private lateinit var tempCircle: TextView
     private lateinit var humCircle: TextView
 
+    private val isTesting = true
+
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         enableEdgeToEdge()
@@ -78,6 +83,15 @@ class MainActivity : AppCompatActivity() {
 
             connectToHC05()
         }
+
+        if (isTesting) {
+            Toast.makeText(this, "Running in testing mode", Toast.LENGTH_SHORT).show()
+            Log.d(tag, "Starting fake data stream")
+
+            Thread {
+                listenForData()
+            }.start()
+        }
     }
 
     private fun connectToHC05() {
@@ -119,7 +133,11 @@ class MainActivity : AppCompatActivity() {
     }
 
     private fun listenForData() {
-        val inputStream = bluetoothSocket?.inputStream ?: return
+        val inputStream = if (isTesting) {
+            fakeTestingData()
+        } else {
+            bluetoothSocket?.inputStream ?: return
+        }
         val reader = BufferedReader(InputStreamReader(inputStream))
 
         while (true) {
@@ -215,4 +233,31 @@ class MainActivity : AppCompatActivity() {
         humChart.invalidate()
     }
 
+    private fun fakeTestingData(): InputStream {
+        val pipedInput = PipedInputStream()
+        val pipedOutput = PipedOutputStream(pipedInput)
+
+        Thread {
+            val random = Random()
+
+            while (true) {
+                val temp = 0.0 + random.nextFloat() * 50.0
+                val hum = 10.0 + random.nextFloat() * 80.0
+
+                val line = String.format(Locale.US, "%.1f;%.1f", temp, hum)
+
+                try {
+                    pipedOutput.write("$line\n".toByteArray())
+                    pipedOutput.flush()
+                    Log.d(tag, "Fake sent: $line")
+                    Thread.sleep(1000)
+                } catch (e: IOException) {
+                    Log.e(tag, "Fake stream write failed", e)
+                    break
+                }
+            }
+        }.start()
+
+        return pipedInput
+    }
 }