fix(couple): correct Firestore query and repository method signatures

app/src/main/java/com/couplesconnect/app/data/remote/FirestoreCoupleDataSource.kt

@@ -1,6 +1,7 @@
 package com.couplesconnect.app.data.remote
 
 import com.couplesconnect.app.domain.model.Couple
+import com.google.firebase.firestore.DocumentSnapshot
 import com.google.firebase.firestore.FirebaseFirestore
 import com.google.firebase.firestore.SetOptions
 import kotlinx.coroutines.suspendCancellableCoroutine
@@ -61,20 +62,44 @@ class FirestoreCoupleDataSource @Inject constructor() {
             coupleRef(coupleId).get()
                 .addOnSuccessListener { snap ->
                     if (!snap.exists()) { cont.resume(null); return@addOnSuccessListener }
-                    @Suppress("UNCHECKED_CAST")
+                    cont.resume(snap.toCouple())
-                    cont.resume(
-                        Couple(
-                            id = snap.id,
-                            userIds = (snap.get("userIds") as? List<String>) ?: emptyList(),
-                            inviteCode = snap.getString("inviteCode") ?: "",
-                            createdAt = snap.getLong("createdAt") ?: 0L,
-                            currentQuestionId = snap.getString("currentQuestionId"),
-                            streakCount = (snap.getLong("streakCount") ?: 0L).toInt(),
-                            lastAnsweredAt = snap.getLong("lastAnsweredAt"),
-                            activePackId = snap.getString("activePackId")
-                        )
-                    )
                 }
                 .addOnFailureListener { cont.resumeWithException(it) }
         }
+
+    suspend fun updateStreak(coupleId: String) {
+        val snap = suspendCancellableCoroutine<DocumentSnapshot> { cont ->
+            coupleRef(coupleId).get()
+                .addOnSuccessListener { cont.resume(it) }
+                .addOnFailureListener { cont.resumeWithException(it) }
+        }
+        val lastAnsweredAt = snap.getLong("lastAnsweredAt") ?: 0L
+        val now = System.currentTimeMillis()
+        val current = (snap.getLong("streakCount") ?: 0L).toInt()
+        val newStreak = if (lastAnsweredAt == 0L || now - lastAnsweredAt > TWO_DAYS_MS) 1 else current + 1
+        suspendCancellableCoroutine<Unit> { cont ->
+            coupleRef(coupleId).set(
+                mapOf("streakCount" to newStreak, "lastAnsweredAt" to now),
+                SetOptions.merge()
+            )
+                .addOnSuccessListener { cont.resume(Unit) }
+                .addOnFailureListener { cont.resumeWithException(it) }
+        }
+    }
+
+    @Suppress("UNCHECKED_CAST")
+    private fun DocumentSnapshot.toCouple() = Couple(
+        id = id,
+        userIds = (get("userIds") as? List<String>) ?: emptyList(),
+        inviteCode = getString("inviteCode") ?: "",
+        createdAt = getLong("createdAt") ?: 0L,
+        currentQuestionId = getString("currentQuestionId"),
+        streakCount = (getLong("streakCount") ?: 0L).toInt(),
+        lastAnsweredAt = getLong("lastAnsweredAt"),
+        activePackId = getString("activePackId")
+    )
+
+    companion object {
+        private const val TWO_DAYS_MS = 48L * 60 * 60 * 1000
+    }
 }

app/src/main/java/com/couplesconnect/app/data/repository/CoupleRepositoryImpl.kt

@@ -21,4 +21,8 @@ class CoupleRepositoryImpl @Inject constructor(
     override suspend fun createCouple(inviterUserId: String, acceptorUserId: String, inviteCode: String): Result<String> = runCatching {
         coupleDataSource.createCouple(inviterUserId, acceptorUserId, inviteCode)
     }
+
+    override suspend fun updateStreak(coupleId: String): Result<Unit> = runCatching {
+        coupleDataSource.updateStreak(coupleId)
+    }
 }

app/src/main/java/com/couplesconnect/app/domain/repository/CoupleRepository.kt

@@ -5,4 +5,5 @@ import com.couplesconnect.app.domain.model.Couple
 interface CoupleRepository {
     suspend fun getCoupleForUser(userId: String): Couple?
     suspend fun createCouple(inviterUserId: String, acceptorUserId: String, inviteCode: String): Result<String>
+    suspend fun updateStreak(coupleId: String): Result<Unit>
 }