Multi-account support and streaming fixes

- Allow multiple linked accounts per service (YouTube, Twitch)
- LinkedAccount PK changed from serviceId to backend UUID
- StreamDestination now references linkedAccountId
- Room DB migration v2→v3 for new schema
- Unlink endpoint changed to DELETE by account ID
- Accounts UI always shows "Add Account" for all providers
- preparePlan matches destinations by ID instead of serviceId

app/src/main/java/com/omixlab/lckcontrol/data/local/LckDatabase.kt

@@ -16,7 +16,7 @@ import com.omixlab.lckcontrol.data.local.entity.StreamPlanEntity
         StreamPlanEntity::class,
         StreamDestinationEntity::class,
     ],
-    version = 2,
+    version = 3,
     exportSchema = false,
 )
 abstract class LckDatabase : RoomDatabase() {
@@ -69,5 +69,32 @@ abstract class LckDatabase : RoomDatabase() {
                 db.execSQL("ALTER TABLE stream_destinations_new RENAME TO stream_destinations")
             }
         }
+
+        val MIGRATION_2_3 = object : Migration(2, 3) {
+            override fun migrate(db: SupportSQLiteDatabase) {
+                // 1. Rebuild linked_accounts with 'id' as PK instead of 'serviceId'
+                db.execSQL("""
+                    CREATE TABLE linked_accounts_new (
+                        id TEXT NOT NULL PRIMARY KEY,
+                        serviceId TEXT NOT NULL,
+                        displayName TEXT NOT NULL,
+                        accountId TEXT NOT NULL,
+                        avatarUrl TEXT
+                    )
+                """.trimIndent())
+                // Migrate existing rows: use accountId as temporary id (will be
+                // replaced on next sync from backend)
+                db.execSQL("""
+                    INSERT INTO linked_accounts_new (id, serviceId, displayName, accountId, avatarUrl)
+                    SELECT serviceId || '_' || accountId, serviceId, displayName, accountId, avatarUrl
+                    FROM linked_accounts
+                """.trimIndent())
+                db.execSQL("DROP TABLE linked_accounts")
+                db.execSQL("ALTER TABLE linked_accounts_new RENAME TO linked_accounts")
+
+                // 2. Add linkedAccountId column to stream_destinations
+                db.execSQL("ALTER TABLE stream_destinations ADD COLUMN linkedAccountId TEXT NOT NULL DEFAULT ''")
+            }
+        }
     }
 }

app/src/main/java/com/omixlab/lckcontrol/data/local/dao/LinkedAccountDao.kt

@@ -17,7 +17,10 @@ interface LinkedAccountDao {
     suspend fun getAll(): List<LinkedAccountEntity>
 
     @Query("SELECT * FROM linked_accounts WHERE serviceId = :serviceId")
-    suspend fun getByService(serviceId: String): LinkedAccountEntity?
+    suspend fun getByService(serviceId: String): List<LinkedAccountEntity>
+
+    @Query("SELECT * FROM linked_accounts WHERE id = :id")
+    suspend fun getById(id: String): LinkedAccountEntity?
 
     @Insert(onConflict = OnConflictStrategy.REPLACE)
     suspend fun upsert(account: LinkedAccountEntity)
@@ -25,6 +28,9 @@ interface LinkedAccountDao {
     @Delete
     suspend fun delete(account: LinkedAccountEntity)
 
+    @Query("DELETE FROM linked_accounts WHERE id = :id")
+    suspend fun deleteById(id: String)
+
     @Query("DELETE FROM linked_accounts WHERE serviceId = :serviceId")
     suspend fun deleteByService(serviceId: String)
 }

app/src/main/java/com/omixlab/lckcontrol/data/local/entity/LinkedAccountEntity.kt

@@ -5,7 +5,8 @@ import androidx.room.PrimaryKey
 
 @Entity(tableName = "linked_accounts")
 data class LinkedAccountEntity(
-    @PrimaryKey val serviceId: String,
+    @PrimaryKey val id: String,
+    val serviceId: String,
     val displayName: String,
     val accountId: String,
     val avatarUrl: String? = null,

app/src/main/java/com/omixlab/lckcontrol/data/local/entity/StreamDestinationEntity.kt

@@ -22,6 +22,7 @@ data class StreamDestinationEntity(
     @PrimaryKey val id: String = UUID.randomUUID().toString(),
     val planId: String,
     val service: String,
+    val linkedAccountId: String = "",
     val title: String,
     val description: String = "",
     val privacyStatus: String = "public",

app/src/main/java/com/omixlab/lckcontrol/data/remote/ApiModels.kt

@@ -64,7 +64,7 @@ data class CreateStreamPlanRequest(
 
 @JsonClass(generateAdapter = true)
 data class CreateDestinationRequest(
-    val serviceId: String,
+    val linkedAccountId: String,
     val title: String,
     val description: String? = null,
     val privacyStatus: String? = null,
@@ -86,6 +86,7 @@ data class StreamPlanResponse(
 data class StreamDestinationResponse(
     val id: String,
     val serviceId: String,
+    val linkedAccountId: String,
     val title: String,
     val description: String,
     val privacyStatus: String,
@@ -105,6 +106,7 @@ data class PrepareResponse(
 
 @JsonClass(generateAdapter = true)
 data class PreparedDestination(
+    val id: String,
     val serviceId: String,
     val rtmpUrl: String,
     val streamKey: String,

app/src/main/java/com/omixlab/lckcontrol/data/remote/LckApiService.kt

@@ -35,8 +35,8 @@ interface LckApiService {
     @POST("providers/twitch/callback")
     suspend fun twitchCallback(@Body body: ProviderCallbackRequest): LinkedAccountResponse
 
-    @DELETE("providers/{serviceId}")
-    suspend fun unlinkAccount(@Path("serviceId") serviceId: String): SuccessResponse
+    @DELETE("providers/accounts/{id}")
+    suspend fun unlinkAccount(@Path("id") id: String): SuccessResponse
 
     // ── Streams ──────────────────────────────────────────
 

app/src/main/java/com/omixlab/lckcontrol/data/repository/AccountRepository.kt

@@ -26,9 +26,9 @@ class AccountRepository @Inject constructor(
     /** Fetch accounts from backend and sync to Room cache */
     suspend fun syncAccounts() {
         val remote = apiService.getLinkedAccounts()
-        // Clear local and replace with remote data
         val entities = remote.map { account ->
             LinkedAccountEntity(
+                id = account.id,
                 serviceId = account.serviceId,
                 displayName = account.displayName,
                 accountId = account.accountId,
@@ -37,10 +37,10 @@ class AccountRepository @Inject constructor(
         }
         // Get current local accounts to detect removals
         val local = accountDao.getAll()
-        val remoteServiceIds = entities.map { it.serviceId }.toSet()
+        val remoteIds = entities.map { it.id }.toSet()
         for (localAccount in local) {
-            if (localAccount.serviceId !in remoteServiceIds) {
-                accountDao.deleteByService(localAccount.serviceId)
+            if (localAccount.id !in remoteIds) {
+                accountDao.deleteById(localAccount.id)
             }
         }
         for (entity in entities) {
@@ -73,12 +73,13 @@ class AccountRepository @Inject constructor(
     }
 
     /** Unlink account via backend and update local cache */
-    suspend fun unlinkAccount(serviceId: String) {
-        apiService.unlinkAccount(serviceId)
-        accountDao.deleteByService(serviceId)
+    suspend fun unlinkAccount(accountId: String) {
+        apiService.unlinkAccount(accountId)
+        accountDao.deleteById(accountId)
     }
 
     private fun LinkedAccountEntity.toLinkedAccount() = LinkedAccount(
+        id = id,
         serviceId = serviceId,
         displayName = displayName,
         accountId = accountId,

app/src/main/java/com/omixlab/lckcontrol/data/repository/StreamPlanRepository.kt

@@ -47,7 +47,7 @@ class StreamPlanRepository @Inject constructor(
             name = name,
             destinations = destinations.map { dest ->
                 CreateDestinationRequest(
-                    serviceId = dest.service,
+                    linkedAccountId = dest.linkedAccountId,
                     title = dest.title,
                     description = dest.description,
                     privacyStatus = dest.privacyStatus,
@@ -64,20 +64,15 @@ class StreamPlanRepository @Inject constructor(
     /** Prepare plan via backend — returns RTMP info */
     suspend fun preparePlan(planId: String): PrepareResponse {
         val response = apiService.prepareStreamPlan(planId)
-        // Update local cache with RTMP info
+        // Update local cache with RTMP info by destination ID
         for (dest in response.destinations) {
-            // Find local destination by serviceId within this plan
-            val local = planDao.getById(planId)?.destinations
-                ?.find { it.service == dest.serviceId }
-            if (local != null) {
-                planDao.updateDestinationStream(
-                    id = local.id,
-                    rtmpUrl = dest.rtmpUrl,
-                    streamKey = dest.streamKey,
-                    broadcastId = dest.broadcastId,
-                    status = "READY",
-                )
-            }
+            planDao.updateDestinationStream(
+                id = dest.id,
+                rtmpUrl = dest.rtmpUrl,
+                streamKey = dest.streamKey,
+                broadcastId = dest.broadcastId,
+                status = "READY",
+            )
         }
         planDao.updateStatus(planId, "READY")
         return response
@@ -107,6 +102,7 @@ class StreamPlanRepository @Inject constructor(
                 id = d.id,
                 planId = remote.id,
                 service = d.serviceId,
+                linkedAccountId = d.linkedAccountId,
                 title = d.title,
                 description = d.description,
                 privacyStatus = d.privacyStatus,
@@ -130,6 +126,7 @@ class StreamPlanRepository @Inject constructor(
 
     private fun StreamDestinationEntity.toStreamDestination() = StreamDestination(
         service = service,
+        linkedAccountId = linkedAccountId,
         title = title,
         description = description,
         privacyStatus = privacyStatus,

app/src/main/java/com/omixlab/lckcontrol/di/DatabaseModule.kt

@@ -20,7 +20,7 @@ object DatabaseModule {
     @Singleton
     fun provideDatabase(@ApplicationContext context: Context): LckDatabase =
         Room.databaseBuilder(context, LckDatabase::class.java, "lck_control.db")
-            .addMigrations(LckDatabase.MIGRATION_1_2)
+            .addMigrations(LckDatabase.MIGRATION_1_2, LckDatabase.MIGRATION_2_3)
             .build()
 
     @Provides

app/src/main/java/com/omixlab/lckcontrol/ui/accounts/AccountsScreen.kt

@@ -68,7 +68,7 @@ fun AccountsScreen(
         ) {
             item { Spacer(Modifier.height(8.dp)) }
 
-            items(accounts, key = { it.serviceId }) { account ->
+            items(accounts, key = { it.id }) { account ->
                 ElevatedCard(modifier = Modifier.fillMaxWidth()) {
                     Row(
                         modifier = Modifier
@@ -80,36 +80,31 @@ fun AccountsScreen(
                             Text(account.displayName, style = MaterialTheme.typography.titleSmall)
                             Text(account.serviceId, style = MaterialTheme.typography.bodySmall)
                         }
-                        IconButton(onClick = { viewModel.unlinkAccount(account.serviceId) }) {
+                        IconButton(onClick = { viewModel.unlinkAccount(account.id) }) {
                             Icon(Icons.Default.LinkOff, contentDescription = "Unlink")
                         }
                     }
                 }
             }
 
-            // Show link buttons for providers not yet linked
-            val linkedServiceIds = accounts.map { it.serviceId }.toSet()
-            val unlinked = viewModel.getUnlinkedProviders(linkedServiceIds)
+            // Always show link buttons — users can add multiple accounts per service
+            item {
+                Spacer(Modifier.height(8.dp))
+                Text("Add Account", style = MaterialTheme.typography.titleMedium)
+                Spacer(Modifier.height(4.dp))
+            }
 
-            if (unlinked.isNotEmpty()) {
-                item {
-                    Spacer(Modifier.height(8.dp))
-                    Text("Add Account", style = MaterialTheme.typography.titleMedium)
-                    Spacer(Modifier.height(4.dp))
-                }
-
-                items(unlinked, key = { it.serviceId }) { provider ->
-                    OutlinedButton(
-                        onClick = {
-                            val activity = context as? Activity ?: return@OutlinedButton
-                            viewModel.linkAccount(activity, provider.serviceId)
-                        },
-                        modifier = Modifier.fillMaxWidth(),
-                    ) {
-                        Icon(Icons.Default.Add, contentDescription = null)
-                        Spacer(Modifier.padding(4.dp))
-                        Text("Link ${provider.displayName}")
-                    }
+            items(ALL_PROVIDERS, key = { it.serviceId }) { provider ->
+                OutlinedButton(
+                    onClick = {
+                        val activity = context as? Activity ?: return@OutlinedButton
+                        viewModel.linkAccount(activity, provider.serviceId)
+                    },
+                    modifier = Modifier.fillMaxWidth(),
+                ) {
+                    Icon(Icons.Default.Add, contentDescription = null)
+                    Spacer(Modifier.padding(4.dp))
+                    Text("Link ${provider.displayName}")
                 }
             }
 

app/src/main/java/com/omixlab/lckcontrol/ui/accounts/AccountsViewModel.kt

@@ -48,9 +48,6 @@ class AccountsViewModel @Inject constructor(
         }
     }
 
-    fun getUnlinkedProviders(linkedServiceIds: Set<String>): List<AvailableProvider> =
-        ALL_PROVIDERS.filter { it.serviceId !in linkedServiceIds }
-
     fun linkAccount(activity: Activity, serviceId: String) {
         viewModelScope.launch {
             _linkError.value = null
@@ -68,10 +65,10 @@ class AccountsViewModel @Inject constructor(
         }
     }
 
-    fun unlinkAccount(serviceId: String) {
+    fun unlinkAccount(accountId: String) {
         viewModelScope.launch {
             try {
-                accountRepository.unlinkAccount(serviceId)
+                accountRepository.unlinkAccount(accountId)
             } catch (e: Exception) {
                 _linkError.value = e.message ?: "Failed to unlink account"
             }

shared/src/main/java/com/omixlab/lckcontrol/shared/LinkedAccount.kt

@@ -4,6 +4,7 @@ import android.os.Parcel
 import android.os.Parcelable
 
 data class LinkedAccount(
+    val id: String,
     val serviceId: String,
     val displayName: String,
     val accountId: String,
@@ -12,6 +13,7 @@ data class LinkedAccount(
 ) : Parcelable {
 
     constructor(parcel: Parcel) : this(
+        id = parcel.readString()!!,
         serviceId = parcel.readString()!!,
         displayName = parcel.readString()!!,
         accountId = parcel.readString()!!,
@@ -20,6 +22,7 @@ data class LinkedAccount(
     )
 
     override fun writeToParcel(parcel: Parcel, flags: Int) {
+        parcel.writeString(id)
         parcel.writeString(serviceId)
         parcel.writeString(displayName)
         parcel.writeString(accountId)

shared/src/main/java/com/omixlab/lckcontrol/shared/StreamDestination.kt

@@ -5,6 +5,7 @@ import android.os.Parcelable
 
 data class StreamDestination(
     val service: String,
+    val linkedAccountId: String = "",
     val title: String,
     val description: String = "",
     val privacyStatus: String = "public",
@@ -18,6 +19,7 @@ data class StreamDestination(
 
     constructor(parcel: Parcel) : this(
         service = parcel.readString()!!,
+        linkedAccountId = parcel.readString() ?: "",
         title = parcel.readString()!!,
         description = parcel.readString() ?: "",
         privacyStatus = parcel.readString() ?: "public",
@@ -31,6 +33,7 @@ data class StreamDestination(
 
     override fun writeToParcel(parcel: Parcel, flags: Int) {
         parcel.writeString(service)
+        parcel.writeString(linkedAccountId)
         parcel.writeString(title)
         parcel.writeString(description)
         parcel.writeString(privacyStatus)