Чтение продуктов для главного и дискаунт экранов из апишки. Великая победа над ремоут медиатором.

app/src/main/java/com/example/shawarma/AppModule.kt

@@ -3,6 +3,7 @@ package com.example.shawarma
 import android.app.Application
 import androidx.room.Room
 import com.example.shawarma.data.api.MyServerService
+import com.example.shawarma.data.api.repos.RestProductRepository
 import com.example.shawarma.data.api.repos.RestUserRepository
 import com.example.shawarma.data.db.AppDatabase
 import com.example.shawarma.data.repos.OrderProductRepository
@@ -49,7 +50,13 @@ object AppModule {
     @Provides
     @Singleton
     fun provideProductRepository(db: AppDatabase) : ProductRepository {
-        return ProductRepository(db.productDao(), db.orderProductDao())
+        return ProductRepository(database = db, db.productDao(), db.orderProductDao())
+    }
+
+    @Provides
+    @Singleton
+    fun provideRestProductRepository(service: MyServerService) : RestProductRepository {
+        return RestProductRepository(service)
     }
 
     @Provides

app/src/main/java/com/example/shawarma/data/api/MyServerService.kt

@@ -1,5 +1,6 @@
 package com.example.shawarma.data.api
 
+import com.example.shawarma.data.api.models.ProductListResponse
 import com.example.shawarma.data.api.models.TokenModelRemote
 import com.example.shawarma.data.api.models.UserModelRemote
 import com.jakewharton.retrofit2.converter.kotlinx.serialization.asConverterFactory
@@ -8,7 +9,10 @@ import okhttp3.MediaType.Companion.toMediaType
 import okhttp3.logging.HttpLoggingInterceptor
 import retrofit2.Retrofit
 import retrofit2.http.Body
+import retrofit2.http.GET
+import retrofit2.http.Header
 import retrofit2.http.POST
+import retrofit2.http.Path
 
 
 interface MyServerService {
@@ -22,6 +26,20 @@ interface MyServerService {
         @Body user: UserModelRemote
     ) : TokenModelRemote
 
+    @POST("check/login")
+    suspend fun checkLogin(
+        @Body user: UserModelRemote
+    ) :UserModelRemote?
+
+    @GET("user/products/{after}")
+    suspend fun getProductsList(@Path("after") after: Int, @Header("Authorization") token: String) : ProductListResponse
+
+    @GET("user/discounts/{after}")
+    suspend fun getDiscountsList(@Path("after") after: Int, @Header("Authorization") token: String) : ProductListResponse
+
+    @GET("user/items/{after}")
+    suspend fun getItemsList(@Path("after") after: Int, @Header("Authorization") token: String) : ProductListResponse
+
 
     companion object {
         private const val BASE_URL = "https://10.0.2.2:80/api/"

app/src/main/java/com/example/shawarma/data/api/mediators/ProductRemoteMediator.kt

@@ -0,0 +1,91 @@
+package com.example.shawarma.data.api.mediators
+
+import androidx.paging.ExperimentalPagingApi
+import androidx.paging.LoadType
+import androidx.paging.PagingState
+import androidx.paging.RemoteMediator
+import androidx.room.withTransaction
+import com.example.shawarma.data.api.MyServerService
+import com.example.shawarma.data.api.models.ProductListResponse
+import com.example.shawarma.data.api.models.toProductModel
+import com.example.shawarma.data.db.AppDatabase
+import com.example.shawarma.data.models.ProductModel
+import java.io.IOException
+
+@OptIn(ExperimentalPagingApi::class)
+class ProductRemoteMediator (
+    private val database: AppDatabase,
+    private val serverService: MyServerService,
+    private val query: String,
+    private val token: String
+) : RemoteMediator<Int, ProductModel>(){
+
+    private val productDao = database.productDao()
+
+    override suspend fun load(
+        loadType: LoadType,
+        state: PagingState<Int, ProductModel>
+    ): MediatorResult {
+        return try {
+            // The network load method takes an optional `after=<user.id>` parameter. For every
+            // page after the first, we pass the last user ID to let it continue from where it
+            // left off. For REFRESH, pass `null` to load the first page.
+            var loadKey = when (loadType) {
+                LoadType.REFRESH -> null
+                // In this example, we never need to prepend, since REFRESH will always load the
+                // first page in the list. Immediately return, reporting end of pagination.
+                LoadType.PREPEND -> return MediatorResult.Success(endOfPaginationReached = true)
+                LoadType.APPEND -> {
+                    val lastItem = state.lastItemOrNull()
+                        ?: return MediatorResult.Success(endOfPaginationReached = true)
+
+                    // We must explicitly check if the last item is `null` when appending,
+                    // since passing `null` to networkService is only valid for initial load.
+                    // If lastItem is `null` it means no items were loaded after the initial
+                    // REFRESH and there are no more items to load.
+
+                    lastItem.id
+                }
+            }
+
+            // Suspending network load via Retrofit. This doesn't need to be wrapped in a
+            // withContext(Dispatcher.IO) { ... } block since Retrofit's Coroutine CallAdapter
+            // dispatches on a worker thread.
+            if (loadKey == null) {
+                loadKey = 0
+            }
+            val response: ProductListResponse = when (query) {
+                "home" -> {
+                    serverService.getProductsList(after = loadKey, token = token)
+                }
+                "discounts" -> {
+                    serverService.getDiscountsList(after = loadKey, token = token)
+                }
+                "items" -> {
+                    serverService.getItemsList(after = loadKey, token = token)
+                }
+
+                else -> {ProductListResponse()}
+            }
+
+
+            database.withTransaction {
+                if (loadType == LoadType.REFRESH) {
+                    productDao.deleteByQuery(query)
+                }
+
+                // Insert new users into database, which invalidates the current
+                // PagingData, allowing Paging to present the updates in the DB.
+                val products = mutableListOf<ProductModel>()
+                for (prod in response.products) {
+                    products.add(prod.toProductModel())
+                }
+                productDao.insertAll(products)
+            }
+
+            MediatorResult.Success(endOfPaginationReached = response.nextKey == -1)
+        } catch (e: IOException) {
+            MediatorResult.Error(e)
+        }
+    }
+}

app/src/main/java/com/example/shawarma/data/api/models/ProductModelRemote.kt

@@ -0,0 +1,26 @@
+package com.example.shawarma.data.api.models
+
+import com.example.shawarma.data.models.ProductModel
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class ProductModelRemote(
+    val id: Int = 0,
+    val title: String = "",
+    val price: Int = 0,
+    val old_price: Int? = null
+)
+
+@Serializable
+data class ProductListResponse(
+    val products: List<ProductModelRemote> = listOf(),
+    val nextKey: Int? = null
+)
+
+fun ProductModelRemote.toProductModel(): ProductModel = ProductModel(
+    id, title, price, old_price
+)
+
+fun ProductModel.toProductModelRemote(): ProductModelRemote = ProductModelRemote(
+    title = title, price = price, old_price = oldPrice
+)

app/src/main/java/com/example/shawarma/data/api/models/UserModelRemote.kt

@@ -5,16 +5,17 @@ import kotlinx.serialization.Serializable
 
 @Serializable
 data class TokenModelRemote(
-    val access_token: String = ""
+    val access_token: String = "",
+    val message: String = ""
 )
 
-
 @Serializable
 data class UserModelRemote(
     val id: Int = 0,
     val login: String = "",
     val password:String = "",
-    val role:String = ""
+    val role:String = "",
+    val message: String = ""
 )
 
 fun UserModelRemote.toUserModel(): UserModel = UserModel(

app/src/main/java/com/example/shawarma/data/api/repos/RestProductRepository.kt

@@ -0,0 +1,10 @@
+package com.example.shawarma.data.api.repos
+
+import com.example.shawarma.data.api.MyServerService
+import javax.inject.Inject
+
+class RestProductRepository @Inject constructor(
+    private val service: MyServerService
+) {
+
+}

app/src/main/java/com/example/shawarma/data/api/repos/RestUserRepository.kt

@@ -2,6 +2,7 @@ package com.example.shawarma.data.api.repos
 
 import com.example.shawarma.data.api.MyServerService
 import com.example.shawarma.data.api.models.TokenModelRemote
+import com.example.shawarma.data.api.models.UserModelRemote
 import com.example.shawarma.data.api.models.toUserModelRemote
 import com.example.shawarma.data.models.UserModel
 import javax.inject.Inject
@@ -16,4 +17,8 @@ class RestUserRepository @Inject constructor(
     suspend fun getToken(user: UserModel): TokenModelRemote {
         return service.getToken(user.toUserModelRemote())
     }
+
+    suspend fun checkLogin(user: UserModel): UserModelRemote? {
+        return service.checkLogin(user.toUserModelRemote())
+    }
 }

app/src/main/java/com/example/shawarma/data/interfaces/dao/ProductDao.kt

@@ -13,6 +13,12 @@ interface ProductDao {
     @Insert
     suspend fun insert(product: ProductModel)
 
+    suspend fun insertAll(products: List<ProductModel>) {
+        for (product in products) {
+            insert(product)
+        }
+    }
+
     @Update
     suspend fun update(product: ProductModel)
 
@@ -39,4 +45,25 @@ interface ProductDao {
 
     @Query("select * from products")
     fun getPagedItems(): PagingSource<Int, ProductModel>
+
+    @Query("delete from products where products.product_old_price is null")
+    fun deleteAllProducts()
+
+    @Query("delete from products where products.product_old_price is not null")
+    fun deleteAllDiscountProducts()
+
+    @Query("delete from products")
+    fun deleteAllItems()
+
+    fun deleteByQuery(query: String) {
+        if (query == "home") {
+            deleteAllProducts()
+        }
+        if (query == "discounts") {
+            deleteAllDiscountProducts()
+        }
+        if (query == "items") {
+            deleteAllItems()
+        }
+    }
 }

app/src/main/java/com/example/shawarma/data/repos/ProductRepository.kt

@@ -1,8 +1,12 @@
 package com.example.shawarma.data.repos
 
+import androidx.paging.ExperimentalPagingApi
 import androidx.paging.Pager
 import androidx.paging.PagingConfig
 import androidx.paging.PagingData
+import com.example.shawarma.data.api.MyServerService
+import com.example.shawarma.data.api.mediators.ProductRemoteMediator
+import com.example.shawarma.data.db.AppDatabase
 import com.example.shawarma.data.interfaces.dao.OrderProductDao
 import com.example.shawarma.data.interfaces.dao.ProductDao
 import com.example.shawarma.data.models.ProductModel
@@ -10,6 +14,7 @@ import kotlinx.coroutines.flow.Flow
 import javax.inject.Inject
 
 class ProductRepository @Inject constructor(
+    private val database: AppDatabase,
     private val productDao: ProductDao,
     private val orderProductDao: OrderProductDao
 ) {
@@ -23,32 +28,27 @@ class ProductRepository @Inject constructor(
         orderProductDao.deleteByProductId(product.id!!)
         return productDao.delete(product)
     }
-    /*fun getAll(): Flow<List<ProductModel>> {
-        return productDao.getAll()
-    }
-    fun getDiscounts(): Flow<List<ProductModel>> {
-        return productDao.getDiscounts()
-    }
-    fun getItems(): Flow<List<ProductModel>> {
-        return productDao.getItems()
-    }*/
     fun getById(id: Int): Flow<ProductModel> {
         return productDao.getById(id)
     }
-    fun getAllProductsPaged(): Flow<PagingData<ProductModel>> = Pager(
+    @OptIn(ExperimentalPagingApi::class)
+    fun getAllProductsPaged(token: String): Flow<PagingData<ProductModel>> = Pager(
         config = PagingConfig(
             pageSize = 6,
             enablePlaceholders = false
         ),
-        pagingSourceFactory = productDao::getPaged
+        pagingSourceFactory = productDao::getPaged,
+        remoteMediator = ProductRemoteMediator(database = database, serverService = MyServerService.getInstance(), query = "home", token = token)
     ).flow
 
-    fun getAllDiscountsPaged(): Flow<PagingData<ProductModel>> = Pager(
+    @OptIn(ExperimentalPagingApi::class)
+    fun getAllDiscountsPaged(token: String): Flow<PagingData<ProductModel>> = Pager(
         config = PagingConfig(
             pageSize = 6,
             enablePlaceholders = false
         ),
-        pagingSourceFactory = productDao::getPagedDiscounts
+        pagingSourceFactory = productDao::getPagedDiscounts,
+        remoteMediator = ProductRemoteMediator(database = database, serverService = MyServerService.getInstance(), query = "discounts", token = token)
     ).flow
 
     fun getAllItemsPaged(): Flow<PagingData<ProductModel>> = Pager(

app/src/main/java/com/example/shawarma/screens/authorization/AuthorizationScreen.kt

@@ -59,6 +59,13 @@ fun AuthorizationCard(navHostController: NavHostController) {
     if (userViewModel.token.observeAsState().value != null) {
         preferencesManager.saveData("token", userViewModel.token.value.toString())
 
+        if (login.value.text == "admin") {
+            preferencesManager.saveData("user_role", "ADMIN")
+        }
+        else {
+            preferencesManager.saveData("user_role", "USER")
+        }
+
         navHostController.navigate(ScreenPaths.home.name) {
             popUpTo(ScreenPaths.authorization.name) {
                 inclusive = true

app/src/main/java/com/example/shawarma/screens/discount/DiscountScreen.kt

@@ -58,9 +58,13 @@ fun DiscountScreen() {
 
 @Composable
 fun DiscountList(){
+    val preferencesManager = PreferencesManager(LocalContext.current)
+    val searchToken = preferencesManager.getData("token", "")
+
     val homeViewModel: HomeViewModel = hiltViewModel<HomeViewModel>()
 
-    val productsListUiState = homeViewModel.discountListUiState.collectAsLazyPagingItems()
+
+    val productsListUiState = homeViewModel.getDiscountList(searchToken).collectAsLazyPagingItems()
 
     Box(
         modifier = Modifier

app/src/main/java/com/example/shawarma/screens/home/HomeScreen.kt

@@ -57,9 +57,13 @@ fun HomeScreen() {
 
 @Composable
 fun HomeList(){
+    val preferencesManager = PreferencesManager(LocalContext.current)
+    val searchToken = preferencesManager.getData("token", "")
+
     val homeViewModel: HomeViewModel = hiltViewModel<HomeViewModel>()
 
-    val productsListUiState = homeViewModel.productListUiState.collectAsLazyPagingItems()
+
+    val productsListUiState = homeViewModel.getProductList(searchToken).collectAsLazyPagingItems()
 
 
     Box(

app/src/main/java/com/example/shawarma/viewmodels/HomeViewModel.kt

@@ -14,6 +14,7 @@ import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.launch
+import java.util.Calendar
 import java.util.Date
 import javax.inject.Inject
 
@@ -24,9 +25,13 @@ class HomeViewModel @Inject constructor(
     private val orderProductRepository: OrderProductRepository
 ) : ViewModel() {
 
-    val productListUiState: Flow<PagingData<ProductModel>> = productRepository.getAllProductsPaged()
+    fun getProductList(token:String): Flow<PagingData<ProductModel>> {
+        return productRepository.getAllProductsPaged(token)
+    }
 
-    val discountListUiState: Flow<PagingData<ProductModel>> = productRepository.getAllDiscountsPaged()
+    fun getDiscountList(token: String): Flow<PagingData<ProductModel>> {
+        return productRepository.getAllDiscountsPaged(token)
+    }
 
 
     fun addProductToCart(productId: Int, userId: String) {
@@ -36,7 +41,10 @@ class HomeViewModel @Inject constructor(
             val product = productRepository.getById(productId).first()
             val order = orderRepository.getUnpaidByUser(userId.toInt()).first()
             if (order == null) {
-                val newOrderId = orderRepository.insert(OrderModel(null, OrderStatus.Неоплачено.name, userId.toInt(), Date()))
+                val calendar: Calendar = Calendar.getInstance()
+                calendar.time = Date()
+                calendar.add(Calendar.HOUR_OF_DAY, 4)
+                val newOrderId = orderRepository.insert(OrderModel(null, OrderStatus.Неоплачено.name, userId.toInt(),calendar.time))
                 orderProductRepository.insert(OrderProductModel(newOrderId.toInt(), productId, 1, product.price))
             }
             else {

app/src/main/java/com/example/shawarma/viewmodels/OrdersViewModel.kt

@@ -6,7 +6,6 @@ import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import com.example.shawarma.data.models.OrderStatus
 import com.example.shawarma.data.models.OrderWithProducts
-import com.example.shawarma.data.repos.OrderProductRepository
 import com.example.shawarma.data.repos.OrderRepository
 import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.launch
@@ -14,8 +13,7 @@ import javax.inject.Inject
 
 @HiltViewModel
 class OrdersViewModel @Inject constructor(
-    private val orderRepository: OrderRepository,
+    private val orderRepository: OrderRepository
-    private val orderProductRepository: OrderProductRepository
 ) : ViewModel() {
     private val _preparingOrders = MutableLiveData<List<OrderWithProducts>>()
     private val _preparedOrders = MutableLiveData<List<OrderWithProducts>>()

app/src/main/java/com/example/shawarma/viewmodels/UserViewModel.kt

@@ -6,7 +6,6 @@ import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import com.example.shawarma.data.api.repos.RestUserRepository
 import com.example.shawarma.data.models.UserModel
-import com.example.shawarma.data.repos.UserRepository
 import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
@@ -15,13 +14,8 @@ import javax.inject.Inject
 
 @HiltViewModel
 class UserViewModel @Inject constructor(
-    private val userRepository: UserRepository,
     private val restUserRepository: RestUserRepository
 ) : ViewModel() {
-    private val _userModel = MutableLiveData<UserModel?>()
-    val userModel: LiveData<UserModel?>
-        get() = _userModel
-
     private val _token = MutableLiveData<String?>()
     val token: LiveData<String?>
         get() = _token
@@ -33,7 +27,7 @@ class UserViewModel @Inject constructor(
     fun login(login: String, password: String){
         viewModelScope.launch {
             withContext(Dispatchers.Main) {
-                val token_response = restUserRepository.getToken(UserModel(id = null, login = login, password = password, role = "USER"))
+                val token_response = restUserRepository.getToken(UserModel(id = null, login = login, password = password, role = ""))
                 if (token_response.access_token.isNotEmpty()) {
                     _token.postValue(token_response.access_token)
                     _authorizationState.postValue(true)
@@ -46,14 +40,12 @@ class UserViewModel @Inject constructor(
             }
         }
     }
-
-
     fun calmAuthorizationState() {
         _authorizationState.postValue(null)
     }
 
-    private val _registrationState = MutableLiveData<Boolean?>()
+    private val _registrationState = MutableLiveData<Boolean>()
-    val registrationState: LiveData<Boolean?>
+    val registrationState: LiveData<Boolean>
         get() = _registrationState
 
     fun register(login: String, password: String, passwordRepeat: String) {
@@ -72,25 +64,25 @@ class UserViewModel @Inject constructor(
         }
         viewModelScope.launch {
             withContext(Dispatchers.Main) {
-                userRepository.login(login, password).collect() { user ->
+                val user_response = restUserRepository.checkLogin(UserModel(null, login, password, ""))
-                    if (user == null) {
+                if (user_response != null) {
+                    if (user_response.login.isNullOrEmpty()) {
                         if (login == "admin" && password == "admin") {
                             restUserRepository.insert(UserModel(null, login, password, "ADMIN"))
                             _registrationState.postValue(true)
-                        }
+                        } else {
-                        else {
                             restUserRepository.insert(UserModel(null, login, password, "USER"))
                             _registrationState.postValue(true)
                         }
-                    }
+                    } else {
-                    else {
+                        if (registrationState.value != true) {
-                        _registrationState.postValue(false)
+                            _registrationState.postValue(false)
+                        }
                     }
                 }
             }
         }
     }
-
     fun calmRegistrationState() {
         _registrationState.postValue(null)
     }