Added saving data to internal storage for later use.

Added dialog on internal storage usage, and for first start without internet connection

app/build.gradle.kts

@@ -1,3 +1,4 @@
+
 plugins {
     alias(libs.plugins.android.application)
     alias(libs.plugins.kotlin.android)
@@ -64,5 +65,6 @@ dependencies {
     implementation(libs.kotlinx.coroutines.core)
     implementation(libs.vico.compose.m3)
     implementation(libs.cicerone)
+    implementation(libs.androidx.datastore)
 
-}
+}

app/src/main/java/ru/vendetti/bitcoin_summarizer/CryptoFragment.kt

@@ -1,21 +1,33 @@
 package ru.vendetti.bitcoin_summarizer
 
 import android.annotation.SuppressLint
+import android.content.Context
+import android.content.pm.PackageManager
 import android.os.Bundle
+import android.util.Log
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
+import androidx.activity.compose.rememberLauncherForActivityResult
+import androidx.activity.result.contract.ActivityResultContracts
 import androidx.compose.foundation.background
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.wrapContentSize
 import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Menu
-import androidx.compose.material.icons.filled.MoreVert
+import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.ButtonColors
+import androidx.compose.material3.ButtonDefaults
+import androidx.compose.material3.Card
 import androidx.compose.material3.CenterAlignedTopAppBar
 import androidx.compose.material3.DrawerValue
 import androidx.compose.material3.ExperimentalMaterial3Api
@@ -23,11 +35,10 @@ import androidx.compose.material3.HorizontalDivider
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.MediumTopAppBar
-import androidx.compose.material3.ModalDrawerSheet
 import androidx.compose.material3.ModalNavigationDrawer
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
 import androidx.compose.material3.TopAppBarDefaults
 import androidx.compose.material3.rememberDrawerState
 import androidx.compose.material3.rememberTopAppBarState
@@ -42,13 +53,19 @@ import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.vector.ImageVector
 import androidx.compose.ui.input.nestedscroll.nestedScroll
 import androidx.compose.ui.platform.ComposeView
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
+import androidx.compose.ui.window.Dialog
+import androidx.core.content.ContextCompat
 import androidx.fragment.app.Fragment
+import com.google.gson.Gson
 import com.patrykandpatrick.vico.compose.cartesian.CartesianChartHost
 import com.patrykandpatrick.vico.compose.cartesian.axis.rememberAxisLabelComponent
 import com.patrykandpatrick.vico.compose.cartesian.axis.rememberAxisLineComponent
@@ -80,6 +97,9 @@ import kotlinx.coroutines.launch
 import ru.vendetti.bitcoin_summarizer.ui.theme.BitcoinSummarizerTheme
 import ru.vendetti.bitcoin_summarizer.ui.theme.Flame
 import ru.vendetti.bitcoin_summarizer.ui.theme.Green2
+import java.io.FileInputStream
+import java.io.FileOutputStream
+import java.lang.StringBuilder
 import java.text.DecimalFormat
 import java.time.Instant
 import java.time.format.DateTimeFormatter
@@ -102,11 +122,51 @@ class CryptoFragment: Fragment() {
     }
 }
 
+@Composable
+fun ShowAlertDialog(
+    onDismissRequest: () -> Unit,
+    onConfirmation: () -> Unit,
+    dialogTitle: String,
+    dialogText: String,
+) {
+    AlertDialog(
+        icon = {},
+        title = {
+            Text(text = dialogTitle)
+        },
+        text = {
+            Text(text = dialogText)
+        },
+        onDismissRequest = {
+            onDismissRequest()
+        },
+        confirmButton = {},
+        dismissButton = {
+            TextButton(
+                onClick = {
+                    onDismissRequest()
+                }
+            ) {
+                Text(
+                    text = "Окей",
+                    color = MaterialTheme.colorScheme.onPrimary
+                )
+            }
+        },
+        containerColor = MaterialTheme.colorScheme.primary,
+        titleContentColor = MaterialTheme.colorScheme.onPrimary,
+        textContentColor = MaterialTheme.colorScheme.onPrimary,
+    )
+}
+
 @SuppressLint("MutableCollectionMutableState", "SimpleDateFormat")
 @OptIn(ExperimentalMaterial3Api::class)
 @Preview
 @Composable
 fun CryptoComposable() {
+    val openAlertDialog1 = remember { mutableStateOf(false) }
+    val openAlertDialog2 = remember { mutableStateOf(false) }
+
     // Создаем репозиторий для работы с API
     val cryptoRepository = remember { CryptoRepository(RetrofitClient.apiService) }
     // Состояния для хранения результатов запросов
@@ -116,8 +176,36 @@ fun CryptoComposable() {
 
     var fearGreedIndexDaysCount by remember { mutableIntStateOf(30) }
 
+    val gson = Gson()
+
+    val context = LocalContext.current
+
+    when {
+        openAlertDialog1.value -> {
+            ShowAlertDialog(
+                onDismissRequest = {openAlertDialog1.value = false},
+                onConfirmation = {},
+                dialogTitle = "Внимание!",
+                dialogText = "Отсутствует интернет-подключение, загружаю сохраненные данные. " +
+                        "" +
+                        "Обратите внимание, что данные могут быть неактуальными.",
+            )
+        }
+        openAlertDialog2.value -> {
+            ShowAlertDialog(
+                onDismissRequest = {
+                    openAlertDialog2.value = false
+                    App.INSTANCE.router.exit()
+                                   },
+                onConfirmation = {},
+                dialogTitle = "Внимание!",
+                dialogText = "При первом подключении необходимо подключение к интернету!",
+            )
+        }
+    }
+
     // Запускаем корутину для выполнения сетевых запросов
-    LaunchedEffect(fearGreedIndexDaysCount) {
+    LaunchedEffect(fearGreedIndexDaysCount, context) {
         try {
             // Запрос Bitcoin Ticker
             val tickerResponse = cryptoRepository.fetchBitcoinTicker()
@@ -131,31 +219,53 @@ fun CryptoComposable() {
             val fearResponse = cryptoRepository.fetchFearAndGreedData(fearGreedIndexDaysCount)
             fearGreedDataList = fearResponse?.dataList as ArrayList<FearAndGreedData>
             fearGreedDataList.reverse()
-        }catch (e: Exception) {
-            bitcoinTicker = TickerData(
-                id = "",
-                name = "",
-                symbol = "",
-                rank = "",
-                priceUsd = "",
-                priceBtc = "",
-                volume24hUsd = "",
-                marketCapUsd = "",
-                availableSupply = "",
-                totalSupply = "",
-                maxSupply = "",
-                percentChange1h = "",
-                percentChange24h = "",
-                percentChange7d = "",
-                lastUpdated = ""
+
+            // *** Сохраняем на диск ***
+            // 1) Сбор данных в один класс
+            val fullStatistics = StatisticsFull(
+                FGI_list = fearGreedDataList,
+                TickerData = bitcoinTicker,
+                GlobalData = globalData,
             )
-            globalData = GlobalResponse(
-                activeCryptocurrencies = "",
-                totalMarketCapUsd = "",
-                total24hVolumeUsd = "",
-                bitcoinPercentageOfMarketCap = ""
-            )
-            fearGreedDataList = ArrayList<FearAndGreedData>()
+
+            // 2) Перевод класса в json-строку
+            val statisticsJsonString = gson.toJson(fullStatistics)
+
+            // 3) Сохранение в файл во внутреннем хранилище
+            val fos: FileOutputStream =
+                context.openFileOutput("statistics.txt", Context.MODE_PRIVATE)
+            fos.write(statisticsJsonString.toByteArray())
+            fos.flush()
+            fos.close()
+        }
+        catch (e: Exception) {
+            try {
+                // *** Загрузка данных из файла ***
+                // 1) Получение строки из файла
+                val fis: FileInputStream =
+                    context.openFileInput("statistics.txt")
+                var a: Int
+                val temp = StringBuilder()
+                while (fis.read().also { a = it } != -1) {
+                    temp.append(a.toChar())
+                }
+
+                // Показ предупреждения.
+                openAlertDialog1.value = true
+
+                val statisticsJsonString = temp.toString()
+
+                // 2) Перевод строки в класс
+                val statisticsFull = gson.fromJson(statisticsJsonString, StatisticsFull::class.java)
+
+                // 3) Распределение данных по переменным
+                bitcoinTicker = statisticsFull.TickerData
+                globalData = statisticsFull.GlobalData
+                fearGreedDataList = statisticsFull.FGI_list
+            }
+            catch (e: Exception) {
+                openAlertDialog2.value = true
+            }
         }
     }
 

app/src/main/java/ru/vendetti/bitcoin_summarizer/StatisticsFull.kt

@@ -0,0 +1,7 @@
+package ru.vendetti.bitcoin_summarizer
+
+class StatisticsFull (
+    val FGI_list: ArrayList<FearAndGreedData>,
+    val TickerData: TickerData,
+    val GlobalData: GlobalResponse,
+)