Add DSBDownloader

Add update DSBActivity MainContent

app/src/main/AndroidManifest.xml

@@ -2,6 +2,8 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools">
 
+    <uses-permission android:name="android.permission.INTERNET" />
+
     <application
         android:allowBackup="true"
         android:dataExtractionRules="@xml/data_extraction_rules"

app/src/main/java/com/schoolapp/cleverclass/DSBActivity.kt

@@ -1,12 +1,18 @@
 package com.schoolapp.cleverclass
 
+import android.graphics.BitmapFactory
 import android.os.Bundle
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
+import androidx.compose.foundation.Image
 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.size
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.ArrowBack
 import androidx.compose.material3.ExperimentalMaterial3Api
@@ -19,12 +25,24 @@ import androidx.compose.material3.TopAppBar
 import androidx.compose.material3.TopAppBarDefaults
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.asImageBitmap
 import androidx.compose.ui.unit.dp
 import com.schoolapp.cleverclass.ui.theme.CleverClassTheme
+import kotlinx.coroutines.DelicateCoroutinesApi
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.GlobalScope
+import kotlinx.coroutines.launch
+import java.io.File
 
 class DSBActivity : ComponentActivity() {
+    @OptIn(DelicateCoroutinesApi::class)
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
+
+        GlobalScope.launch(Dispatchers.IO) {
+            downloadDSB(this@DSBActivity)
+        }
+
         setContent {
             CleverClassTheme {
                 Surface(
@@ -42,7 +60,7 @@ class DSBActivity : ComponentActivity() {
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
 fun DSBContent(activity: ComponentActivity){
-    Column() {
+    Column {
         TopAppBar(
             colors = TopAppBarDefaults.centerAlignedTopAppBarColors(MaterialTheme.colorScheme.primaryContainer),
             title = {
@@ -63,8 +81,27 @@ fun DSBContent(activity: ComponentActivity){
             modifier = Modifier.fillMaxWidth()
         )
 
-        Column() {
+        Column(modifier = Modifier.verticalScroll(rememberScrollState())) {
+            val mainFolder = File(activity.filesDir, "dataDSB")
 
+            mainFolder.listFiles()?.forEach { folder ->
+                DayPrefab(folder = folder)
+                Spacer(modifier = Modifier.height(48.dp))
+            }
+        }
+    }
+}
+
+@Composable
+fun DayPrefab(folder: File){
+    val imageFiles = folder.listFiles { file -> file.extension == "jpg" }?.toList()
+
+    Column {
+        imageFiles?.forEach {
+            val imageBitmap = BitmapFactory.decodeFile(it.absolutePath)
+
+            Image(bitmap = imageBitmap.asImageBitmap(), contentDescription = null)
+            Spacer(modifier = Modifier.height(8.dp))
         }
     }
 }

app/src/main/java/com/schoolapp/cleverclass/DSBDownloader.kt

@@ -0,0 +1,179 @@
+package com.schoolapp.cleverclass
+
+import android.content.Context
+import android.util.Base64
+import android.util.Log
+import org.json.JSONObject
+import java.io.ByteArrayOutputStream
+import java.io.File
+import java.net.HttpURLConnection
+import java.net.URL
+import java.util.zip.GZIPInputStream
+import java.util.zip.GZIPOutputStream
+import java.io.ByteArrayInputStream
+import java.io.FileOutputStream
+import java.time.LocalDateTime
+import java.util.UUID
+
+
+suspend fun downloadDSB(context: Context){
+    val mainDir = createDataFolder(context)
+
+    val jsonResponse = downloadDataTask()
+
+    downloadImagesTask(jsonResponse, mainDir)
+}
+
+private fun downloadDataTask() : String {
+    return try {
+        val requestBody = createRequestBody()
+        val jsonRequest = createJsonRequest(requestBody)
+
+        val responseData = fetchData(jsonRequest)
+
+        responseData
+    } catch (e: Exception) {
+        Log.e("HTTP", "Error: ${e.message}")
+        "-1"
+    }
+}
+
+private fun createRequestBody(): String {
+    val username = "149002"
+    val password = "Vertretungsplan"
+    val currentDateTime = LocalDateTime.now().toString()
+
+    val requestBody = JSONObject().apply {
+        put("UserId", username)
+        put("UserPw", password)
+        put("AppVersion", "2.5.9")
+        put("Language", "de")
+        put("OsVersion", "28 8.0")
+        put("AppId", UUID.randomUUID().toString())
+        put("Device", "SM-G930F")
+        put("BundleId", "de.heinekingmedia.dsbmobile")
+        put("Date", currentDateTime)
+        put("LastUpdate", currentDateTime)
+    }
+
+    return Base64.encodeToString(GZIPCompress(requestBody.toString().toByteArray()), Base64.DEFAULT)
+}
+
+private fun createJsonRequest(requestBody: String): JSONObject {
+    return JSONObject().apply {
+        put("req", JSONObject().apply {
+            put("Data", requestBody)
+            put("DataType", 1)
+        })
+    }
+}
+
+private fun fetchData(jsonRequest: JSONObject): String {
+    val url = URL("https://app.dsbcontrol.de/JsonHandler.ashx/GetData")
+    val connection = (url.openConnection() as HttpURLConnection).apply {
+        requestMethod = "POST"
+        setRequestProperty("Content-Type", "application/json")
+        doOutput = true
+    }
+
+    connection.outputStream.use { outputStream ->
+        outputStream.write(jsonRequest.toString().toByteArray())
+    }
+
+    return if (connection.responseCode == HttpURLConnection.HTTP_OK) {
+        val responseData = connection.inputStream.bufferedReader().use { it.readText() }
+        val compressedResponseData = JSONObject(responseData).getString("d")
+        decompressGZIPAndDecodeBase64(compressedResponseData)
+    } else {
+        Log.e("HTTP", "Error response code: ${connection.responseCode}")
+        ""
+    }
+}
+
+private fun GZIPCompress(data: ByteArray): ByteArray {
+    return ByteArrayOutputStream().use { outputStream ->
+        GZIPOutputStream(outputStream).bufferedWriter().use { it.write(String(data)) }
+        outputStream.toByteArray()
+    }
+}
+
+private fun decompressGZIPAndDecodeBase64(compressedData: String): String {
+    val compressedByteArray = Base64.decode(compressedData, Base64.DEFAULT)
+    val inputStream = ByteArrayInputStream(compressedByteArray)
+    val outputStream = ByteArrayOutputStream()
+    GZIPInputStream(inputStream).use { gzipInputStream ->
+        val buffer = ByteArray(1024)
+        var len: Int
+        while (gzipInputStream.read(buffer).also { len = it } > 0) {
+            outputStream.write(buffer, 0, len)
+        }
+    }
+    return outputStream.toString("UTF-8")
+}
+
+private fun downloadImagesTask(jsonResponse: String, mainDir : File){
+    clearFolder(mainDir)
+
+    val jsonResponseObject = JSONObject(jsonResponse)
+    val jsonDaysObject = jsonResponseObject.getJSONArray("ResultMenuItems").getJSONObject(0).getJSONArray("Childs").getJSONObject(0).getJSONObject("Root").getJSONArray("Childs")
+
+    for (d in 0 until jsonDaysObject.length()) {
+        val jsonDayObject = jsonDaysObject.getJSONObject(d)
+        val dayID = jsonDayObject.get("Id")
+
+        val day = File(mainDir, dayID.toString())
+        day.mkdir()
+
+        val jsonPagesObject = jsonDayObject.getJSONArray("Childs")
+
+        for (p in 0 until jsonPagesObject.length()) {
+            val jsonPageObject = jsonPagesObject.getJSONObject(p)
+            val pageIndex = jsonPageObject.get("Index")
+            val imageLink = jsonPageObject.get("Detail").toString()
+
+            downloadImage(day, URL(imageLink), "$pageIndex.jpg")
+        }
+    }
+}
+
+private fun downloadImage(folder: File, url: URL, fileName: String){
+    val file = File(folder, fileName)
+
+    val connection = url.openConnection()
+    val inputStream = connection.getInputStream()
+    val outputStream = FileOutputStream(file)
+
+    val buffer = ByteArray(1024)
+    var bytesRead: Int
+
+    while (inputStream.read(buffer).also { bytesRead = it } != -1) {
+        outputStream.write(buffer, 0, bytesRead)
+    }
+
+    inputStream.close()
+    outputStream.close()
+}
+
+private fun createDataFolder(context: Context) : File {
+    val folderName = "dataDSB"
+    val folder = File(context.filesDir, folderName)
+
+    if (!folder.exists()) {
+        folder.mkdir()
+    }
+    return folder
+}
+
+private fun clearFolder(directory: File) {
+    if (directory.exists()) {
+        val files = directory.listFiles()
+        if (files != null) {
+            for (file in files) {
+                if (file.isDirectory) {
+                    clearFolder(file)
+                }
+                file.delete()
+            }
+        }
+    }
+}