Convert ImagesFragment to Kotlin

app/src/main/java/ai/elimu/content_provider/ui/image/ImagesFragment.kt

@@ -0,0 +1,189 @@
+package ai.elimu.content_provider.ui.image
+
+import ai.elimu.content_provider.BaseApplication
+import ai.elimu.content_provider.R
+import ai.elimu.content_provider.rest.ImagesService
+import ai.elimu.content_provider.room.GsonToRoomConverter
+import ai.elimu.content_provider.room.db.RoomDb
+import ai.elimu.content_provider.room.entity.Image_Word
+import ai.elimu.content_provider.util.FileHelper
+import ai.elimu.content_provider.util.MultimediaDownloader
+import ai.elimu.model.v2.gson.content.ImageGson
+import android.os.Bundle
+import android.util.Log
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.ProgressBar
+import android.widget.TextView
+import androidx.fragment.app.Fragment
+import androidx.lifecycle.Observer
+import androidx.lifecycle.ViewModelProvider
+import com.google.android.material.snackbar.Snackbar
+import retrofit2.Call
+import retrofit2.Callback
+import retrofit2.Response
+import java.io.FileNotFoundException
+import java.io.FileOutputStream
+import java.io.IOException
+import java.util.concurrent.Executors
+
+class ImagesFragment : Fragment() {
+    private var imagesViewModel: ImagesViewModel? = null
+
+    private var progressBar: ProgressBar? = null
+
+    private var textView: TextView? = null
+
+    private val TAG = ImagesFragment::class.java.name
+
+    override fun onCreateView(
+        inflater: LayoutInflater,
+        container: ViewGroup?,
+        savedInstanceState: Bundle?
+    ): View? {
+        Log.i(TAG, "onCreateView")
+
+        imagesViewModel = ViewModelProvider(this).get(ImagesViewModel::class.java)
+        val root = inflater.inflate(R.layout.fragment_images, container, false)
+        progressBar = root.findViewById(R.id.progress_bar_images)
+        textView = root.findViewById(R.id.text_images) as? TextView
+        imagesViewModel!!.text.observe(viewLifecycleOwner, object : Observer<String?> {
+            override fun onChanged(s: String?) {
+                Log.i(TAG, "onChanged")
+                textView?.text = s
+            }
+        })
+        return root
+    }
+
+    override fun onStart() {
+        Log.i(TAG, "onStart")
+        super.onStart()
+
+        // Download Images from REST API, and store them in the database
+        val baseApplication = activity!!.application as BaseApplication
+        val retrofit = baseApplication.retrofit
+        val imagesService = retrofit.create(ImagesService::class.java)
+        val imageGsonsCall = imagesService.listImages()
+        Log.i(TAG, "imageGsonsCall.request(): " + imageGsonsCall.request())
+        imageGsonsCall.enqueue(object : Callback<List<ImageGson>> {
+            override fun onResponse(
+                call: Call<List<ImageGson>>,
+                response: Response<List<ImageGson>>
+            ) {
+                Log.i(TAG, "onResponse")
+
+                Log.i(TAG, "response: $response")
+                if (response.isSuccessful) {
+                    val imageGsons = response.body()!!
+                    Log.i(TAG, "imageGsons.size(): " + imageGsons.size)
+
+                    if (imageGsons.size > 0) {
+                        processResponseBody(imageGsons)
+                    }
+                } else {
+                    // Handle error
+                    Snackbar.make(textView!!, response.toString(), Snackbar.LENGTH_LONG)
+                        .setBackgroundTint(resources.getColor(R.color.deep_orange_darken_4))
+                        .show()
+                    progressBar!!.visibility = View.GONE
+                }
+            }
+
+            override fun onFailure(call: Call<List<ImageGson>>, t: Throwable) {
+                Log.e(TAG, "onFailure", t)
+
+                Log.e(TAG, "t.getCause():", t.cause)
+
+                // Handle error
+                Snackbar.make(textView!!, t.cause.toString(), Snackbar.LENGTH_LONG)
+                    .setBackgroundTint(resources.getColor(R.color.deep_orange_darken_4))
+                    .show()
+                progressBar!!.visibility = View.GONE
+            }
+        })
+    }
+
+    private fun processResponseBody(imageGsons: List<ImageGson>) {
+        Log.i(TAG, "processResponseBody")
+
+        val executorService = Executors.newSingleThreadExecutor()
+        executorService.execute(object : Runnable {
+            override fun run() {
+                Log.i(TAG, "run")
+
+                val roomDb = RoomDb.getDatabase(context)
+                val imageDao = roomDb.imageDao()
+                val image_WordDao = roomDb.image_WordDao()
+
+                // Empty the database table before downloading up-to-date content
+                image_WordDao.deleteAll()
+                imageDao.deleteAll()
+
+                // TODO: also delete corresponding image files (only those that are no longer used)
+                for (imageGson in imageGsons) {
+                    Log.i(TAG, "imageGson.getId(): " + imageGson.id)
+
+                    val image = GsonToRoomConverter.getImage(imageGson)
+
+                    // Check if the corresponding image file has already been downloaded
+                    val imageFile = FileHelper.getImageFile(imageGson, context)
+                    Log.i(TAG, "imageFile: $imageFile")
+                    Log.i(TAG, "imageFile.exists(): " + imageFile.exists())
+                    if (!imageFile.exists()) {
+                        // Download file bytes
+                        val baseApplication = activity!!.application as BaseApplication
+                        val downloadUrl = if (imageGson.bytesUrl.startsWith("http"))
+                            imageGson.bytesUrl
+                        else
+                            baseApplication.baseUrl + imageGson.bytesUrl
+                        Log.i(TAG, "downloadUrl: $downloadUrl")
+                        val bytes = MultimediaDownloader.downloadFileBytes(downloadUrl)
+                        Log.i(TAG, "bytes.length: " + bytes.size)
+
+                        // Store the downloaded file in the external storage directory
+                        try {
+                            val fileOutputStream = FileOutputStream(imageFile)
+                            fileOutputStream.write(bytes)
+                        } catch (e: FileNotFoundException) {
+                            Log.e(TAG, null, e)
+                        } catch (e: IOException) {
+                            Log.e(TAG, null, e)
+                        }
+                        Log.i(TAG, "imageFile.exists(): " + imageFile.exists())
+                    }
+
+                    // Store the Image in the database
+                    imageDao.insert(image)
+                    Log.i(TAG, "Stored Image in database with ID " + image.id)
+
+                    // Store all the Image's Word labels in the database
+                    val wordGsons = imageGson.words
+                    Log.i(TAG, "wordGsons.size(): " + wordGsons.size)
+                    for (wordGson in wordGsons) {
+                        Log.i(TAG, "wordGson.getId(): " + wordGson.id)
+                        val image_Word = Image_Word()
+                        image_Word.image_id = imageGson.id
+                        image_Word.words_id = wordGson.id
+                        image_WordDao.insert(image_Word)
+                        Log.i(
+                            TAG,
+                            "Stored Image_Word in database. Image_id: " + image_Word.image_id + ", words_id: " + image_Word.words_id
+                        )
+                    }
+                }
+
+                // Update the UI
+                val images = imageDao.loadAll()
+                Log.i(TAG, "images.size(): " + images.size)
+                activity!!.runOnUiThread {
+                    textView!!.text = "images.size(): " + images.size
+                    Snackbar.make(textView!!, "images.size(): " + images.size, Snackbar.LENGTH_LONG)
+                        .show()
+                    progressBar!!.visibility = View.GONE
+                }
+            }
+        })
+    }
+}