Added a task to generate in the background the CSV representation of the filtered transactions with the same columns as the PDF export option.

app/src/main/java/cy/agorise/bitsybitshareswallet/fragments/TransactionsFragment.kt

@@ -20,10 +20,7 @@ import com.jakewharton.rxbinding3.appcompat.queryTextChangeEvents
 import cy.agorise.bitsybitshareswallet.R
 import cy.agorise.bitsybitshareswallet.adapters.TransfersDetailsAdapter
 import cy.agorise.bitsybitshareswallet.database.joins.TransferDetail
-import cy.agorise.bitsybitshareswallet.utils.BounceTouchListener
-import cy.agorise.bitsybitshareswallet.utils.Constants
-import cy.agorise.bitsybitshareswallet.utils.PDFGeneratorTask
-import cy.agorise.bitsybitshareswallet.utils.toast
+import cy.agorise.bitsybitshareswallet.utils.*
 import cy.agorise.bitsybitshareswallet.viewmodels.TransferDetailViewModel
 import io.reactivex.android.schedulers.AndroidSchedulers
 import io.reactivex.disposables.CompositeDisposable
@@ -32,6 +29,7 @@ import java.io.File
 import java.util.*
 import java.util.concurrent.TimeUnit
 import kotlin.collections.ArrayList
+import kotlin.math.exp
 
 class TransactionsFragment : Fragment(), FilterOptionsDialog.OnFilterOptionsSelectedListener {
 
@@ -280,6 +278,9 @@ class TransactionsFragment : Fragment(), FilterOptionsDialog.OnFilterOptionsSele
         if (exportPDF)
             activity?.let { PDFGeneratorTask(it).execute(filteredTransfersDetails) }
 
+        if (exportCSV)
+            activity?.let { CSVGenerationTask(it).execute(filteredTransfersDetails) }
+
     }
 
     override fun onDestroy() {

app/src/main/java/cy/agorise/bitsybitshareswallet/utils/CSVGenerationTask.kt

@@ -0,0 +1,97 @@
+package cy.agorise.bitsybitshareswallet.utils
+
+import android.content.Context
+import android.os.AsyncTask
+import android.os.Environment
+import android.util.Log
+import com.opencsv.CSVWriter
+import cy.agorise.bitsybitshareswallet.R
+import cy.agorise.bitsybitshareswallet.database.joins.TransferDetail
+import java.io.File
+import java.io.FileWriter
+import java.lang.ref.WeakReference
+import java.text.SimpleDateFormat
+import java.util.*
+
+/**
+ * AsyncTask subclass used to move the PDF generation procedure to a background thread
+ * and inform the UI of the progress.
+ */
+class CSVGenerationTask(context: Context) : AsyncTask<List<TransferDetail>, Int, String>() {
+
+    companion object {
+        private const val TAG = "CSVGenerationTask"
+    }
+
+    private val mContext: WeakReference<Context> = WeakReference(context)
+
+    override fun doInBackground(vararg params: List<TransferDetail>): String {
+        return createCSVDocument(params[0])
+    }
+
+    private fun createCSVDocument(transferDetails: List<TransferDetail>): String {
+        return try {
+            // Create and configure a new CSV file to save the transfers list
+            val externalStorageFolder = Environment.getExternalStorageDirectory().absolutePath + File.separator +
+                    Constants.EXTERNAL_STORAGE_FOLDER
+            val fileName = mContext.get()?.resources?.let {
+                "${it.getString(R.string.app_name)}-${it.getString(R.string.title_transactions)}"} + ".csv"
+            val file = File(externalStorageFolder, fileName)
+            file.createNewFile()
+            val csvWriter = CSVWriter(FileWriter(file))
+
+            // Add the table header
+            val row = Array(7) {""}     // Array initialized with empty strings
+            val columnNames = arrayOf(R.string.title_from, R.string.title_to, R.string.title_memo, R.string.title_date,
+                R.string.title_time, R.string.title_asset_amount, R.string.title_fiat_equivalent)
+            for ((i, columnName) in columnNames.withIndex()) {
+                row[i] = mContext.get()?.getString(columnName) ?: ""
+            }
+            csvWriter.writeNext(row)
+
+            // Configure date and time formats to reuse in all the transfers
+            val locale = mContext.get()?.resources?.configuration?.locale
+            val calendar = Calendar.getInstance()
+            val dateFormat = SimpleDateFormat("MM-dd-yyyy", locale)
+            val timeFormat = SimpleDateFormat("HH:MM:ss", locale)
+
+            // Save all the transfers information
+            for ( (index, transferDetail) in transferDetails.withIndex()) {
+                calendar.timeInMillis = transferDetail.date * 1000
+                val date = calendar.time
+
+                row[0] = transferDetail.from ?: ""          // From
+                row[1] = transferDetail.to ?: ""            // To
+                row[2] = transferDetail.memo                // Memo
+                row[3] = dateFormat.format(date)            // Date
+                row[4] = timeFormat.format(date)            // Time
+
+                // Asset Amount
+                val assetPrecision = transferDetail.assetPrecision
+                val assetAmount = transferDetail.assetAmount.toDouble() / Math.pow(10.0, assetPrecision.toDouble())
+                row[5] = String.format("%.${assetPrecision}f %s", assetAmount, transferDetail.assetSymbol)
+
+                // Fiat Equivalent TODO add once Nelson finishes
+                row[6] = ""
+
+                csvWriter.writeNext(row)
+
+                // TODO update progress
+            }
+
+            csvWriter.close()
+            "CSV generated and saved: ${file.absolutePath}"
+        } catch (e: Exception) {
+            Log.e(TAG, "Exception while trying to generate a CSV. Msg: " + e.message)
+            "Unable to generate CSV. Please retry. Error: ${e.message}"
+        }
+    }
+
+    override fun onProgressUpdate(values: Array<Int>) {
+        // TODO show progress
+    }
+
+    override fun onPostExecute(message: String) {
+        mContext.get()?.toast(message)
+    }
+}