app/src/main/java/net/ktnx/mobileledger/async/RetrieveTransactionsTask.java

   1 /*
   2  * Copyright © 2018 Damyan Ivanov.
   3  * This file is part of Mobile-Ledger.
   4  * Mobile-Ledger is free software: you can distribute it and/or modify it
   5  * under the term of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your opinion), any later version.
   8  *
   9  * Mobile-Ledger is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  12  * GNU General Public License terms for details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with Mobile-Ledger. If not, see <https://www.gnu.org/licenses/>.
  16  */
  17
  18 package net.ktnx.mobileledger.async;
  19
  20 import android.annotation.SuppressLint;
  21 import android.content.Context;
  22 import android.content.SharedPreferences;
  23 import android.database.sqlite.SQLiteDatabase;
  24 import android.os.AsyncTask;
  25 import android.util.Log;
  26
  27 import net.ktnx.mobileledger.R;
  28 import net.ktnx.mobileledger.TransactionListActivity;
  29 import net.ktnx.mobileledger.model.LedgerTransaction;
  30 import net.ktnx.mobileledger.model.LedgerTransactionItem;
  31 import net.ktnx.mobileledger.utils.MLDB;
  32 import net.ktnx.mobileledger.utils.NetworkUtil;
  33
  34 import java.io.BufferedReader;
  35 import java.io.FileNotFoundException;
  36 import java.io.IOException;
  37 import java.io.InputStream;
  38 import java.io.InputStreamReader;
  39 import java.lang.ref.WeakReference;
  40 import java.net.HttpURLConnection;
  41 import java.net.MalformedURLException;
  42 import java.util.regex.Matcher;
  43 import java.util.regex.Pattern;
  44
  45
  46 public class RetrieveTransactionsTask extends
  47         AsyncTask<RetrieveTransactionsTask.Params, RetrieveTransactionsTask.Progress, Void> {
  48     private static final Pattern transactionStartPattern = Pattern.compile("<tr class=\"title\" " +
  49                                                                            "id=\"transaction-(\\d+)\"><td class=\"date\"[^\\\"]*>([\\d.-]+)</td>");
  50     private static final Pattern transactionDescriptionPattern =
  51             Pattern.compile("<tr class=\"posting\" title=\"(\\S+)\\s(.+)");
  52     private static final Pattern transactionDetailsPattern =
  53             Pattern.compile("^\\s+" + "(\\S[\\S\\s]+\\S)\\s\\s+([-+]?\\d[\\d,.]*)");
  54     private static final Pattern endPattern = Pattern.compile("\\bid=\"addmodal\"");
  55     protected WeakReference<TransactionListActivity> contextRef;
  56     protected int error;
  57     private boolean success;
  58     public RetrieveTransactionsTask(WeakReference<TransactionListActivity> contextRef) {
  59         this.contextRef = contextRef;
  60     }
  61     private static final void L(String msg) {
  62         Log.d("transaction-parser", msg);
  63     }
  64     @Override
  65     protected void onProgressUpdate(Progress... values) {
  66         super.onProgressUpdate(values);
  67         TransactionListActivity context = getContext();
  68         if (context == null) return;
  69         context.onRetrieveProgress(values[0]);
  70     }
  71     @Override
  72     protected void onPreExecute() {
  73         super.onPreExecute();
  74         TransactionListActivity context = getContext();
  75         if (context == null) return;
  76         context.onRetrieveStart();
  77     }
  78     @Override
  79     protected void onPostExecute(Void aVoid) {
  80         super.onPostExecute(aVoid);
  81         TransactionListActivity context = getContext();
  82         if (context == null) return;
  83         context.onRetrieveDone(success);
  84     }
  85     @SuppressLint("DefaultLocale")
  86     @Override
  87     protected Void doInBackground(Params... params) {
  88         Progress progress = new Progress();
  89         success = false;
  90         try {
  91             HttpURLConnection http =
  92                     NetworkUtil.prepare_connection(params[0].getBackendPref(), "journal");
  93             http.setAllowUserInteraction(false);
  94             publishProgress(progress);
  95             Context ctx = contextRef.get();
  96             if (ctx == null) return null;
  97             try (SQLiteDatabase db = MLDB.getWritableDatabase(ctx)) {
  98                 try (InputStream resp = http.getInputStream()) {
  99                     if (http.getResponseCode() != 200) throw new IOException(
 100                             String.format("HTTP error %d", http.getResponseCode()));
 101                     db.beginTransaction();
 102                     try {
 103                         db.execSQL("DELETE FROM transactions;");
 104                         db.execSQL("DELETE FROM transaction_accounts");
 105
 106                         int state = ParserState.EXPECTING_JOURNAL;
 107                         String line;
 108                         BufferedReader buf =
 109                                 new BufferedReader(new InputStreamReader(resp, "UTF-8"));
 110
 111                         int transactionCount = 0;
 112                         int transactionId = 0;
 113                         LedgerTransaction transaction = null;
 114                         LINES:
 115                         while ((line = buf.readLine()) != null) {
 116                             if (isCancelled()) break;
 117                             Matcher m;
 118                             //L(String.format("State is %d", state));
 119                             switch (state) {
 120                                 case ParserState.EXPECTING_JOURNAL:
 121                                     if (!line.isEmpty() && (line.charAt(0) == ' ')) continue;
 122                                     if (line.equals("<h2>General Journal</h2>")) {
 123                                         state = ParserState.EXPECTING_TRANSACTION;
 124                                         L("→ expecting transaction");
 125                                     }
 126                                     break;
 127                                 case ParserState.EXPECTING_TRANSACTION:
 128                                     if (!line.isEmpty() && (line.charAt(0) == ' ')) continue;
 129                                     m = transactionStartPattern.matcher(line);
 130                                     if (m.find()) {
 131                                         transactionId = Integer.valueOf(m.group(1));
 132                                         state = ParserState.EXPECTING_TRANSACTION_DESCRIPTION;
 133                                         L(String.format(
 134                                                 "found transaction %d → expecting " + "description",
 135                                                 transactionId));
 136                                         progress.setProgress(++transactionCount);
 137                                         if (progress.getTotal() == Progress.INDETERMINATE)
 138                                             progress.setTotal(transactionId);
 139                                         publishProgress(progress);
 140                                     }
 141                                     m = endPattern.matcher(line);
 142                                     if (m.find()) {
 143                                         L("--- transaction list complete ---");
 144                                         success = true;
 145                                         break LINES;
 146                                     }
 147                                     break;
 148                                 case ParserState.EXPECTING_TRANSACTION_DESCRIPTION:
 149                                     if (!line.isEmpty() && (line.charAt(0) == ' ')) continue;
 150                                     m = transactionDescriptionPattern.matcher(line);
 151                                     if (m.find()) {
 152                                         if (transactionId == 0)
 153                                             throw new TransactionParserException(
 154                                                     "Transaction Id is 0 while expecting " +
 155                                                     "description");
 156
 157                                         transaction =
 158                                                 new LedgerTransaction(transactionId, m.group(1),
 159                                                         m.group(2));
 160                                         state = ParserState.EXPECTING_TRANSACTION_DETAILS;
 161                                         L(String.format("transaction %d created for %s (%s) →" +
 162                                                         " expecting details", transactionId,
 163                                                 m.group(1), m.group(2)));
 164                                     }
 165                                     break;
 166                                 case ParserState.EXPECTING_TRANSACTION_DETAILS:
 167                                     if (line.isEmpty()) {
 168                                         // transaction data collected
 169                                         transaction.insertInto(db);
 170
 171                                         state = ParserState.EXPECTING_TRANSACTION;
 172                                         L(String.format(
 173                                                 "transaction %s saved → expecting " + "transaction",
 174                                                 transaction.getId()));
 175
 176 // sounds like a good idea, but transaction-1 may not be the first one chronologically
 177 // for example, when you add the initial seeding transaction after entering some others
 178 //                                            if (transactionId == 1) {
 179 //                                                L("This was the initial transaction. Terminating " +
 180 //                                                  "parser");
 181 //                                                break LINES;
 182 //                                            }
 183                                     }
 184                                     else {
 185                                         m = transactionDetailsPattern.matcher(line);
 186                                         if (m.find()) {
 187                                             String acc_name = m.group(1);
 188                                             String amount = m.group(2);
 189                                             amount = amount.replace(',', '.');
 190                                             transaction.add_item(new LedgerTransactionItem(acc_name,
 191                                                     Float.valueOf(amount)));
 192                                             L(String.format("%s = %s", acc_name, amount));
 193                                         }
 194                                         else throw new IllegalStateException(
 195                                                 String.format("Can't parse transaction details"));
 196                                     }
 197                                     break;
 198                                 default:
 199                                     throw new RuntimeException(
 200                                             String.format("Unknown " + "parser state %d", state));
 201                             }
 202                         }
 203                         if (!isCancelled()) db.setTransactionSuccessful();
 204                     }
 205                     finally {
 206                         db.endTransaction();
 207                     }
 208                 }
 209             }
 210         }
 211         catch (MalformedURLException e) {
 212             error = R.string.err_bad_backend_url;
 213             e.printStackTrace();
 214         }
 215         catch (FileNotFoundException e) {
 216             error = R.string.err_bad_auth;
 217             e.printStackTrace();
 218         }
 219         catch (IOException e) {
 220             error = R.string.err_net_io_error;
 221             e.printStackTrace();
 222         }
 223         return null;
 224     }
 225     TransactionListActivity getContext() {
 226         return contextRef.get();
 227     }
 228
 229     public static class Params {
 230         static final int DEFAULT_LIMIT = 100;
 231         private SharedPreferences backendPref;
 232         private String accountsRoot;
 233         private int limit;
 234
 235         public Params(SharedPreferences backendPref) {
 236             this.backendPref = backendPref;
 237             this.accountsRoot = null;
 238             this.limit = DEFAULT_LIMIT;
 239         }
 240         Params(SharedPreferences backendPref, String accountsRoot) {
 241             this(backendPref, accountsRoot, DEFAULT_LIMIT);
 242         }
 243         Params(SharedPreferences backendPref, String accountsRoot, int limit) {
 244             this.backendPref = backendPref;
 245             this.accountsRoot = accountsRoot;
 246             this.limit = limit;
 247         }
 248         String getAccountsRoot() {
 249             return accountsRoot;
 250         }
 251         SharedPreferences getBackendPref() {
 252             return backendPref;
 253         }
 254         int getLimit() {
 255             return limit;
 256         }
 257     }
 258
 259     public class Progress {
 260         public static final int INDETERMINATE = -1;
 261         private int progress;
 262         private int total;
 263         Progress() {
 264             this(INDETERMINATE, INDETERMINATE);
 265         }
 266         Progress(int progress, int total) {
 267             this.progress = progress;
 268             this.total = total;
 269         }
 270         public int getProgress() {
 271             return progress;
 272         }
 273         protected void setProgress(int progress) {
 274             this.progress = progress;
 275         }
 276         public int getTotal() {
 277             return total;
 278         }
 279         protected void setTotal(int total) {
 280             this.total = total;
 281         }
 282     }
 283
 284     private class TransactionParserException extends IllegalStateException {
 285         TransactionParserException(String message) {
 286             super(message);
 287         }
 288     }
 289
 290     private class ParserState {
 291         static final int EXPECTING_JOURNAL = 0;
 292         static final int EXPECTING_TRANSACTION = 1;
 293         static final int EXPECTING_TRANSACTION_DESCRIPTION = 2;
 294         static final int EXPECTING_TRANSACTION_DETAILS = 3;
 295     }
 296 }