app/src/main/java/net/ktnx/mobileledger/ui/new_transaction/NewTransactionModel.java

   1 /*
   2  * Copyright © 2021 Damyan Ivanov.
   3  * This file is part of MoLe.
   4  * MoLe 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  * MoLe 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 MoLe. If not, see <https://www.gnu.org/licenses/>.
  16  */
  17
  18 package net.ktnx.mobileledger.ui.new_transaction;
  19
  20 import android.annotation.SuppressLint;
  21 import android.text.TextUtils;
  22
  23 import androidx.annotation.NonNull;
  24 import androidx.annotation.Nullable;
  25 import androidx.lifecycle.LifecycleOwner;
  26 import androidx.lifecycle.LiveData;
  27 import androidx.lifecycle.MutableLiveData;
  28 import androidx.lifecycle.Observer;
  29 import androidx.lifecycle.ViewModel;
  30
  31 import net.ktnx.mobileledger.BuildConfig;
  32 import net.ktnx.mobileledger.db.DB;
  33 import net.ktnx.mobileledger.db.Profile;
  34 import net.ktnx.mobileledger.db.TemplateAccount;
  35 import net.ktnx.mobileledger.db.TemplateHeader;
  36 import net.ktnx.mobileledger.db.TransactionWithAccounts;
  37 import net.ktnx.mobileledger.model.Data;
  38 import net.ktnx.mobileledger.model.InertMutableLiveData;
  39 import net.ktnx.mobileledger.model.LedgerTransaction;
  40 import net.ktnx.mobileledger.model.LedgerTransactionAccount;
  41 import net.ktnx.mobileledger.model.MatchedTemplate;
  42 import net.ktnx.mobileledger.utils.Globals;
  43 import net.ktnx.mobileledger.utils.Logger;
  44 import net.ktnx.mobileledger.utils.Misc;
  45 import net.ktnx.mobileledger.utils.SimpleDate;
  46
  47 import org.jetbrains.annotations.NotNull;
  48
  49 import java.text.ParseException;
  50 import java.util.ArrayList;
  51 import java.util.Calendar;
  52 import java.util.GregorianCalendar;
  53 import java.util.HashMap;
  54 import java.util.List;
  55 import java.util.Locale;
  56 import java.util.Objects;
  57 import java.util.Set;
  58 import java.util.concurrent.atomic.AtomicInteger;
  59 import java.util.regex.MatchResult;
  60
  61 enum ItemType {generalData, transactionRow}
  62
  63 enum FocusedElement {Account, Comment, Amount, Description, TransactionComment}
  64
  65
  66 public class NewTransactionModel extends ViewModel {
  67     private static final int MIN_ITEMS = 3;
  68     private final MutableLiveData<Boolean> showCurrency = new MutableLiveData<>(false);
  69     private final MutableLiveData<Boolean> isSubmittable = new InertMutableLiveData<>(false);
  70     private final MutableLiveData<Boolean> showComments = new MutableLiveData<>(true);
  71     private final MutableLiveData<List<Item>> items = new MutableLiveData<>();
  72     private final MutableLiveData<Boolean> simulateSave = new InertMutableLiveData<>(false);
  73     private final AtomicInteger busyCounter = new AtomicInteger(0);
  74     private final MutableLiveData<Boolean> busyFlag = new InertMutableLiveData<>(false);
  75     private final Observer<Profile> profileObserver = profile -> {
  76         showCurrency.postValue(profile.getShowCommodityByDefault());
  77         showComments.postValue(profile.getShowCommentsByDefault());
  78     };
  79     private final MutableLiveData<FocusInfo> focusInfo = new MutableLiveData<>();
  80     private boolean observingDataProfile;
  81     public NewTransactionModel() {
  82         reset();
  83     }
  84     public LiveData<Boolean> getShowCurrency() {
  85         return showCurrency;
  86     }
  87     public LiveData<List<Item>> getItems() {
  88         return items;
  89     }
  90     private void setItems(@NonNull List<Item> newList) {
  91         checkTransactionSubmittable(newList);
  92         setItemsWithoutSubmittableChecks(newList);
  93     }
  94     private void replaceItems(@NonNull List<Item> newList) {
  95         renumberItems();
  96
  97         setItems(newList);
  98     }
  99     /**
 100      * make old items replaceable in-place. makes the new values visually blend in
 101      */
 102     private void renumberItems() {
 103         final List<Item> list = items.getValue();
 104         if (list == null) {
 105             return;
 106         }
 107
 108         int id = 0;
 109         for (Item item : list)
 110             item.id = id++;
 111     }
 112     private void setItemsWithoutSubmittableChecks(@NonNull List<Item> list) {
 113         final int cnt = list.size();
 114         for (int i = 1; i < cnt - 1; i++) {
 115             final TransactionAccount item = list.get(i)
 116                                                 .toTransactionAccount();
 117             if (item.isLast) {
 118                 TransactionAccount replacement = new TransactionAccount(item);
 119                 replacement.isLast = false;
 120                 list.set(i, replacement);
 121             }
 122         }
 123         final TransactionAccount last = list.get(cnt - 1)
 124                                             .toTransactionAccount();
 125         if (!last.isLast) {
 126             TransactionAccount replacement = new TransactionAccount(last);
 127             replacement.isLast = true;
 128             list.set(cnt - 1, replacement);
 129         }
 130
 131         if (BuildConfig.DEBUG)
 132             dumpItemList("Before setValue()", list);
 133         items.setValue(list);
 134     }
 135     private List<Item> copyList() {
 136         List<Item> copy = new ArrayList<>();
 137         List<Item> oldList = items.getValue();
 138
 139         if (oldList != null)
 140             for (Item item : oldList) {
 141                 copy.add(Item.from(item));
 142             }
 143
 144         return copy;
 145     }
 146     private List<Item> copyListWithoutItem(int position) {
 147         List<Item> copy = new ArrayList<>();
 148         List<Item> oldList = items.getValue();
 149
 150         if (oldList != null) {
 151             int i = 0;
 152             for (Item item : oldList) {
 153                 if (i++ == position)
 154                     continue;
 155                 copy.add(Item.from(item));
 156             }
 157         }
 158
 159         return copy;
 160     }
 161     private List<Item> shallowCopyList() {
 162         return new ArrayList<>(items.getValue());
 163     }
 164     LiveData<Boolean> getShowComments() {
 165         return showComments;
 166     }
 167     void observeDataProfile(LifecycleOwner activity) {
 168         if (!observingDataProfile)
 169             Data.observeProfile(activity, profileObserver);
 170         observingDataProfile = true;
 171     }
 172     boolean getSimulateSaveFlag() {
 173         Boolean value = simulateSave.getValue();
 174         if (value == null)
 175             return false;
 176         return value;
 177     }
 178     LiveData<Boolean> getSimulateSave() {
 179         return simulateSave;
 180     }
 181     void toggleSimulateSave() {
 182         simulateSave.setValue(!getSimulateSaveFlag());
 183     }
 184     LiveData<Boolean> isSubmittable() {
 185         return this.isSubmittable;
 186     }
 187     void reset() {
 188         Logger.debug("new-trans", "Resetting model");
 189         List<Item> list = new ArrayList<>();
 190         Item.resetIdDispenser();
 191         list.add(new TransactionHead(""));
 192         list.add(new TransactionAccount(""));
 193         list.add(new TransactionAccount(""));
 194         noteFocusChanged(0, FocusedElement.Description);
 195         renumberItems();
 196         isSubmittable.setValue(false);
 197         setItemsWithoutSubmittableChecks(list);
 198     }
 199     boolean accountsInInitialState() {
 200         final List<Item> list = items.getValue();
 201
 202         if (list == null)
 203             return true;
 204
 205         for (Item item : list) {
 206             if (!(item instanceof TransactionAccount))
 207                 continue;
 208
 209             TransactionAccount accRow = (TransactionAccount) item;
 210             if (!accRow.isEmpty())
 211                 return false;
 212         }
 213
 214         return true;
 215     }
 216     void applyTemplate(MatchedTemplate matchedTemplate, String text) {
 217         SimpleDate transactionDate = null;
 218         final MatchResult matchResult = matchedTemplate.matchResult;
 219         final TemplateHeader templateHead = matchedTemplate.templateHead;
 220         {
 221             int day = extractIntFromMatches(matchResult, templateHead.getDateDayMatchGroup(),
 222                     templateHead.getDateDay());
 223             int month = extractIntFromMatches(matchResult, templateHead.getDateMonthMatchGroup(),
 224                     templateHead.getDateMonth());
 225             int year = extractIntFromMatches(matchResult, templateHead.getDateYearMatchGroup(),
 226                     templateHead.getDateYear());
 227
 228             if (year > 0 || month > 0 || day > 0) {
 229                 SimpleDate today = SimpleDate.today();
 230                 if (year <= 0)
 231                     year = today.year;
 232                 if (month <= 0)
 233                     month = today.month;
 234                 if (day <= 0)
 235                     day = today.day;
 236
 237                 transactionDate = new SimpleDate(year, month, day);
 238
 239                 Logger.debug("pattern", "setting transaction date to " + transactionDate);
 240             }
 241         }
 242
 243         List<Item> present = copyList();
 244
 245         TransactionHead head = new TransactionHead(present.get(0)
 246                                                           .toTransactionHead());
 247         if (transactionDate != null)
 248             head.setDate(transactionDate);
 249
 250         final String transactionDescription = extractStringFromMatches(matchResult,
 251                 templateHead.getTransactionDescriptionMatchGroup(),
 252                 templateHead.getTransactionDescription());
 253         if (Misc.emptyIsNull(transactionDescription) != null)
 254             head.setDescription(transactionDescription);
 255
 256         final String transactionComment = extractStringFromMatches(matchResult,
 257                 templateHead.getTransactionCommentMatchGroup(),
 258                 templateHead.getTransactionComment());
 259         if (Misc.emptyIsNull(transactionComment) != null)
 260             head.setComment(transactionComment);
 261
 262         Item.resetIdDispenser();
 263         List<Item> newItems = new ArrayList<>();
 264
 265         newItems.add(head);
 266
 267         for (int i = 1; i < present.size(); i++) {
 268             final TransactionAccount row = present.get(i)
 269                                                   .toTransactionAccount();
 270             if (!row.isEmpty())
 271                 newItems.add(new TransactionAccount(row));
 272         }
 273
 274         DB.get()
 275           .getTemplateDAO()
 276           .getTemplateWithAccountsAsync(templateHead.getId(), entry -> {
 277               int rowIndex = 0;
 278               final boolean accountsInInitialState = accountsInInitialState();
 279               for (TemplateAccount acc : entry.accounts) {
 280                   rowIndex++;
 281
 282                   String accountName =
 283                           extractStringFromMatches(matchResult, acc.getAccountNameMatchGroup(),
 284                                   acc.getAccountName());
 285                   String accountComment =
 286                           extractStringFromMatches(matchResult, acc.getAccountCommentMatchGroup(),
 287                                   acc.getAccountComment());
 288                   Float amount = extractFloatFromMatches(matchResult, acc.getAmountMatchGroup(),
 289                           acc.getAmount());
 290                   if (amount != null && acc.getNegateAmount() != null && acc.getNegateAmount())
 291                       amount = -amount;
 292
 293                   // TODO currency
 294                   TransactionAccount accRow = new TransactionAccount(accountName);
 295                   accRow.setComment(accountComment);
 296                   if (amount != null)
 297                       accRow.setAmount(amount);
 298
 299                   newItems.add(accRow);
 300               }
 301
 302               Misc.onMainThread(() -> replaceItems(newItems));
 303           });
 304     }
 305     private int extractIntFromMatches(MatchResult m, Integer group, Integer literal) {
 306         if (literal != null)
 307             return literal;
 308
 309         if (group != null) {
 310             int grp = group;
 311             if (grp > 0 & grp <= m.groupCount())
 312                 try {
 313                     return Integer.parseInt(m.group(grp));
 314                 }
 315                 catch (NumberFormatException e) {
 316                     Logger.debug("new-trans", "Error extracting matched number", e);
 317                 }
 318         }
 319
 320         return 0;
 321     }
 322     private String extractStringFromMatches(MatchResult m, Integer group, String literal) {
 323         if (literal != null)
 324             return literal;
 325
 326         if (group != null) {
 327             int grp = group;
 328             if (grp > 0 & grp <= m.groupCount())
 329                 return m.group(grp);
 330         }
 331
 332         return null;
 333     }
 334     private Float extractFloatFromMatches(MatchResult m, Integer group, Float literal) {
 335         if (literal != null)
 336             return literal;
 337
 338         if (group != null) {
 339             int grp = group;
 340             if (grp > 0 & grp <= m.groupCount())
 341                 try {
 342                     return Float.valueOf(m.group(grp));
 343                 }
 344                 catch (NumberFormatException e) {
 345                     Logger.debug("new-trans", "Error extracting matched number", e);
 346                 }
 347         }
 348
 349         return null;
 350     }
 351     void removeItem(int pos) {
 352         Logger.debug("new-trans", String.format(Locale.US, "Removing item at position %d", pos));
 353         List<Item> newList = copyListWithoutItem(pos);
 354         final FocusInfo fi = focusInfo.getValue();
 355         if ((fi != null) && (pos < fi.position))
 356             noteFocusChanged(fi.position - 1, fi.element);
 357         setItems(newList);
 358     }
 359     void noteFocusChanged(int position, FocusedElement element) {
 360         FocusInfo present = focusInfo.getValue();
 361         if (present == null || present.position != position || present.element != element)
 362             focusInfo.setValue(new FocusInfo(position, element));
 363     }
 364     public LiveData<FocusInfo> getFocusInfo() {
 365         return focusInfo;
 366     }
 367     void moveItem(int fromIndex, int toIndex) {
 368         List<Item> newList = shallowCopyList();
 369         Item item = newList.remove(fromIndex);
 370         newList.add(toIndex, item);
 371
 372         FocusInfo fi = focusInfo.getValue();
 373         if (fi != null && fi.position == fromIndex)
 374             noteFocusChanged(toIndex, fi.element);
 375
 376         items.setValue(newList); // same count, same submittable state
 377     }
 378     void moveItemLast(List<Item> list, int index) {
 379         /*   0
 380              1   <-- index
 381              2
 382              3   <-- desired position
 383                  (no bottom filler)
 384          */
 385         int itemCount = list.size();
 386
 387         if (index < itemCount - 1)
 388             list.add(list.remove(index));
 389     }
 390     void toggleCurrencyVisible() {
 391         final boolean newValue = !Objects.requireNonNull(showCurrency.getValue());
 392
 393         // remove currency from all items, or reset currency to the default
 394         // no need to clone the list, because the removal of the currency won't lead to
 395         // visual changes -- the currency fields will be hidden or reset to default anyway
 396         // still, there may be changes in the submittable state
 397         final List<Item> list = Objects.requireNonNull(this.items.getValue());
 398         for (int i = 1; i < list.size(); i++) {
 399             ((TransactionAccount) list.get(i)).setCurrency(newValue ? Data.getProfile()
 400                                                                           .getDefaultCommodity()
 401                                                                     : null);
 402         }
 403         checkTransactionSubmittable(null);
 404         showCurrency.setValue(newValue);
 405     }
 406     void stopObservingBusyFlag(Observer<Boolean> observer) {
 407         busyFlag.removeObserver(observer);
 408     }
 409     void incrementBusyCounter() {
 410         int newValue = busyCounter.incrementAndGet();
 411         if (newValue == 1)
 412             busyFlag.postValue(true);
 413     }
 414     void decrementBusyCounter() {
 415         int newValue = busyCounter.decrementAndGet();
 416         if (newValue == 0)
 417             busyFlag.postValue(false);
 418     }
 419     public LiveData<Boolean> getBusyFlag() {
 420         return busyFlag;
 421     }
 422     public void toggleShowComments() {
 423         showComments.setValue(!Objects.requireNonNull(showComments.getValue()));
 424     }
 425     public LedgerTransaction constructLedgerTransaction() {
 426         List<Item> list = Objects.requireNonNull(items.getValue());
 427         TransactionHead head = list.get(0)
 428                                    .toTransactionHead();
 429         SimpleDate date = head.getDate();
 430         LedgerTransaction tr = head.asLedgerTransaction();
 431
 432         tr.setComment(head.getComment());
 433         LedgerTransactionAccount emptyAmountAccount = null;
 434         float emptyAmountAccountBalance = 0;
 435         for (int i = 1; i < list.size(); i++) {
 436             TransactionAccount item = list.get(i)
 437                                           .toTransactionAccount();
 438             LedgerTransactionAccount acc = new LedgerTransactionAccount(item.getAccountName()
 439                                                                             .trim(),
 440                     item.getCurrency());
 441             if (acc.getAccountName()
 442                    .isEmpty())
 443                 continue;
 444
 445             acc.setComment(item.getComment());
 446
 447             if (item.isAmountSet()) {
 448                 acc.setAmount(item.getAmount());
 449                 emptyAmountAccountBalance += item.getAmount();
 450             }
 451             else {
 452                 emptyAmountAccount = acc;
 453             }
 454
 455             tr.addAccount(acc);
 456         }
 457
 458         if (emptyAmountAccount != null)
 459             emptyAmountAccount.setAmount(-emptyAmountAccountBalance);
 460
 461         return tr;
 462     }
 463     void loadTransactionIntoModel(@NonNull TransactionWithAccounts tr) {
 464         List<Item> newList = new ArrayList<>();
 465         Item.resetIdDispenser();
 466
 467         TransactionHead head = new TransactionHead(tr.transaction.getDescription());
 468         head.setComment(tr.transaction.getComment());
 469
 470         newList.add(head);
 471
 472         List<LedgerTransactionAccount> accounts = new ArrayList<>();
 473         for (net.ktnx.mobileledger.db.TransactionAccount acc : tr.accounts) {
 474             accounts.add(new LedgerTransactionAccount(acc));
 475         }
 476
 477         TransactionAccount firstNegative = null;
 478         TransactionAccount firstPositive = null;
 479         int singleNegativeIndex = -1;
 480         int singlePositiveIndex = -1;
 481         int negativeCount = 0;
 482         for (int i = 0; i < accounts.size(); i++) {
 483             LedgerTransactionAccount acc = accounts.get(i);
 484             TransactionAccount item =
 485                     new TransactionAccount(acc.getAccountName(), acc.getCurrency());
 486             newList.add(item);
 487
 488             item.setAccountName(acc.getAccountName());
 489             item.setComment(acc.getComment());
 490             if (acc.isAmountSet()) {
 491                 item.setAmount(acc.getAmount());
 492                 if (acc.getAmount() < 0) {
 493                     if (firstNegative == null) {
 494                         firstNegative = item;
 495                         singleNegativeIndex = i + 1;
 496                     }
 497                     else
 498                         singleNegativeIndex = -1;
 499                 }
 500                 else {
 501                     if (firstPositive == null) {
 502                         firstPositive = item;
 503                         singlePositiveIndex = i + 1;
 504                     }
 505                     else
 506                         singlePositiveIndex = -1;
 507                 }
 508             }
 509             else
 510                 item.resetAmount();
 511         }
 512         if (BuildConfig.DEBUG)
 513             dumpItemList("Loaded previous transaction", newList);
 514
 515         if (singleNegativeIndex != -1) {
 516             firstNegative.resetAmount();
 517             moveItemLast(newList, singleNegativeIndex);
 518         }
 519         else if (singlePositiveIndex != -1) {
 520             firstPositive.resetAmount();
 521             moveItemLast(newList, singlePositiveIndex);
 522         }
 523
 524         Misc.onMainThread(() -> {
 525             setItems(newList);
 526             noteFocusChanged(1, FocusedElement.Amount);
 527         });
 528     }
 529     /**
 530      * A transaction is submittable if:
 531      * 0) has description
 532      * 1) has at least two account names
 533      * 2) each row with amount has account name
 534      * 3) for each commodity:
 535      * 3a) amounts must balance to 0, or
 536      * 3b) there must be exactly one empty amount (with account)
 537      * 4) empty accounts with empty amounts are ignored
 538      * Side effects:
 539      * 5) a row with an empty account name or empty amount is guaranteed to exist for each
 540      * commodity
 541      * 6) at least two rows need to be present in the ledger
 542      *
 543      * @param list - the item list to check. Can be the displayed list or a list that will be
 544      *             displayed soon
 545      */
 546     @SuppressLint("DefaultLocale")
 547     void checkTransactionSubmittable(@Nullable List<Item> list) {
 548         boolean workingWithLiveList = false;
 549         if (list == null) {
 550             list = copyList();
 551             workingWithLiveList = true;
 552         }
 553
 554         if (BuildConfig.DEBUG)
 555             dumpItemList(String.format("Before submittable checks (%s)",
 556                     workingWithLiveList ? "LIVE LIST" : "custom list"), list);
 557
 558         int accounts = 0;
 559         final BalanceForCurrency balance = new BalanceForCurrency();
 560         final String descriptionText = list.get(0)
 561                                            .toTransactionHead()
 562                                            .getDescription();
 563         boolean submittable = true;
 564         boolean listChanged = false;
 565         final ItemsForCurrency itemsForCurrency = new ItemsForCurrency();
 566         final ItemsForCurrency itemsWithEmptyAmountForCurrency = new ItemsForCurrency();
 567         final ItemsForCurrency itemsWithAccountAndEmptyAmountForCurrency = new ItemsForCurrency();
 568         final ItemsForCurrency itemsWithEmptyAccountForCurrency = new ItemsForCurrency();
 569         final ItemsForCurrency itemsWithAmountForCurrency = new ItemsForCurrency();
 570         final ItemsForCurrency itemsWithAccountForCurrency = new ItemsForCurrency();
 571         final ItemsForCurrency emptyRowsForCurrency = new ItemsForCurrency();
 572         final List<Item> emptyRows = new ArrayList<>();
 573
 574         try {
 575             if ((descriptionText == null) || descriptionText.trim()
 576                                                             .isEmpty())
 577             {
 578                 Logger.debug("submittable", "Transaction not submittable: missing description");
 579                 submittable = false;
 580             }
 581
 582             for (int i = 1; i < list.size(); i++) {
 583                 TransactionAccount item = list.get(i)
 584                                               .toTransactionAccount();
 585
 586                 String accName = item.getAccountName()
 587                                      .trim();
 588                 String currName = item.getCurrency();
 589
 590                 itemsForCurrency.add(currName, item);
 591
 592                 if (accName.isEmpty()) {
 593                     itemsWithEmptyAccountForCurrency.add(currName, item);
 594
 595                     if (item.isAmountSet()) {
 596                         // 2) each amount has account name
 597                         Logger.debug("submittable", String.format(
 598                                 "Transaction not submittable: row %d has no account name, but" +
 599                                 " has" + " amount %1.2f", i + 1, item.getAmount()));
 600                         submittable = false;
 601                     }
 602                     else {
 603                         emptyRowsForCurrency.add(currName, item);
 604                     }
 605                 }
 606                 else {
 607                     accounts++;
 608                     itemsWithAccountForCurrency.add(currName, item);
 609                 }
 610
 611                 if (!item.isAmountValid()) {
 612                     Logger.debug("submittable",
 613                             String.format("Not submittable: row %d has an invalid amount", i + 1));
 614                     submittable = false;
 615                 }
 616                 else if (item.isAmountSet()) {
 617                     itemsWithAmountForCurrency.add(currName, item);
 618                     balance.add(currName, item.getAmount());
 619                 }
 620                 else {
 621                     itemsWithEmptyAmountForCurrency.add(currName, item);
 622
 623                     if (!accName.isEmpty())
 624                         itemsWithAccountAndEmptyAmountForCurrency.add(currName, item);
 625                 }
 626             }
 627
 628             // 1) has at least two account names
 629             if (accounts < 2) {
 630                 if (accounts == 0)
 631                     Logger.debug("submittable", "Transaction not submittable: no account names");
 632                 else if (accounts == 1)
 633                     Logger.debug("submittable",
 634                             "Transaction not submittable: only one account name");
 635                 else
 636                     Logger.debug("submittable",
 637                             String.format("Transaction not submittable: only %d account names",
 638                                     accounts));
 639                 submittable = false;
 640             }
 641
 642             // 3) for each commodity:
 643             // 3a) amount must balance to 0, or
 644             // 3b) there must be exactly one empty amount (with account)
 645             for (String balCurrency : itemsForCurrency.currencies()) {
 646                 float currencyBalance = balance.get(balCurrency);
 647                 if (Misc.isZero(currencyBalance)) {
 648                     // remove hints from all amount inputs in that currency
 649                     for (int i = 1; i < list.size(); i++) {
 650                         TransactionAccount acc = list.get(i)
 651                                                      .toTransactionAccount();
 652                         if (Misc.equalStrings(acc.getCurrency(), balCurrency)) {
 653                             if (BuildConfig.DEBUG)
 654                                 Logger.debug("submittable",
 655                                         String.format(Locale.US, "Resetting hint of %d:'%s' [%s]",
 656                                                 i, Misc.nullIsEmpty(acc.getAccountName()),
 657                                                 balCurrency));
 658                             // skip if the amount is set, in which case the hint is not
 659                             // important/visible
 660                             if (!acc.isAmountSet() && acc.amountHintIsSet &&
 661                                 !TextUtils.isEmpty(acc.getAmountHint()))
 662                             {
 663                                 acc.setAmountHint(null);
 664                                 listChanged = true;
 665                             }
 666                         }
 667                     }
 668                 }
 669                 else {
 670                     List<Item> tmpList =
 671                             itemsWithAccountAndEmptyAmountForCurrency.getList(balCurrency);
 672                     int balanceReceiversCount = tmpList.size();
 673                     if (balanceReceiversCount != 1) {
 674                         if (BuildConfig.DEBUG) {
 675                             if (balanceReceiversCount == 0)
 676                                 Logger.debug("submittable", String.format(
 677                                         "Transaction not submittable [%s]: non-zero balance " +
 678                                         "with no empty amounts with accounts", balCurrency));
 679                             else
 680                                 Logger.debug("submittable", String.format(
 681                                         "Transaction not submittable [%s]: non-zero balance " +
 682                                         "with multiple empty amounts with accounts", balCurrency));
 683                         }
 684                         submittable = false;
 685                     }
 686
 687                     List<Item> emptyAmountList =
 688                             itemsWithEmptyAmountForCurrency.getList(balCurrency);
 689
 690                     // suggest off-balance amount to a row and remove hints on other rows
 691                     Item receiver = null;
 692                     if (!tmpList.isEmpty())
 693                         receiver = tmpList.get(0);
 694                     else if (!emptyAmountList.isEmpty())
 695                         receiver = emptyAmountList.get(0);
 696
 697                     for (int i = 0; i < list.size(); i++) {
 698                         Item item = list.get(i);
 699                         if (!(item instanceof TransactionAccount))
 700                             continue;
 701
 702                         TransactionAccount acc = item.toTransactionAccount();
 703                         if (!Misc.equalStrings(acc.getCurrency(), balCurrency))
 704                             continue;
 705
 706                         if (item == receiver) {
 707                             final String hint = String.format("%1.2f", -currencyBalance);
 708                             if (!acc.isAmountHintSet() ||
 709                                 !Misc.equalStrings(acc.getAmountHint(), hint))
 710                             {
 711                                 Logger.debug("submittable",
 712                                         String.format("Setting amount hint of {%s} to %s [%s]",
 713                                                 acc.toString(), hint, balCurrency));
 714                                 acc.setAmountHint(hint);
 715                                 listChanged = true;
 716                             }
 717                         }
 718                         else {
 719                             if (BuildConfig.DEBUG)
 720                                 Logger.debug("submittable",
 721                                         String.format("Resetting hint of '%s' [%s]",
 722                                                 Misc.nullIsEmpty(acc.getAccountName()),
 723                                                 balCurrency));
 724                             if (acc.amountHintIsSet && !TextUtils.isEmpty(acc.getAmountHint())) {
 725                                 acc.setAmountHint(null);
 726                                 listChanged = true;
 727                             }
 728                         }
 729                     }
 730                 }
 731             }
 732
 733             // 5) a row with an empty account name or empty amount is guaranteed to exist for
 734             // each commodity
 735             for (String balCurrency : balance.currencies()) {
 736                 int currEmptyRows = itemsWithEmptyAccountForCurrency.size(balCurrency);
 737                 int currRows = itemsForCurrency.size(balCurrency);
 738                 int currAccounts = itemsWithAccountForCurrency.size(balCurrency);
 739                 int currAmounts = itemsWithAmountForCurrency.size(balCurrency);
 740                 if ((currEmptyRows == 0) &&
 741                     ((currRows == currAccounts) || (currRows == currAmounts)))
 742                 {
 743                     // perhaps there already is an unused empty row for another currency that
 744                     // is not used?
 745 //                        boolean foundIt = false;
 746 //                        for (Item item : emptyRows) {
 747 //                            Currency itemCurrency = item.getCurrency();
 748 //                            String itemCurrencyName =
 749 //                                    (itemCurrency == null) ? "" : itemCurrency.getName();
 750 //                            if (Misc.isZero(balance.get(itemCurrencyName))) {
 751 //                                item.setCurrency(Currency.loadByName(balCurrency));
 752 //                                item.setAmountHint(
 753 //                                        String.format("%1.2f", -balance.get(balCurrency)));
 754 //                                foundIt = true;
 755 //                                break;
 756 //                            }
 757 //                        }
 758 //
 759 //                        if (!foundIt)
 760                     final TransactionAccount newAcc = new TransactionAccount("", balCurrency);
 761                     final float bal = balance.get(balCurrency);
 762                     if (!Misc.isZero(bal) && currAmounts == currRows)
 763                         newAcc.setAmountHint(String.format("%4.2f", -bal));
 764                     Logger.debug("submittable",
 765                             String.format("Adding new item with %s for currency %s",
 766                                     newAcc.getAmountHint(), balCurrency));
 767                     list.add(newAcc);
 768                     listChanged = true;
 769                 }
 770             }
 771
 772             // drop extra empty rows, not needed
 773             for (String currName : emptyRowsForCurrency.currencies()) {
 774                 List<Item> emptyItems = emptyRowsForCurrency.getList(currName);
 775                 while ((list.size() > MIN_ITEMS) && (emptyItems.size() > 1)) {
 776                     // the list is a copy, so the empty item is no longer present
 777                     Item itemToRemove = emptyItems.remove(1);
 778                     removeItemById(list, itemToRemove.id);
 779                     listChanged = true;
 780                 }
 781
 782                 // unused currency, remove last item (which is also an empty one)
 783                 if ((list.size() > MIN_ITEMS) && (emptyItems.size() == 1)) {
 784                     List<Item> currItems = itemsForCurrency.getList(currName);
 785
 786                     if (currItems.size() == 1) {
 787                         // the list is a copy, so the empty item is no longer present
 788                         removeItemById(list, emptyItems.get(0).id);
 789                         listChanged = true;
 790                     }
 791                 }
 792             }
 793
 794             // 6) at least two rows need to be present in the ledger
 795             //    (the list also contains header and trailer)
 796             while (list.size() < MIN_ITEMS) {
 797                 list.add(new TransactionAccount(""));
 798                 listChanged = true;
 799             }
 800
 801             Logger.debug("submittable", submittable ? "YES" : "NO");
 802             isSubmittable.setValue(submittable);
 803
 804             if (BuildConfig.DEBUG)
 805                 dumpItemList("After submittable checks", list);
 806         }
 807         catch (NumberFormatException e) {
 808             Logger.debug("submittable", "NO (because of NumberFormatException)");
 809             isSubmittable.setValue(false);
 810         }
 811         catch (Exception e) {
 812             e.printStackTrace();
 813             Logger.debug("submittable", "NO (because of an Exception)");
 814             isSubmittable.setValue(false);
 815         }
 816
 817         if (listChanged && workingWithLiveList) {
 818             setItemsWithoutSubmittableChecks(list);
 819         }
 820     }
 821     private void removeItemById(@NotNull List<Item> list, int id) {
 822         if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.N) {
 823             list.removeIf(item -> item.id == id);
 824         }
 825         else {
 826             for (Item item : list) {
 827                 if (item.id == id) {
 828                     list.remove(item);
 829                     break;
 830                 }
 831             }
 832         }
 833     }
 834     @SuppressLint("DefaultLocale")
 835     private void dumpItemList(@NotNull String msg, @NotNull List<Item> list) {
 836         Logger.debug("submittable", "== Dump of all items " + msg);
 837         for (int i = 1; i < list.size(); i++) {
 838             TransactionAccount item = list.get(i)
 839                                           .toTransactionAccount();
 840             Logger.debug("submittable", String.format("%d:%s", i, item.toString()));
 841         }
 842     }
 843     public void setItemCurrency(int position, String newCurrency) {
 844         TransactionAccount item = Objects.requireNonNull(items.getValue())
 845                                          .get(position)
 846                                          .toTransactionAccount();
 847         final String oldCurrency = item.getCurrency();
 848
 849         if (Misc.equalStrings(oldCurrency, newCurrency))
 850             return;
 851
 852         List<Item> newList = copyList();
 853         newList.get(position)
 854                .toTransactionAccount()
 855                .setCurrency(newCurrency);
 856
 857         setItems(newList);
 858     }
 859     public boolean accountListIsEmpty() {
 860         List<Item> items = Objects.requireNonNull(this.items.getValue());
 861
 862         for (Item item : items) {
 863             if (!(item instanceof TransactionAccount))
 864                 continue;
 865
 866             if (!((TransactionAccount) item).isEmpty())
 867                 return false;
 868         }
 869
 870         return true;
 871     }
 872
 873     public static class FocusInfo {
 874         int position;
 875         FocusedElement element;
 876         public FocusInfo(int position, FocusedElement element) {
 877             this.position = position;
 878             this.element = element;
 879         }
 880     }
 881
 882     static abstract class Item {
 883         private static int idDispenser = 0;
 884         protected int id;
 885         private Item() {
 886             if (this instanceof TransactionHead)
 887                 id = 0;
 888             else
 889                 synchronized (Item.class) {
 890                     id = ++idDispenser;
 891                 }
 892         }
 893         public Item(int id) {
 894             this.id = id;
 895         }
 896         public static Item from(Item origin) {
 897             if (origin instanceof TransactionHead)
 898                 return new TransactionHead((TransactionHead) origin);
 899             if (origin instanceof TransactionAccount)
 900                 return new TransactionAccount((TransactionAccount) origin);
 901             throw new RuntimeException("Don't know how to handle " + origin);
 902         }
 903         private static void resetIdDispenser() {
 904             idDispenser = 0;
 905         }
 906         public int getId() {
 907             return id;
 908         }
 909         public abstract ItemType getType();
 910         public TransactionHead toTransactionHead() {
 911             if (this instanceof TransactionHead)
 912                 return (TransactionHead) this;
 913
 914             throw new IllegalStateException("Wrong item type " + this);
 915         }
 916         public TransactionAccount toTransactionAccount() {
 917             if (this instanceof TransactionAccount)
 918                 return (TransactionAccount) this;
 919
 920             throw new IllegalStateException("Wrong item type " + this);
 921         }
 922         public boolean equalContents(@Nullable Object item) {
 923             if (item == null)
 924                 return false;
 925
 926             if (!getClass().equals(item.getClass()))
 927                 return false;
 928
 929             // shortcut - comparing same instance
 930             if (item == this)
 931                 return true;
 932
 933             if (this instanceof TransactionHead)
 934                 return ((TransactionHead) item).equalContents((TransactionHead) this);
 935             if (this instanceof TransactionAccount)
 936                 return ((TransactionAccount) item).equalContents((TransactionAccount) this);
 937
 938             throw new RuntimeException("Don't know how to handle " + this);
 939         }
 940     }
 941
 942
 943 //==========================================================================================
 944
 945     public static class TransactionHead extends Item {
 946         private SimpleDate date;
 947         private String description;
 948         private String comment;
 949         TransactionHead(String description) {
 950             super();
 951             this.description = description;
 952         }
 953         public TransactionHead(TransactionHead origin) {
 954             super(origin.id);
 955             date = origin.date;
 956             description = origin.description;
 957             comment = origin.comment;
 958         }
 959         public SimpleDate getDate() {
 960             return date;
 961         }
 962         public void setDate(SimpleDate date) {
 963             this.date = date;
 964         }
 965         public void setDate(String text) throws ParseException {
 966             if (Misc.emptyIsNull(text) == null) {
 967                 date = null;
 968                 return;
 969             }
 970
 971             date = Globals.parseLedgerDate(text);
 972         }
 973         /**
 974          * getFormattedDate()
 975          *
 976          * @return nicely formatted, shortest available date representation
 977          */
 978         String getFormattedDate() {
 979             if (date == null)
 980                 return null;
 981
 982             Calendar today = GregorianCalendar.getInstance();
 983
 984             if (today.get(Calendar.YEAR) != date.year) {
 985                 return String.format(Locale.US, "%d/%02d/%02d", date.year, date.month, date.day);
 986             }
 987
 988             if (today.get(Calendar.MONTH) + 1 != date.month) {
 989                 return String.format(Locale.US, "%d/%02d", date.month, date.day);
 990             }
 991
 992             return String.valueOf(date.day);
 993         }
 994         @NonNull
 995         @Override
 996         public String toString() {
 997             @SuppressLint("DefaultLocale") StringBuilder b = new StringBuilder(
 998                     String.format("id:%d/%s", id, Integer.toHexString(hashCode())));
 999
1000             if (TextUtils.isEmpty(description))
1001                 b.append(" «no description»");
1002             else
1003                 b.append(String.format(" '%s'", description));
1004
1005             if (date != null)
1006                 b.append(String.format("@%s", date.toString()));
1007
1008             if (!TextUtils.isEmpty(comment))
1009                 b.append(String.format(" /%s/", comment));
1010
1011             return b.toString();
1012         }
1013         public String getDescription() {
1014             return description;
1015         }
1016         public void setDescription(String description) {
1017             this.description = description;
1018         }
1019         public String getComment() {
1020             return comment;
1021         }
1022         public void setComment(String comment) {
1023             this.comment = comment;
1024         }
1025         @Override
1026         public ItemType getType() {
1027             return ItemType.generalData;
1028         }
1029         public LedgerTransaction asLedgerTransaction() {
1030             return new LedgerTransaction(0, date, description, Data.getProfile());
1031         }
1032         public boolean equalContents(TransactionHead other) {
1033             if (other == null)
1034                 return false;
1035
1036             return Objects.equals(date, other.date) &&
1037                    Misc.equalStrings(description, other.description) &&
1038                    Misc.equalStrings(comment, other.comment);
1039         }
1040     }
1041
1042     public static class TransactionAccount extends Item {
1043         private String accountName;
1044         private String amountHint;
1045         private String comment;
1046         private String currency;
1047         private float amount;
1048         private boolean amountSet;
1049         private boolean amountValid = true;
1050         private FocusedElement focusedElement = FocusedElement.Account;
1051         private boolean amountHintIsSet = false;
1052         private boolean isLast = false;
1053         private int accountNameCursorPosition;
1054         public TransactionAccount(TransactionAccount origin) {
1055             super(origin.id);
1056             accountName = origin.accountName;
1057             amount = origin.amount;
1058             amountSet = origin.amountSet;
1059             amountHint = origin.amountHint;
1060             amountHintIsSet = origin.amountHintIsSet;
1061             comment = origin.comment;
1062             currency = origin.currency;
1063             amountValid = origin.amountValid;
1064             focusedElement = origin.focusedElement;
1065             isLast = origin.isLast;
1066             accountNameCursorPosition = origin.accountNameCursorPosition;
1067         }
1068         public TransactionAccount(LedgerTransactionAccount account) {
1069             super();
1070             currency = account.getCurrency();
1071             amount = account.getAmount();
1072         }
1073         public TransactionAccount(String accountName) {
1074             super();
1075             this.accountName = accountName;
1076         }
1077         public TransactionAccount(String accountName, String currency) {
1078             super();
1079             this.accountName = accountName;
1080             this.currency = currency;
1081         }
1082         public boolean isLast() {
1083             return isLast;
1084         }
1085         public boolean isAmountSet() {
1086             return amountSet;
1087         }
1088         public String getAccountName() {
1089             return accountName;
1090         }
1091         public void setAccountName(String accountName) {
1092             this.accountName = accountName;
1093         }
1094         public float getAmount() {
1095             if (!amountSet)
1096                 throw new IllegalStateException("Amount is not set");
1097             return amount;
1098         }
1099         public void setAmount(float amount) {
1100             this.amount = amount;
1101             amountSet = true;
1102         }
1103         public void resetAmount() {
1104             amountSet = false;
1105         }
1106         @Override
1107         public ItemType getType() {
1108             return ItemType.transactionRow;
1109         }
1110         public String getAmountHint() {
1111             return amountHint;
1112         }
1113         public void setAmountHint(String amountHint) {
1114             this.amountHint = amountHint;
1115             amountHintIsSet = !TextUtils.isEmpty(amountHint);
1116         }
1117         public String getComment() {
1118             return comment;
1119         }
1120         public void setComment(String comment) {
1121             this.comment = comment;
1122         }
1123         public String getCurrency() {
1124             return currency;
1125         }
1126         public void setCurrency(String currency) {
1127             this.currency = currency;
1128         }
1129         public boolean isAmountValid() {
1130             return amountValid;
1131         }
1132         public void setAmountValid(boolean amountValid) {
1133             this.amountValid = amountValid;
1134         }
1135         public FocusedElement getFocusedElement() {
1136             return focusedElement;
1137         }
1138         public void setFocusedElement(FocusedElement focusedElement) {
1139             this.focusedElement = focusedElement;
1140         }
1141         public boolean isAmountHintSet() {
1142             return amountHintIsSet;
1143         }
1144         public void setAmountHintIsSet(boolean amountHintIsSet) {
1145             this.amountHintIsSet = amountHintIsSet;
1146         }
1147         public boolean isEmpty() {
1148             return !amountSet && Misc.emptyIsNull(accountName) == null &&
1149                    Misc.emptyIsNull(comment) == null;
1150         }
1151         @SuppressLint("DefaultLocale")
1152         @Override
1153         public String toString() {
1154             StringBuilder b = new StringBuilder();
1155             b.append(String.format("id:%d/%s", id, Integer.toHexString(hashCode())));
1156             if (!TextUtils.isEmpty(accountName))
1157                 b.append(String.format(" acc'%s'", accountName));
1158
1159             if (amountSet)
1160                 b.append(String.format(" %4.2f", amount));
1161             else if (amountHintIsSet)
1162                 b.append(String.format(" (%s)", amountHint));
1163
1164             if (!TextUtils.isEmpty(currency))
1165                 b.append(" ")
1166                  .append(currency);
1167
1168             if (!TextUtils.isEmpty(comment))
1169                 b.append(String.format(" /%s/", comment));
1170
1171             if (isLast)
1172                 b.append(" last");
1173
1174             return b.toString();
1175         }
1176         public boolean equalContents(TransactionAccount other) {
1177             if (other == null)
1178                 return false;
1179
1180             boolean equal = Misc.equalStrings(accountName, other.accountName);
1181             equal = equal && Misc.equalStrings(comment, other.comment) &&
1182                     (amountSet ? other.amountSet && amount == other.amount : !other.amountSet);
1183
1184             // compare amount hint only if there is no amount
1185             if (!amountSet)
1186                 equal = equal && (amountHintIsSet ? other.amountHintIsSet &&
1187                                                     Misc.equalStrings(amountHint, other.amountHint)
1188                                                   : !other.amountHintIsSet);
1189             equal = equal && Misc.equalStrings(currency, other.currency) && isLast == other.isLast;
1190
1191             Logger.debug("new-trans",
1192                     String.format("Comparing {%s} and {%s}: %s", this.toString(), other.toString(),
1193                             equal));
1194             return equal;
1195         }
1196         public int getAccountNameCursorPosition() {
1197             return accountNameCursorPosition;
1198         }
1199         public void setAccountNameCursorPosition(int position) {
1200             this.accountNameCursorPosition = position;
1201         }
1202     }
1203
1204     private static class BalanceForCurrency {
1205         private final HashMap<String, Float> hashMap = new HashMap<>();
1206         float get(String currencyName) {
1207             Float f = hashMap.get(currencyName);
1208             if (f == null) {
1209                 f = 0f;
1210                 hashMap.put(currencyName, f);
1211             }
1212             return f;
1213         }
1214         void add(String currencyName, float amount) {
1215             hashMap.put(currencyName, get(currencyName) + amount);
1216         }
1217         Set<String> currencies() {
1218             return hashMap.keySet();
1219         }
1220         boolean containsCurrency(String currencyName) {
1221             return hashMap.containsKey(currencyName);
1222         }
1223     }
1224
1225     private static class ItemsForCurrency {
1226         private final HashMap<String, List<Item>> hashMap = new HashMap<>();
1227         @NonNull
1228         List<NewTransactionModel.Item> getList(@Nullable String currencyName) {
1229             List<NewTransactionModel.Item> list = hashMap.get(currencyName);
1230             if (list == null) {
1231                 list = new ArrayList<>();
1232                 hashMap.put(currencyName, list);
1233             }
1234             return list;
1235         }
1236         void add(@Nullable String currencyName, @NonNull NewTransactionModel.Item item) {
1237             getList(currencyName).add(item);
1238         }
1239         int size(@Nullable String currencyName) {
1240             return this.getList(currencyName)
1241                        .size();
1242         }
1243         Set<String> currencies() {
1244             return hashMap.keySet();
1245         }
1246     }
1247 }