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.os.Handler;
  22 import android.os.Looper;
  23 import android.text.TextUtils;
  24
  25 import androidx.annotation.NonNull;
  26 import androidx.annotation.Nullable;
  27 import androidx.lifecycle.LifecycleOwner;
  28 import androidx.lifecycle.LiveData;
  29 import androidx.lifecycle.MutableLiveData;
  30 import androidx.lifecycle.Observer;
  31 import androidx.lifecycle.ViewModel;
  32
  33 import net.ktnx.mobileledger.BuildConfig;
  34 import net.ktnx.mobileledger.db.DB;
  35 import net.ktnx.mobileledger.db.TemplateAccount;
  36 import net.ktnx.mobileledger.db.TemplateHeader;
  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.model.MobileLedgerProfile;
  43 import net.ktnx.mobileledger.utils.Globals;
  44 import net.ktnx.mobileledger.utils.Logger;
  45 import net.ktnx.mobileledger.utils.Misc;
  46 import net.ktnx.mobileledger.utils.SimpleDate;
  47
  48 import org.jetbrains.annotations.NotNull;
  49
  50 import java.text.ParseException;
  51 import java.util.ArrayList;
  52 import java.util.Calendar;
  53 import java.util.GregorianCalendar;
  54 import java.util.HashMap;
  55 import java.util.List;
  56 import java.util.Locale;
  57 import java.util.Objects;
  58 import java.util.Set;
  59 import java.util.concurrent.atomic.AtomicInteger;
  60 import java.util.regex.MatchResult;
  61
  62 enum ItemType {generalData, transactionRow}
  63
  64 enum FocusedElement {Account, Comment, Amount, Description, TransactionComment}
  65
  66
  67 public class NewTransactionModel extends ViewModel {
  68     private static final int MIN_ITEMS = 3;
  69     private final MutableLiveData<Boolean> showCurrency = new MutableLiveData<>(false);
  70     private final MutableLiveData<Boolean> isSubmittable = new InertMutableLiveData<>(false);
  71     private final MutableLiveData<Boolean> showComments = new MutableLiveData<>(true);
  72     private final MutableLiveData<List<Item>> items = new MutableLiveData<>();
  73     private final MutableLiveData<Boolean> simulateSave = new InertMutableLiveData<>(false);
  74     private final AtomicInteger busyCounter = new AtomicInteger(0);
  75     private final MutableLiveData<Boolean> busyFlag = new InertMutableLiveData<>(false);
  76     private final Observer<MobileLedgerProfile> profileObserver = profile -> {
  77         showCurrency.postValue(profile.getShowCommodityByDefault());
  78         showComments.postValue(profile.getShowCommentsByDefault());
  79     };
  80     private final MutableLiveData<FocusInfo> focusInfo = new MutableLiveData<>();
  81     private boolean observingDataProfile;
  82     public NewTransactionModel() {
  83         reset();
  84     }
  85     public LiveData<Boolean> getShowCurrency() {
  86         return showCurrency;
  87     }
  88     public LiveData<List<Item>> getItems() {
  89         return items;
  90     }
  91     private void setItems(@NonNull List<Item> newList) {
  92         checkTransactionSubmittable(newList);
  93         setItemsWithoutSubmittableChecks(newList);
  94     }
  95     private void replaceItems(@NonNull List<Item> newList) {
  96         renumberItems();
  97
  98         setItems(newList);
  99     }
 100     /**
 101      * make old items replaceable in-place. makes the new values visually blend in
 102      */
 103     private void renumberItems() {
 104         final List<Item> list = items.getValue();
 105         if (list == null) {
 106             return;
 107         }
 108
 109         int id = 0;
 110         for (Item item : list)
 111             item.id = id++;
 112     }
 113     private void setItemsWithoutSubmittableChecks(@NonNull List<Item> list) {
 114         final int cnt = list.size();
 115         for (int i = 1; i < cnt - 1; i++) {
 116             final TransactionAccount item = list.get(i)
 117                                                 .toTransactionAccount();
 118             if (item.isLast) {
 119                 TransactionAccount replacement = new TransactionAccount(item);
 120                 replacement.isLast = false;
 121                 list.set(i, replacement);
 122             }
 123         }
 124         final TransactionAccount last = list.get(cnt - 1)
 125                                             .toTransactionAccount();
 126         if (!last.isLast) {
 127             TransactionAccount replacement = new TransactionAccount(last);
 128             replacement.isLast = true;
 129             list.set(cnt - 1, replacement);
 130         }
 131
 132         if (BuildConfig.DEBUG)
 133             dumpItemList("Before setValue()", list);
 134         items.setValue(list);
 135     }
 136     private List<Item> copyList() {
 137         List<Item> copy = new ArrayList<>();
 138         List<Item> oldList = items.getValue();
 139
 140         if (oldList != null)
 141             for (Item item : oldList) {
 142                 copy.add(Item.from(item));
 143             }
 144
 145         return copy;
 146     }
 147     private List<Item> copyListWithoutItem(int position) {
 148         List<Item> copy = new ArrayList<>();
 149         List<Item> oldList = items.getValue();
 150
 151         if (oldList != null) {
 152             int i = 0;
 153             for (Item item : oldList) {
 154                 if (i++ == position)
 155                     continue;
 156                 copy.add(Item.from(item));
 157             }
 158         }
 159
 160         return copy;
 161     }
 162     private List<Item> shallowCopyList() {
 163         return new ArrayList<>(items.getValue());
 164     }
 165     LiveData<Boolean> getShowComments() {
 166         return showComments;
 167     }
 168     void observeDataProfile(LifecycleOwner activity) {
 169         if (!observingDataProfile)
 170             Data.observeProfile(activity, profileObserver);
 171         observingDataProfile = true;
 172     }
 173     boolean getSimulateSaveFlag() {
 174         Boolean value = simulateSave.getValue();
 175         if (value == null)
 176             return false;
 177         return value;
 178     }
 179     LiveData<Boolean> getSimulateSave() {
 180         return simulateSave;
 181     }
 182     void toggleSimulateSave() {
 183         simulateSave.setValue(!getSimulateSaveFlag());
 184     }
 185     LiveData<Boolean> isSubmittable() {
 186         return this.isSubmittable;
 187     }
 188     void reset() {
 189         Logger.debug("new-trans", "Resetting model");
 190         List<Item> list = new ArrayList<>();
 191         Item.resetIdDispenser();
 192         list.add(new TransactionHead(""));
 193         list.add(new TransactionAccount(""));
 194         list.add(new TransactionAccount(""));
 195         noteFocusChanged(0, FocusedElement.Description);
 196         renumberItems();
 197         isSubmittable.setValue(false);
 198         setItemsWithoutSubmittableChecks(list);
 199     }
 200     boolean accountsInInitialState() {
 201         final List<Item> list = items.getValue();
 202
 203         if (list == null)
 204             return true;
 205
 206         for (Item item : list) {
 207             if (!(item instanceof TransactionAccount))
 208                 continue;
 209
 210             TransactionAccount accRow = (TransactionAccount) item;
 211             if (!accRow.isEmpty())
 212                 return false;
 213         }
 214
 215         return true;
 216     }
 217     void applyTemplate(MatchedTemplate matchedTemplate, String text) {
 218         SimpleDate transactionDate = null;
 219         final MatchResult matchResult = matchedTemplate.matchResult;
 220         final TemplateHeader templateHead = matchedTemplate.templateHead;
 221         {
 222             int day = extractIntFromMatches(matchResult, templateHead.getDateDayMatchGroup(),
 223                     templateHead.getDateDay());
 224             int month = extractIntFromMatches(matchResult, templateHead.getDateMonthMatchGroup(),
 225                     templateHead.getDateMonth());
 226             int year = extractIntFromMatches(matchResult, templateHead.getDateYearMatchGroup(),
 227                     templateHead.getDateYear());
 228
 229             if (year > 0 || month > 0 || day > 0) {
 230                 SimpleDate today = SimpleDate.today();
 231                 if (year <= 0)
 232                     year = today.year;
 233                 if (month <= 0)
 234                     month = today.month;
 235                 if (day <= 0)
 236                     day = today.day;
 237
 238                 transactionDate = new SimpleDate(year, month, day);
 239
 240                 Logger.debug("pattern", "setting transaction date to " + transactionDate);
 241             }
 242         }
 243
 244         List<Item> present = copyList();
 245
 246         TransactionHead head = new TransactionHead(present.get(0)
 247                                                           .toTransactionHead());
 248         if (transactionDate != null)
 249             head.setDate(transactionDate);
 250
 251         final String transactionDescription = extractStringFromMatches(matchResult,
 252                 templateHead.getTransactionDescriptionMatchGroup(),
 253                 templateHead.getTransactionDescription());
 254         if (Misc.emptyIsNull(transactionDescription) != null)
 255             head.setDescription(transactionDescription);
 256
 257         final String transactionComment = extractStringFromMatches(matchResult,
 258                 templateHead.getTransactionCommentMatchGroup(),
 259                 templateHead.getTransactionComment());
 260         if (Misc.emptyIsNull(transactionComment) != null)
 261             head.setComment(transactionComment);
 262
 263         Item.resetIdDispenser();
 264         List<Item> newItems = new ArrayList<>();
 265
 266         newItems.add(head);
 267
 268         for (int i = 1; i < present.size(); i++) {
 269             final TransactionAccount row = present.get(i)
 270                                                   .toTransactionAccount();
 271             if (!row.isEmpty())
 272                 newItems.add(new TransactionAccount(row));
 273         }
 274
 275         DB.get()
 276           .getTemplateDAO()
 277           .getTemplateWithAccountsAsync(templateHead.getId(), entry -> {
 278               int rowIndex = 0;
 279               final boolean accountsInInitialState = accountsInInitialState();
 280               for (TemplateAccount acc : entry.accounts) {
 281                   rowIndex++;
 282
 283                   String accountName =
 284                           extractStringFromMatches(matchResult, acc.getAccountNameMatchGroup(),
 285                                   acc.getAccountName());
 286                   String accountComment =
 287                           extractStringFromMatches(matchResult, acc.getAccountCommentMatchGroup(),
 288                                   acc.getAccountComment());
 289                   Float amount = extractFloatFromMatches(matchResult, acc.getAmountMatchGroup(),
 290                           acc.getAmount());
 291                   if (amount != null && acc.getNegateAmount() != null && acc.getNegateAmount())
 292                       amount = -amount;
 293
 294                   // TODO currency
 295                   TransactionAccount accRow = new TransactionAccount(accountName);
 296                   accRow.setComment(accountComment);
 297                   if (amount != null)
 298                       accRow.setAmount(amount);
 299
 300                   newItems.add(accRow);
 301               }
 302
 303               new Handler(Looper.getMainLooper()).post(() -> replaceItems(newItems));
 304           });
 305     }
 306     private int extractIntFromMatches(MatchResult m, Integer group, Integer literal) {
 307         if (literal != null)
 308             return literal;
 309
 310         if (group != null) {
 311             int grp = group;
 312             if (grp > 0 & grp <= m.groupCount())
 313                 try {
 314                     return Integer.parseInt(m.group(grp));
 315                 }
 316                 catch (NumberFormatException e) {
 317                     Logger.debug("new-trans", "Error extracting matched number", e);
 318                 }
 319         }
 320
 321         return 0;
 322     }
 323     private String extractStringFromMatches(MatchResult m, Integer group, String literal) {
 324         if (literal != null)
 325             return literal;
 326
 327         if (group != null) {
 328             int grp = group;
 329             if (grp > 0 & grp <= m.groupCount())
 330                 return m.group(grp);
 331         }
 332
 333         return null;
 334     }
 335     private Float extractFloatFromMatches(MatchResult m, Integer group, Float literal) {
 336         if (literal != null)
 337             return literal;
 338
 339         if (group != null) {
 340             int grp = group;
 341             if (grp > 0 & grp <= m.groupCount())
 342                 try {
 343                     return Float.valueOf(m.group(grp));
 344                 }
 345                 catch (NumberFormatException e) {
 346                     Logger.debug("new-trans", "Error extracting matched number", e);
 347                 }
 348         }
 349
 350         return null;
 351     }
 352     void removeItem(int pos) {
 353         Logger.debug("new-trans", String.format(Locale.US, "Removing item at position %d", pos));
 354         List<Item> newList = copyListWithoutItem(pos);
 355         final FocusInfo fi = focusInfo.getValue();
 356         if ((fi != null) && (pos < fi.position))
 357             noteFocusChanged(fi.position - 1, fi.element);
 358         setItems(newList);
 359     }
 360     void noteFocusChanged(int position, FocusedElement element) {
 361         FocusInfo present = focusInfo.getValue();
 362         if (present == null || present.position != position || present.element != element)
 363             focusInfo.setValue(new FocusInfo(position, element));
 364     }
 365     public LiveData<FocusInfo> getFocusInfo() {
 366         return focusInfo;
 367     }
 368     void moveItem(int fromIndex, int toIndex) {
 369         List<Item> newList = shallowCopyList();
 370         Item item = newList.remove(fromIndex);
 371         newList.add(toIndex, item);
 372
 373         FocusInfo fi = focusInfo.getValue();
 374         if (fi != null && fi.position == fromIndex)
 375             noteFocusChanged(toIndex, fi.element);
 376
 377         items.setValue(newList); // same count, same submittable state
 378     }
 379     void moveItemLast(List<Item> list, int index) {
 380         /*   0
 381              1   <-- index
 382              2
 383              3   <-- desired position
 384                  (no bottom filler)
 385          */
 386         int itemCount = list.size();
 387
 388         if (index < itemCount - 1)
 389             list.add(list.remove(index));
 390     }
 391     void toggleCurrencyVisible() {
 392         final boolean newValue = !Objects.requireNonNull(showCurrency.getValue());
 393
 394         // remove currency from all items, or reset currency to the default
 395         // no need to clone the list, because the removal of the currency won't lead to
 396         // visual changes -- the currency fields will be hidden or reset to default anyway
 397         // still, there may be changes in the submittable state
 398         final List<Item> list = Objects.requireNonNull(this.items.getValue());
 399         for (int i = 1; i < list.size(); i++) {
 400             ((TransactionAccount) list.get(i)).setCurrency(newValue ? Data.getProfile()
 401                                                                           .getDefaultCommodity()
 402                                                                     : null);
 403         }
 404         checkTransactionSubmittable(null);
 405         showCurrency.setValue(newValue);
 406     }
 407     void stopObservingBusyFlag(Observer<Boolean> observer) {
 408         busyFlag.removeObserver(observer);
 409     }
 410     void incrementBusyCounter() {
 411         int newValue = busyCounter.incrementAndGet();
 412         if (newValue == 1)
 413             busyFlag.postValue(true);
 414     }
 415     void decrementBusyCounter() {
 416         int newValue = busyCounter.decrementAndGet();
 417         if (newValue == 0)
 418             busyFlag.postValue(false);
 419     }
 420     public LiveData<Boolean> getBusyFlag() {
 421         return busyFlag;
 422     }
 423     public void toggleShowComments() {
 424         showComments.setValue(!Objects.requireNonNull(showComments.getValue()));
 425     }
 426     public LedgerTransaction constructLedgerTransaction() {
 427         List<Item> list = Objects.requireNonNull(items.getValue());
 428         TransactionHead head = list.get(0)
 429                                    .toTransactionHead();
 430         SimpleDate date = head.getDate();
 431         LedgerTransaction tr = head.asLedgerTransaction();
 432
 433         tr.setComment(head.getComment());
 434         LedgerTransactionAccount emptyAmountAccount = null;
 435         float emptyAmountAccountBalance = 0;
 436         for (int i = 1; i < list.size(); i++) {
 437             TransactionAccount item = list.get(i)
 438                                           .toTransactionAccount();
 439             LedgerTransactionAccount acc = new LedgerTransactionAccount(item.getAccountName()
 440                                                                             .trim(),
 441                     item.getCurrency());
 442             if (acc.getAccountName()
 443                    .isEmpty())
 444                 continue;
 445
 446             acc.setComment(item.getComment());
 447
 448             if (item.isAmountSet()) {
 449                 acc.setAmount(item.getAmount());
 450                 emptyAmountAccountBalance += item.getAmount();
 451             }
 452             else {
 453                 emptyAmountAccount = acc;
 454             }
 455
 456             tr.addAccount(acc);
 457         }
 458
 459         if (emptyAmountAccount != null)
 460             emptyAmountAccount.setAmount(-emptyAmountAccountBalance);
 461
 462         return tr;
 463     }
 464     void loadTransactionIntoModel(long profileId, int transactionId) {
 465         List<Item> newList = new ArrayList<>();
 466         Item.resetIdDispenser();
 467         LedgerTransaction tr;
 468         MobileLedgerProfile profile = Data.getProfile(profileId);
 469         if (profile == null)
 470             throw new RuntimeException(String.format(
 471                     "Unable to find profile %s, which is supposed to contain transaction %d",
 472                     profileId, transactionId));
 473
 474         tr = profile.loadTransaction(transactionId);
 475         TransactionHead head = new TransactionHead(tr.getDescription());
 476         head.setComment(tr.getComment());
 477
 478         newList.add(head);
 479
 480         List<LedgerTransactionAccount> accounts = tr.getAccounts();
 481
 482         TransactionAccount firstNegative = null;
 483         TransactionAccount firstPositive = null;
 484         int singleNegativeIndex = -1;
 485         int singlePositiveIndex = -1;
 486         int negativeCount = 0;
 487         for (int i = 0; i < accounts.size(); i++) {
 488             LedgerTransactionAccount acc = accounts.get(i);
 489             TransactionAccount item =
 490                     new TransactionAccount(acc.getAccountName(), acc.getCurrency());
 491             newList.add(item);
 492
 493             item.setAccountName(acc.getAccountName());
 494             item.setComment(acc.getComment());
 495             if (acc.isAmountSet()) {
 496                 item.setAmount(acc.getAmount());
 497                 if (acc.getAmount() < 0) {
 498                     if (firstNegative == null) {
 499                         firstNegative = item;
 500                         singleNegativeIndex = i + 1;
 501                     }
 502                     else
 503                         singleNegativeIndex = -1;
 504                 }
 505                 else {
 506                     if (firstPositive == null) {
 507                         firstPositive = item;
 508                         singlePositiveIndex = i + 1;
 509                     }
 510                     else
 511                         singlePositiveIndex = -1;
 512                 }
 513             }
 514             else
 515                 item.resetAmount();
 516         }
 517         if (BuildConfig.DEBUG)
 518             dumpItemList("Loaded previous transaction", newList);
 519
 520         if (singleNegativeIndex != -1) {
 521             firstNegative.resetAmount();
 522             moveItemLast(newList, singleNegativeIndex);
 523         }
 524         else if (singlePositiveIndex != -1) {
 525             firstPositive.resetAmount();
 526             moveItemLast(newList, singlePositiveIndex);
 527         }
 528
 529         setItems(newList);
 530
 531         noteFocusChanged(1, FocusedElement.Amount);
 532     }
 533     /**
 534      * A transaction is submittable if:
 535      * 0) has description
 536      * 1) has at least two account names
 537      * 2) each row with amount has account name
 538      * 3) for each commodity:
 539      * 3a) amounts must balance to 0, or
 540      * 3b) there must be exactly one empty amount (with account)
 541      * 4) empty accounts with empty amounts are ignored
 542      * Side effects:
 543      * 5) a row with an empty account name or empty amount is guaranteed to exist for each
 544      * commodity
 545      * 6) at least two rows need to be present in the ledger
 546      *
 547      * @param list - the item list to check. Can be the displayed list or a list that will be
 548      *             displayed soon
 549      */
 550     @SuppressLint("DefaultLocale")
 551     void checkTransactionSubmittable(@Nullable List<Item> list) {
 552         boolean workingWithLiveList = false;
 553         if (list == null) {
 554             list = copyList();
 555             workingWithLiveList = true;
 556         }
 557
 558         if (BuildConfig.DEBUG)
 559             dumpItemList(String.format("Before submittable checks (%s)",
 560                     workingWithLiveList ? "LIVE LIST" : "custom list"), list);
 561
 562         int accounts = 0;
 563         final BalanceForCurrency balance = new BalanceForCurrency();
 564         final String descriptionText = list.get(0)
 565                                            .toTransactionHead()
 566                                            .getDescription();
 567         boolean submittable = true;
 568         boolean listChanged = false;
 569         final ItemsForCurrency itemsForCurrency = new ItemsForCurrency();
 570         final ItemsForCurrency itemsWithEmptyAmountForCurrency = new ItemsForCurrency();
 571         final ItemsForCurrency itemsWithAccountAndEmptyAmountForCurrency = new ItemsForCurrency();
 572         final ItemsForCurrency itemsWithEmptyAccountForCurrency = new ItemsForCurrency();
 573         final ItemsForCurrency itemsWithAmountForCurrency = new ItemsForCurrency();
 574         final ItemsForCurrency itemsWithAccountForCurrency = new ItemsForCurrency();
 575         final ItemsForCurrency emptyRowsForCurrency = new ItemsForCurrency();
 576         final List<Item> emptyRows = new ArrayList<>();
 577
 578         try {
 579             if ((descriptionText == null) || descriptionText.trim()
 580                                                             .isEmpty())
 581             {
 582                 Logger.debug("submittable", "Transaction not submittable: missing description");
 583                 submittable = false;
 584             }
 585
 586             for (int i = 1; i < list.size(); i++) {
 587                 TransactionAccount item = list.get(i)
 588                                               .toTransactionAccount();
 589
 590                 String accName = item.getAccountName()
 591                                      .trim();
 592                 String currName = item.getCurrency();
 593
 594                 itemsForCurrency.add(currName, item);
 595
 596                 if (accName.isEmpty()) {
 597                     itemsWithEmptyAccountForCurrency.add(currName, item);
 598
 599                     if (item.isAmountSet()) {
 600                         // 2) each amount has account name
 601                         Logger.debug("submittable", String.format(
 602                                 "Transaction not submittable: row %d has no account name, but" +
 603                                 " has" + " amount %1.2f", i + 1, item.getAmount()));
 604                         submittable = false;
 605                     }
 606                     else {
 607                         emptyRowsForCurrency.add(currName, item);
 608                     }
 609                 }
 610                 else {
 611                     accounts++;
 612                     itemsWithAccountForCurrency.add(currName, item);
 613                 }
 614
 615                 if (!item.isAmountValid()) {
 616                     Logger.debug("submittable",
 617                             String.format("Not submittable: row %d has an invalid amount", i + 1));
 618                     submittable = false;
 619                 }
 620                 else if (item.isAmountSet()) {
 621                     itemsWithAmountForCurrency.add(currName, item);
 622                     balance.add(currName, item.getAmount());
 623                 }
 624                 else {
 625                     itemsWithEmptyAmountForCurrency.add(currName, item);
 626
 627                     if (!accName.isEmpty())
 628                         itemsWithAccountAndEmptyAmountForCurrency.add(currName, item);
 629                 }
 630             }
 631
 632             // 1) has at least two account names
 633             if (accounts < 2) {
 634                 if (accounts == 0)
 635                     Logger.debug("submittable", "Transaction not submittable: no account names");
 636                 else if (accounts == 1)
 637                     Logger.debug("submittable",
 638                             "Transaction not submittable: only one account name");
 639                 else
 640                     Logger.debug("submittable",
 641                             String.format("Transaction not submittable: only %d account names",
 642                                     accounts));
 643                 submittable = false;
 644             }
 645
 646             // 3) for each commodity:
 647             // 3a) amount must balance to 0, or
 648             // 3b) there must be exactly one empty amount (with account)
 649             for (String balCurrency : itemsForCurrency.currencies()) {
 650                 float currencyBalance = balance.get(balCurrency);
 651                 if (Misc.isZero(currencyBalance)) {
 652                     // remove hints from all amount inputs in that currency
 653                     for (int i = 1; i < list.size(); i++) {
 654                         TransactionAccount acc = list.get(i)
 655                                                      .toTransactionAccount();
 656                         if (Misc.equalStrings(acc.getCurrency(), balCurrency)) {
 657                             if (BuildConfig.DEBUG)
 658                                 Logger.debug("submittable",
 659                                         String.format(Locale.US, "Resetting hint of %d:'%s' [%s]",
 660                                                 i, Misc.nullIsEmpty(acc.getAccountName()),
 661                                                 balCurrency));
 662                             // skip if the amount is set, in which case the hint is not
 663                             // important/visible
 664                             if (!acc.isAmountSet() && acc.amountHintIsSet &&
 665                                 !TextUtils.isEmpty(acc.getAmountHint()))
 666                             {
 667                                 acc.setAmountHint(null);
 668                                 listChanged = true;
 669                             }
 670                         }
 671                     }
 672                 }
 673                 else {
 674                     List<Item> tmpList =
 675                             itemsWithAccountAndEmptyAmountForCurrency.getList(balCurrency);
 676                     int balanceReceiversCount = tmpList.size();
 677                     if (balanceReceiversCount != 1) {
 678                         if (BuildConfig.DEBUG) {
 679                             if (balanceReceiversCount == 0)
 680                                 Logger.debug("submittable", String.format(
 681                                         "Transaction not submittable [%s]: non-zero balance " +
 682                                         "with no empty amounts with accounts", balCurrency));
 683                             else
 684                                 Logger.debug("submittable", String.format(
 685                                         "Transaction not submittable [%s]: non-zero balance " +
 686                                         "with multiple empty amounts with accounts", balCurrency));
 687                         }
 688                         submittable = false;
 689                     }
 690
 691                     List<Item> emptyAmountList =
 692                             itemsWithEmptyAmountForCurrency.getList(balCurrency);
 693
 694                     // suggest off-balance amount to a row and remove hints on other rows
 695                     Item receiver = null;
 696                     if (!tmpList.isEmpty())
 697                         receiver = tmpList.get(0);
 698                     else if (!emptyAmountList.isEmpty())
 699                         receiver = emptyAmountList.get(0);
 700
 701                     for (int i = 0; i < list.size(); i++) {
 702                         Item item = list.get(i);
 703                         if (!(item instanceof TransactionAccount))
 704                             continue;
 705
 706                         TransactionAccount acc = item.toTransactionAccount();
 707                         if (!Misc.equalStrings(acc.getCurrency(), balCurrency))
 708                             continue;
 709
 710                         if (item == receiver) {
 711                             final String hint = String.format("%1.2f", -currencyBalance);
 712                             if (!acc.isAmountHintSet() ||
 713                                 !Misc.equalStrings(acc.getAmountHint(), hint))
 714                             {
 715                                 Logger.debug("submittable",
 716                                         String.format("Setting amount hint of {%s} to %s [%s]",
 717                                                 acc.toString(), hint, balCurrency));
 718                                 acc.setAmountHint(hint);
 719                                 listChanged = true;
 720                             }
 721                         }
 722                         else {
 723                             if (BuildConfig.DEBUG)
 724                                 Logger.debug("submittable",
 725                                         String.format("Resetting hint of '%s' [%s]",
 726                                                 Misc.nullIsEmpty(acc.getAccountName()),
 727                                                 balCurrency));
 728                             if (acc.amountHintIsSet && !TextUtils.isEmpty(acc.getAmountHint())) {
 729                                 acc.setAmountHint(null);
 730                                 listChanged = true;
 731                             }
 732                         }
 733                     }
 734                 }
 735             }
 736
 737             // 5) a row with an empty account name or empty amount is guaranteed to exist for
 738             // each commodity
 739             for (String balCurrency : balance.currencies()) {
 740                 int currEmptyRows = itemsWithEmptyAccountForCurrency.size(balCurrency);
 741                 int currRows = itemsForCurrency.size(balCurrency);
 742                 int currAccounts = itemsWithAccountForCurrency.size(balCurrency);
 743                 int currAmounts = itemsWithAmountForCurrency.size(balCurrency);
 744                 if ((currEmptyRows == 0) &&
 745                     ((currRows == currAccounts) || (currRows == currAmounts)))
 746                 {
 747                     // perhaps there already is an unused empty row for another currency that
 748                     // is not used?
 749 //                        boolean foundIt = false;
 750 //                        for (Item item : emptyRows) {
 751 //                            Currency itemCurrency = item.getCurrency();
 752 //                            String itemCurrencyName =
 753 //                                    (itemCurrency == null) ? "" : itemCurrency.getName();
 754 //                            if (Misc.isZero(balance.get(itemCurrencyName))) {
 755 //                                item.setCurrency(Currency.loadByName(balCurrency));
 756 //                                item.setAmountHint(
 757 //                                        String.format("%1.2f", -balance.get(balCurrency)));
 758 //                                foundIt = true;
 759 //                                break;
 760 //                            }
 761 //                        }
 762 //
 763 //                        if (!foundIt)
 764                     final TransactionAccount newAcc = new TransactionAccount("", balCurrency);
 765                     final float bal = balance.get(balCurrency);
 766                     if (!Misc.isZero(bal) && currAmounts == currRows)
 767                         newAcc.setAmountHint(String.format("%4.2f", -bal));
 768                     Logger.debug("submittable",
 769                             String.format("Adding new item with %s for currency %s",
 770                                     newAcc.getAmountHint(), balCurrency));
 771                     list.add(newAcc);
 772                     listChanged = true;
 773                 }
 774             }
 775
 776             // drop extra empty rows, not needed
 777             for (String currName : emptyRowsForCurrency.currencies()) {
 778                 List<Item> emptyItems = emptyRowsForCurrency.getList(currName);
 779                 while ((list.size() > MIN_ITEMS) && (emptyItems.size() > 1)) {
 780                     // the list is a copy, so the empty item is no longer present
 781                     Item itemToRemove = emptyItems.remove(1);
 782                     removeItemById(list, itemToRemove.id);
 783                     listChanged = true;
 784                 }
 785
 786                 // unused currency, remove last item (which is also an empty one)
 787                 if ((list.size() > MIN_ITEMS) && (emptyItems.size() == 1)) {
 788                     List<Item> currItems = itemsForCurrency.getList(currName);
 789
 790                     if (currItems.size() == 1) {
 791                         // the list is a copy, so the empty item is no longer present
 792                         removeItemById(list, emptyItems.get(0).id);
 793                         listChanged = true;
 794                     }
 795                 }
 796             }
 797
 798             // 6) at least two rows need to be present in the ledger
 799             //    (the list also contains header and trailer)
 800             while (list.size() < MIN_ITEMS) {
 801                 list.add(new TransactionAccount(""));
 802                 listChanged = true;
 803             }
 804
 805             Logger.debug("submittable", submittable ? "YES" : "NO");
 806             isSubmittable.setValue(submittable);
 807
 808             if (BuildConfig.DEBUG)
 809                 dumpItemList("After submittable checks", list);
 810         }
 811         catch (NumberFormatException e) {
 812             Logger.debug("submittable", "NO (because of NumberFormatException)");
 813             isSubmittable.setValue(false);
 814         }
 815         catch (Exception e) {
 816             e.printStackTrace();
 817             Logger.debug("submittable", "NO (because of an Exception)");
 818             isSubmittable.setValue(false);
 819         }
 820
 821         if (listChanged && workingWithLiveList) {
 822             setItemsWithoutSubmittableChecks(list);
 823         }
 824     }
 825     private void removeItemById(@NotNull List<Item> list, int id) {
 826         if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.N) {
 827             list.removeIf(item -> item.id == id);
 828         }
 829         else {
 830             for (Item item : list) {
 831                 if (item.id == id) {
 832                     list.remove(item);
 833                     break;
 834                 }
 835             }
 836         }
 837     }
 838     @SuppressLint("DefaultLocale")
 839     private void dumpItemList(@NotNull String msg, @NotNull List<Item> list) {
 840         Logger.debug("submittable", "== Dump of all items " + msg);
 841         for (int i = 1; i < list.size(); i++) {
 842             TransactionAccount item = list.get(i)
 843                                           .toTransactionAccount();
 844             Logger.debug("submittable", String.format("%d:%s", i, item.toString()));
 845         }
 846     }
 847     public void setItemCurrency(int position, String newCurrency) {
 848         TransactionAccount item = Objects.requireNonNull(items.getValue())
 849                                          .get(position)
 850                                          .toTransactionAccount();
 851         final String oldCurrency = item.getCurrency();
 852
 853         if (Misc.equalStrings(oldCurrency, newCurrency))
 854             return;
 855
 856         List<Item> newList = copyList();
 857         newList.get(position)
 858                .toTransactionAccount()
 859                .setCurrency(newCurrency);
 860
 861         setItems(newList);
 862     }
 863     public boolean accountListIsEmpty() {
 864         List<Item> items = Objects.requireNonNull(this.items.getValue());
 865
 866         for (Item item : items) {
 867             if (!(item instanceof TransactionAccount))
 868                 continue;
 869
 870             if (!((TransactionAccount) item).isEmpty())
 871                 return false;
 872         }
 873
 874         return true;
 875     }
 876
 877     public static class FocusInfo {
 878         int position;
 879         FocusedElement element;
 880         public FocusInfo(int position, FocusedElement element) {
 881             this.position = position;
 882             this.element = element;
 883         }
 884     }
 885
 886     static abstract class Item {
 887         private static int idDispenser = 0;
 888         protected int id;
 889         private Item() {
 890             if (this instanceof TransactionHead)
 891                 id = 0;
 892             else
 893                 synchronized (Item.class) {
 894                     id = ++idDispenser;
 895                 }
 896         }
 897         public Item(int id) {
 898             this.id = id;
 899         }
 900         public static Item from(Item origin) {
 901             if (origin instanceof TransactionHead)
 902                 return new TransactionHead((TransactionHead) origin);
 903             if (origin instanceof TransactionAccount)
 904                 return new TransactionAccount((TransactionAccount) origin);
 905             throw new RuntimeException("Don't know how to handle " + origin);
 906         }
 907         private static void resetIdDispenser() {
 908             idDispenser = 0;
 909         }
 910         public int getId() {
 911             return id;
 912         }
 913         public abstract ItemType getType();
 914         public TransactionHead toTransactionHead() {
 915             if (this instanceof TransactionHead)
 916                 return (TransactionHead) this;
 917
 918             throw new IllegalStateException("Wrong item type " + this);
 919         }
 920         public TransactionAccount toTransactionAccount() {
 921             if (this instanceof TransactionAccount)
 922                 return (TransactionAccount) this;
 923
 924             throw new IllegalStateException("Wrong item type " + this);
 925         }
 926         public boolean equalContents(@Nullable Object item) {
 927             if (item == null)
 928                 return false;
 929
 930             if (!getClass().equals(item.getClass()))
 931                 return false;
 932
 933             // shortcut - comparing same instance
 934             if (item == this)
 935                 return true;
 936
 937             if (this instanceof TransactionHead)
 938                 return ((TransactionHead) item).equalContents((TransactionHead) this);
 939             if (this instanceof TransactionAccount)
 940                 return ((TransactionAccount) item).equalContents((TransactionAccount) this);
 941
 942             throw new RuntimeException("Don't know how to handle " + this);
 943         }
 944     }
 945
 946
 947 //==========================================================================================
 948
 949     public static class TransactionHead extends Item {
 950         private SimpleDate date;
 951         private String description;
 952         private String comment;
 953         TransactionHead(String description) {
 954             super();
 955             this.description = description;
 956         }
 957         public TransactionHead(TransactionHead origin) {
 958             super(origin.id);
 959             date = origin.date;
 960             description = origin.description;
 961             comment = origin.comment;
 962         }
 963         public SimpleDate getDate() {
 964             return date;
 965         }
 966         public void setDate(SimpleDate date) {
 967             this.date = date;
 968         }
 969         public void setDate(String text) throws ParseException {
 970             if (Misc.emptyIsNull(text) == null) {
 971                 date = null;
 972                 return;
 973             }
 974
 975             date = Globals.parseLedgerDate(text);
 976         }
 977         /**
 978          * getFormattedDate()
 979          *
 980          * @return nicely formatted, shortest available date representation
 981          */
 982         String getFormattedDate() {
 983             if (date == null)
 984                 return null;
 985
 986             Calendar today = GregorianCalendar.getInstance();
 987
 988             if (today.get(Calendar.YEAR) != date.year) {
 989                 return String.format(Locale.US, "%d/%02d/%02d", date.year, date.month, date.day);
 990             }
 991
 992             if (today.get(Calendar.MONTH) + 1 != date.month) {
 993                 return String.format(Locale.US, "%d/%02d", date.month, date.day);
 994             }
 995
 996             return String.valueOf(date.day);
 997         }
 998         @NonNull
 999         @Override
1000         public String toString() {
1001             @SuppressLint("DefaultLocale") StringBuilder b = new StringBuilder(
1002                     String.format("id:%d/%s", id, Integer.toHexString(hashCode())));
1003
1004             if (TextUtils.isEmpty(description))
1005                 b.append(" «no description»");
1006             else
1007                 b.append(String.format(" '%s'", description));
1008
1009             if (date != null)
1010                 b.append(String.format("@%s", date.toString()));
1011
1012             if (!TextUtils.isEmpty(comment))
1013                 b.append(String.format(" /%s/", comment));
1014
1015             return b.toString();
1016         }
1017         public String getDescription() {
1018             return description;
1019         }
1020         public void setDescription(String description) {
1021             this.description = description;
1022         }
1023         public String getComment() {
1024             return comment;
1025         }
1026         public void setComment(String comment) {
1027             this.comment = comment;
1028         }
1029         @Override
1030         public ItemType getType() {
1031             return ItemType.generalData;
1032         }
1033         public LedgerTransaction asLedgerTransaction() {
1034             return new LedgerTransaction(null, date, description, Data.getProfile());
1035         }
1036         public boolean equalContents(TransactionHead other) {
1037             if (other == null)
1038                 return false;
1039
1040             return Objects.equals(date, other.date) &&
1041                    Misc.equalStrings(description, other.description) &&
1042                    Misc.equalStrings(comment, other.comment);
1043         }
1044     }
1045
1046     public static class TransactionAccount extends Item {
1047         private String accountName;
1048         private String amountHint;
1049         private String comment;
1050         private String currency;
1051         private float amount;
1052         private boolean amountSet;
1053         private boolean amountValid = true;
1054         private FocusedElement focusedElement = FocusedElement.Account;
1055         private boolean amountHintIsSet = false;
1056         private boolean isLast = false;
1057         private int accountNameCursorPosition;
1058         public TransactionAccount(TransactionAccount origin) {
1059             super(origin.id);
1060             accountName = origin.accountName;
1061             amount = origin.amount;
1062             amountSet = origin.amountSet;
1063             amountHint = origin.amountHint;
1064             amountHintIsSet = origin.amountHintIsSet;
1065             comment = origin.comment;
1066             currency = origin.currency;
1067             amountValid = origin.amountValid;
1068             focusedElement = origin.focusedElement;
1069             isLast = origin.isLast;
1070             accountNameCursorPosition = origin.accountNameCursorPosition;
1071         }
1072         public TransactionAccount(LedgerTransactionAccount account) {
1073             super();
1074             currency = account.getCurrency();
1075             amount = account.getAmount();
1076         }
1077         public TransactionAccount(String accountName) {
1078             super();
1079             this.accountName = accountName;
1080         }
1081         public TransactionAccount(String accountName, String currency) {
1082             super();
1083             this.accountName = accountName;
1084             this.currency = currency;
1085         }
1086         public boolean isLast() {
1087             return isLast;
1088         }
1089         public boolean isAmountSet() {
1090             return amountSet;
1091         }
1092         public String getAccountName() {
1093             return accountName;
1094         }
1095         public void setAccountName(String accountName) {
1096             this.accountName = accountName;
1097         }
1098         public float getAmount() {
1099             if (!amountSet)
1100                 throw new IllegalStateException("Amount is not set");
1101             return amount;
1102         }
1103         public void setAmount(float amount) {
1104             this.amount = amount;
1105             amountSet = true;
1106         }
1107         public void resetAmount() {
1108             amountSet = false;
1109         }
1110         @Override
1111         public ItemType getType() {
1112             return ItemType.transactionRow;
1113         }
1114         public String getAmountHint() {
1115             return amountHint;
1116         }
1117         public void setAmountHint(String amountHint) {
1118             this.amountHint = amountHint;
1119             amountHintIsSet = !TextUtils.isEmpty(amountHint);
1120         }
1121         public String getComment() {
1122             return comment;
1123         }
1124         public void setComment(String comment) {
1125             this.comment = comment;
1126         }
1127         public String getCurrency() {
1128             return currency;
1129         }
1130         public void setCurrency(String currency) {
1131             this.currency = currency;
1132         }
1133         public boolean isAmountValid() {
1134             return amountValid;
1135         }
1136         public void setAmountValid(boolean amountValid) {
1137             this.amountValid = amountValid;
1138         }
1139         public FocusedElement getFocusedElement() {
1140             return focusedElement;
1141         }
1142         public void setFocusedElement(FocusedElement focusedElement) {
1143             this.focusedElement = focusedElement;
1144         }
1145         public boolean isAmountHintSet() {
1146             return amountHintIsSet;
1147         }
1148         public void setAmountHintIsSet(boolean amountHintIsSet) {
1149             this.amountHintIsSet = amountHintIsSet;
1150         }
1151         public boolean isEmpty() {
1152             return !amountSet && Misc.emptyIsNull(accountName) == null &&
1153                    Misc.emptyIsNull(comment) == null;
1154         }
1155         @SuppressLint("DefaultLocale")
1156         @Override
1157         public String toString() {
1158             StringBuilder b = new StringBuilder();
1159             b.append(String.format("id:%d/%s", id, Integer.toHexString(hashCode())));
1160             if (!TextUtils.isEmpty(accountName))
1161                 b.append(String.format(" acc'%s'", accountName));
1162
1163             if (amountSet)
1164                 b.append(String.format(" %4.2f", amount));
1165             else if (amountHintIsSet)
1166                 b.append(String.format(" (%s)", amountHint));
1167
1168             if (!TextUtils.isEmpty(currency))
1169                 b.append(" ")
1170                  .append(currency);
1171
1172             if (!TextUtils.isEmpty(comment))
1173                 b.append(String.format(" /%s/", comment));
1174
1175             if (isLast)
1176                 b.append(" last");
1177
1178             return b.toString();
1179         }
1180         public boolean equalContents(TransactionAccount other) {
1181             if (other == null)
1182                 return false;
1183
1184             boolean equal = Misc.equalStrings(accountName, other.accountName);
1185             equal = equal && Misc.equalStrings(comment, other.comment) &&
1186                     (amountSet ? other.amountSet && amount == other.amount : !other.amountSet);
1187
1188             // compare amount hint only if there is no amount
1189             if (!amountSet)
1190                 equal = equal && (amountHintIsSet ? other.amountHintIsSet &&
1191                                                     Misc.equalStrings(amountHint, other.amountHint)
1192                                                   : !other.amountHintIsSet);
1193             equal = equal && Misc.equalStrings(currency, other.currency) && isLast == other.isLast;
1194
1195             Logger.debug("new-trans",
1196                     String.format("Comparing {%s} and {%s}: %s", this.toString(), other.toString(),
1197                             equal));
1198             return equal;
1199         }
1200         public int getAccountNameCursorPosition() {
1201             return accountNameCursorPosition;
1202         }
1203         public void setAccountNameCursorPosition(int position) {
1204             this.accountNameCursorPosition = position;
1205         }
1206     }
1207
1208     private static class BalanceForCurrency {
1209         private final HashMap<String, Float> hashMap = new HashMap<>();
1210         float get(String currencyName) {
1211             Float f = hashMap.get(currencyName);
1212             if (f == null) {
1213                 f = 0f;
1214                 hashMap.put(currencyName, f);
1215             }
1216             return f;
1217         }
1218         void add(String currencyName, float amount) {
1219             hashMap.put(currencyName, get(currencyName) + amount);
1220         }
1221         Set<String> currencies() {
1222             return hashMap.keySet();
1223         }
1224         boolean containsCurrency(String currencyName) {
1225             return hashMap.containsKey(currencyName);
1226         }
1227     }
1228
1229     private static class ItemsForCurrency {
1230         private final HashMap<String, List<Item>> hashMap = new HashMap<>();
1231         @NonNull
1232         List<NewTransactionModel.Item> getList(@Nullable String currencyName) {
1233             List<NewTransactionModel.Item> list = hashMap.get(currencyName);
1234             if (list == null) {
1235                 list = new ArrayList<>();
1236                 hashMap.put(currencyName, list);
1237             }
1238             return list;
1239         }
1240         void add(@Nullable String currencyName, @NonNull NewTransactionModel.Item item) {
1241             getList(currencyName).add(item);
1242         }
1243         int size(@Nullable String currencyName) {
1244             return this.getList(currencyName)
1245                        .size();
1246         }
1247         Set<String> currencies() {
1248             return hashMap.keySet();
1249         }
1250     }
1251 }