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         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               new Handler(Looper.getMainLooper()).post(() -> setItems(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(String profileUUID, int transactionId) {
 464         List<Item> newList = new ArrayList<>();
 465         Item.resetIdDispenser();
 466         LedgerTransaction tr;
 467         MobileLedgerProfile profile = Data.getProfile(profileUUID);
 468         if (profile == null)
 469             throw new RuntimeException(String.format(
 470                     "Unable to find profile %s, which is supposed to contain transaction %d",
 471                     profileUUID, transactionId));
 472
 473         tr = profile.loadTransaction(transactionId);
 474         TransactionHead head = new TransactionHead(tr.getDescription());
 475         head.setComment(tr.getComment());
 476
 477         newList.add(head);
 478
 479         List<LedgerTransactionAccount> accounts = tr.getAccounts();
 480
 481         TransactionAccount firstNegative = null;
 482         TransactionAccount firstPositive = null;
 483         int singleNegativeIndex = -1;
 484         int singlePositiveIndex = -1;
 485         int negativeCount = 0;
 486         for (int i = 0; i < accounts.size(); i++) {
 487             LedgerTransactionAccount acc = accounts.get(i);
 488             TransactionAccount item =
 489                     new TransactionAccount(acc.getAccountName(), acc.getCurrency());
 490             newList.add(item);
 491
 492             item.setAccountName(acc.getAccountName());
 493             item.setComment(acc.getComment());
 494             if (acc.isAmountSet()) {
 495                 item.setAmount(acc.getAmount());
 496                 if (acc.getAmount() < 0) {
 497                     if (firstNegative == null) {
 498                         firstNegative = item;
 499                         singleNegativeIndex = i + 1;
 500                     }
 501                     else
 502                         singleNegativeIndex = -1;
 503                 }
 504                 else {
 505                     if (firstPositive == null) {
 506                         firstPositive = item;
 507                         singlePositiveIndex = i + 1;
 508                     }
 509                     else
 510                         singlePositiveIndex = -1;
 511                 }
 512             }
 513             else
 514                 item.resetAmount();
 515         }
 516         if (BuildConfig.DEBUG)
 517             dumpItemList("Loaded previous transaction", newList);
 518
 519         if (singleNegativeIndex != -1) {
 520             firstNegative.resetAmount();
 521             moveItemLast(newList, singleNegativeIndex);
 522         }
 523         else if (singlePositiveIndex != -1) {
 524             firstPositive.resetAmount();
 525             moveItemLast(newList, singlePositiveIndex);
 526         }
 527
 528         setItems(newList);
 529
 530         noteFocusChanged(1, FocusedElement.Amount);
 531     }
 532     /**
 533      * A transaction is submittable if:
 534      * 0) has description
 535      * 1) has at least two account names
 536      * 2) each row with amount has account name
 537      * 3) for each commodity:
 538      * 3a) amounts must balance to 0, or
 539      * 3b) there must be exactly one empty amount (with account)
 540      * 4) empty accounts with empty amounts are ignored
 541      * Side effects:
 542      * 5) a row with an empty account name or empty amount is guaranteed to exist for each
 543      * commodity
 544      * 6) at least two rows need to be present in the ledger
 545      *
 546      * @param list - the item list to check. Can be the displayed list or a list that will be
 547      *             displayed soon
 548      */
 549     @SuppressLint("DefaultLocale")
 550     void checkTransactionSubmittable(@Nullable List<Item> list) {
 551         boolean workingWithLiveList = false;
 552         if (list == null) {
 553             list = copyList();
 554             workingWithLiveList = true;
 555         }
 556
 557         if (BuildConfig.DEBUG)
 558             dumpItemList(String.format("Before submittable checks (%s)",
 559                     workingWithLiveList ? "LIVE LIST" : "custom list"), list);
 560
 561         int accounts = 0;
 562         final BalanceForCurrency balance = new BalanceForCurrency();
 563         final String descriptionText = list.get(0)
 564                                            .toTransactionHead()
 565                                            .getDescription();
 566         boolean submittable = true;
 567         boolean listChanged = false;
 568         final ItemsForCurrency itemsForCurrency = new ItemsForCurrency();
 569         final ItemsForCurrency itemsWithEmptyAmountForCurrency = new ItemsForCurrency();
 570         final ItemsForCurrency itemsWithAccountAndEmptyAmountForCurrency = new ItemsForCurrency();
 571         final ItemsForCurrency itemsWithEmptyAccountForCurrency = new ItemsForCurrency();
 572         final ItemsForCurrency itemsWithAmountForCurrency = new ItemsForCurrency();
 573         final ItemsForCurrency itemsWithAccountForCurrency = new ItemsForCurrency();
 574         final ItemsForCurrency emptyRowsForCurrency = new ItemsForCurrency();
 575         final List<Item> emptyRows = new ArrayList<>();
 576
 577         try {
 578             if ((descriptionText == null) || descriptionText.trim()
 579                                                             .isEmpty())
 580             {
 581                 Logger.debug("submittable", "Transaction not submittable: missing description");
 582                 submittable = false;
 583             }
 584
 585             for (int i = 1; i < list.size(); i++) {
 586                 TransactionAccount item = list.get(i)
 587                                               .toTransactionAccount();
 588
 589                 String accName = item.getAccountName()
 590                                      .trim();
 591                 String currName = item.getCurrency();
 592
 593                 itemsForCurrency.add(currName, item);
 594
 595                 if (accName.isEmpty()) {
 596                     itemsWithEmptyAccountForCurrency.add(currName, item);
 597
 598                     if (item.isAmountSet()) {
 599                         // 2) each amount has account name
 600                         Logger.debug("submittable", String.format(
 601                                 "Transaction not submittable: row %d has no account name, but" +
 602                                 " has" + " amount %1.2f", i + 1, item.getAmount()));
 603                         submittable = false;
 604                     }
 605                     else {
 606                         emptyRowsForCurrency.add(currName, item);
 607                     }
 608                 }
 609                 else {
 610                     accounts++;
 611                     itemsWithAccountForCurrency.add(currName, item);
 612                 }
 613
 614                 if (!item.isAmountValid()) {
 615                     Logger.debug("submittable",
 616                             String.format("Not submittable: row %d has an invalid amount", i + 1));
 617                     submittable = false;
 618                 }
 619                 else if (item.isAmountSet()) {
 620                     itemsWithAmountForCurrency.add(currName, item);
 621                     balance.add(currName, item.getAmount());
 622                 }
 623                 else {
 624                     itemsWithEmptyAmountForCurrency.add(currName, item);
 625
 626                     if (!accName.isEmpty())
 627                         itemsWithAccountAndEmptyAmountForCurrency.add(currName, item);
 628                 }
 629             }
 630
 631             // 1) has at least two account names
 632             if (accounts < 2) {
 633                 if (accounts == 0)
 634                     Logger.debug("submittable", "Transaction not submittable: no account names");
 635                 else if (accounts == 1)
 636                     Logger.debug("submittable",
 637                             "Transaction not submittable: only one account name");
 638                 else
 639                     Logger.debug("submittable",
 640                             String.format("Transaction not submittable: only %d account names",
 641                                     accounts));
 642                 submittable = false;
 643             }
 644
 645             // 3) for each commodity:
 646             // 3a) amount must balance to 0, or
 647             // 3b) there must be exactly one empty amount (with account)
 648             for (String balCurrency : itemsForCurrency.currencies()) {
 649                 float currencyBalance = balance.get(balCurrency);
 650                 if (Misc.isZero(currencyBalance)) {
 651                     // remove hints from all amount inputs in that currency
 652                     for (int i = 1; i < list.size(); i++) {
 653                         TransactionAccount acc = list.get(i)
 654                                                      .toTransactionAccount();
 655                         if (Misc.equalStrings(acc.getCurrency(), balCurrency)) {
 656                             if (BuildConfig.DEBUG)
 657                                 Logger.debug("submittable",
 658                                         String.format(Locale.US, "Resetting hint of %d:'%s' [%s]",
 659                                                 i, Misc.nullIsEmpty(acc.getAccountName()),
 660                                                 balCurrency));
 661                             // skip if the amount is set, in which case the hint is not
 662                             // important/visible
 663                             if (!acc.isAmountSet() && acc.amountHintIsSet &&
 664                                 !TextUtils.isEmpty(acc.getAmountHint()))
 665                             {
 666                                 acc.setAmountHint(null);
 667                                 listChanged = true;
 668                             }
 669                         }
 670                     }
 671                 }
 672                 else {
 673                     List<Item> tmpList =
 674                             itemsWithAccountAndEmptyAmountForCurrency.getList(balCurrency);
 675                     int balanceReceiversCount = tmpList.size();
 676                     if (balanceReceiversCount != 1) {
 677                         if (BuildConfig.DEBUG) {
 678                             if (balanceReceiversCount == 0)
 679                                 Logger.debug("submittable", String.format(
 680                                         "Transaction not submittable [%s]: non-zero balance " +
 681                                         "with no empty amounts with accounts", balCurrency));
 682                             else
 683                                 Logger.debug("submittable", String.format(
 684                                         "Transaction not submittable [%s]: non-zero balance " +
 685                                         "with multiple empty amounts with accounts", balCurrency));
 686                         }
 687                         submittable = false;
 688                     }
 689
 690                     List<Item> emptyAmountList =
 691                             itemsWithEmptyAmountForCurrency.getList(balCurrency);
 692
 693                     // suggest off-balance amount to a row and remove hints on other rows
 694                     Item receiver = null;
 695                     if (!tmpList.isEmpty())
 696                         receiver = tmpList.get(0);
 697                     else if (!emptyAmountList.isEmpty())
 698                         receiver = emptyAmountList.get(0);
 699
 700                     for (int i = 0; i < list.size(); i++) {
 701                         Item item = list.get(i);
 702                         if (!(item instanceof TransactionAccount))
 703                             continue;
 704
 705                         TransactionAccount acc = item.toTransactionAccount();
 706                         if (!Misc.equalStrings(acc.getCurrency(), balCurrency))
 707                             continue;
 708
 709                         if (item == receiver) {
 710                             final String hint = String.format("%1.2f", -currencyBalance);
 711                             if (!acc.isAmountHintSet() ||
 712                                 !Misc.equalStrings(acc.getAmountHint(), hint))
 713                             {
 714                                 Logger.debug("submittable",
 715                                         String.format("Setting amount hint of {%s} to %s [%s]",
 716                                                 acc.toString(), hint, balCurrency));
 717                                 acc.setAmountHint(hint);
 718                                 listChanged = true;
 719                             }
 720                         }
 721                         else {
 722                             if (BuildConfig.DEBUG)
 723                                 Logger.debug("submittable",
 724                                         String.format("Resetting hint of '%s' [%s]",
 725                                                 Misc.nullIsEmpty(acc.getAccountName()),
 726                                                 balCurrency));
 727                             if (acc.amountHintIsSet && !TextUtils.isEmpty(acc.getAmountHint())) {
 728                                 acc.setAmountHint(null);
 729                                 listChanged = true;
 730                             }
 731                         }
 732                     }
 733                 }
 734             }
 735
 736             // 5) a row with an empty account name or empty amount is guaranteed to exist for
 737             // each commodity
 738             for (String balCurrency : balance.currencies()) {
 739                 int currEmptyRows = itemsWithEmptyAccountForCurrency.size(balCurrency);
 740                 int currRows = itemsForCurrency.size(balCurrency);
 741                 int currAccounts = itemsWithAccountForCurrency.size(balCurrency);
 742                 int currAmounts = itemsWithAmountForCurrency.size(balCurrency);
 743                 if ((currEmptyRows == 0) &&
 744                     ((currRows == currAccounts) || (currRows == currAmounts)))
 745                 {
 746                     // perhaps there already is an unused empty row for another currency that
 747                     // is not used?
 748 //                        boolean foundIt = false;
 749 //                        for (Item item : emptyRows) {
 750 //                            Currency itemCurrency = item.getCurrency();
 751 //                            String itemCurrencyName =
 752 //                                    (itemCurrency == null) ? "" : itemCurrency.getName();
 753 //                            if (Misc.isZero(balance.get(itemCurrencyName))) {
 754 //                                item.setCurrency(Currency.loadByName(balCurrency));
 755 //                                item.setAmountHint(
 756 //                                        String.format("%1.2f", -balance.get(balCurrency)));
 757 //                                foundIt = true;
 758 //                                break;
 759 //                            }
 760 //                        }
 761 //
 762 //                        if (!foundIt)
 763                     final TransactionAccount newAcc = new TransactionAccount("", balCurrency);
 764                     final float bal = balance.get(balCurrency);
 765                     if (!Misc.isZero(bal) && currAmounts == currRows)
 766                         newAcc.setAmountHint(String.format("%4.2f", -bal));
 767                     Logger.debug("submittable",
 768                             String.format("Adding new item with %s for currency %s",
 769                                     newAcc.getAmountHint(), balCurrency));
 770                     list.add(newAcc);
 771                     listChanged = true;
 772                 }
 773             }
 774
 775             // drop extra empty rows, not needed
 776             for (String currName : emptyRowsForCurrency.currencies()) {
 777                 List<Item> emptyItems = emptyRowsForCurrency.getList(currName);
 778                 while ((list.size() > MIN_ITEMS) && (emptyItems.size() > 1)) {
 779                     // the list is a copy, so the empty item is no longer present
 780                     Item itemToRemove = emptyItems.remove(1);
 781                     removeItemById(list, itemToRemove.id);
 782                     listChanged = true;
 783                 }
 784
 785                 // unused currency, remove last item (which is also an empty one)
 786                 if ((list.size() > MIN_ITEMS) && (emptyItems.size() == 1)) {
 787                     List<Item> currItems = itemsForCurrency.getList(currName);
 788
 789                     if (currItems.size() == 1) {
 790                         // the list is a copy, so the empty item is no longer present
 791                         removeItemById(list, emptyItems.get(0).id);
 792                         listChanged = true;
 793                     }
 794                 }
 795             }
 796
 797             // 6) at least two rows need to be present in the ledger
 798             //    (the list also contains header and trailer)
 799             while (list.size() < MIN_ITEMS) {
 800                 list.add(new TransactionAccount(""));
 801                 listChanged = true;
 802             }
 803
 804             Logger.debug("submittable", submittable ? "YES" : "NO");
 805             isSubmittable.setValue(submittable);
 806
 807             if (BuildConfig.DEBUG)
 808                 dumpItemList("After submittable checks", list);
 809         }
 810         catch (NumberFormatException e) {
 811             Logger.debug("submittable", "NO (because of NumberFormatException)");
 812             isSubmittable.setValue(false);
 813         }
 814         catch (Exception e) {
 815             e.printStackTrace();
 816             Logger.debug("submittable", "NO (because of an Exception)");
 817             isSubmittable.setValue(false);
 818         }
 819
 820         if (listChanged && workingWithLiveList) {
 821             setItemsWithoutSubmittableChecks(list);
 822         }
 823     }
 824     private void removeItemById(@NotNull List<Item> list, int id) {
 825         if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.N) {
 826             list.removeIf(item -> item.id == id);
 827         }
 828         else {
 829             for (Item item : list) {
 830                 if (item.id == id) {
 831                     list.remove(item);
 832                     break;
 833                 }
 834             }
 835         }
 836     }
 837     @SuppressLint("DefaultLocale")
 838     private void dumpItemList(@NotNull String msg, @NotNull List<Item> list) {
 839         Logger.debug("submittable", "== Dump of all items " + msg);
 840         for (int i = 1; i < list.size(); i++) {
 841             TransactionAccount item = list.get(i)
 842                                           .toTransactionAccount();
 843             Logger.debug("submittable", String.format("%d:%s", i, item.toString()));
 844         }
 845     }
 846     public void setItemCurrency(int position, String newCurrency) {
 847         TransactionAccount item = Objects.requireNonNull(items.getValue())
 848                                          .get(position)
 849                                          .toTransactionAccount();
 850         final String oldCurrency = item.getCurrency();
 851
 852         if (Misc.equalStrings(oldCurrency, newCurrency))
 853             return;
 854
 855         List<Item> newList = copyList();
 856         newList.get(position)
 857                .toTransactionAccount()
 858                .setCurrency(newCurrency);
 859
 860         setItems(newList);
 861     }
 862     public boolean accountListIsEmpty() {
 863         List<Item> items = Objects.requireNonNull(this.items.getValue());
 864
 865         for (Item item : items) {
 866             if (!(item instanceof TransactionAccount))
 867                 continue;
 868
 869             if (!((TransactionAccount) item).isEmpty())
 870                 return false;
 871         }
 872
 873         return true;
 874     }
 875
 876     public static class FocusInfo {
 877         int position;
 878         FocusedElement element;
 879         public FocusInfo(int position, FocusedElement element) {
 880             this.position = position;
 881             this.element = element;
 882         }
 883     }
 884
 885     static abstract class Item {
 886         private static int idDispenser = 0;
 887         protected int id;
 888         private Item() {
 889             if (this instanceof TransactionHead)
 890                 id = 0;
 891             else
 892                 synchronized (Item.class) {
 893                     id = ++idDispenser;
 894                 }
 895         }
 896         public Item(int id) {
 897             this.id = id;
 898         }
 899         public static Item from(Item origin) {
 900             if (origin instanceof TransactionHead)
 901                 return new TransactionHead((TransactionHead) origin);
 902             if (origin instanceof TransactionAccount)
 903                 return new TransactionAccount((TransactionAccount) origin);
 904             throw new RuntimeException("Don't know how to handle " + origin);
 905         }
 906         private static void resetIdDispenser() {
 907             idDispenser = 0;
 908         }
 909         public int getId() {
 910             return id;
 911         }
 912         public abstract ItemType getType();
 913         public TransactionHead toTransactionHead() {
 914             if (this instanceof TransactionHead)
 915                 return (TransactionHead) this;
 916
 917             throw new IllegalStateException("Wrong item type " + this);
 918         }
 919         public TransactionAccount toTransactionAccount() {
 920             if (this instanceof TransactionAccount)
 921                 return (TransactionAccount) this;
 922
 923             throw new IllegalStateException("Wrong item type " + this);
 924         }
 925         public boolean equalContents(@Nullable Object item) {
 926             if (item == null)
 927                 return false;
 928
 929             if (!getClass().equals(item.getClass()))
 930                 return false;
 931
 932             // shortcut - comparing same instance
 933             if (item == this)
 934                 return true;
 935
 936             if (this instanceof TransactionHead)
 937                 return ((TransactionHead) item).equalContents((TransactionHead) this);
 938             if (this instanceof TransactionAccount)
 939                 return ((TransactionAccount) item).equalContents((TransactionAccount) this);
 940
 941             throw new RuntimeException("Don't know how to handle " + this);
 942         }
 943     }
 944
 945
 946 //==========================================================================================
 947
 948     public static class TransactionHead extends Item {
 949         private SimpleDate date;
 950         private String description;
 951         private String comment;
 952         TransactionHead(String description) {
 953             super();
 954             this.description = description;
 955         }
 956         public TransactionHead(TransactionHead origin) {
 957             super(origin.id);
 958             date = origin.date;
 959             description = origin.description;
 960             comment = origin.comment;
 961         }
 962         public SimpleDate getDate() {
 963             return date;
 964         }
 965         public void setDate(SimpleDate date) {
 966             this.date = date;
 967         }
 968         public void setDate(String text) throws ParseException {
 969             if (Misc.emptyIsNull(text) == null) {
 970                 date = null;
 971                 return;
 972             }
 973
 974             date = Globals.parseLedgerDate(text);
 975         }
 976         /**
 977          * getFormattedDate()
 978          *
 979          * @return nicely formatted, shortest available date representation
 980          */
 981         String getFormattedDate() {
 982             if (date == null)
 983                 return null;
 984
 985             Calendar today = GregorianCalendar.getInstance();
 986
 987             if (today.get(Calendar.YEAR) != date.year) {
 988                 return String.format(Locale.US, "%d/%02d/%02d", date.year, date.month, date.day);
 989             }
 990
 991             if (today.get(Calendar.MONTH) + 1 != date.month) {
 992                 return String.format(Locale.US, "%d/%02d", date.month, date.day);
 993             }
 994
 995             return String.valueOf(date.day);
 996         }
 997         @NonNull
 998         @Override
 999         public String toString() {
1000             @SuppressLint("DefaultLocale") StringBuilder b = new StringBuilder(
1001                     String.format("id:%d/%s", id, Integer.toHexString(hashCode())));
1002
1003             if (TextUtils.isEmpty(description))
1004                 b.append(" «no description»");
1005             else
1006                 b.append(String.format(" '%s'", description));
1007
1008             if (date != null)
1009                 b.append(String.format("@%s", date.toString()));
1010
1011             if (!TextUtils.isEmpty(comment))
1012                 b.append(String.format(" /%s/", comment));
1013
1014             return b.toString();
1015         }
1016         public String getDescription() {
1017             return description;
1018         }
1019         public void setDescription(String description) {
1020             this.description = description;
1021         }
1022         public String getComment() {
1023             return comment;
1024         }
1025         public void setComment(String comment) {
1026             this.comment = comment;
1027         }
1028         @Override
1029         public ItemType getType() {
1030             return ItemType.generalData;
1031         }
1032         public LedgerTransaction asLedgerTransaction() {
1033             return new LedgerTransaction(null, date, description, Data.getProfile());
1034         }
1035         public boolean equalContents(TransactionHead other) {
1036             if (other == null)
1037                 return false;
1038
1039             return Objects.equals(date, other.date) &&
1040                    Misc.equalStrings(description, other.description) &&
1041                    Misc.equalStrings(comment, other.comment);
1042         }
1043     }
1044
1045     public static class TransactionAccount extends Item {
1046         private String accountName;
1047         private String amountHint;
1048         private String comment;
1049         private String currency;
1050         private float amount;
1051         private boolean amountSet;
1052         private boolean amountValid = true;
1053         private FocusedElement focusedElement = FocusedElement.Account;
1054         private boolean amountHintIsSet = false;
1055         private boolean isLast = false;
1056         private int accountNameCursorPosition;
1057         public TransactionAccount(TransactionAccount origin) {
1058             super(origin.id);
1059             accountName = origin.accountName;
1060             amount = origin.amount;
1061             amountSet = origin.amountSet;
1062             amountHint = origin.amountHint;
1063             amountHintIsSet = origin.amountHintIsSet;
1064             comment = origin.comment;
1065             currency = origin.currency;
1066             amountValid = origin.amountValid;
1067             focusedElement = origin.focusedElement;
1068             isLast = origin.isLast;
1069             accountNameCursorPosition = origin.accountNameCursorPosition;
1070         }
1071         public TransactionAccount(LedgerTransactionAccount account) {
1072             super();
1073             currency = account.getCurrency();
1074             amount = account.getAmount();
1075         }
1076         public TransactionAccount(String accountName) {
1077             super();
1078             this.accountName = accountName;
1079         }
1080         public TransactionAccount(String accountName, String currency) {
1081             super();
1082             this.accountName = accountName;
1083             this.currency = currency;
1084         }
1085         public boolean isLast() {
1086             return isLast;
1087         }
1088         public boolean isAmountSet() {
1089             return amountSet;
1090         }
1091         public String getAccountName() {
1092             return accountName;
1093         }
1094         public void setAccountName(String accountName) {
1095             this.accountName = accountName;
1096         }
1097         public float getAmount() {
1098             if (!amountSet)
1099                 throw new IllegalStateException("Amount is not set");
1100             return amount;
1101         }
1102         public void setAmount(float amount) {
1103             this.amount = amount;
1104             amountSet = true;
1105         }
1106         public void resetAmount() {
1107             amountSet = false;
1108         }
1109         @Override
1110         public ItemType getType() {
1111             return ItemType.transactionRow;
1112         }
1113         public String getAmountHint() {
1114             return amountHint;
1115         }
1116         public void setAmountHint(String amountHint) {
1117             this.amountHint = amountHint;
1118             amountHintIsSet = !TextUtils.isEmpty(amountHint);
1119         }
1120         public String getComment() {
1121             return comment;
1122         }
1123         public void setComment(String comment) {
1124             this.comment = comment;
1125         }
1126         public String getCurrency() {
1127             return currency;
1128         }
1129         public void setCurrency(String currency) {
1130             this.currency = currency;
1131         }
1132         public boolean isAmountValid() {
1133             return amountValid;
1134         }
1135         public void setAmountValid(boolean amountValid) {
1136             this.amountValid = amountValid;
1137         }
1138         public FocusedElement getFocusedElement() {
1139             return focusedElement;
1140         }
1141         public void setFocusedElement(FocusedElement focusedElement) {
1142             this.focusedElement = focusedElement;
1143         }
1144         public boolean isAmountHintSet() {
1145             return amountHintIsSet;
1146         }
1147         public void setAmountHintIsSet(boolean amountHintIsSet) {
1148             this.amountHintIsSet = amountHintIsSet;
1149         }
1150         public boolean isEmpty() {
1151             return !amountSet && Misc.emptyIsNull(accountName) == null &&
1152                    Misc.emptyIsNull(comment) == null;
1153         }
1154         @SuppressLint("DefaultLocale")
1155         @Override
1156         public String toString() {
1157             StringBuilder b = new StringBuilder();
1158             b.append(String.format("id:%d/%s", id, Integer.toHexString(hashCode())));
1159             if (!TextUtils.isEmpty(accountName))
1160                 b.append(String.format(" acc'%s'", accountName));
1161
1162             if (amountSet)
1163                 b.append(String.format(" %4.2f", amount));
1164             else if (amountHintIsSet)
1165                 b.append(String.format(" (%s)", amountHint));
1166
1167             if (!TextUtils.isEmpty(currency))
1168                 b.append(" ")
1169                  .append(currency);
1170
1171             if (!TextUtils.isEmpty(comment))
1172                 b.append(String.format(" /%s/", comment));
1173
1174             if (isLast)
1175                 b.append(" last");
1176
1177             return b.toString();
1178         }
1179         public boolean equalContents(TransactionAccount other) {
1180             if (other == null)
1181                 return false;
1182
1183             boolean equal = Misc.equalStrings(accountName, other.accountName);
1184             equal = equal && Misc.equalStrings(comment, other.comment) &&
1185                     (amountSet ? other.amountSet && amount == other.amount : !other.amountSet);
1186
1187             // compare amount hint only if there is no amount
1188             if (!amountSet)
1189                 equal = equal && (amountHintIsSet ? other.amountHintIsSet &&
1190                                                     Misc.equalStrings(amountHint, other.amountHint)
1191                                                   : !other.amountHintIsSet);
1192             equal = equal && Misc.equalStrings(currency, other.currency) && isLast == other.isLast;
1193
1194             Logger.debug("new-trans",
1195                     String.format("Comparing {%s} and {%s}: %s", this.toString(), other.toString(),
1196                             equal));
1197             return equal;
1198         }
1199         public int getAccountNameCursorPosition() {
1200             return accountNameCursorPosition;
1201         }
1202         public void setAccountNameCursorPosition(int position) {
1203             this.accountNameCursorPosition = position;
1204         }
1205     }
1206
1207     private static class BalanceForCurrency {
1208         private final HashMap<String, Float> hashMap = new HashMap<>();
1209         float get(String currencyName) {
1210             Float f = hashMap.get(currencyName);
1211             if (f == null) {
1212                 f = 0f;
1213                 hashMap.put(currencyName, f);
1214             }
1215             return f;
1216         }
1217         void add(String currencyName, float amount) {
1218             hashMap.put(currencyName, get(currencyName) + amount);
1219         }
1220         Set<String> currencies() {
1221             return hashMap.keySet();
1222         }
1223         boolean containsCurrency(String currencyName) {
1224             return hashMap.containsKey(currencyName);
1225         }
1226     }
1227
1228     private static class ItemsForCurrency {
1229         private final HashMap<String, List<Item>> hashMap = new HashMap<>();
1230         @NonNull
1231         List<NewTransactionModel.Item> getList(@Nullable String currencyName) {
1232             List<NewTransactionModel.Item> list = hashMap.get(currencyName);
1233             if (list == null) {
1234                 list = new ArrayList<>();
1235                 hashMap.put(currencyName, list);
1236             }
1237             return list;
1238         }
1239         void add(@Nullable String currencyName, @NonNull NewTransactionModel.Item item) {
1240             getList(currencyName).add(item);
1241         }
1242         int size(@Nullable String currencyName) {
1243             return this.getList(currencyName)
1244                        .size();
1245         }
1246         Set<String> currencies() {
1247             return hashMap.keySet();
1248         }
1249     }
1250 }