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

   1 /*
   2  * Copyright © 2021 Damyan Ivanov.
   3  * This file is part of MoLe.
   4  * MoLe is free software: you can distribute it and/or modify it
   5  * under the term of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your opinion), any later version.
   8  *
   9  * MoLe is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  12  * GNU General Public License terms for details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with MoLe. If not, see <https://www.gnu.org/licenses/>.
  16  */
  17
  18 package net.ktnx.mobileledger.ui.new_transaction;
  19
  20 import android.annotation.SuppressLint;
  21 import android.text.TextUtils;
  22
  23 import androidx.annotation.NonNull;
  24 import androidx.annotation.Nullable;
  25 import androidx.lifecycle.LifecycleOwner;
  26 import androidx.lifecycle.LiveData;
  27 import androidx.lifecycle.MutableLiveData;
  28 import androidx.lifecycle.Observer;
  29 import androidx.lifecycle.ViewModel;
  30
  31 import net.ktnx.mobileledger.BuildConfig;
  32 import net.ktnx.mobileledger.db.Currency;
  33 import net.ktnx.mobileledger.db.DB;
  34 import net.ktnx.mobileledger.db.Profile;
  35 import net.ktnx.mobileledger.db.TemplateAccount;
  36 import net.ktnx.mobileledger.db.TemplateHeader;
  37 import net.ktnx.mobileledger.db.TransactionWithAccounts;
  38 import net.ktnx.mobileledger.model.Data;
  39 import net.ktnx.mobileledger.model.InertMutableLiveData;
  40 import net.ktnx.mobileledger.model.LedgerTransaction;
  41 import net.ktnx.mobileledger.model.LedgerTransactionAccount;
  42 import net.ktnx.mobileledger.model.MatchedTemplate;
  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<Profile> 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         renumberItems(items.getValue());
 105     }
 106     private void renumberItems(List<Item> list) {
 107         if (list == null) {
 108             return;
 109         }
 110
 111         int id = 0;
 112         for (Item item : list)
 113             item.id = id++;
 114     }
 115     private void setItemsWithoutSubmittableChecks(@NonNull List<Item> list) {
 116         final int cnt = list.size();
 117         for (int i = 1; i < cnt - 1; i++) {
 118             final TransactionAccount item = list.get(i)
 119                                                 .toTransactionAccount();
 120             if (item.isLast) {
 121                 TransactionAccount replacement = new TransactionAccount(item);
 122                 replacement.isLast = false;
 123                 list.set(i, replacement);
 124             }
 125         }
 126         final TransactionAccount last = list.get(cnt - 1)
 127                                             .toTransactionAccount();
 128         if (!last.isLast) {
 129             TransactionAccount replacement = new TransactionAccount(last);
 130             replacement.isLast = true;
 131             list.set(cnt - 1, replacement);
 132         }
 133
 134         if (BuildConfig.DEBUG)
 135             dumpItemList("Before setValue()", list);
 136         items.setValue(list);
 137     }
 138     private List<Item> copyList() {
 139         List<Item> copy = new ArrayList<>();
 140         List<Item> oldList = items.getValue();
 141
 142         if (oldList != null)
 143             for (Item item : oldList) {
 144                 copy.add(Item.from(item));
 145             }
 146
 147         return copy;
 148     }
 149     private List<Item> copyListWithoutItem(int position) {
 150         List<Item> copy = new ArrayList<>();
 151         List<Item> oldList = items.getValue();
 152
 153         if (oldList != null) {
 154             int i = 0;
 155             for (Item item : oldList) {
 156                 if (i++ == position)
 157                     continue;
 158                 copy.add(Item.from(item));
 159             }
 160         }
 161
 162         return copy;
 163     }
 164     private List<Item> shallowCopyList() {
 165         return new ArrayList<>(items.getValue());
 166     }
 167     LiveData<Boolean> getShowComments() {
 168         return showComments;
 169     }
 170     void observeDataProfile(LifecycleOwner activity) {
 171         if (!observingDataProfile)
 172             Data.observeProfile(activity, profileObserver);
 173         observingDataProfile = true;
 174     }
 175     boolean getSimulateSaveFlag() {
 176         Boolean value = simulateSave.getValue();
 177         if (value == null)
 178             return false;
 179         return value;
 180     }
 181     LiveData<Boolean> getSimulateSave() {
 182         return simulateSave;
 183     }
 184     void toggleSimulateSave() {
 185         simulateSave.setValue(!getSimulateSaveFlag());
 186     }
 187     LiveData<Boolean> isSubmittable() {
 188         return this.isSubmittable;
 189     }
 190     void reset() {
 191         Logger.debug("new-trans", "Resetting model");
 192         List<Item> list = new ArrayList<>();
 193         Item.resetIdDispenser();
 194         list.add(new TransactionHead(""));
 195         final String defaultCurrency = Objects.requireNonNull(Data.getProfile())
 196                                               .getDefaultCommodity();
 197         list.add(new TransactionAccount("", defaultCurrency));
 198         list.add(new TransactionAccount("", defaultCurrency));
 199         noteFocusChanged(0, FocusedElement.Description);
 200         renumberItems();
 201         isSubmittable.setValue(false);
 202         setItemsWithoutSubmittableChecks(list);
 203     }
 204     boolean accountsInInitialState() {
 205         final List<Item> list = items.getValue();
 206
 207         if (list == null)
 208             return true;
 209
 210         for (Item item : list) {
 211             if (!(item instanceof TransactionAccount))
 212                 continue;
 213
 214             TransactionAccount accRow = (TransactionAccount) item;
 215             if (!accRow.isEmpty())
 216                 return false;
 217         }
 218
 219         return true;
 220     }
 221     void applyTemplate(MatchedTemplate matchedTemplate, String text) {
 222         SimpleDate transactionDate = null;
 223         final MatchResult matchResult = matchedTemplate.matchResult;
 224         final TemplateHeader templateHead = matchedTemplate.templateHead;
 225         {
 226             int day = extractIntFromMatches(matchResult, templateHead.getDateDayMatchGroup(),
 227                     templateHead.getDateDay());
 228             int month = extractIntFromMatches(matchResult, templateHead.getDateMonthMatchGroup(),
 229                     templateHead.getDateMonth());
 230             int year = extractIntFromMatches(matchResult, templateHead.getDateYearMatchGroup(),
 231                     templateHead.getDateYear());
 232
 233             if (year > 0 || month > 0 || day > 0) {
 234                 SimpleDate today = SimpleDate.today();
 235                 if (year <= 0)
 236                     year = today.year;
 237                 if (month <= 0)
 238                     month = today.month;
 239                 if (day <= 0)
 240                     day = today.day;
 241
 242                 transactionDate = new SimpleDate(year, month, day);
 243
 244                 Logger.debug("pattern", "setting transaction date to " + transactionDate);
 245             }
 246         }
 247
 248         List<Item> present = copyList();
 249
 250         TransactionHead head = new TransactionHead(present.get(0)
 251                                                           .toTransactionHead());
 252         if (transactionDate != null)
 253             head.setDate(transactionDate);
 254
 255         final String transactionDescription = extractStringFromMatches(matchResult,
 256                 templateHead.getTransactionDescriptionMatchGroup(),
 257                 templateHead.getTransactionDescription());
 258         if (Misc.emptyIsNull(transactionDescription) != null)
 259             head.setDescription(transactionDescription);
 260
 261         final String transactionComment = extractStringFromMatches(matchResult,
 262                 templateHead.getTransactionCommentMatchGroup(),
 263                 templateHead.getTransactionComment());
 264         if (Misc.emptyIsNull(transactionComment) != null)
 265             head.setComment(transactionComment);
 266
 267         List<Item> newItems = new ArrayList<>();
 268
 269         newItems.add(head);
 270
 271         for (int i = 1; i < present.size(); i++) {
 272             final TransactionAccount row = present.get(i)
 273                                                   .toTransactionAccount();
 274             if (!row.isEmpty())
 275                 newItems.add(new TransactionAccount(row));
 276         }
 277
 278         DB.get()
 279           .getTemplateDAO()
 280           .getTemplateWithAccountsAsync(templateHead.getId(), entry -> {
 281               int rowIndex = 0;
 282               final boolean accountsInInitialState = accountsInInitialState();
 283               for (TemplateAccount acc : entry.accounts) {
 284                   rowIndex++;
 285
 286                   String accountName =
 287                           extractStringFromMatches(matchResult, acc.getAccountNameMatchGroup(),
 288                                   acc.getAccountName());
 289                   String accountComment =
 290                           extractStringFromMatches(matchResult, acc.getAccountCommentMatchGroup(),
 291                                   acc.getAccountComment());
 292                   Float amount = extractFloatFromMatches(matchResult, acc.getAmountMatchGroup(),
 293                           acc.getAmount());
 294                   if (amount != null && acc.getNegateAmount() != null && acc.getNegateAmount())
 295                       amount = -amount;
 296
 297                   TransactionAccount accRow = new TransactionAccount(accountName);
 298                   accRow.setComment(accountComment);
 299                   if (amount != null)
 300                       accRow.setAmount(amount);
 301                   accRow.setCurrency(
 302                           extractCurrencyFromMatches(matchResult, acc.getCurrencyMatchGroup(),
 303                                   acc.getCurrencyObject()));
 304
 305                   newItems.add(accRow);
 306               }
 307
 308               renumberItems(newItems);
 309               Misc.onMainThread(() -> replaceItems(newItems));
 310           });
 311     }
 312     private String extractCurrencyFromMatches(MatchResult m, Integer group, Currency literal) {
 313         return extractStringFromMatches(m, group, (literal == null) ? "" : literal.getName());
 314     }
 315     private int extractIntFromMatches(MatchResult m, Integer group, Integer literal) {
 316         if (literal != null)
 317             return literal;
 318
 319         if (group != null) {
 320             int grp = group;
 321             if (grp > 0 && grp <= m.groupCount())
 322                 try {
 323                     return Integer.parseInt(m.group(grp));
 324                 }
 325                 catch (NumberFormatException e) {
 326                     Logger.debug("new-trans", "Error extracting matched number", e);
 327                 }
 328         }
 329
 330         return 0;
 331     }
 332     private String extractStringFromMatches(MatchResult m, Integer group, String literal) {
 333         if (literal != null)
 334             return literal;
 335
 336         if (group != null) {
 337             int grp = group;
 338             if (grp > 0 && grp <= m.groupCount())
 339                 return m.group(grp);
 340         }
 341
 342         return null;
 343     }
 344     private Float extractFloatFromMatches(MatchResult m, Integer group, Float literal) {
 345         if (literal != null)
 346             return literal;
 347
 348         if (group != null) {
 349             int grp = group;
 350             if (grp > 0 && grp <= m.groupCount())
 351                 try {
 352                     return Float.valueOf(m.group(grp));
 353                 }
 354                 catch (NumberFormatException e) {
 355                     Logger.debug("new-trans", "Error extracting matched number", e);
 356                 }
 357         }
 358
 359         return null;
 360     }
 361     void removeItem(int pos) {
 362         Logger.debug("new-trans", String.format(Locale.US, "Removing item at position %d", pos));
 363         List<Item> newList = copyListWithoutItem(pos);
 364         final FocusInfo fi = focusInfo.getValue();
 365         if ((fi != null) && (pos < fi.position))
 366             noteFocusChanged(fi.position - 1, fi.element);
 367         setItems(newList);
 368     }
 369     void noteFocusChanged(int position, FocusedElement element) {
 370         FocusInfo present = focusInfo.getValue();
 371         if (present == null || present.position != position || present.element != element)
 372             focusInfo.setValue(new FocusInfo(position, element));
 373     }
 374     public LiveData<FocusInfo> getFocusInfo() {
 375         return focusInfo;
 376     }
 377     void moveItem(int fromIndex, int toIndex) {
 378         List<Item> newList = shallowCopyList();
 379         Item item = newList.remove(fromIndex);
 380         newList.add(toIndex, item);
 381
 382         FocusInfo fi = focusInfo.getValue();
 383         if (fi != null && fi.position == fromIndex)
 384             noteFocusChanged(toIndex, fi.element);
 385
 386         items.setValue(newList); // same count, same submittable state
 387     }
 388     void moveItemLast(List<Item> list, int index) {
 389         /*   0
 390              1   <-- index
 391              2
 392              3   <-- desired position
 393                  (no bottom filler)
 394          */
 395         int itemCount = list.size();
 396
 397         if (index < itemCount - 1)
 398             list.add(list.remove(index));
 399     }
 400     void toggleCurrencyVisible() {
 401         final boolean newValue = !Objects.requireNonNull(showCurrency.getValue());
 402
 403         // remove currency from all items, or reset currency to the default
 404         // no need to clone the list, because the removal of the currency won't lead to
 405         // visual changes -- the currency fields will be hidden or reset to default anyway
 406         // still, there may be changes in the submittable state
 407         final List<Item> list = Objects.requireNonNull(this.items.getValue());
 408         for (int i = 1; i < list.size(); i++) {
 409             ((TransactionAccount) list.get(i)).setCurrency(newValue ? Data.getProfile()
 410                                                                           .getDefaultCommodity()
 411                                                                     : null);
 412         }
 413         checkTransactionSubmittable(null);
 414         showCurrency.setValue(newValue);
 415     }
 416     void stopObservingBusyFlag(Observer<Boolean> observer) {
 417         busyFlag.removeObserver(observer);
 418     }
 419     void incrementBusyCounter() {
 420         int newValue = busyCounter.incrementAndGet();
 421         if (newValue == 1)
 422             busyFlag.postValue(true);
 423     }
 424     void decrementBusyCounter() {
 425         int newValue = busyCounter.decrementAndGet();
 426         if (newValue == 0)
 427             busyFlag.postValue(false);
 428     }
 429     public LiveData<Boolean> getBusyFlag() {
 430         return busyFlag;
 431     }
 432     public void toggleShowComments() {
 433         showComments.setValue(!Objects.requireNonNull(showComments.getValue()));
 434     }
 435     public LedgerTransaction constructLedgerTransaction() {
 436         List<Item> list = Objects.requireNonNull(items.getValue());
 437         TransactionHead head = list.get(0)
 438                                    .toTransactionHead();
 439         LedgerTransaction tr = head.asLedgerTransaction();
 440
 441         tr.setComment(head.getComment());
 442         LedgerTransactionAccount emptyAmountAccount = null;
 443         float emptyAmountAccountBalance = 0;
 444         for (int i = 1; i < list.size(); i++) {
 445             TransactionAccount item = list.get(i)
 446                                           .toTransactionAccount();
 447             LedgerTransactionAccount acc = new LedgerTransactionAccount(item.getAccountName()
 448                                                                             .trim(),
 449                     item.getCurrency());
 450             if (acc.getAccountName()
 451                    .isEmpty())
 452                 continue;
 453
 454             acc.setComment(item.getComment());
 455
 456             if (item.isAmountSet()) {
 457                 acc.setAmount(item.getAmount());
 458                 emptyAmountAccountBalance += item.getAmount();
 459             }
 460             else {
 461                 emptyAmountAccount = acc;
 462             }
 463
 464             tr.addAccount(acc);
 465         }
 466
 467         if (emptyAmountAccount != null)
 468             emptyAmountAccount.setAmount(-emptyAmountAccountBalance);
 469
 470         return tr;
 471     }
 472     void loadTransactionIntoModel(@NonNull TransactionWithAccounts tr) {
 473         List<Item> newList = new ArrayList<>();
 474         Item.resetIdDispenser();
 475
 476         Item currentHead = items.getValue()
 477                                 .get(0);
 478         TransactionHead head = new TransactionHead(tr.transaction.getDescription());
 479         head.setComment(tr.transaction.getComment());
 480         if (currentHead instanceof TransactionHead)
 481             head.setDate(((TransactionHead) currentHead).date);
 482
 483         newList.add(head);
 484
 485         List<LedgerTransactionAccount> accounts = new ArrayList<>();
 486         for (net.ktnx.mobileledger.db.TransactionAccount acc : tr.accounts) {
 487             accounts.add(new LedgerTransactionAccount(acc));
 488         }
 489
 490         TransactionAccount firstNegative = null;
 491         TransactionAccount firstPositive = null;
 492         int singleNegativeIndex = -1;
 493         int singlePositiveIndex = -1;
 494         int negativeCount = 0;
 495         for (int i = 0; i < accounts.size(); i++) {
 496             LedgerTransactionAccount acc = accounts.get(i);
 497             TransactionAccount item =
 498                     new TransactionAccount(acc.getAccountName(), acc.getCurrency());
 499             newList.add(item);
 500
 501             item.setAccountName(acc.getAccountName());
 502             item.setComment(acc.getComment());
 503             if (acc.isAmountSet()) {
 504                 item.setAmount(acc.getAmount());
 505                 if (acc.getAmount() < 0) {
 506                     if (firstNegative == null) {
 507                         firstNegative = item;
 508                         singleNegativeIndex = i + 1;
 509                     }
 510                     else
 511                         singleNegativeIndex = -1;
 512                 }
 513                 else {
 514                     if (firstPositive == null) {
 515                         firstPositive = item;
 516                         singlePositiveIndex = i + 1;
 517                     }
 518                     else
 519                         singlePositiveIndex = -1;
 520                 }
 521             }
 522             else
 523                 item.resetAmount();
 524         }
 525         if (BuildConfig.DEBUG)
 526             dumpItemList("Loaded previous transaction", newList);
 527
 528         if (singleNegativeIndex != -1) {
 529             firstNegative.resetAmount();
 530             moveItemLast(newList, singleNegativeIndex);
 531         }
 532         else if (singlePositiveIndex != -1) {
 533             firstPositive.resetAmount();
 534             moveItemLast(newList, singlePositiveIndex);
 535         }
 536
 537         Misc.onMainThread(() -> {
 538             setItems(newList);
 539             noteFocusChanged(1, FocusedElement.Amount);
 540         });
 541     }
 542     /**
 543      * A transaction is submittable if:
 544      * 0) has description
 545      * 1) has at least two account names
 546      * 2) each row with amount has account name
 547      * 3) for each commodity:
 548      * 3a) amounts must balance to 0, or
 549      * 3b) there must be exactly one empty amount (with account)
 550      * 4) empty accounts with empty amounts are ignored
 551      * Side effects:
 552      * 5) a row with an empty account name or empty amount is guaranteed to exist for each
 553      * commodity
 554      * 6) at least two rows need to be present in the ledger
 555      *
 556      * @param list - the item list to check. Can be the displayed list or a list that will be
 557      *             displayed soon
 558      */
 559     @SuppressLint("DefaultLocale")
 560     void checkTransactionSubmittable(@Nullable List<Item> list) {
 561         boolean workingWithLiveList = false;
 562         if (list == null) {
 563             list = copyList();
 564             workingWithLiveList = true;
 565         }
 566
 567         if (BuildConfig.DEBUG)
 568             dumpItemList(String.format("Before submittable checks (%s)",
 569                     workingWithLiveList ? "LIVE LIST" : "custom list"), list);
 570
 571         int accounts = 0;
 572         final BalanceForCurrency balance = new BalanceForCurrency();
 573         final String descriptionText = list.get(0)
 574                                            .toTransactionHead()
 575                                            .getDescription();
 576         boolean submittable = true;
 577         boolean listChanged = false;
 578         final ItemsForCurrency itemsForCurrency = new ItemsForCurrency();
 579         final ItemsForCurrency itemsWithEmptyAmountForCurrency = new ItemsForCurrency();
 580         final ItemsForCurrency itemsWithAccountAndEmptyAmountForCurrency = new ItemsForCurrency();
 581         final ItemsForCurrency itemsWithEmptyAccountForCurrency = new ItemsForCurrency();
 582         final ItemsForCurrency itemsWithAmountForCurrency = new ItemsForCurrency();
 583         final ItemsForCurrency itemsWithAccountForCurrency = new ItemsForCurrency();
 584         final ItemsForCurrency emptyRowsForCurrency = new ItemsForCurrency();
 585         final List<Item> emptyRows = new ArrayList<>();
 586
 587         try {
 588             if ((descriptionText == null) || descriptionText.trim()
 589                                                             .isEmpty())
 590             {
 591                 Logger.debug("submittable", "Transaction not submittable: missing description");
 592                 submittable = false;
 593             }
 594
 595             for (int i = 1; i < list.size(); i++) {
 596                 TransactionAccount item = list.get(i)
 597                                               .toTransactionAccount();
 598
 599                 String accName = item.getAccountName()
 600                                      .trim();
 601                 String currName = item.getCurrency();
 602
 603                 itemsForCurrency.add(currName, item);
 604
 605                 if (accName.isEmpty()) {
 606                     itemsWithEmptyAccountForCurrency.add(currName, item);
 607
 608                     if (item.isAmountSet()) {
 609                         // 2) each amount has account name
 610                         Logger.debug("submittable", String.format(
 611                                 "Transaction not submittable: row %d has no account name, but" +
 612                                 " has" + " amount %1.2f", i + 1, item.getAmount()));
 613                         submittable = false;
 614                     }
 615                     else {
 616                         emptyRowsForCurrency.add(currName, item);
 617                     }
 618                 }
 619                 else {
 620                     accounts++;
 621                     itemsWithAccountForCurrency.add(currName, item);
 622                 }
 623
 624                 if (!item.isAmountValid()) {
 625                     Logger.debug("submittable",
 626                             String.format("Not submittable: row %d has an invalid amount", i + 1));
 627                     submittable = false;
 628                 }
 629                 else if (item.isAmountSet()) {
 630                     itemsWithAmountForCurrency.add(currName, item);
 631                     balance.add(currName, item.getAmount());
 632                 }
 633                 else {
 634                     itemsWithEmptyAmountForCurrency.add(currName, item);
 635
 636                     if (!accName.isEmpty())
 637                         itemsWithAccountAndEmptyAmountForCurrency.add(currName, item);
 638                 }
 639             }
 640
 641             // 1) has at least two account names
 642             if (accounts < 2) {
 643                 if (accounts == 0)
 644                     Logger.debug("submittable", "Transaction not submittable: no account names");
 645                 else if (accounts == 1)
 646                     Logger.debug("submittable",
 647                             "Transaction not submittable: only one account name");
 648                 else
 649                     Logger.debug("submittable",
 650                             String.format("Transaction not submittable: only %d account names",
 651                                     accounts));
 652                 submittable = false;
 653             }
 654
 655             // 3) for each commodity:
 656             // 3a) amount must balance to 0, or
 657             // 3b) there must be exactly one empty amount (with account)
 658             for (String balCurrency : itemsForCurrency.currencies()) {
 659                 float currencyBalance = balance.get(balCurrency);
 660                 if (Misc.isZero(currencyBalance)) {
 661                     // remove hints from all amount inputs in that currency
 662                     for (int i = 1; i < list.size(); i++) {
 663                         TransactionAccount acc = list.get(i)
 664                                                      .toTransactionAccount();
 665                         if (Misc.equalStrings(acc.getCurrency(), balCurrency)) {
 666                             if (BuildConfig.DEBUG)
 667                                 Logger.debug("submittable",
 668                                         String.format(Locale.US, "Resetting hint of %d:'%s' [%s]",
 669                                                 i, Misc.nullIsEmpty(acc.getAccountName()),
 670                                                 balCurrency));
 671                             // skip if the amount is set, in which case the hint is not
 672                             // important/visible
 673                             if (!acc.isAmountSet() && acc.amountHintIsSet &&
 674                                 !TextUtils.isEmpty(acc.getAmountHint()))
 675                             {
 676                                 acc.setAmountHint(null);
 677                                 listChanged = true;
 678                             }
 679                         }
 680                     }
 681                 }
 682                 else {
 683                     List<Item> tmpList =
 684                             itemsWithAccountAndEmptyAmountForCurrency.getList(balCurrency);
 685                     int balanceReceiversCount = tmpList.size();
 686                     if (balanceReceiversCount != 1) {
 687                         if (BuildConfig.DEBUG) {
 688                             if (balanceReceiversCount == 0)
 689                                 Logger.debug("submittable", String.format(
 690                                         "Transaction not submittable [%s]: non-zero balance " +
 691                                         "with no empty amounts with accounts", balCurrency));
 692                             else
 693                                 Logger.debug("submittable", String.format(
 694                                         "Transaction not submittable [%s]: non-zero balance " +
 695                                         "with multiple empty amounts with accounts", balCurrency));
 696                         }
 697                         submittable = false;
 698                     }
 699
 700                     List<Item> emptyAmountList =
 701                             itemsWithEmptyAmountForCurrency.getList(balCurrency);
 702
 703                     // suggest off-balance amount to a row and remove hints on other rows
 704                     Item receiver = null;
 705                     if (!tmpList.isEmpty())
 706                         receiver = tmpList.get(0);
 707                     else if (!emptyAmountList.isEmpty())
 708                         receiver = emptyAmountList.get(0);
 709
 710                     for (int i = 0; i < list.size(); i++) {
 711                         Item item = list.get(i);
 712                         if (!(item instanceof TransactionAccount))
 713                             continue;
 714
 715                         TransactionAccount acc = item.toTransactionAccount();
 716                         if (!Misc.equalStrings(acc.getCurrency(), balCurrency))
 717                             continue;
 718
 719                         if (item == receiver) {
 720                             final String hint = String.format("%1.2f", -currencyBalance);
 721                             if (!acc.isAmountHintSet() ||
 722                                 !Misc.equalStrings(acc.getAmountHint(), hint))
 723                             {
 724                                 Logger.debug("submittable",
 725                                         String.format("Setting amount hint of {%s} to %s [%s]",
 726                                                 acc.toString(), hint, balCurrency));
 727                                 acc.setAmountHint(hint);
 728                                 listChanged = true;
 729                             }
 730                         }
 731                         else {
 732                             if (BuildConfig.DEBUG)
 733                                 Logger.debug("submittable",
 734                                         String.format("Resetting hint of '%s' [%s]",
 735                                                 Misc.nullIsEmpty(acc.getAccountName()),
 736                                                 balCurrency));
 737                             if (acc.amountHintIsSet && !TextUtils.isEmpty(acc.getAmountHint())) {
 738                                 acc.setAmountHint(null);
 739                                 listChanged = true;
 740                             }
 741                         }
 742                     }
 743                 }
 744             }
 745
 746             // 5) a row with an empty account name or empty amount is guaranteed to exist for
 747             // each commodity
 748             for (String balCurrency : balance.currencies()) {
 749                 int currEmptyRows = itemsWithEmptyAccountForCurrency.size(balCurrency);
 750                 int currRows = itemsForCurrency.size(balCurrency);
 751                 int currAccounts = itemsWithAccountForCurrency.size(balCurrency);
 752                 int currAmounts = itemsWithAmountForCurrency.size(balCurrency);
 753                 if ((currEmptyRows == 0) &&
 754                     ((currRows == currAccounts) || (currRows == currAmounts)))
 755                 {
 756                     // perhaps there already is an unused empty row for another currency that
 757                     // is not used?
 758 //                        boolean foundIt = false;
 759 //                        for (Item item : emptyRows) {
 760 //                            Currency itemCurrency = item.getCurrency();
 761 //                            String itemCurrencyName =
 762 //                                    (itemCurrency == null) ? "" : itemCurrency.getName();
 763 //                            if (Misc.isZero(balance.get(itemCurrencyName))) {
 764 //                                item.setCurrency(Currency.loadByName(balCurrency));
 765 //                                item.setAmountHint(
 766 //                                        String.format("%1.2f", -balance.get(balCurrency)));
 767 //                                foundIt = true;
 768 //                                break;
 769 //                            }
 770 //                        }
 771 //
 772 //                        if (!foundIt)
 773                     final TransactionAccount newAcc = new TransactionAccount("", balCurrency);
 774                     final float bal = balance.get(balCurrency);
 775                     if (!Misc.isZero(bal) && currAmounts == currRows)
 776                         newAcc.setAmountHint(String.format("%4.2f", -bal));
 777                     Logger.debug("submittable",
 778                             String.format("Adding new item with %s for currency %s",
 779                                     newAcc.getAmountHint(), balCurrency));
 780                     list.add(newAcc);
 781                     listChanged = true;
 782                 }
 783             }
 784
 785             // drop extra empty rows, not needed
 786             for (String currName : emptyRowsForCurrency.currencies()) {
 787                 List<Item> emptyItems = emptyRowsForCurrency.getList(currName);
 788                 while ((list.size() > MIN_ITEMS) && (emptyItems.size() > 1)) {
 789                     // the list is a copy, so the empty item is no longer present
 790                     Item itemToRemove = emptyItems.remove(1);
 791                     removeItemById(list, itemToRemove.id);
 792                     listChanged = true;
 793                 }
 794
 795                 // unused currency, remove last item (which is also an empty one)
 796                 if ((list.size() > MIN_ITEMS) && (emptyItems.size() == 1)) {
 797                     List<Item> currItems = itemsForCurrency.getList(currName);
 798
 799                     if (currItems.size() == 1) {
 800                         // the list is a copy, so the empty item is no longer present
 801                         removeItemById(list, emptyItems.get(0).id);
 802                         listChanged = true;
 803                     }
 804                 }
 805             }
 806
 807             // 6) at least two rows need to be present in the ledger
 808             //    (the list also contains header and trailer)
 809             while (list.size() < MIN_ITEMS) {
 810                 list.add(new TransactionAccount(""));
 811                 listChanged = true;
 812             }
 813
 814             Logger.debug("submittable", submittable ? "YES" : "NO");
 815             isSubmittable.setValue(submittable);
 816
 817             if (BuildConfig.DEBUG)
 818                 dumpItemList("After submittable checks", list);
 819         }
 820         catch (NumberFormatException e) {
 821             Logger.debug("submittable", "NO (because of NumberFormatException)");
 822             isSubmittable.setValue(false);
 823         }
 824         catch (Exception e) {
 825             e.printStackTrace();
 826             Logger.debug("submittable", "NO (because of an Exception)");
 827             isSubmittable.setValue(false);
 828         }
 829
 830         if (listChanged && workingWithLiveList) {
 831             setItemsWithoutSubmittableChecks(list);
 832         }
 833     }
 834     private void removeItemById(@NotNull List<Item> list, int id) {
 835         if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.N) {
 836             list.removeIf(item -> item.id == id);
 837         }
 838         else {
 839             for (Item item : list) {
 840                 if (item.id == id) {
 841                     list.remove(item);
 842                     break;
 843                 }
 844             }
 845         }
 846     }
 847     @SuppressLint("DefaultLocale")
 848     private void dumpItemList(@NotNull String msg, @NotNull List<Item> list) {
 849         Logger.debug("submittable", "== Dump of all items " + msg);
 850         for (int i = 1; i < list.size(); i++) {
 851             TransactionAccount item = list.get(i)
 852                                           .toTransactionAccount();
 853             Logger.debug("submittable", String.format("%d:%s", i, item.toString()));
 854         }
 855     }
 856     public void setItemCurrency(int position, String newCurrency) {
 857         TransactionAccount item = Objects.requireNonNull(items.getValue())
 858                                          .get(position)
 859                                          .toTransactionAccount();
 860         final String oldCurrency = item.getCurrency();
 861
 862         if (Misc.equalStrings(oldCurrency, newCurrency))
 863             return;
 864
 865         List<Item> newList = copyList();
 866         newList.get(position)
 867                .toTransactionAccount()
 868                .setCurrency(newCurrency);
 869
 870         setItems(newList);
 871     }
 872     public boolean accountListIsEmpty() {
 873         List<Item> items = Objects.requireNonNull(this.items.getValue());
 874
 875         for (Item item : items) {
 876             if (!(item instanceof TransactionAccount))
 877                 continue;
 878
 879             if (!((TransactionAccount) item).isEmpty())
 880                 return false;
 881         }
 882
 883         return true;
 884     }
 885
 886     public static class FocusInfo {
 887         int position;
 888         FocusedElement element;
 889         public FocusInfo(int position, FocusedElement element) {
 890             this.position = position;
 891             this.element = element;
 892         }
 893     }
 894
 895     static abstract class Item {
 896         private static int idDispenser = 0;
 897         protected int id;
 898         private Item() {
 899             if (this instanceof TransactionHead)
 900                 id = 0;
 901             else
 902                 synchronized (Item.class) {
 903                     id = ++idDispenser;
 904                 }
 905         }
 906         public Item(int id) {
 907             this.id = id;
 908         }
 909         public static Item from(Item origin) {
 910             if (origin instanceof TransactionHead)
 911                 return new TransactionHead((TransactionHead) origin);
 912             if (origin instanceof TransactionAccount)
 913                 return new TransactionAccount((TransactionAccount) origin);
 914             throw new RuntimeException("Don't know how to handle " + origin);
 915         }
 916         private static void resetIdDispenser() {
 917             idDispenser = 0;
 918         }
 919         public int getId() {
 920             return id;
 921         }
 922         public abstract ItemType getType();
 923         public TransactionHead toTransactionHead() {
 924             if (this instanceof TransactionHead)
 925                 return (TransactionHead) this;
 926
 927             throw new IllegalStateException("Wrong item type " + this);
 928         }
 929         public TransactionAccount toTransactionAccount() {
 930             if (this instanceof TransactionAccount)
 931                 return (TransactionAccount) this;
 932
 933             throw new IllegalStateException("Wrong item type " + this);
 934         }
 935         public boolean equalContents(@Nullable Object item) {
 936             if (item == null)
 937                 return false;
 938
 939             if (!getClass().equals(item.getClass()))
 940                 return false;
 941
 942             // shortcut - comparing same instance
 943             if (item == this)
 944                 return true;
 945
 946             if (this instanceof TransactionHead)
 947                 return ((TransactionHead) item).equalContents((TransactionHead) this);
 948             if (this instanceof TransactionAccount)
 949                 return ((TransactionAccount) item).equalContents((TransactionAccount) this);
 950
 951             throw new RuntimeException("Don't know how to handle " + this);
 952         }
 953     }
 954
 955
 956 //==========================================================================================
 957
 958     public static class TransactionHead extends Item {
 959         private SimpleDate date;
 960         private String description;
 961         private String comment;
 962         TransactionHead(String description) {
 963             super();
 964             this.description = description;
 965         }
 966         public TransactionHead(TransactionHead origin) {
 967             super(origin.id);
 968             date = origin.date;
 969             description = origin.description;
 970             comment = origin.comment;
 971         }
 972         public SimpleDate getDate() {
 973             return date;
 974         }
 975         public void setDate(SimpleDate date) {
 976             this.date = date;
 977         }
 978         public void setDate(String text) throws ParseException {
 979             if (Misc.emptyIsNull(text) == null) {
 980                 date = null;
 981                 return;
 982             }
 983
 984             date = Globals.parseLedgerDate(text);
 985         }
 986         /**
 987          * getFormattedDate()
 988          *
 989          * @return nicely formatted, shortest available date representation
 990          */
 991         String getFormattedDate() {
 992             if (date == null)
 993                 return null;
 994
 995             Calendar today = GregorianCalendar.getInstance();
 996
 997             if (today.get(Calendar.YEAR) != date.year) {
 998                 return String.format(Locale.US, "%d/%02d/%02d", date.year, date.month, date.day);
 999             }
1000
1001             if (today.get(Calendar.MONTH) + 1 != date.month) {
1002                 return String.format(Locale.US, "%d/%02d", date.month, date.day);
1003             }
1004
1005             return String.valueOf(date.day);
1006         }
1007         @NonNull
1008         @Override
1009         public String toString() {
1010             @SuppressLint("DefaultLocale") StringBuilder b = new StringBuilder(
1011                     String.format("id:%d/%s", id, Integer.toHexString(hashCode())));
1012
1013             if (TextUtils.isEmpty(description))
1014                 b.append(" «no description»");
1015             else
1016                 b.append(String.format(" '%s'", description));
1017
1018             if (date != null)
1019                 b.append(String.format("@%s", date.toString()));
1020
1021             if (!TextUtils.isEmpty(comment))
1022                 b.append(String.format(" /%s/", comment));
1023
1024             return b.toString();
1025         }
1026         public String getDescription() {
1027             return description;
1028         }
1029         public void setDescription(String description) {
1030             this.description = description;
1031         }
1032         public String getComment() {
1033             return comment;
1034         }
1035         public void setComment(String comment) {
1036             this.comment = comment;
1037         }
1038         @Override
1039         public ItemType getType() {
1040             return ItemType.generalData;
1041         }
1042         public LedgerTransaction asLedgerTransaction() {
1043             return new LedgerTransaction(0, (date == null) ? SimpleDate.today() : date, description,
1044                     Data.getProfile());
1045         }
1046         public boolean equalContents(TransactionHead other) {
1047             if (other == null)
1048                 return false;
1049
1050             return Objects.equals(date, other.date) &&
1051                    Misc.equalStrings(description, other.description) &&
1052                    Misc.equalStrings(comment, other.comment);
1053         }
1054     }
1055
1056     public static class TransactionAccount extends Item {
1057         private String accountName;
1058         private String amountHint;
1059         private String comment;
1060         private String currency;
1061         private float amount;
1062         private boolean amountSet;
1063         private boolean amountValid = true;
1064         private FocusedElement focusedElement = FocusedElement.Account;
1065         private boolean amountHintIsSet = false;
1066         private boolean isLast = false;
1067         private int accountNameCursorPosition;
1068         public TransactionAccount(TransactionAccount origin) {
1069             super(origin.id);
1070             accountName = origin.accountName;
1071             amount = origin.amount;
1072             amountSet = origin.amountSet;
1073             amountHint = origin.amountHint;
1074             amountHintIsSet = origin.amountHintIsSet;
1075             comment = origin.comment;
1076             currency = origin.currency;
1077             amountValid = origin.amountValid;
1078             focusedElement = origin.focusedElement;
1079             isLast = origin.isLast;
1080             accountNameCursorPosition = origin.accountNameCursorPosition;
1081         }
1082         public TransactionAccount(LedgerTransactionAccount account) {
1083             super();
1084             currency = account.getCurrency();
1085             amount = account.getAmount();
1086         }
1087         public TransactionAccount(String accountName) {
1088             super();
1089             this.accountName = accountName;
1090         }
1091         public TransactionAccount(String accountName, String currency) {
1092             super();
1093             this.accountName = accountName;
1094             this.currency = currency;
1095         }
1096         public boolean isLast() {
1097             return isLast;
1098         }
1099         public boolean isAmountSet() {
1100             return amountSet;
1101         }
1102         public String getAccountName() {
1103             return accountName;
1104         }
1105         public void setAccountName(String accountName) {
1106             this.accountName = accountName;
1107         }
1108         public float getAmount() {
1109             if (!amountSet)
1110                 throw new IllegalStateException("Amount is not set");
1111             return amount;
1112         }
1113         public void setAmount(float amount) {
1114             this.amount = amount;
1115             amountSet = true;
1116         }
1117         public void resetAmount() {
1118             amountSet = false;
1119         }
1120         @Override
1121         public ItemType getType() {
1122             return ItemType.transactionRow;
1123         }
1124         public String getAmountHint() {
1125             return amountHint;
1126         }
1127         public void setAmountHint(String amountHint) {
1128             this.amountHint = amountHint;
1129             amountHintIsSet = !TextUtils.isEmpty(amountHint);
1130         }
1131         public String getComment() {
1132             return comment;
1133         }
1134         public void setComment(String comment) {
1135             this.comment = comment;
1136         }
1137         public String getCurrency() {
1138             return currency;
1139         }
1140         public void setCurrency(String currency) {
1141             this.currency = currency;
1142         }
1143         public boolean isAmountValid() {
1144             return amountValid;
1145         }
1146         public void setAmountValid(boolean amountValid) {
1147             this.amountValid = amountValid;
1148         }
1149         public FocusedElement getFocusedElement() {
1150             return focusedElement;
1151         }
1152         public void setFocusedElement(FocusedElement focusedElement) {
1153             this.focusedElement = focusedElement;
1154         }
1155         public boolean isAmountHintSet() {
1156             return amountHintIsSet;
1157         }
1158         public void setAmountHintIsSet(boolean amountHintIsSet) {
1159             this.amountHintIsSet = amountHintIsSet;
1160         }
1161         public boolean isEmpty() {
1162             return !amountSet && Misc.emptyIsNull(accountName) == null &&
1163                    Misc.emptyIsNull(comment) == null;
1164         }
1165         @SuppressLint("DefaultLocale")
1166         @Override
1167         public String toString() {
1168             StringBuilder b = new StringBuilder();
1169             b.append(String.format("id:%d/%s", id, Integer.toHexString(hashCode())));
1170             if (!TextUtils.isEmpty(accountName))
1171                 b.append(String.format(" acc'%s'", accountName));
1172
1173             if (amountSet)
1174                 b.append(String.format(" %4.2f", amount));
1175             else if (amountHintIsSet)
1176                 b.append(String.format(" (%s)", amountHint));
1177
1178             if (!TextUtils.isEmpty(currency))
1179                 b.append(" ")
1180                  .append(currency);
1181
1182             if (!TextUtils.isEmpty(comment))
1183                 b.append(String.format(" /%s/", comment));
1184
1185             if (isLast)
1186                 b.append(" last");
1187
1188             return b.toString();
1189         }
1190         public boolean equalContents(TransactionAccount other) {
1191             if (other == null)
1192                 return false;
1193
1194             boolean equal = Misc.equalStrings(accountName, other.accountName);
1195             equal = equal && Misc.equalStrings(comment, other.comment) &&
1196                     (amountSet ? other.amountSet && amount == other.amount : !other.amountSet);
1197
1198             // compare amount hint only if there is no amount
1199             if (!amountSet)
1200                 equal = equal && (amountHintIsSet ? other.amountHintIsSet &&
1201                                                     Misc.equalStrings(amountHint, other.amountHint)
1202                                                   : !other.amountHintIsSet);
1203             equal = equal && Misc.equalStrings(currency, other.currency) && isLast == other.isLast;
1204
1205             Logger.debug("new-trans",
1206                     String.format("Comparing {%s} and {%s}: %s", this.toString(), other.toString(),
1207                             equal));
1208             return equal;
1209         }
1210         public int getAccountNameCursorPosition() {
1211             return accountNameCursorPosition;
1212         }
1213         public void setAccountNameCursorPosition(int position) {
1214             this.accountNameCursorPosition = position;
1215         }
1216     }
1217
1218     private static class BalanceForCurrency {
1219         private final HashMap<String, Float> hashMap = new HashMap<>();
1220         float get(String currencyName) {
1221             Float f = hashMap.get(currencyName);
1222             if (f == null) {
1223                 f = 0f;
1224                 hashMap.put(currencyName, f);
1225             }
1226             return f;
1227         }
1228         void add(String currencyName, float amount) {
1229             hashMap.put(currencyName, get(currencyName) + amount);
1230         }
1231         Set<String> currencies() {
1232             return hashMap.keySet();
1233         }
1234         boolean containsCurrency(String currencyName) {
1235             return hashMap.containsKey(currencyName);
1236         }
1237     }
1238
1239     private static class ItemsForCurrency {
1240         private final HashMap<String, List<Item>> hashMap = new HashMap<>();
1241         @NonNull
1242         List<NewTransactionModel.Item> getList(@Nullable String currencyName) {
1243             List<NewTransactionModel.Item> list = hashMap.get(currencyName);
1244             if (list == null) {
1245                 list = new ArrayList<>();
1246                 hashMap.put(currencyName, list);
1247             }
1248             return list;
1249         }
1250         void add(@Nullable String currencyName, @NonNull NewTransactionModel.Item item) {
1251             getList(currencyName).add(item);
1252         }
1253         int size(@Nullable String currencyName) {
1254             return this.getList(currencyName)
1255                        .size();
1256         }
1257         Set<String> currencies() {
1258             return hashMap.keySet();
1259         }
1260     }
1261 }