app/src/main/java/net/ktnx/mobileledger/model/LedgerTransaction.java

   1 /*
   2  * Copyright © 2018 Damyan Ivanov.
   3  * This file is part of Mobile-Ledger.
   4  * Mobile-Ledger is free software: you can distribute it and/or modify it
   5  * under the term of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your opinion), any later version.
   8  *
   9  * Mobile-Ledger is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  12  * GNU General Public License terms for details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with Mobile-Ledger. If not, see <https://www.gnu.org/licenses/>.
  16  */
  17
  18 package net.ktnx.mobileledger.model;
  19
  20 import android.database.Cursor;
  21 import android.database.sqlite.SQLiteDatabase;
  22
  23 import net.ktnx.mobileledger.utils.Digest;
  24
  25 import java.nio.charset.Charset;
  26 import java.security.NoSuchAlgorithmException;
  27 import java.util.ArrayList;
  28 import java.util.Comparator;
  29 import java.util.Iterator;
  30
  31 public class LedgerTransaction {
  32     private static final String DIGEST_TYPE = "SHA-256";
  33     public final Comparator<LedgerTransactionItem> comparator =
  34             new Comparator<LedgerTransactionItem>() {
  35                 @Override
  36                 public int compare(LedgerTransactionItem o1, LedgerTransactionItem o2) {
  37                     int res = o1.getAccountName().compareTo(o2.getAccountName());
  38                     if (res != 0) return res;
  39                     res = o1.getCurrency().compareTo(o2.getCurrency());
  40                     if (res != 0) return res;
  41                     return Float.compare(o1.getAmount(), o2.getAmount());
  42                 }
  43             };
  44     private Integer id;
  45     private String date;
  46     private String description;
  47     private ArrayList<LedgerTransactionItem> items;
  48     private String dataHash;
  49     private boolean dataLoaded;
  50     public LedgerTransaction(Integer id, String date, String description) {
  51         this.id = id;
  52         this.date = date;
  53         this.description = description;
  54         this.items = new ArrayList<>();
  55         this.dataHash = null;
  56         dataLoaded = false;
  57     }
  58     public LedgerTransaction(String date, String description) {
  59         this(null, date, description);
  60     }
  61     public LedgerTransaction(int id) {
  62         this(id, null, null);
  63     }
  64     public void add_item(LedgerTransactionItem item) {
  65         items.add(item);
  66         dataHash = null;
  67     }
  68     public String getDate() {
  69         return date;
  70     }
  71     public void setDate(String date) {
  72         this.date = date;
  73         dataHash = null;
  74     }
  75     public String getDescription() {
  76         return description;
  77     }
  78     public void setDescription(String description) {
  79         this.description = description;
  80         dataHash = null;
  81     }
  82     public Iterator<LedgerTransactionItem> getItemsIterator() {
  83         return new Iterator<LedgerTransactionItem>() {
  84             private int pointer = 0;
  85             @Override
  86             public boolean hasNext() {
  87                 return pointer < items.size();
  88             }
  89
  90             @Override
  91             public LedgerTransactionItem next() {
  92                 return hasNext() ? items.get(pointer++) : null;
  93             }
  94         };
  95     }
  96     public int getId() {
  97         return id;
  98     }
  99     public void insertInto(SQLiteDatabase db) {
 100         fillDataHash();
 101         db.execSQL("INSERT INTO transactions(id, date, description, data_hash) values(?,?,?,?)",
 102                 new Object[]{id, date, description, dataHash});
 103
 104         for (LedgerTransactionItem item : items) {
 105             db.execSQL("INSERT INTO transaction_accounts(transaction_id, account_name, amount, " +
 106                        "currency) values(?, ?, ?, ?)",
 107                     new Object[]{id, item.getAccountName(), item.getAmount(), item.getCurrency()});
 108         }
 109     }
 110     private void fillDataHash() {
 111         if (dataHash != null) return;
 112         try {
 113             Digest sha = new Digest(DIGEST_TYPE);
 114             StringBuilder data = new StringBuilder();
 115             data.append(getId());
 116             data.append('\0');
 117             data.append(getDescription());
 118             data.append('\0');
 119             for (LedgerTransactionItem item : items) {
 120                 data.append(item.getAccountName());
 121                 data.append('\0');
 122                 data.append(item.getCurrency());
 123                 data.append('\0');
 124                 data.append(item.getAmount());
 125             }
 126             sha.update(data.toString().getBytes(Charset.forName("UTF-8")));
 127             dataHash = sha.digestToHexString();
 128         }
 129         catch (NoSuchAlgorithmException e) {
 130             throw new RuntimeException(
 131                     String.format("Unable to get instance of %s digest", DIGEST_TYPE), e);
 132         }
 133     }
 134     public void loadData(SQLiteDatabase db) {
 135         if (dataLoaded) return;
 136
 137         try (Cursor cTr = db.rawQuery("SELECT date, description from transactions WHERE id=?",
 138                 new String[]{String.valueOf(id)}))
 139         {
 140             if (cTr.moveToFirst()) {
 141                 date = cTr.getString(0);
 142                 description = cTr.getString(1);
 143
 144                 try (Cursor cAcc = db.rawQuery("SELECT account_name, amount, currency FROM " +
 145                                                "transaction_accounts WHERE transaction_id = ?",
 146                         new String[]{String.valueOf(id)}))
 147                 {
 148                     while (cAcc.moveToNext()) {
 149                         add_item(new LedgerTransactionItem(cAcc.getString(0), cAcc.getFloat(1),
 150                                 cAcc.getString(2)));
 151                     }
 152
 153                     dataLoaded = true;
 154                 }
 155             }
 156         }
 157
 158     }
 159 }