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 import android.util.Log;
  23
  24 import net.ktnx.mobileledger.utils.Digest;
  25
  26 import java.nio.charset.Charset;
  27 import java.security.NoSuchAlgorithmException;
  28 import java.util.ArrayList;
  29 import java.util.Comparator;
  30 import java.util.Iterator;
  31
  32 public class LedgerTransaction {
  33     private static final String DIGEST_TYPE = "SHA-256";
  34     public final Comparator<LedgerTransactionAccount> comparator =
  35             new Comparator<LedgerTransactionAccount>() {
  36                 @Override
  37                 public int compare(LedgerTransactionAccount o1, LedgerTransactionAccount o2) {
  38                     int res = o1.getAccountName().compareTo(o2.getAccountName());
  39                     if (res != 0) return res;
  40                     res = o1.getCurrency().compareTo(o2.getCurrency());
  41                     if (res != 0) return res;
  42                     return Float.compare(o1.getAmount(), o2.getAmount());
  43                 }
  44             };
  45     private Integer id;
  46     private String date;
  47     private String description;
  48     private ArrayList<LedgerTransactionAccount> items;
  49     private String dataHash;
  50     private boolean dataLoaded;
  51     public LedgerTransaction(Integer id, String date, String description) {
  52         this.id = id;
  53         this.date = date;
  54         this.description = description;
  55         this.items = new ArrayList<>();
  56         this.dataHash = null;
  57         dataLoaded = false;
  58     }
  59     public LedgerTransaction(String date, String description) {
  60         this(null, date, description);
  61     }
  62     public LedgerTransaction(int id) {
  63         this(id, null, null);
  64     }
  65     public void addAccount(LedgerTransactionAccount item) {
  66         items.add(item);
  67         dataHash = null;
  68     }
  69     public String getDate() {
  70         return date;
  71     }
  72     public void setDate(String date) {
  73         this.date = date;
  74         dataHash = null;
  75     }
  76     public String getDescription() {
  77         return description;
  78     }
  79     public void setDescription(String description) {
  80         this.description = description;
  81         dataHash = null;
  82     }
  83     public Iterator<LedgerTransactionAccount> getAccountsIterator() {
  84         return new Iterator<LedgerTransactionAccount>() {
  85             private int pointer = 0;
  86             @Override
  87             public boolean hasNext() {
  88                 return pointer < items.size();
  89             }
  90
  91             @Override
  92             public LedgerTransactionAccount next() {
  93                 return hasNext() ? items.get(pointer++) : null;
  94             }
  95         };
  96     }
  97     public int getId() {
  98         return id;
  99     }
 100     public void insertInto(SQLiteDatabase db) {
 101         fillDataHash();
 102         db.execSQL("INSERT INTO transactions(id, date, description, data_hash) values(?,?,?,?)",
 103                 new Object[]{id, date, description, dataHash});
 104
 105         for (LedgerTransactionAccount item : items) {
 106             db.execSQL("INSERT INTO transaction_accounts(transaction_id, account_name, amount, " +
 107                        "currency) values(?, ?, ?, ?)",
 108                     new Object[]{id, item.getAccountName(), item.getAmount(), item.getCurrency()});
 109         }
 110     }
 111     private void fillDataHash() {
 112         if (dataHash != null) return;
 113         try {
 114             Digest sha = new Digest(DIGEST_TYPE);
 115             StringBuilder data = new StringBuilder();
 116             data.append(getId());
 117             data.append('\0');
 118             data.append(getDescription());
 119             data.append('\0');
 120             for (LedgerTransactionAccount item : items) {
 121                 data.append(item.getAccountName());
 122                 data.append('\0');
 123                 data.append(item.getCurrency());
 124                 data.append('\0');
 125                 data.append(item.getAmount());
 126             }
 127             sha.update(data.toString().getBytes(Charset.forName("UTF-8")));
 128             dataHash = sha.digestToHexString();
 129         }
 130         catch (NoSuchAlgorithmException e) {
 131             throw new RuntimeException(
 132                     String.format("Unable to get instance of %s digest", DIGEST_TYPE), e);
 133         }
 134     }
 135     public boolean existsInDb(SQLiteDatabase db) {
 136         fillDataHash();
 137         try (Cursor c = db
 138                 .rawQuery("SELECT 1 from transactions where data_hash = ?", new String[]{dataHash}))
 139         {
 140             boolean result = c.moveToFirst();
 141             Log.d("transactions", String.format("Transaction %d (%s) %s", id, dataHash,
 142                     result ? "already present" : "not present"));
 143             return result;
 144         }
 145     }
 146     public void loadData(SQLiteDatabase db) {
 147         if (dataLoaded) return;
 148
 149         try (Cursor cTr = db.rawQuery("SELECT date, description from transactions WHERE id=?",
 150                 new String[]{String.valueOf(id)}))
 151         {
 152             if (cTr.moveToFirst()) {
 153                 date = cTr.getString(0);
 154                 description = cTr.getString(1);
 155
 156                 try (Cursor cAcc = db.rawQuery("SELECT account_name, amount, currency FROM " +
 157                                                "transaction_accounts WHERE transaction_id = ?",
 158                         new String[]{String.valueOf(id)}))
 159                 {
 160                     while (cAcc.moveToNext()) {
 161                         addAccount(new LedgerTransactionAccount(cAcc.getString(0), cAcc.getFloat(1),
 162                                 cAcc.getString(2)));
 163                     }
 164
 165                     dataLoaded = true;
 166                 }
 167             }
 168         }
 169
 170     }
 171 }