CategoryDao.java :  » UnTagged » my-accounts » org » amphiprion » myaccount » database » Android Open Source

/*
 * @copyright 2010 Gerald Jacobson
 * @license GNU General Public License
 * 
 * This file is part of My Accounts.
 *
 * My Accounts is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * My Accounts is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with My Accounts.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.amphiprion.myaccount.database;

import java.util.ArrayList;
import java.util.List;

import org.amphiprion.myaccount.database.entity.Category;
import org.amphiprion.myaccount.database.entity.Rule;

import android.content.Context;
import android.database.Cursor;

/**
 * This class is responsible of all database category access.
 * 
 * @author amphiprion
 * 
 */
public class CategoryDao extends AbstractDao {
  /** The singleton. */
  private static CategoryDao instance;

  /**
   * Hidden constructor.
   * 
   * @param context
   *            the application context
   */
  private CategoryDao(Context context) {
    super(context);
  }

  /**
   * Return the singleton.
   * 
   * @param context
   *            the application context
   * @return the singleton
   */
  public static CategoryDao getInstance(Context context) {
    if (instance == null) {
      instance = new CategoryDao(context);
    }
    return instance;
  }

  /**
   * Return all existing categories.
   * 
   * @return the category list
   */
  public List<Category> getCategories() {
    String sql = "SELECT c." + Category.DbField.ID + ",c." + Category.DbField.NAME + ",c."
        + Category.DbField.IMAGE_NAME + ",p." + Category.DbField.ID + ",p." + Category.DbField.NAME
        + " from CATEGORY c left outer join CATEGORY p on c." + Category.DbField.PARENT + "=p."
        + Category.DbField.ID + " order by c." + Category.DbField.NAME + " asc";
    Cursor cursor = getDatabase().rawQuery(sql, new String[] {});
    ArrayList<Category> result = new ArrayList<Category>();
    if (cursor.moveToFirst()) {
      do {
        Category a = new Category(cursor.getString(0));
        a.setName(cursor.getString(1));
        a.setImage(cursor.getString(2));
        String pId = cursor.getString(3);
        if (pId != null) {
          Category p = new Category(pId);
          p.setName(cursor.getString(4));
          a.setParent(p);
        }
        result.add(a);
      } while (cursor.moveToNext());
    }
    cursor.close();
    return result;
  }

  /**
   * Persist a new category.
   * 
   * @param category
   *            the new category
   */
  public void createCategory(Category category) {
    getDatabase().beginTransaction();
    try {

      String sql = "insert into CATEGORY (" + Category.DbField.ID + "," + Category.DbField.NAME + ","
          + Category.DbField.IMAGE_NAME + "," + Category.DbField.PARENT + ") values ('" + category.getId()
          + "','" + encodeString(category.getName()) + "',"
          + (category.getImage() == null ? "null" : "'" + encodeString(category.getImage()) + "'") + ","
          + (category.getParent() != null ? "'" + encodeString(category.getParent().getId()) + "'" : null)
          + ")";

      execSQL(sql);
      RuleDao ruleDao = RuleDao.getInstance(getContext());
      for (Rule rule : category.getRules()) {
        ruleDao.create(rule);
      }
      getDatabase().setTransactionSuccessful();
    } finally {
      getDatabase().endTransaction();
    }
  }

  /**
   * Update an existing category
   * 
   * @param category
   *            the category to update
   */
  public void updateCategory(Category category) {
    getDatabase().beginTransaction();
    try {

      String sql = "update CATEGORY set " + Category.DbField.NAME + "='" + encodeString(category.getName())
          + "'," + Category.DbField.IMAGE_NAME + "="
          + (category.getImage() == null ? "null" : "'" + encodeString(category.getImage()) + "'") + ","
          + Category.DbField.PARENT + "="
          + (category.getParent() != null ? "'" + encodeString(category.getParent().getId()) + "'" : null)
          + " WHERE " + Category.DbField.ID + "='" + encodeString(category.getId()) + "'";

      execSQL(sql);

      RuleDao ruleDao = RuleDao.getInstance(getContext());
      for (Rule rule : category.getRules()) {
        if (rule.getState() == Rule.DbState.CREATE) {
          ruleDao.create(rule);
        } else if (rule.getState() == Rule.DbState.UPDATE) {
          ruleDao.update(rule);
        } else {
          ruleDao.delete(rule);
        }
      }

      getDatabase().setTransactionSuccessful();
    } finally {
      getDatabase().endTransaction();
    }
  }

  public List<Category> getPossibleParentFor(Category category) {
    String sql = "SELECT " + Category.DbField.ID + "," + Category.DbField.NAME + "," + Category.DbField.PARENT
        + " from CATEGORY WHERE " + Category.DbField.PARENT + " is null and " + Category.DbField.ID + "<>'"
        + encodeString(category.getId()) + "' order by " + Category.DbField.NAME + " asc";
    Cursor cursor = getDatabase().rawQuery(sql, new String[] {});
    ArrayList<Category> result = new ArrayList<Category>();
    if (cursor.moveToFirst()) {
      do {
        Category a = new Category(cursor.getString(0));
        a.setName(cursor.getString(1));
        result.add(a);
      } while (cursor.moveToNext());
    }
    cursor.close();
    return result;
  }

  /**
   * Delete the given category.
   * 
   * @param category
   *            the category to delete
   */
  public void delete(Category category) {
    getDatabase().beginTransaction();
    try {

      String sql = "UPDATE CATEGORY SET " + Category.DbField.PARENT + "=null WHERE " + Category.DbField.PARENT
          + "='" + encodeString(category.getId()) + "'";
      execSQL(sql);

      sql = "DELETE FROM CATEGORY WHERE " + Category.DbField.ID + "='" + encodeString(category.getId()) + "'";
      execSQL(sql);

      getDatabase().setTransactionSuccessful();
    } finally {
      getDatabase().endTransaction();
    }
  }

}