UNCCGameDay/src/com/uncc/gameday/alerts/AlertDB.java

package com.uncc.gameday.alerts;

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

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

/* Responsible for handling persistence/fetching of alerts */

/**
 * The Class AlertDB.
 */
public class AlertDB extends SQLiteOpenHelper {
	
	/** The Constant DATABASE_VERSION. */
	private static final int DATABASE_VERSION = 1;
	
	/** The Constant DATABASE_NAME. */
	private static final String DATABASE_NAME = "AlertDataBase";
	
	/** The Constant TABLE_ALERTS. */
	private static final String TABLE_ALERTS = "alerts";

	/** The Constant KEY_ALARM_DATE. */
	private static final String KEY_ALARM_DATE = "alarm_date";
	
	/** The Constant KEY_MESSAGE. */
	private static final String KEY_MESSAGE = "message";
	
	/** The Constant KEY_SHOWN. */
	private static final String KEY_SHOWN = "shown";
	
	/** The Constant KEY_TYPE. */
	private static final String KEY_TYPE = "type";
	

	/**
	 * Instantiates our wrapper around the SQLiteOpenHelper
	 *
	 * @param context - The context to open the database in
	 */
	public AlertDB(Context context){
		super(context, DATABASE_NAME, null, DATABASE_VERSION);
	}
	
	/**
	 * Create the initial Database
	 */
	@Override
	public void onCreate(SQLiteDatabase db) {
		String CREATE_ALERTS_TABLE = "CREATE TABLE " + TABLE_ALERTS + "("
				+ KEY_MESSAGE + " STRING PRIMARY KEY," + KEY_ALARM_DATE + " LONG,"
				+ KEY_SHOWN + " INT," + KEY_TYPE + " STRING" + ")";
		db.execSQL(CREATE_ALERTS_TABLE);
	}
	
	/**
	 * Upgrade the database on application update
	 */
	@Override
	public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
		//drop older table if it exists
		db.execSQL("DROP OLDER TABLE " + TABLE_ALERTS);
		
		//recreate tables
		onCreate(db);
		
	}

	/**
	 * Persist an alert into the database
	 *
	 * @param a - The Alert to persist
	 */
	public void persist(Alert a) {
		
		SQLiteDatabase db = this.getWritableDatabase();
		
		ContentValues values = new ContentValues();
		values.put(KEY_MESSAGE, a.getMessage());
		
		long dateValue = a.getAlarmDate().getTime();
		values.put(KEY_ALARM_DATE, dateValue);
		values.put(KEY_SHOWN, a.isShown());
		values.put(KEY_TYPE, a.getType());

		db.insert(TABLE_ALERTS, null, values);
		db.close();
	}
	
	/**
	 * Persist a list of alerts into the database -
	 * helper method for easy iteration
	 *
	 * @param alerts - The alerts to store
	 */
	public void persistMultiple(List<Alert> alerts) {
    	
		for(int i = 0; i < alerts.size(); i++)
    	{
    		persist(alerts.get(i));
    	}
		
	}
	
	/**
	 * Fetch an alert by date
	 * TODO: Unused. Remove?
	 *
	 * @param d - The date to fetch an alert from
	 * @return the Alert
	 */
	public Alert fetch(Date d) {
		
		return null;
	}
	
	/**
	 * Fetch multiple alerts from the Database
	 * TODO: Unused. Remove?
	 *
	 * @param dates the dates to fetch alerts from
	 * @return the list
	 */
	public List<Alert> fetchMultiple(List<Date> dates) {
		
		return null;
	}
	
	/**
	 * Delete an alert from the Database whenever the Alert message matches
	 *
	 * @param alert the alert
	 */
	public void deleteAlert(Alert alert) {
		SQLiteDatabase db = this.getWritableDatabase();
		db.delete(TABLE_ALERTS, KEY_MESSAGE + " = ?", 
				new String[] { String.valueOf(alert.getMessage()) });
		db.close();
		
		}

	
	
	/**
	 * Fetch all alerts from the Database, and mark as read
	 *
	 * @return the list
	 */
	public List<Alert> fetchAll() {
		
		List<Alert> alertList = new ArrayList<Alert>();
		
		String selectQuery = "SELECT  * FROM " + TABLE_ALERTS;
		
		SQLiteDatabase db = this.getWritableDatabase();
		Cursor cursor = db.rawQuery(selectQuery, null);
		
		//for each alert in database
		//add it to alert list to be shown
		//and modify it in DB to be classified as shown
		if (cursor.moveToFirst())
		{
			do
			{
				Alert alert = new Alert();
				alert.setMessage(cursor.getString(0));
				alert.setAlarmDate(new Date(cursor.getLong(1)));
				alert.setShown(cursor.getInt(2));
				updateAlert(alert);
				
				alertList.add(alert);
			} while (cursor.moveToNext());
			
		}	
		db.close();
		return alertList;
	}
	
	/**
	 * Fetch unread alerts from the database, and mark them as read
	 *
	 * @return the list
	 */
	public List<Alert> fetchUnread() {
		
		List<Alert> alertList = new ArrayList<Alert>();
		String selectQuery = "SELECT  * FROM " + TABLE_ALERTS;
	
		SQLiteDatabase db = this.getWritableDatabase();
		Cursor cursor = db.rawQuery(selectQuery, null);
		
		//for each alert in database
		//given it is classified as unread
		//add it to alert list to be shown
		//and modify it in DB to be classified as shown
		if (cursor.moveToFirst())
		{
			do
			{
				Alert alert = new Alert();
				if(cursor.getInt(2) == 0)
				{
					alert.setMessage(cursor.getString(0));
					alert.setAlarmDate(new Date(cursor.getLong(1)));
					alert.setShown(cursor.getInt(2));
					
					updateAlert(alert);
					alertList.add(alert);	
				}
			} while (cursor.moveToNext());
			
		}	
		db.close();
		return alertList;
	}

	/**
	 * Update an alert to be marked as shown
	 *
	 * @param alert the alert
	 * @return the int
	 */
	private int updateAlert(Alert alert) {
		
		SQLiteDatabase db = this.getWritableDatabase();
		
		ContentValues values = new ContentValues();
		
		long dateValue = alert.getAlarmDate().getTime();
		values.put(KEY_ALARM_DATE, dateValue);
		values.put(KEY_SHOWN, 1);
		
		return db.update(TABLE_ALERTS, values, KEY_MESSAGE + " = ?",
				new String[] { String.valueOf(alert.getMessage()) });
		
	}

}