anotherim/src/de/gultsch/chat/persistance/DatabaseBackend.java

package de.gultsch.chat.persistance;

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

import de.gultsch.chat.entities.Account;
import de.gultsch.chat.entities.Contact;
import de.gultsch.chat.entities.Conversation;
import de.gultsch.chat.entities.Message;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class DatabaseBackend extends SQLiteOpenHelper {

	private static DatabaseBackend instance = null;

	private static final String DATABASE_NAME = "history";
	private static final int DATABASE_VERSION = 1;

	public DatabaseBackend(Context context) {
		super(context, DATABASE_NAME, null, DATABASE_VERSION);
	}

	@Override
	public void onCreate(SQLiteDatabase db) {
		db.execSQL("create table " + Conversation.TABLENAME + " ("
				+ Conversation.UUID + " TEXT PRIMARY KEY, " + Conversation.NAME
				+ " TEXT, " + Conversation.PHOTO_URI + " TEXT, "
				+ Conversation.ACCOUNT + " TEXT, " + Conversation.CONTACT
				+ " TEXT, " + Conversation.CREATED + " NUMBER, "
				+ Conversation.STATUS + " NUMBER)");
		db.execSQL("create table " + Message.TABLENAME + "( " + Message.UUID
				+ " TEXT PRIMARY KEY, " + Message.CONVERSATION + " TEXT, " + Message.TIME_SENT +" NUMBER, "
				+ Message.COUNTERPART + " TEXT, " + Message.BODY + " TEXT, "
				+ Message.ENCRYPTION + " NUMBER, " + Message.STATUS
				+ " NUMBER)");
	}

	@Override
	public void onUpgrade(SQLiteDatabase db, int arg1, int arg2) {
		// TODO Auto-generated method stub

	}

	public static synchronized DatabaseBackend getInstance(Context context) {
		if (instance == null) {
			instance = new DatabaseBackend(context);
		}
		return instance;
	}

	public void createConversation(Conversation conversation) {
		SQLiteDatabase db = this.getWritableDatabase();
		db.insert(Conversation.TABLENAME, null, conversation.getContentValues());
	}

	public void createMessage(Message message) {
		SQLiteDatabase db = this.getWritableDatabase();
		db.insert(Message.TABLENAME, null, message.getContentValues());
	}

	public int getConversationCount() {
		SQLiteDatabase db = this.getReadableDatabase();
		Cursor cursor = db.rawQuery(
				"select count(uuid) as count from "+Conversation.TABLENAME+" where "+Conversation.STATUS+"="+Conversation.STATUS_AVAILABLE, null);
		cursor.moveToFirst();
		return cursor.getInt(0);
	}

	public List<Conversation> getConversations(int status) {
		List<Conversation> list = new ArrayList<Conversation>();
		SQLiteDatabase db = this.getReadableDatabase();
		String[] selectionArgs = { "" + status };
		Cursor cursor = db.rawQuery("select * from " + Conversation.TABLENAME
				+ " where " + Conversation.STATUS + " = ? order by "
				+ Conversation.CREATED + " desc", selectionArgs);
		while (cursor.moveToNext()) {
			list.add(Conversation.fromCursor(cursor));
		}
		return list;
	}

	public List<Message> getMessages(Conversation conversation, int limit) {
		List<Message> list = new ArrayList<Message>();
		SQLiteDatabase db = this.getReadableDatabase();
		String[] selectionArgs = { conversation.getUuid() };
		Cursor cursor = db.query(Message.TABLENAME, null,Message.CONVERSATION +"=?", selectionArgs, null, null,
				Message.TIME_SENT+" DESC",String.valueOf(limit));
		if (cursor.getCount() > 0 ) {
			cursor.moveToLast();
			do {
				list.add(Message.fromCursor(cursor));
			} while (cursor.moveToPrevious());
		}
		return list;
	}

	public Conversation findConversation(Account account, Contact contact) {
		SQLiteDatabase db = this.getReadableDatabase();
		String[] selectionArgs = { account.getUuid() , contact.getJid() };
		Cursor cursor = db.query(Conversation.TABLENAME, null,Conversation.ACCOUNT+"=? AND "+Conversation.CONTACT+"=?", selectionArgs, null, null, null);
		if (cursor.getCount() == 0) return null;
		cursor.moveToFirst();
		return Conversation.fromCursor(cursor);
	}

	public void updateConversation(Conversation conversation) {
		SQLiteDatabase db = this.getReadableDatabase();
		String[] args = {conversation.getUuid()};
		db.update(Conversation.TABLENAME, conversation.getContentValues(),Conversation.UUID+"=?",args);
	}

}