ChannelMetadataDAO.java

package com.buddycloud.model.dao;

import java.util.Map;

import org.json.JSONException;
import org.json.JSONObject;

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

import com.buddycloud.model.db.BuddycloudSQLiteOpenHelper;
import com.buddycloud.model.db.ChannelMetadataTableHelper;

public class ChannelMetadataDAO implements DAO<JSONObject, JSONObject> {
	
	private static ChannelMetadataDAO instance;
	
	private SQLiteDatabase db;
	private BuddycloudSQLiteOpenHelper helper;
	
	private final String[] COLUMNS = new String[]{
			ChannelMetadataTableHelper.COLUMN_ID, 
			ChannelMetadataTableHelper.COLUMN_TITLE, 
			ChannelMetadataTableHelper.COLUMN_DESCRIPTION,
			ChannelMetadataTableHelper.COLUMN_CHANNEL_TYPE,
			ChannelMetadataTableHelper.COLUMN_ACCESS_MODEL,
			ChannelMetadataTableHelper.COLUMN_CREATION_DATE,
			ChannelMetadataTableHelper.COLUMN_DEFAULT_AFFILIATION};
	
	
	private ChannelMetadataDAO(Context context) {
		this.helper = BuddycloudSQLiteOpenHelper.getInstance(context);
		this.db = helper.getWritableDatabase();
	}
	
	
	public static ChannelMetadataDAO getInstance(Context context) {
		if (instance == null) {
			instance = new ChannelMetadataDAO(context);
		}
		
		return instance;
	}

	
	private ContentValues buildValues(String channel, String title, String description, String channelType,
			String accessModel, String creationDate, String defaultAffiliation) {
		ContentValues values = new ContentValues();
		values.put(ChannelMetadataTableHelper.COLUMN_ID, channel);
		values.put(ChannelMetadataTableHelper.COLUMN_TITLE, title);
		values.put(ChannelMetadataTableHelper.COLUMN_DESCRIPTION, description);
		values.put(ChannelMetadataTableHelper.COLUMN_CHANNEL_TYPE, channelType);
		values.put(ChannelMetadataTableHelper.COLUMN_ACCESS_MODEL, accessModel);
		values.put(ChannelMetadataTableHelper.COLUMN_CREATION_DATE, creationDate);
		values.put(ChannelMetadataTableHelper.COLUMN_DEFAULT_AFFILIATION, defaultAffiliation);
		
		return values;
	}
	
	private ContentValues buildValues(String channel, JSONObject json) {
		String title = json.optString("title");
		String description = json.optString("description");
		String channelType = json.optString("channel_type");
		String accessModel = json.optString("access_model");
		String creationDate = json.optString("creation_date");
		String defaultAffiliation = json.optString("default_affiliation");
		
		return buildValues(channel, title, description, channelType, accessModel, creationDate, defaultAffiliation);
	}
	
	public boolean insert(String channel, JSONObject json) {
		ContentValues values = buildValues(channel, json);
		if (values != null) {
			long rowId = db.insert(ChannelMetadataTableHelper.TABLE_NAME, null, values);
			return rowId != -1;
		}
		
		return false;
	}
	
	public boolean update(String channel, JSONObject json) {
		ContentValues values = buildValues(channel, json);
		if (values != null) {
			String filter = ChannelMetadataTableHelper.COLUMN_ID + "=\"" + channel + "\"";
			int rowsAffected = db.update(ChannelMetadataTableHelper.TABLE_NAME, 
					values, filter, null);
			return rowsAffected == 1;
		}
		
		return false;
	}
	
	public JSONObject get(String channel) {
		String filter = ChannelMetadataTableHelper.COLUMN_ID + "=\"" + channel + "\"";
		return DAOHelper.queryUniqueOnSameThread(db, false, ChannelMetadataTableHelper.TABLE_NAME, COLUMNS, filter,
				null, null, null, null, null, cursorParser());
	}

	private DAOCursorParser cursorParser() {
		DAOCursorParser cursorParser = new DAOCursorParser() {
			@Override
			public JSONObject parse(Cursor c) {
				return cursorToJSON(c);
			}
		};
		return cursorParser;
	}
	
	public Map<String, JSONObject> getAll() {
		return DAOHelper.queryMapOnSameThread(db, false, ChannelMetadataTableHelper.TABLE_NAME,
				COLUMNS, null, null, null, null, null, null, cursorParser(), 
				ChannelMetadataTableHelper.COLUMN_ID);
	}
	
	private JSONObject cursorToJSON(Cursor cursor) {
		JSONObject json = new JSONObject();
		try {
			json.put(ChannelMetadataTableHelper.COLUMN_ID, 
					getString(cursor, ChannelMetadataTableHelper.COLUMN_ID));
			json.put(ChannelMetadataTableHelper.COLUMN_TITLE, 
					getString(cursor, ChannelMetadataTableHelper.COLUMN_TITLE));
			json.put(ChannelMetadataTableHelper.COLUMN_DESCRIPTION, 
					getString(cursor, ChannelMetadataTableHelper.COLUMN_DESCRIPTION));
			json.put(ChannelMetadataTableHelper.COLUMN_CHANNEL_TYPE, 
					getString(cursor, ChannelMetadataTableHelper.COLUMN_CHANNEL_TYPE));
			json.put(ChannelMetadataTableHelper.COLUMN_ACCESS_MODEL, 
					getString(cursor, ChannelMetadataTableHelper.COLUMN_ACCESS_MODEL));
			json.put(ChannelMetadataTableHelper.COLUMN_CREATION_DATE, 
					getString(cursor, ChannelMetadataTableHelper.COLUMN_CREATION_DATE));
			json.put(ChannelMetadataTableHelper.COLUMN_DEFAULT_AFFILIATION, 
					getString(cursor, ChannelMetadataTableHelper.COLUMN_DEFAULT_AFFILIATION));
		} catch (JSONException e) {
			return null;
		}
		
		return json;
	}
	
	private String getString(Cursor cursor, String columnName) {
		return cursor.getString(cursor.getColumnIndex(columnName));
	}
}