/*
 * Copyright 2012 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.android.apps.iosched.io;

import android.content.ContentProviderOperation;
import android.content.Context;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringWriter;
import java.io.Writer;
import java.util.ArrayList;

/**
 * An abstract object that is in charge of parsing JSON data with a given, known structure, into
 * a list of content provider operations (inserts, updates, etc.) representing the data.
 */
public abstract class JSONHandler {
    protected static Context mContext;

    protected JSONHandler(Context context) {
        mContext = context;
    }

    public abstract ArrayList<ContentProviderOperation> parse(String json) throws IOException;

    /**
     * Loads the JSON text resource with the given ID and returns the JSON content.
     */
    public static String loadResourceJson(Context context, int resource) throws IOException {
        InputStream is = context.getResources().openRawResource(resource);
        Writer writer = new StringWriter();
        char[] buffer = new char[1024];
        try {
            Reader reader = new BufferedReader(new InputStreamReader(is, "UTF-8"));
            int n;
            while ((n = reader.read(buffer)) != -1) {
                writer.write(buffer, 0, n);
            }
        } finally {
            is.close();
        }

        return writer.toString();
    }
}