/*
 * Copyright 2007 Netflix, 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 net.oauth;

import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;

/**
 * A pool of OAuthConsumers that are constructed from Properties. Each consumer
 * has a name, which is a property of the OAuthConsumer. Other properties come
 * from Properties whose names are prefixed with the consumer's name. For
 * example, a consumer's credentials come from properties named
 * [name].consumerKey and [name].consumerSecret.
 * 
 * @author John Kristian
 * @hide
 */
public class ConsumerProperties {

    public static URL getResource(String name, ClassLoader loader)
            throws IOException {
        URL resource = loader.getResource(name);
        if (resource == null) {
            throw new IOException("resource not found: " + name);
        }
        return resource;
    }

    public static Properties getProperties(URL source) throws IOException {
        InputStream input = source.openStream();
        try {
            Properties p = new Properties();
            p.load(input);
            return p;
        } finally {
            input.close();
        }
    }

    public ConsumerProperties(String resourceName, ClassLoader loader)
            throws IOException {
        this(getProperties(getResource(resourceName, loader)));
    }

    public ConsumerProperties(Properties consumerProperties) {
        this.consumerProperties = consumerProperties;
    }

    private final Properties consumerProperties;

    private final Map<String, OAuthConsumer> pool = new HashMap<String, OAuthConsumer>();

    /** Get the consumer with the given name. */
    public OAuthConsumer getConsumer(String name) throws MalformedURLException {
        OAuthConsumer consumer;
        synchronized (pool) {
            consumer = pool.get(name);
        }
        if (consumer == null) {
            consumer = newConsumer(name);
        }
        synchronized (pool) {
            OAuthConsumer first = pool.get(name);
            if (first == null) {
                pool.put(name, consumer);
            } else {
                /*
                 * Another thread just constructed an identical OAuthConsumer.
                 * Use that one (and discard the one we just constructed).
                 */
                consumer = first;
            }
        }
        return consumer;
    }

    protected OAuthConsumer newConsumer(String name)
            throws MalformedURLException {
        String base = consumerProperties.getProperty(name
                + ".serviceProvider.baseURL");
        URL baseURL = (base == null) ? null : new URL(base);
        OAuthServiceProvider serviceProvider = new OAuthServiceProvider(getURL(
                baseURL, name + ".serviceProvider.requestTokenURL"), getURL(
                baseURL, name + ".serviceProvider.userAuthorizationURL"),
                getURL(baseURL, name + ".serviceProvider.accessTokenURL"));
        OAuthConsumer consumer = new OAuthConsumer(consumerProperties
                .getProperty(name + ".callbackURL"), consumerProperties
                .getProperty(name + ".consumerKey"), consumerProperties
                .getProperty(name + ".consumerSecret"), serviceProvider);
        consumer.setProperty("name", name);
        if (baseURL != null) {
            consumer.setProperty("serviceProvider.baseURL", baseURL);
        }
        for (Map.Entry prop : consumerProperties.entrySet()) {
            String propName = (String) prop.getKey();
            if (propName.startsWith(name + ".consumer.")) {
                String c = propName.substring(name.length() + 10);
                consumer.setProperty(c, prop.getValue());
            }
        }
        return consumer;
    }

    private String getURL(URL base, String name) throws MalformedURLException {
        String url = consumerProperties.getProperty(name);
        if (base != null) {
            url = (new URL(base, url)).toExternalForm();
        }
        return url;
    }

}