package org.apidesign.exceptions.trycatchredo.usage;

import java.io.ByteArrayInputStream;

import java.io.ByteArrayOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.net.MalformedURLException;

import java.net.URL;

import java.net.URLConnection;

import java.net.URLStreamHandler;

import java.net.URLStreamHandlerFactory;

import java.util.HashMap;

import java.util.Map;

/** Support for special "memory://" URLs. Useful when testing network communication.

 *

 * @author Jaroslav Tulach

 */

public final class MemoryURL extends URLStreamHandler {

    private MemoryURL() {

    }

    public static void initialize() {

    }

    static {

        class F implements URLStreamHandlerFactory {

            public URLStreamHandler createURLStreamHandler(String protocol) {

                if (protocol.startsWith("memory")) {

                    return new MemoryURL();

                }

                return null;

            }

        }

        F f = new F();

        URL.setURLStreamHandlerFactory(f);

    }

    private static Map<String,InputStream> contents = new HashMap<String,InputStream>();

    private static Map<String,OutputStream> outputs = new HashMap<String,OutputStream>();

    public static void registerURL(String u, String content, OutputStream out) throws MalformedURLException {

        contents.put(u, new ByteArrayInputStream(content.getBytes()));

        outputs.put(u, out);

    }

    public static String getOutputForURL(String u) {

        OutputStream out = outputs.get(u);

        return out.toString();

    }

    protected URLConnection openConnection(URL u) throws IOException {

        return new MC(u);

    }

    private static final class MC extends URLConnection {

        private InputStream values;

        private OutputStream out;

        public MC(URL u) {

            super(u);

            out = outputs.get(u.toExternalForm());

            if (out == null) {

                out = new ByteArrayOutputStream();

                outputs.put(u.toExternalForm(), out);

            }

        }

        public void connect() throws IOException {

            if (values != null) {

                return;

            }

            values = contents.remove(url.toExternalForm());

            if (values == null) {

                throw new IOException("No such content: " + url);

            }

        }

        @Override

        public InputStream getInputStream() throws IOException {

            connect();

            return values;

        }

        @Override

        public OutputStream getOutputStream() throws IOException {

            if (out == null) {

                out = new ByteArrayOutputStream();

            }

            return out;

        }

    }

}