/*
 * Copyright (C) 2015, Sasa Zivkov <sasa.zivkov@sap.com> and others
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Distribution License v. 1.0 which is available at
 * https://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

package org.eclipse.jgit.pgm.debug;

import java.io.File;
import java.io.IOException;
import java.net.InetAddress;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.UnknownHostException;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.text.MessageFormat;

import org.eclipse.jetty.server.Connector;
import org.eclipse.jetty.server.HttpConfiguration;
import org.eclipse.jetty.server.HttpConnectionFactory;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.server.ServerConnector;
import org.eclipse.jetty.server.handler.ContextHandlerCollection;
import org.eclipse.jetty.servlet.ServletContextHandler;
import org.eclipse.jetty.servlet.ServletHolder;
import org.eclipse.jgit.errors.ConfigInvalidException;
import org.eclipse.jgit.lfs.server.LargeFileRepository;
import org.eclipse.jgit.lfs.server.LfsProtocolServlet;
import org.eclipse.jgit.lfs.server.fs.FileLfsRepository;
import org.eclipse.jgit.lfs.server.fs.FileLfsServlet;
import org.eclipse.jgit.lfs.server.s3.S3Config;
import org.eclipse.jgit.lfs.server.s3.S3Repository;
import org.eclipse.jgit.pgm.Command;
import org.eclipse.jgit.pgm.TextBuiltin;
import org.eclipse.jgit.pgm.internal.CLIText;
import org.eclipse.jgit.storage.file.FileBasedConfig;
import org.eclipse.jgit.util.FS;
import org.kohsuke.args4j.Argument;
import org.kohsuke.args4j.Option;

@Command(common = true, usage = "usage_runLfsStore")
class LfsStore extends TextBuiltin {

	/**
	 * Tiny web application server for testing
	 */
	static class AppServer {

		private final Server server;

		private final ServerConnector connector;

		private final ContextHandlerCollection contexts;

		private URI uri;

		AppServer(int port) {
			server = new Server();

			HttpConfiguration http_config = new HttpConfiguration();
			http_config.setOutputBufferSize(32768);

			connector = new ServerConnector(server,
					new HttpConnectionFactory(http_config));
			connector.setPort(port);
			try {
				String host = InetAddress.getByName("localhost") //$NON-NLS-1$
						.getHostAddress();
				connector.setHost(host);
				if (host.contains(":") && !host.startsWith("[")) //$NON-NLS-1$ //$NON-NLS-2$
					host = "[" + host + "]"; //$NON-NLS-1$//$NON-NLS-2$
				uri = new URI("http://" + host + ":" + port); //$NON-NLS-1$ //$NON-NLS-2$
			} catch (UnknownHostException e) {
				throw new RuntimeException("Cannot find localhost", e); //$NON-NLS-1$
			} catch (URISyntaxException e) {
				throw new RuntimeException("Unexpected URI error on " + uri, e); //$NON-NLS-1$
			}

			contexts = new ContextHandlerCollection();
			server.setHandler(contexts);
			server.setConnectors(new Connector[] { connector });
		}

		/**
		 * Create a new servlet context within the server.
		 * <p>
		 * This method should be invoked before the server is started, once for
		 * each context the caller wants to register.
		 *
		 * @param path
		 *            path of the context; use "/" for the root context if
		 *            binding to the root is desired.
		 * @return the context to add servlets into.
		 */
		ServletContextHandler addContext(String path) {
			assertNotRunning();
			if ("".equals(path)) //$NON-NLS-1$
				path = "/"; //$NON-NLS-1$

			ServletContextHandler ctx = new ServletContextHandler();
			ctx.setContextPath(path);
			contexts.addHandler(ctx);

			return ctx;
		}

		void start() throws Exception {
			server.start();
		}

		void stop() throws Exception {
			server.stop();
		}

		URI getURI() {
			return uri;
		}

		private void assertNotRunning() {
			if (server.isRunning()) {
				throw new IllegalStateException("server is running"); //$NON-NLS-1$
			}
		}
	}

	private enum StoreType {
		FS, S3;
	}

	private enum StorageClass {
		REDUCED_REDUNDANCY, STANDARD
	}

	private static final String OBJECTS = "objects/"; //$NON-NLS-1$

	private static final String STORE_PATH = "/" + OBJECTS + "*"; //$NON-NLS-1$//$NON-NLS-2$

	private static final String PROTOCOL_PATH = "/lfs/objects/batch"; //$NON-NLS-1$

	@Option(name = "--port", aliases = {"-p" },
			metaVar = "metaVar_port", usage = "usage_LFSPort")
	int port;

	@Option(name = "--store", metaVar = "metaVar_lfsStorage", usage = "usage_LFSRunStore")
	StoreType storeType;

	@Option(name = "--store-url", aliases = {"-u" }, metaVar = "metaVar_url",
			usage = "usage_LFSStoreUrl")
	String storeUrl;

	@Option(name = "--region", aliases = {"-r" },
			metaVar = "metaVar_s3Region", usage = "usage_S3Region")
	String region; // $NON-NLS-1$

	@Option(name = "--bucket", aliases = {"-b" },
			metaVar = "metaVar_s3Bucket", usage = "usage_S3Bucket")
	String bucket; // $NON-NLS-1$

	@Option(name = "--storage-class", aliases = {"-c" },
			metaVar = "metaVar_s3StorageClass", usage = "usage_S3StorageClass")
	StorageClass storageClass = StorageClass.REDUCED_REDUNDANCY;

	@Option(name = "--expire", aliases = {"-e" },
			metaVar = "metaVar_seconds", usage = "usage_S3Expiration")
	int expirationSeconds = 600;

	@Option(name = "--no-ssl-verify", usage = "usage_S3NoSslVerify")
	boolean disableSslVerify = false;

	@Argument(required = false, metaVar = "metaVar_directory", usage = "usage_LFSDirectory")
	String directory;

	String protocolUrl;

	String accessKey;

	String secretKey;

	/** {@inheritDoc} */
	@Override
	protected boolean requiresRepository() {
		return false;
	}

	/** {@inheritDoc} */
	@Override
	protected void run() throws Exception {
		AppServer server = new AppServer(port);
		URI baseURI = server.getURI();
		ServletContextHandler app = server.addContext("/"); //$NON-NLS-1$

		final LargeFileRepository repository;
		switch (storeType) {
		case FS:
			Path dir = Paths.get(directory);
			FileLfsRepository fsRepo = new FileLfsRepository(
					getStoreUrl(baseURI), dir);
			FileLfsServlet content = new FileLfsServlet(fsRepo, 30000);
			app.addServlet(new ServletHolder(content), STORE_PATH);
			repository = fsRepo;
			break;

		case S3:
			readAWSKeys();
			checkOptions();
			S3Config config = new S3Config(region, bucket,
					storageClass.toString(), accessKey, secretKey,
					expirationSeconds, disableSslVerify);
			repository = new S3Repository(config);
			break;
		default:
			throw new IllegalArgumentException(MessageFormat
					.format(CLIText.get().lfsUnknownStoreType, storeType));
		}

		LfsProtocolServlet protocol = new LfsProtocolServlet() {

			private static final long serialVersionUID = 1L;

			@Override
			protected LargeFileRepository getLargeFileRepository(
					LfsRequest request, String path, String auth) {
				return repository;
			}
		};
		app.addServlet(new ServletHolder(protocol), PROTOCOL_PATH);

		server.start();

		outw.println(MessageFormat.format(CLIText.get().lfsProtocolUrl,
				getProtocolUrl(baseURI)));
		if (storeType == StoreType.FS) {
			outw.println(MessageFormat.format(CLIText.get().lfsStoreDirectory,
					directory));
			outw.println(MessageFormat.format(CLIText.get().lfsStoreUrl,
					getStoreUrl(baseURI)));
		}
	}

	private void checkOptions() {
		if (bucket == null || bucket.length() == 0) {
			throw die(MessageFormat.format(CLIText.get().s3InvalidBucket,
					bucket));
		}
	}

	private void readAWSKeys() throws IOException, ConfigInvalidException {
		String credentialsPath = System.getProperty("user.home") //$NON-NLS-1$
				+ "/.aws/credentials"; //$NON-NLS-1$
		FileBasedConfig c = new FileBasedConfig(new File(credentialsPath),
				FS.DETECTED);
		c.load();
		accessKey = c.getString("default", null, "accessKey"); //$NON-NLS-1$//$NON-NLS-2$
		secretKey = c.getString("default", null, "secretKey"); //$NON-NLS-1$ //$NON-NLS-2$
		if (accessKey == null || accessKey.isEmpty()) {
			throw die(MessageFormat.format(CLIText.get().lfsNoAccessKey,
					credentialsPath));
		}
		if (secretKey == null || secretKey.isEmpty()) {
			throw die(MessageFormat.format(CLIText.get().lfsNoSecretKey,
					credentialsPath));
		}
	}

	private String getStoreUrl(URI baseURI) {
		if (storeUrl == null) {
			if (storeType == StoreType.FS) {
				storeUrl = baseURI + "/" + OBJECTS; //$NON-NLS-1$
			} else {
				die("Local store not running and no --store-url specified"); //$NON-NLS-1$
			}
		}
		return storeUrl;
	}

	private String getProtocolUrl(URI baseURI) {
		if (protocolUrl == null) {
			protocolUrl = baseURI + PROTOCOL_PATH;
		}
		return protocolUrl;
	}
}