/*
 * Copyright (C) 2009, Mykola Nikishov <mn@mn.com.ua>
 * Copyright (C) 2008, Robin Rosenberg <robin.rosenberg@dewire.com>
 * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
 * and other copyright owners as documented in the project's IP log.
 *
 * This program and the accompanying materials are made available
 * under the terms of the Eclipse Distribution License v1.0 which
 * accompanies this distribution, is reproduced below, and is
 * available at http://www.eclipse.org/org/documents/edl-v10.php
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials provided
 *   with the distribution.
 *
 * - Neither the name of the Eclipse Foundation, Inc. nor the
 *   names of its contributors may be used to endorse or promote
 *   products derived from this software without specific prior
 *   written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.eclipse.jgit.transport;

import java.net.URISyntaxException;
import java.net.URL;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.eclipse.jgit.lib.Constants;

/**
 * This URI like construct used for referencing Git archives over the net, as
 * well as locally stored archives. The most important difference compared to
 * RFC 2396 URI's is that no URI encoding/decoding ever takes place. A space or
 * any special character is written as-is.
 */
public class URIish {
	private static final Pattern FULL_URI = Pattern
			.compile("^(?:([a-z][a-z0-9+-]+)://(?:([^/]+?)(?::([^/]+?))?@)?(?:([^/]+?))?(?::(\\d+))?)?((?:[A-Za-z]:)?/.+)$");

	private static final Pattern SCP_URI = Pattern
			.compile("^(?:([^@]+?)@)?([^:]+?):(.+)$");

	private String scheme;

	private String path;

	private String user;

	private String pass;

	private int port = -1;

	private String host;

	/**
	 * Parse and construct an {@link URIish} from a string
	 *
	 * @param s
	 * @throws URISyntaxException
	 */
	public URIish(String s) throws URISyntaxException {
		s = s.replace('\\', '/');
		Matcher matcher = FULL_URI.matcher(s);
		if (matcher.matches()) {
			scheme = matcher.group(1);
			user = matcher.group(2);
			pass = matcher.group(3);
			host = matcher.group(4);
			if (matcher.group(5) != null)
				port = Integer.parseInt(matcher.group(5));
			path = matcher.group(6);
			if (path.length() >= 3
			&& path.charAt(0) == '/'
			&& path.charAt(2) == ':'
			&& (path.charAt(1) >= 'A' && path.charAt(1) <= 'Z'
			 || path.charAt(1) >= 'a' && path.charAt(1) <= 'z'))
				path = path.substring(1);
		} else {
			matcher = SCP_URI.matcher(s);
			if (matcher.matches()) {
				user = matcher.group(1);
				host = matcher.group(2);
				path = matcher.group(3);
			} else
				throw new URISyntaxException(s, "Cannot parse Git URI-ish");
		}
	}

	/**
	 * Construct a URIish from a standard URL.
	 *
	 * @param u
	 *            the source URL to convert from.
	 */
	public URIish(final URL u) {
		scheme = u.getProtocol();
		path = u.getPath();

		final String ui = u.getUserInfo();
		if (ui != null) {
			final int d = ui.indexOf(':');
			user = d < 0 ? ui : ui.substring(0, d);
			pass = d < 0 ? null : ui.substring(d + 1);
		}

		port = u.getPort();
		host = u.getHost();
	}

	/** Create an empty, non-configured URI. */
	public URIish() {
		// Configure nothing.
	}

	private URIish(final URIish u) {
		this.scheme = u.scheme;
		this.path = u.path;
		this.user = u.user;
		this.pass = u.pass;
		this.port = u.port;
		this.host = u.host;
	}

	/**
	 * @return true if this URI references a repository on another system.
	 */
	public boolean isRemote() {
		return getHost() != null;
	}

	/**
	 * @return host name part or null
	 */
	public String getHost() {
		return host;
	}

	/**
	 * Return a new URI matching this one, but with a different host.
	 *
	 * @param n
	 *            the new value for host.
	 * @return a new URI with the updated value.
	 */
	public URIish setHost(final String n) {
		final URIish r = new URIish(this);
		r.host = n;
		return r;
	}

	/**
	 * @return protocol name or null for local references
	 */
	public String getScheme() {
		return scheme;
	}

	/**
	 * Return a new URI matching this one, but with a different scheme.
	 *
	 * @param n
	 *            the new value for scheme.
	 * @return a new URI with the updated value.
	 */
	public URIish setScheme(final String n) {
		final URIish r = new URIish(this);
		r.scheme = n;
		return r;
	}

	/**
	 * @return path name component
	 */
	public String getPath() {
		return path;
	}

	/**
	 * Return a new URI matching this one, but with a different path.
	 *
	 * @param n
	 *            the new value for path.
	 * @return a new URI with the updated value.
	 */
	public URIish setPath(final String n) {
		final URIish r = new URIish(this);
		r.path = n;
		return r;
	}

	/**
	 * @return user name requested for transfer or null
	 */
	public String getUser() {
		return user;
	}

	/**
	 * Return a new URI matching this one, but with a different user.
	 *
	 * @param n
	 *            the new value for user.
	 * @return a new URI with the updated value.
	 */
	public URIish setUser(final String n) {
		final URIish r = new URIish(this);
		r.user = n;
		return r;
	}

	/**
	 * @return password requested for transfer or null
	 */
	public String getPass() {
		return pass;
	}

	/**
	 * Return a new URI matching this one, but with a different password.
	 *
	 * @param n
	 *            the new value for password.
	 * @return a new URI with the updated value.
	 */
	public URIish setPass(final String n) {
		final URIish r = new URIish(this);
		r.pass = n;
		return r;
	}

	/**
	 * @return port number requested for transfer or -1 if not explicit
	 */
	public int getPort() {
		return port;
	}

	/**
	 * Return a new URI matching this one, but with a different port.
	 *
	 * @param n
	 *            the new value for port.
	 * @return a new URI with the updated value.
	 */
	public URIish setPort(final int n) {
		final URIish r = new URIish(this);
		r.port = n > 0 ? n : -1;
		return r;
	}

	public int hashCode() {
		int hc = 0;
		if (getScheme() != null)
			hc = hc * 31 + getScheme().hashCode();
		if (getUser() != null)
			hc = hc * 31 + getUser().hashCode();
		if (getPass() != null)
			hc = hc * 31 + getPass().hashCode();
		if (getHost() != null)
			hc = hc * 31 + getHost().hashCode();
		if (getPort() > 0)
			hc = hc * 31 + getPort();
		if (getPath() != null)
			hc = hc * 31 + getPath().hashCode();
		return hc;
	}

	public boolean equals(final Object obj) {
		if (!(obj instanceof URIish))
			return false;
		final URIish b = (URIish) obj;
		if (!eq(getScheme(), b.getScheme()))
			return false;
		if (!eq(getUser(), b.getUser()))
			return false;
		if (!eq(getPass(), b.getPass()))
			return false;
		if (!eq(getHost(), b.getHost()))
			return false;
		if (getPort() != b.getPort())
			return false;
		if (!eq(getPath(), b.getPath()))
			return false;
		return true;
	}

	private static boolean eq(final String a, final String b) {
		if (a == b)
			return true;
		if (a == null || b == null)
			return false;
		return a.equals(b);
	}

	/**
	 * Obtain the string form of the URI, with the password included.
	 *
	 * @return the URI, including its password field, if any.
	 */
	public String toPrivateString() {
		return format(true);
	}

	public String toString() {
		return format(false);
	}

	private String format(final boolean includePassword) {
		final StringBuilder r = new StringBuilder();
		if (getScheme() != null) {
			r.append(getScheme());
			r.append("://");
		}

		if (getUser() != null) {
			r.append(getUser());
			if (includePassword && getPass() != null) {
				r.append(':');
				r.append(getPass());
			}
		}

		if (getHost() != null) {
			if (getUser() != null)
				r.append('@');
			r.append(getHost());
			if (getScheme() != null && getPort() > 0) {
				r.append(':');
				r.append(getPort());
			}
		}

		if (getPath() != null) {
			if (getScheme() != null) {
				if (!getPath().startsWith("/"))
					r.append('/');
			} else if (getHost() != null)
				r.append(':');
			r.append(getPath());
		}

		return r.toString();
	}

	/**
	 * Get the "humanish" part of the path. Some examples of a 'humanish' part
	 * for a full path:
	 * <table>
	 * <tr>
	 * <th>Path</th>
	 * <th>Humanish part</th>
	 * </tr>
	 * <tr>
	 * <td><code>/path/to/repo.git</code></td>
	 * <td rowspan="4"><code>repo</code></td>
	 * </tr>
	 * <tr>
	 * <td><code>/path/to/repo.git/</code></td>
	 * </tr>
	 * <tr>
	 * <td><code>/path/to/repo/.git</code></td>
	 * </tr>
	 * <tr>
	 * <td><code>/path/to/repo/</code></td>
	 * </tr>
	 * <tr>
	 * <td><code>/path//to</code></td>
	 * <td>an empty string</td>
	 * </tr>
	 * </table>
	 *
	 * @return the "humanish" part of the path. May be an empty string. Never
	 *         {@code null}.
	 * @throws IllegalArgumentException
	 *             if it's impossible to determine a humanish part, or path is
	 *             {@code null} or empty
	 * @see #getPath
	 */
	public String getHumanishName() throws IllegalArgumentException {
		if ("".equals(getPath()) || getPath() == null)
			throw new IllegalArgumentException();
		String[] elements = getPath().split("/");
		if (elements.length == 0)
			throw new IllegalArgumentException();
		String result = elements[elements.length - 1];
		if (Constants.DOT_GIT.equals(result))
			result = elements[elements.length - 2];
		else if (result.endsWith(Constants.DOT_GIT_EXT))
			result = result.substring(0, result.length()
					- Constants.DOT_GIT_EXT.length());
		return result;
	}

}