/*
* Copyright (c) 2008, Harald Walker (bitwalker.nl) 
* 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 bitwalker 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 com.wisemapping.util;

/**
 * Container class for user-agent information with operating system and browser details. 
 * Can decode user-agent strings.
 * <br><br>
 * Resources:<br>
 * <a href="http://www.useragentstring.com">User Agent String.Com</a><br>
 * <a href="http://www.user-agents.org">List of User-Agents</a><br>
 * <a href="http://www.zytrax.com/tech/web/browser_ids.htm">Browser ID (User-Agent) Strings</a><br>
 * <a href="http://www.zytrax.com/tech/web/mobile_ids.html">Mobile Browser ID (User-Agent) Strings</a><br>
 * <a href="http://www.joergkrusesweb.de/internet/browser/user-agent.html">Browser-Kennungen</a><br>
 * <a href="http://deviceatlas.com/devices">Device Atlas - Mobile Device Intelligence</a><br>
 * <a href="http://mobileopera.com/reference/ua">Mobile Opera user-agent strings</a><br>
 * <a href="http://en.wikipedia.org/wiki/S60_platform">S60 platform</a><br>
 * <a href="http://msdn.microsoft.com/en-us/library/ms537503.aspx">Understanding User-Agent Strings</a><br>
 * <a href="http://developer.sonyericsson.com/site/global/docstools/browsing/p_browsing.jsp">Sony Ericsson Web Docs & Tools</a><br>
 * <a href="http://developer.apple.com/internet/safari/faq.html#anchor2">What is the Safari user-agent string</a><br>
 * <a href="http://www.pgts.com.au/pgtsj/pgtsj0208c.html">List of User Agent Strings</a><br>
 * <a href="http://blogs.msdn.com/iemobile/archive/2006/08/03/Detecting_IE_Mobile.aspx">Detecting Internet Explorer Mobile's User-Agent on the server</a>
 */

import org.jetbrains.annotations.Nullable;

/**
 * @author harald
 */
public class UserAgent {

    private OperatingSystem operatingSystem = OperatingSystem.UNKNOWN;
    private Browser browser = Browser.UNKNOWN;
    private int id;
    private String userAgentString;

    public UserAgent(OperatingSystem operatingSystem, Browser browser) {
        this.operatingSystem = operatingSystem;
        this.browser = browser;
        this.id = ((operatingSystem.getId() << 16) + browser.getId());
    }

    public UserAgent(@Nullable String userAgentString) {
        if (userAgentString != null) {
            Browser browser = Browser.parseUserAgentString(userAgentString);

            OperatingSystem operatingSystem = OperatingSystem.UNKNOWN;

            // BOTs don't have an interesting OS for us
            if (browser != Browser.BOT)
                operatingSystem = OperatingSystem.parseUserAgentString(userAgentString);

            this.operatingSystem = operatingSystem;
            this.browser = browser;
            this.id = ((operatingSystem.getId() << 16) + browser.getId());
            this.userAgentString = userAgentString;

        } else {
            this.operatingSystem = OperatingSystem.UNKNOWN;
            this.browser = Browser.UNKNOWN;
        }
    }


    /**
     * @param userAgentString
     * @return UserAgent
     */
    public static UserAgent parseUserAgentString(String userAgentString) {
        return new UserAgent(userAgentString);
    }


    /**
     * Detects the detailed version information of the browser. Depends on the userAgent to be available.
     * Use it only after using UserAgent(String) or UserAgent.parseUserAgent(String).
     * Returns null if it can not detect the version information.
     *
     * @return Version
     */
    public Version getBrowserVersion() {
        return this.browser.getVersion(this.userAgentString);
    }

    /**
     * @return the system
     */
    public OperatingSystem getOperatingSystem() {
        return operatingSystem;
    }

    /**
     * @return the browser
     */
    public Browser getBrowser() {
        return browser;
    }

    /**
     * Returns an unique integer value of the operating system & browser combination
     *
     * @return the id
     */
    public int getId() {
        return id;
    }

    /**
     * Combined string representation of both enums
     */
    public String toString() {
        return this.operatingSystem.toString() + "-" + this.browser.toString();
    }

    /**
     * Returns UserAgent based on specified unique id
     *
     * @param id
     * @return
     */
    public static UserAgent valueOf(int id) {
        OperatingSystem operatingSystem = OperatingSystem.valueOf((short) (id >> 16));
        Browser browser = Browser.valueOf((short) (id & 0x0FFFF));
        return new UserAgent(operatingSystem, browser);
    }

    /**
     * Returns UserAgent based on combined string representation
     *
     * @param name
     * @return
     */
    public static UserAgent valueOf(String name) {
        if (name == null)
            throw new NullPointerException("Name is null");

        String[] elements = name.split("-");

        if (elements.length == 2) {
            OperatingSystem operatingSystem = OperatingSystem.valueOf(elements[0]);
            Browser browser = Browser.valueOf(elements[1]);
            return new UserAgent(operatingSystem, browser);
        }

        throw new IllegalArgumentException(
                "Invalid string for userAgent " + name);
    }

    /* (non-Javadoc)
      * @see java.lang.Object#hashCode()
      */
    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((browser == null) ? 0 : browser.hashCode());
        result = prime * result + id;
        result = prime * result
                + ((operatingSystem == null) ? 0 : operatingSystem.hashCode());
        return result;
    }

    /* (non-Javadoc)
      * @see java.lang.Object#equals(java.lang.Object)
      */
    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        final UserAgent other = (UserAgent) obj;
        if (browser == null) {
            if (other.browser != null)
                return false;
        } else if (!browser.equals(other.browser))
            return false;
        if (id != other.id)
            return false;
        if (operatingSystem == null) {
            if (other.operatingSystem != null)
                return false;
        } else if (!operatingSystem.equals(other.operatingSystem))
            return false;
        return true;
    }

}
