/*
 * %W% %E%
 *
 * Copyright (c) 2006, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package sun.misc;

import java.util.StringTokenizer;
import java.util.jar.Attributes;
import java.util.jar.Attributes.Name;
import java.util.ResourceBundle;
import java.util.MissingResourceException;
import java.text.MessageFormat;
import java.lang.Character.*;


/**
 * This class holds all necessary information to install or
 * upgrade a extension on the user's disk
 *
 * @author  Jerome Dochez
 * @version %I%, %G%
 */
public class ExtensionInfo {

    /**
     * <p>
     * public static values returned by the isCompatible method
     * </p>
     */
    public static final int COMPATIBLE = 0;
    public static final int REQUIRE_SPECIFICATION_UPGRADE = 1;
    public static final int REQUIRE_IMPLEMENTATION_UPGRADE = 2;
    public static final int REQUIRE_VENDOR_SWITCH = 3;
    public static final int INCOMPATIBLE = 4;

    /**
     * <p>
     * attributes fully describer an extension. The underlying described 
     * extension may be installed and requested.
     * <p>
     */
    public String title;
    public String name;
    public String specVersion;
    public String specVendor;
    public String implementationVersion;
    public String vendor;
    public String vendorId;
    public String url;

    // For I18N support
    private static final ResourceBundle rb = 
    ResourceBundle.getBundle("sun.misc.resources.Messages");
            
    
    /**
     * <p>
     * Create a new uninitialized extension information object
     * </p>
     */
    public ExtensionInfo() {
    }

    /**
     * <p>
     * Create and initialize an extension information object.
     * The initialization uses the attributes passed as being
     * the content of a manifest file to load the extension
     * information from.
     * Since manifest file may contain information on several
     * extension they may depend on, the extension key parameter
     * is prepanded to the attribute name to make the key used
     * to retrieve the attribute from the manifest file
     * <p>
     * @param extensionKey unique extension key in the manifest
     * @param attr Attributes of a manifest file
     */
    public ExtensionInfo(String extensionKey, Attributes attr) 
    throws NullPointerException 
    {
    String s;
    if (extensionKey!=null) {
        s = extensionKey + "-";
    } else {
        s ="";
    }
    
    String attrKey = s + Name.EXTENSION_NAME.toString();
    name = attr.getValue(attrKey);
    if (name != null)
        name = name.trim();
        
    attrKey = s + Name.SPECIFICATION_TITLE.toString();
    title = attr.getValue(attrKey);
    if (title != null)
        title = title.trim();
        
    attrKey = s + Name.SPECIFICATION_VERSION.toString();
    specVersion = attr.getValue(attrKey);
    if (specVersion != null)
        specVersion = specVersion.trim();
        
    attrKey = s + Name.SPECIFICATION_VENDOR.toString();
    specVendor = attr.getValue(attrKey);
    if (specVendor != null)
        specVendor = specVendor.trim();
        
        attrKey = s + Name.IMPLEMENTATION_VERSION.toString();
    implementationVersion = attr.getValue(attrKey);
    if (implementationVersion != null)
        implementationVersion = implementationVersion.trim();
        
        attrKey = s + Name.IMPLEMENTATION_VENDOR.toString();    
    vendor = attr.getValue(attrKey);
    if (vendor != null)
        vendor = vendor.trim();
        
        attrKey = s + Name.IMPLEMENTATION_VENDOR_ID.toString(); 
    vendorId = attr.getValue(attrKey);
    if (vendorId != null)
        vendorId = vendorId.trim();
        
        attrKey =s + Name.IMPLEMENTATION_URL.toString();    
    url = attr.getValue(attrKey);
    if (url != null)    
        url = url.trim();
    }

    /**
     * <p>
     * @return true if the extension described by this extension information
     * is compatible with the extension described by the extension 
     * information passed as a parameter
     * </p>
     *
     * @param the requested extension information to compare to
     */
    public int isCompatibleWith(ExtensionInfo ei) {
    
    if (name == null || ei.name == null)
        return INCOMPATIBLE;
    if (name.compareTo(ei.name)==0) {
        // is this true, if not spec version is specified, we consider 
        // the value as being "any".
        if (specVersion == null || ei.specVersion == null) 
        return COMPATIBLE;
        
        int version = compareExtensionVersion(specVersion, ei.specVersion);
        if (version<0) {
        // this extension specification is "older"
        if (vendorId != null && ei.vendorId !=null) {
            if (vendorId.compareTo(ei.vendorId)!=0) {
            return REQUIRE_VENDOR_SWITCH;
            }
        }
        return REQUIRE_SPECIFICATION_UPGRADE;
        } else {
        // the extension spec is compatible, let's look at the 
        // implementation attributes
        if (vendorId != null && ei.vendorId != null) {
            // They care who provides the extension
            if (vendorId.compareTo(ei.vendorId)!=0) {
            // They want to use another vendor implementation
            return REQUIRE_VENDOR_SWITCH;
            } else {
            // Vendor matches, let's see the implementation version
            if (implementationVersion != null && ei.implementationVersion != null) {
                // they care about the implementation version 
                version = compareExtensionVersion(implementationVersion, ei.implementationVersion);
                if (version<0) {
                // This extension is an older implementation
                return REQUIRE_IMPLEMENTATION_UPGRADE;
                }
            }
            }
        }
        // All othe cases, we consider the extensions to be compatible
        return COMPATIBLE;
        }
    }
    return INCOMPATIBLE;
    }

    /**
     * <p>
     * helper method to print sensible information on the undelying described 
     * extension
     * </p>
     */
    public String toString() {
        return "Extension : title(" + title + "), name(" + name + "), spec vendor(" +
        specVendor + "), spec version(" + specVersion + "), impl vendor(" +
        vendor + "), impl vendor id(" + vendorId + "), impl version(" +
        implementationVersion + "), impl url(" + url + ")";
    }

    /*
     * <p>
     * helper method to compare two versions. 
     * version are in the x.y.z.t pattern.
     * </p>
     * @param source version to compare to
     * @param target version used to compare against
     * @return < 0 if source < version
     *         > 0 if source > version
     *         = 0 if source = version
     */
    private int compareExtensionVersion(String source, String target)
    throws NumberFormatException
    {
    source = source.toLowerCase();
    target = target.toLowerCase();

    return strictCompareExtensionVersion(source, target);
    }


    /*
     * <p>
     * helper method to compare two versions. 
     * version are in the x.y.z.t pattern.
     * </p>
     * @param source version to compare to
     * @param target version used to compare against
     * @return < 0 if source < version
     *         > 0 if source > version
     *         = 0 if source = version
     */
    private int strictCompareExtensionVersion(String source, String target)
    throws NumberFormatException
    {
    if (source.equals(target))
        return 0;

    StringTokenizer stk = new StringTokenizer(source, ".,");
    StringTokenizer ttk = new StringTokenizer(target, ".,");

    // Compare number
    int n = 0, m = 0, result = 0;

    // Convert token into meaning number for comparision
    if (stk.hasMoreTokens())
        n = convertToken(stk.nextToken().toString());

    // Convert token into meaning number for comparision
    if (ttk.hasMoreTokens())
        m = convertToken(ttk.nextToken().toString());

    if (n > m)
        return 1;
    else if (m > n)
        return -1;
    else
    {
        // Look for index of "." in the string
        int sIdx = source.indexOf(".");
        int tIdx = target.indexOf(".");

        if (sIdx == -1)
        sIdx = source.length() - 1;

        if (tIdx == -1)
        tIdx = target.length() - 1;

        return strictCompareExtensionVersion(source.substring(sIdx + 1),
                             target.substring(tIdx + 1));
    }
    }

    private int convertToken(String token)
    {
        if (token == null || token.equals(""))
        return 0;
        
        int charValue = 0;
    int charVersion = 0;
    int patchVersion = 0;
    int strLength = token.length();   
    int endIndex = strLength;   
    char lastChar;      
    
    Object[] args = {name};
    MessageFormat mf = new MessageFormat(rb.getString("optpkg.versionerror"));
    String versionError = mf.format(args);
    
    // Look for "-" for pre-release
    int prIndex = token.indexOf("-");

    // Look for "_" for patch release
    int patchIndex = token.indexOf("_");

    if (prIndex == -1 && patchIndex == -1)
    {
        // This is a FCS release
        try {
            return Integer.parseInt(token) * 100;
        } catch (NumberFormatException e) {
            System.out.println(versionError);
            return 0;
        }
    }
    else if (patchIndex != -1)
    {
        // This is a patch (update) release
        int prversion;      
        try {
            // Obtain the version
            prversion = Integer.parseInt(token.substring(0, patchIndex));
        
        // Check to see if the patch version is in the n.n.n_nnl format (special release)
            lastChar = token.charAt(strLength-1);
            if (Character.isLetter(lastChar)) {
                // letters a-z have values from 10-35
            charValue = Character.getNumericValue(lastChar);
            endIndex = strLength-1;
            
            // Obtain the patch version id
            patchVersion = Integer.parseInt(token.substring(patchIndex+1, endIndex));
            
            if (charValue >= Character.getNumericValue('a') && charValue <= Character.getNumericValue('z')) {
                // This is a special release
                charVersion = (patchVersion * 100) + charValue;
            } else {
                // character is not a a-z letter, ignore
                charVersion = 0;
                System.out.println(versionError);
            }
            } else {
                // This is a regular update release. Obtain the patch version id
                patchVersion = Integer.parseInt(token.substring(patchIndex+1, endIndex));
            }
        } catch (NumberFormatException e) {
            System.out.println(versionError);
            return 0;
        }
        return prversion * 100 + (patchVersion + charVersion);
    }
    else
    {   
        //This is a milestone release, either a early access, alpha, beta, or RC        

        // Obtain the version
        int mrversion;
        try {
            mrversion = Integer.parseInt(token.substring(0, prIndex));
        } catch (NumberFormatException e) {
            System.out.println(versionError);
            return 0;
        }
        
        // Obtain the patch version string, including the milestone + version
        String prString = token.substring(prIndex + 1);

        // Milestone version
        String msVersion = "";
        int delta = 0;

        if (prString.indexOf("ea") != -1)
        {
        msVersion = prString.substring(2);
        delta = 50;
        }
        else if (prString.indexOf("alpha") != -1)
        {
        msVersion = prString.substring(5);
        delta = 40;
        }
        else if (prString.indexOf("beta") != -1)
        {
        msVersion = prString.substring(4);
        delta = 30;
        }
        else if (prString.indexOf("rc") != -1)
        {
        msVersion = prString.substring(2);
        delta = 20;
        }

        if (msVersion == null || msVersion.equals(""))
        {
        // No version after the milestone, assume 0
        return mrversion * 100 - delta ;
        }
        else
        {
        // Convert the milestone version
        try {
            return mrversion * 100 - delta + Integer.parseInt(msVersion);
        } catch (NumberFormatException e) {
                System.out.println(versionError);
                return 0;
            }
        }
    }
    }
}