/*
 * @(#)Attributes.java	1.30 01/11/29
 *
 * Copyright 2002 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package java.util.jar;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.Collection;
import java.util.AbstractSet;
import java.util.Iterator;

/**
 * The Attributes class maps Manifest attribute names to associated string
 * values. Attribute names are case-insensitive and restricted to the ASCII
 * characters in the set [0-9a-zA-Z_-]. Attribute values can contain any
 * characters and will be UTF8-encoded when written to the output stream.
 *
 * @author  David Connelly
 * @version 1.30, 11/29/01
 * @see	    Manifest
 * @since   JDK1.2
 */
public class Attributes implements Map, Cloneable {
    /**
     * The attribute name-value mappings.
     */
    protected Map map;

    /**
     * Constructs a new, empty Attributes object with default size.
     */
    public Attributes() {
	this(11);
    }

    /**
     * Constructs a new, empty Attributes object with the specified
     * initial size.
     *
     * @param size the initial number of attributes
     */
    public Attributes(int size) {
	map = new HashMap(size);
    }

    /**
     * Constructs a new Attributes object with the same attribute name-value
     * mappings as in the specified Attributes.
     */
    public Attributes(Attributes attr) {
	map = new HashMap(attr);
    }


    /**
     * Returns the value of the specified attribute name, or null if the
     * attribute name was not found.
     *
     * @param name the attribute name
     */
    public Object get(Object name) {
	return map.get(name);
    }

    /**
     * Returns the value of the specified attribute name, specified as
     * a string, or null if the attribute was not found. The attribute
     * name is case-insensitive.
     * <p>
     * This method is defined as:
     * <pre>
     *	    return (String)get(new Attributes.Name((String)name));
     * </pre>
     *
     * @param name the attribute name as a string
     */
    public String getValue(String name) {
        return (String)get(new Attributes.Name((String)name));
    }

    /**
     * Returns the value of the specified Attributes.Name, or null if the
     * attribute was not found.
     * <p>
     * This method is defined as:
     * <pre>
     *     return (String)get(name);
     * </pre>
     *
     * @param name the Attributes.Name object
     */
    public String getValue(Name name) {
	return (String)get(name);
    }

    /**
     * Associates the specified value with the specified attribute name
     * (key) in this Map. If the Map previously contained a mapping for
     * the attribute name, the old value is replaced.
     *
     * @param name the attribute name
     * @param value the attribute value
     * @return the previous value of the attribute, or null if none
     * @exception ClassCastException if the name is not a Attributes.Name
     *            or the value is not a String
     */
    public Object put(Object name, Object value) {
        return map.put((Attributes.Name)name, (String)value);
    }

    /**
     * Associates the specified value with the specified attribute name,
     * specified as a String. The attributes name is case-insensitive.
     * If the Map previously contained a mapping for the attribute name,
     * the old value is replaced.
     * <p>
     * This method is defined as:
     * <pre>
     *	    return (String)put(new Attributes.Name(name), value);
     * </pre>
     *
     * @param the attribute name as a string
     * @param value the attribute value
     * @exception IllegalArgumentException if the attribute name is invalid
     */
    public String putValue(String name, String value) {
	return (String)put(new Name(name), value);
    }

    /**
     * Removes the attribute with the specified name (key) from this Map.
     * Returns the previous attribute value, or null if none.
     *
     * @param name attribute name
     */
    public Object remove(Object name) {
	return map.remove(name);
    }

    /**
     * Returns true if this Map maps one or more attribute names (keys)
     * to the specified value.
     *
     * @param value the attribute value
     */
    public boolean containsValue(Object value) {
	return map.containsValue(value);
    }

    /**
     * Returns true if this Map contains the specified attribute name (key).
     *
     * @param name the attribute name
     */
    public boolean containsKey(Object name) {
	return map.containsKey(name);
    }

    /**
     * Copies all of the attribute name-value mappings from the specified
     * Attributes to this Map. Duplicate mappings will be replaced.
     *
     * @param attr the Attributes to be stored in this map
     * @exception IllegalArgumentException if attr is not a Attributes instance
     */
    public void putAll(Map attr) {
        if (!(attr instanceof Attributes)) {
            throw new IllegalArgumentException
                ("attr is not instance of Attributes");
        }
	map.putAll(attr);
    }

    /**
     * Removes all attributes from this Map.
     */
    public void clear() {
	map.clear();
    }

    /**
     * Returns the number of attributes in this Map.
     */
    public int size() {
	return map.size();
    }

    /**
     * Returns true if this Map contains no attributes.
     */
    public boolean isEmpty() {
	return map.isEmpty();
    }

    /**
     * Returns a Set view of the attribute names (keys) contained in this Map.
     */
    public Set keySet() {
	return map.keySet();
    }

    /**
     * Returns a Collection view of the attribute values contained in this Map.
     */
    public Collection values() {
	return map.values();
    }

    /**
     * Returns a Collection view of the attribute name-value mappings
     * contained in this Map.
     */
    public Set entrySet() {
	return map.entrySet();
    }

    /**
     * Compares the specified Attributes object with this Map for equality.
     * Returns true if the given object is also an instance of Attributes
     * and the two Attributes objects represent the same mappings.
     *
     * @param o the Object to be compared
     * @return true if the specified Object is equal to this Map
     */
    public boolean equals(Object o) {
	return map.equals(o);
    }

    /**
     * Returns the hash code value for this Map.
     */
    public int hashCode() {
	return map.hashCode();
    }

    /**
     * Returns a copy of the Attributes, implemented as follows:
     * <pre>
     *     public Object clone() { return new Attributes(this); }
     * </pre>
     * Since the attribute names and values are themselves immutable,
     * the Attributes returned can be safely modified without affecting
     * the original.
     */
    public Object clone() {
	return new Attributes(this);
    }

    /*
     * Writes the current attributes to the specified data output stream.
     * XXX Need to handle UTF8 values and break up lines longer than 72 bytes
     */
     void write(DataOutputStream os) throws IOException {
	Iterator it = entrySet().iterator();
	while (it.hasNext()) {
	    Map.Entry e = (Map.Entry)it.next();
            StringBuffer buffer = new StringBuffer(
                                        ((Name)e.getKey()).toString());
	    buffer.append(": ");
	    buffer.append((String)e.getValue());
	    buffer.append("\r\n");
            Manifest.make72Safe(buffer);
            os.writeBytes(buffer.toString());
	}
	os.writeBytes("\r\n");
    }

    /*
     * Writes the current attributes to the specified data output stream,
     * make sure to write out the MANIFEST_VERSION or SIGNATURE_VERSION
     * attributes first.
     *
     * XXX Need to handle UTF8 values and break up lines longer than 72 bytes
     */
    void writeMain(DataOutputStream out) throws IOException 
    {
	// write out the *-Version header first, if it exists
	String vername = Name.MANIFEST_VERSION.toString();
	String version = getValue(vername);
	if (version == null) {
	    vername = Name.SIGNATURE_VERSION.toString();
	    version = getValue(vername);
	}

	if (version != null) {
	    out.writeBytes(vername+": "+version+"\r\n");
	}

	// write out all attributes except for the version
	// we wrote out earlier
	Iterator it = entrySet().iterator();
	while (it.hasNext()) {
	    Map.Entry e = (Map.Entry)it.next();
	    String name = ((Name)e.getKey()).toString();
	    if ((version != null) && ! (name.equalsIgnoreCase(vername))) {
                StringBuffer buffer = new StringBuffer(name);
		buffer.append(": ");
		buffer.append((String)e.getValue());
		buffer.append("\r\n");
                Manifest.make72Safe(buffer);
                out.writeBytes(buffer.toString());
	    }
	}
	out.writeBytes("\r\n");
    }

    /*
     * Reads attributes from the specified input stream.
     * XXX Need to handle UTF8 values.
     */
    void read(Manifest.FastInputStream is, byte[] lbuf) throws IOException {
	String name = null, value = null;
	int len;
	while ((len = is.readLine(lbuf)) != -1) {
	    if (lbuf[--len] != '\n') {
		throw new IOException("line too long");
	    }
	    if (len > 0 && lbuf[len-1] == '\r') {
		--len;
	    }
	    if (len == 0) {
		break;
	    }
	    int i = 0;
	    if (lbuf[0] == ' ') {
		// continuation of previous line
		if (name == null) {
		    throw new IOException("misplaced continuation line");
		}
		value = value + new String(lbuf, 0, 1, len-1);
	    } else {
                while (lbuf[i++] != ':') {
                    if (i >= len) {
                        throw new IOException("invalid header field");
                    }
                }
                if (lbuf[i++] != ' ') {
                    throw new IOException("invalid header field");
                }
                name = new String(lbuf, 0, 0, i - 2);
                value = new String(lbuf, 0, i, len - i);
            }

	    try {
		putValue(name, value);
	    } catch (IllegalArgumentException e) {
		throw new IOException("invalid header field name: " + name);
	    }
	}
    }

    /**
     * The Attributes.Name class represents an attribute name stored in
     * this Map. Attribute names are case-insensitive and restricted to
     * the ASCII characters in the set [0-9a-zA-Z_-].
     */
    public static class Name {
	private String name;
	private int hashCode = -1;

	/**
	 * Constructs a new attribute name using the given string name.
	 *
	 * @param name the attribute string name
	 * @exception IllegalArgumentException if the attribute name was
	 *            invalid
	 * @exception NullPointerException if the attribute name was null
	 */
	public Name(String name) {
	    if (name == null) {
		throw new NullPointerException("name");
	    }
	    if (!isValid(name)) {
		throw new IllegalArgumentException(name);
	    }
	    this.name = name.intern();
	}

	private static boolean isValid(String name) {
	    int len = name.length();
	    if (len > 70) {
		return false;
	    }
	    for (int i = 0; i < len; i++) {
		if (!isValid(name.charAt(i))) {
		    return false;
		}
	    }
	    return true;
	}

	private static boolean isValid(char c) {
	    return isAlpha(c) || isDigit(c) || c == '_' || c == '-';
	}

	private static boolean isAlpha(char c) {
	    return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
	}

	private static boolean isDigit(char c) {
	    return c >= '0' && c <= '9';
	}

	/**
	 * Compares this attribute name to another for equality.
	 * @param o the object to compare
	 */
	public boolean equals(Object o) {
	    if (o instanceof Name) {
		return name.equalsIgnoreCase(((Name)o).name);
	    } else {
		return false;
	    }
	}
      
	/**
	 * Computes the hash value for this attribute name.
	 */
        public int hashCode() {
	    if (hashCode == -1) {
		hashCode = name.toLowerCase().hashCode();
	    }
	    return hashCode;
	}

	/**
	 * Returns the attribute name as a String.
	 */
	public String toString() {
	    return name;
	}

        /**
         * <code>Name</code> object for <code>Manifest-Version</code> 
         * manifest attribute. This attribute indicates the version number 
         * of the manifest standard to which a JAR file's manifest conforms.
         * @see <a href="../../../../guide/jar/manifest.html">
         *      Manifest and Signature Specification</a>
         */ 
        public static final Name MANIFEST_VERSION = new Name("Manifest-Version");

        /**
         * <code>Name</code> object for <code>Signature-Version</code> 
         * manifest attribute used when signing JAR files.
         * @see <a href="../../../../guide/jar/manifest.html">
         *      Manifest and Signature Specification</a>
         */             
        public static final Name SIGNATURE_VERSION = new Name("Signature-Version");

        /**
         * <code>Name</code> object for <code>Content-Type</code> 
         * manifest attribute.
         */               
        public static final Name CONTENT_TYPE = new Name("Content-Type");

        /**
         * <code>Name</code> object for <code>Class-Path</code> 
         * manifest attribute. Bundled extensions can use this attribute 
         * to find other JAR files containing needed classes.
         * @see <a href="../../../../guide/extensions/spec.html#bundled">
         *      Extensions Specification</a>
         */   
        public static final Name CLASS_PATH = new Name("Class-Path");

        /**
         * <code>Name</code> object for <code>Main-Class</code> manifest 
         * attribute used for launching applications packaged in JAR files. 
         * The <code>Main-Class</code> attribute is used in conjunction 
         * with the <code>-jar</code> command-line option of the 
         * <tt>java</tt> application launcher.
         */ 
        public static final Name MAIN_CLASS = new Name("Main-Class");

        /**
         * <code>Name</code> object for <code>Sealed</code> manifest attribute 
         * used for sealing.
         * @see <a href="../../../../guide/extensions/spec.html#sealing">
         *      Extension Sealing</a>
         */ 
        public static final Name SEALED = new Name("Sealed");

        /**
         * <code>Name</code> object for <code>Implementation-Title</code> 
         * manifest attribute used for package versioning.
         * @see <a href="../../../../guide/versioning/spec/VersioningSpecification.html#PackageVersioning">
         *      Java Product Versioning Specification</a>
         */
        public static final Name IMPLEMENTATION_TITLE = new Name("Implementation-Title");

        /**
         * <code>Name</code> object for <code>Implementation-Version</code> 
         * manifest attribute used for package versioning.
         * @see <a href="../../../../guide/versioning/spec/VersioningSpecification.html#PackageVersioning">
         *      Java Product Versioning Specification</a>
         */
        public static final Name IMPLEMENTATION_VERSION = new Name("Implementation-Version");

        /**
         * <code>Name</code> object for <code>Implementation-Vendor</code> 
         * manifest attribute used for package versioning.
         * @see <a href="../../../../guide/versioning/spec/VersioningSpecification.html#PackageVersioning">
         *      Java Product Versioning Specification</a>
         */
        public static final Name IMPLEMENTATION_VENDOR = new Name("Implementation-Vendor");

        /**
         * <code>Name</code> object for <code>Specification-Title</code> 
         * manifest attribute used for package versioning.
         * @see <a href="../../../../guide/versioning/spec/VersioningSpecification.html#PackageVersioning">
         *      Java Product Versioning Specification</a>
         */
        public static final Name SPECIFICATION_TITLE = new Name("Specification-Title");

        /**
         * <code>Name</code> object for <code>Specification-Version</code> 
         * manifest attribute used for package versioning.
         * @see <a href="../../../../guide/versioning/spec/VersioningSpecification.html#PackageVersioning">
         *      Java Product Versioning Specification</a>
         */
        public static final Name SPECIFICATION_VERSION = new Name("Specification-Version");

        /**
         * <code>Name</code> object for <code>Specification-Vendor</code> 
         * manifest attribute used for package versioning.
         * @see <a href="../../../../guide/versioning/spec/VersioningSpecification.html#PackageVersioning">
         *      Java Product Versioning Specification</a>
         */
        public static final Name SPECIFICATION_VENDOR = new Name("Specification-Vendor");
    }
}