package org.codehaus.plexus.util.xml.pull;

/*
 * Copyright The Codehaus Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
public class EntityReplacementMap
{
    final String entityName[];

    final char[] entityNameBuf[];

    final String entityReplacement[];

    final char[] entityReplacementBuf[];

    int entityEnd;

    final int entityNameHash[];

    public EntityReplacementMap( String[][] replacements )
    {
        int length = replacements.length;
        entityName = new String[length];
        entityNameBuf = new char[length][];
        entityReplacement = new String[length];
        entityReplacementBuf = new char[length][];
        entityNameHash = new int[length];

        for ( String[] replacement : replacements )
        {
            defineEntityReplacementText( replacement[0], replacement[1] );
        }
    }

    private void defineEntityReplacementText( String entityName, String replacementText )
    {
        if ( !replacementText.startsWith( "&#" ) && this.entityName != null && replacementText.length() > 1 )
        {
            String tmp = replacementText.substring( 1, replacementText.length() - 1 );
            for ( int i = 0; i < this.entityName.length; i++ )
            {
                if ( this.entityName[i] != null && this.entityName[i].equals( tmp ) )
                {
                    replacementText = this.entityReplacement[i];
                }
            }
        }

        // this is to make sure that if interning works we will take advantage of it ...
        char[] entityNameCharData = entityName.toCharArray();
        // noinspection ConstantConditions
        this.entityName[entityEnd] = newString( entityNameCharData, 0, entityName.length() );
        entityNameBuf[entityEnd] = entityNameCharData;

        entityReplacement[entityEnd] = replacementText;
        entityReplacementBuf[entityEnd] = replacementText.toCharArray();
        entityNameHash[entityEnd] = fastHash( entityNameBuf[entityEnd], 0, entityNameBuf[entityEnd].length );
        ++entityEnd;
        // TODO disallow < or & in entity replacement text (or ]]>???)
        // TODO keepEntityNormalizedForAttributeValue cached as well ...
    }

    private String newString( char[] cbuf, int off, int len )
    {
        return new String( cbuf, off, len );
    }

    
simplistic implementation of hash function that has constant time to compute - so it also means
diminishing hash quality for long strings but for XML parsing it should be good enough ...
/**
     * simplistic implementation of hash function that has <b>constant</b> time to compute - so it also means
     * diminishing hash quality for long strings but for XML parsing it should be good enough ...
     */
    private static int fastHash( char ch[], int off, int len )
    {
        if ( len == 0 )
            return 0;
        // assert len >0
        int hash = ch[off]; // hash at beginning
        // try {
        hash = ( hash << 7 ) + ch[off + len - 1]; // hash at the end
        // } catch(ArrayIndexOutOfBoundsException aie) {
        // aie.printStackTrace(); //should never happen ...
        // throw new RuntimeException("this is violation of pre-condition");
        // }
        if ( len > 16 )
            hash = ( hash << 7 ) + ch[off + ( len / 4 )]; // 1/4 from beginning
        if ( len > 8 )
            hash = ( hash << 7 ) + ch[off + ( len / 2 )]; // 1/2 of string size ...
        // notice that hash is at most done 3 times <<7 so shifted by 21 bits 8 bit value
        // so max result == 29 bits so it is quite just below 31 bits for long (2^32) ...
        // assert hash >= 0;
        return hash;
    }

    public static final EntityReplacementMap defaultEntityReplacementMap = new EntityReplacementMap( new String[][] {
        { "nbsp", "\u00a0" }, { "iexcl", "\u00a1" }, { "cent", "\u00a2" }, { "pound", "\u00a3" },
        { "curren", "\u00a4" }, { "yen", "\u00a5" }, { "brvbar", "\u00a6" }, { "sect", "\u00a7" }, { "uml", "\u00a8" },
        { "copy", "\u00a9" }, { "ordf", "\u00aa" }, { "laquo", "\u00ab" }, { "not", "\u00ac" }, { "shy", "\u00ad" },
        { "reg", "\u00ae" }, { "macr", "\u00af" }, { "deg", "\u00b0" }, { "plusmn", "\u00b1" }, { "sup2", "\u00b2" },
        { "sup3", "\u00b3" }, { "acute", "\u00b4" }, { "micro", "\u00b5" }, { "para", "\u00b6" },
        { "middot", "\u00b7" }, { "cedil", "\u00b8" }, { "sup1", "\u00b9" }, { "ordm", "\u00ba" },
        { "raquo", "\u00bb" }, { "frac14", "\u00bc" }, { "frac12", "\u00bd" }, { "frac34", "\u00be" },
        { "iquest", "\u00bf" }, { "Agrave", "\u00c0" }, { "Aacute", "\u00c1" }, { "Acirc", "\u00c2" },
        { "Atilde", "\u00c3" }, { "Auml", "\u00c4" }, { "Aring", "\u00c5" }, { "AElig", "\u00c6" },
        { "Ccedil", "\u00c7" }, { "Egrave", "\u00c8" }, { "Eacute", "\u00c9" }, { "Ecirc", "\u00ca" },
        { "Euml", "\u00cb" }, { "Igrave", "\u00cc" }, { "Iacute", "\u00cd" }, { "Icirc", "\u00ce" },
        { "Iuml", "\u00cf" }, { "ETH", "\u00d0" }, { "Ntilde", "\u00d1" }, { "Ograve", "\u00d2" },
        { "Oacute", "\u00d3" }, { "Ocirc", "\u00d4" }, { "Otilde", "\u00d5" }, { "Ouml", "\u00d6" },
        { "times", "\u00d7" }, { "Oslash", "\u00d8" }, { "Ugrave", "\u00d9" }, { "Uacute", "\u00da" },
        { "Ucirc", "\u00db" }, { "Uuml", "\u00dc" }, { "Yacute", "\u00dd" }, { "THORN", "\u00de" },
        { "szlig", "\u00df" }, { "agrave", "\u00e0" }, { "aacute", "\u00e1" }, { "acirc", "\u00e2" },
        { "atilde", "\u00e3" }, { "auml", "\u00e4" }, { "aring", "\u00e5" }, { "aelig", "\u00e6" },
        { "ccedil", "\u00e7" }, { "egrave", "\u00e8" }, { "eacute", "\u00e9" }, { "ecirc", "\u00ea" },
        { "euml", "\u00eb" }, { "igrave", "\u00ec" }, { "iacute", "\u00ed" }, { "icirc", "\u00ee" },
        { "iuml", "\u00ef" }, { "eth", "\u00f0" }, { "ntilde", "\u00f1" }, { "ograve", "\u00f2" },
        { "oacute", "\u00f3" }, { "ocirc", "\u00f4" }, { "otilde", "\u00f5" }, { "ouml", "\u00f6" },
        { "divide", "\u00f7" }, { "oslash", "\u00f8" }, { "ugrave", "\u00f9" }, { "uacute", "\u00fa" },
        { "ucirc", "\u00fb" }, { "uuml", "\u00fc" }, { "yacute", "\u00fd" }, { "thorn", "\u00fe" },
        { "yuml", "\u00ff" },

        // ----------------------------------------------------------------------
        // Special entities
        // ----------------------------------------------------------------------

        { "OElig", "\u0152" }, { "oelig", "\u0153" }, { "Scaron", "\u0160" }, { "scaron", "\u0161" },
        { "Yuml", "\u0178" }, { "circ", "\u02c6" }, { "tilde", "\u02dc" }, { "ensp", "\u2002" }, { "emsp", "\u2003" },
        { "thinsp", "\u2009" }, { "zwnj", "\u200c" }, { "zwj", "\u200d" }, { "lrm", "\u200e" }, { "rlm", "\u200f" },
        { "ndash", "\u2013" }, { "mdash", "\u2014" }, { "lsquo", "\u2018" }, { "rsquo", "\u2019" },
        { "sbquo", "\u201a" }, { "ldquo", "\u201c" }, { "rdquo", "\u201d" }, { "bdquo", "\u201e" },
        { "dagger", "\u2020" }, { "Dagger", "\u2021" }, { "permil", "\u2030" }, { "lsaquo", "\u2039" },
        { "rsaquo", "\u203a" }, { "euro", "\u20ac" },

        // ----------------------------------------------------------------------
        // Symbol entities
        // ----------------------------------------------------------------------

        { "fnof", "\u0192" }, { "Alpha", "\u0391" }, { "Beta", "\u0392" }, { "Gamma", "\u0393" }, { "Delta", "\u0394" },
        { "Epsilon", "\u0395" }, { "Zeta", "\u0396" }, { "Eta", "\u0397" }, { "Theta", "\u0398" }, { "Iota", "\u0399" },
        { "Kappa", "\u039a" }, { "Lambda", "\u039b" }, { "Mu", "\u039c" }, { "Nu", "\u039d" }, { "Xi", "\u039e" },
        { "Omicron", "\u039f" }, { "Pi", "\u03a0" }, { "Rho", "\u03a1" }, { "Sigma", "\u03a3" }, { "Tau", "\u03a4" },
        { "Upsilon", "\u03a5" }, { "Phi", "\u03a6" }, { "Chi", "\u03a7" }, { "Psi", "\u03a8" }, { "Omega", "\u03a9" },
        { "alpha", "\u03b1" }, { "beta", "\u03b2" }, { "gamma", "\u03b3" }, { "delta", "\u03b4" },
        { "epsilon", "\u03b5" }, { "zeta", "\u03b6" }, { "eta", "\u03b7" }, { "theta", "\u03b8" }, { "iota", "\u03b9" },
        { "kappa", "\u03ba" }, { "lambda", "\u03bb" }, { "mu", "\u03bc" }, { "nu", "\u03bd" }, { "xi", "\u03be" },
        { "omicron", "\u03bf" }, { "pi", "\u03c0" }, { "rho", "\u03c1" }, { "sigmaf", "\u03c2" }, { "sigma", "\u03c3" },
        { "tau", "\u03c4" }, { "upsilon", "\u03c5" }, { "phi", "\u03c6" }, { "chi", "\u03c7" }, { "psi", "\u03c8" },
        { "omega", "\u03c9" }, { "thetasym", "\u03d1" }, { "upsih", "\u03d2" }, { "piv", "\u03d6" },
        { "bull", "\u2022" }, { "hellip", "\u2026" }, { "prime", "\u2032" }, { "Prime", "\u2033" },
        { "oline", "\u203e" }, { "frasl", "\u2044" }, { "weierp", "\u2118" }, { "image", "\u2111" },
        { "real", "\u211c" }, { "trade", "\u2122" }, { "alefsym", "\u2135" }, { "larr", "\u2190" },
        { "uarr", "\u2191" }, { "rarr", "\u2192" }, { "darr", "\u2193" }, { "harr", "\u2194" }, { "crarr", "\u21b5" },
        { "lArr", "\u21d0" }, { "uArr", "\u21d1" }, { "rArr", "\u21d2" }, { "dArr", "\u21d3" }, { "hArr", "\u21d4" },
        { "forall", "\u2200" }, { "part", "\u2202" }, { "exist", "\u2203" }, { "empty", "\u2205" },
        { "nabla", "\u2207" }, { "isin", "\u2208" }, { "notin", "\u2209" }, { "ni", "\u220b" }, { "prod", "\u220f" },
        { "sum", "\u2211" }, { "minus", "\u2212" }, { "lowast", "\u2217" }, { "radic", "\u221a" }, { "prop", "\u221d" },
        { "infin", "\u221e" }, { "ang", "\u2220" }, { "and", "\u2227" }, { "or", "\u2228" }, { "cap", "\u2229" },
        { "cup", "\u222a" }, { "int", "\u222b" }, { "there4", "\u2234" }, { "sim", "\u223c" }, { "cong", "\u2245" },
        { "asymp", "\u2248" }, { "ne", "\u2260" }, { "equiv", "\u2261" }, { "le", "\u2264" }, { "ge", "\u2265" },
        { "sub", "\u2282" }, { "sup", "\u2283" }, { "nsub", "\u2284" }, { "sube", "\u2286" }, { "supe", "\u2287" },
        { "oplus", "\u2295" }, { "otimes", "\u2297" }, { "perp", "\u22a5" }, { "sdot", "\u22c5" },
        { "lceil", "\u2308" }, { "rceil", "\u2309" }, { "lfloor", "\u230a" }, { "rfloor", "\u230b" },
        { "lang", "\u2329" }, { "rang", "\u232a" }, { "loz", "\u25ca" }, { "spades", "\u2660" }, { "clubs", "\u2663" },
        { "hearts", "\u2665" }, { "diams", "\u2666" } } );

}