/*

 * Copyright (c) 2002, 2012, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package com.sun.tools.javah;

import javax.lang.model.element.ExecutableElement;

import javax.lang.model.element.TypeElement;

import javax.lang.model.element.VariableElement;

import javax.lang.model.util.Elements;

import javax.lang.model.util.Types;

/**

 * A utility for mangling java identifiers into C names.  Should make

 * this more fine grained and distribute the functionality to the

 * generators.

 *

 * <p><b>This is NOT part of any supported API.

 * If you write code that depends on this, you do so at your own

 * risk.  This code and its internal interfaces are subject to change

 * or deletion without notice.</b></p>

 *

 * @author  Sucheta Dambalkar(Revised)

 */

public class Mangle {

    public static class Type {

        public static final int CLASS            = 1;

        public static final int FIELDSTUB        = 2;

        public static final int FIELD            = 3;

        public static final int JNI              = 4;

        public static final int SIGNATURE        = 5;

        public static final int METHOD_JDK_1     = 6;

        public static final int METHOD_JNI_SHORT = 7;

        public static final int METHOD_JNI_LONG  = 8;

    }

    private Elements elems;

    private Types types;

    Mangle(Elements elems, Types types) {

        this.elems = elems;

        this.types = types;

    }

    public final String mangle(CharSequence name, int mtype) {

        StringBuilder result = new StringBuilder(100);

        int length = name.length();

        for (int i = 0; i < length; i++) {

            char ch = name.charAt(i);

            if (isalnum(ch)) {

                result.append(ch);

            } else if ((ch == '.') &&

                       mtype == Mangle.Type.CLASS) {

                result.append('_');

            } else if (( ch == '$') &&

                       mtype == Mangle.Type.CLASS) {

                result.append('_');

                result.append('_');

            } else if (ch == '_' && mtype == Mangle.Type.FIELDSTUB) {

                result.append('_');

            } else if (ch == '_' && mtype == Mangle.Type.CLASS) {

                result.append('_');

            } else if (mtype == Mangle.Type.JNI) {

                String esc = null;

                if (ch == '_')

                    esc = "_1";

                else if (ch == '.')

                    esc = "_";

                else if (ch == ';')

                    esc = "_2";

                else if (ch == '[')

                    esc = "_3";

                if (esc != null) {

                    result.append(esc);

                } else {

                    result.append(mangleChar(ch));

                }

            } else if (mtype == Mangle.Type.SIGNATURE) {

                if (isprint(ch)) {

                    result.append(ch);

                } else {

                    result.append(mangleChar(ch));

                }

            } else {

                result.append(mangleChar(ch));

            }

        }

        return result.toString();

    }

    public String mangleMethod(ExecutableElement method, TypeElement clazz,

                                      int mtype) throws TypeSignature.SignatureException {

        StringBuilder result = new StringBuilder(100);

        result.append("Java_");

        if (mtype == Mangle.Type.METHOD_JDK_1) {

            result.append(mangle(clazz.getQualifiedName(), Mangle.Type.CLASS));

            result.append('_');

            result.append(mangle(method.getSimpleName(),

                                 Mangle.Type.FIELD));

            result.append("_stub");

            return result.toString();

        }

        /* JNI */

        result.append(mangle(getInnerQualifiedName(clazz), Mangle.Type.JNI));

        result.append('_');

        result.append(mangle(method.getSimpleName(),

                             Mangle.Type.JNI));

        if (mtype == Mangle.Type.METHOD_JNI_LONG) {

            result.append("__");

            String typesig = signature(method);

            TypeSignature newTypeSig = new TypeSignature(elems);

            String sig = newTypeSig.getTypeSignature(typesig,  method.getReturnType());

            sig = sig.substring(1);

            sig = sig.substring(0, sig.lastIndexOf(')'));

            sig = sig.replace('/', '.');

            result.append(mangle(sig, Mangle.Type.JNI));

        }

        return result.toString();

    }

    //where

        private String getInnerQualifiedName(TypeElement clazz) {

            return elems.getBinaryName(clazz).toString();

        }

    public final String mangleChar(char ch) {

        String s = Integer.toHexString(ch);

        int nzeros = 5 - s.length();

        char[] result = new char[6];

        result[0] = '_';

        for (int i = 1; i <= nzeros; i++)

            result[i] = '0';

        for (int i = nzeros+1, j = 0; i < 6; i++, j++)

            result[i] = s.charAt(j);

        return new String(result);

    }

    // Warning: duplicated in Gen

    private String signature(ExecutableElement e) {

        StringBuilder sb = new StringBuilder();

        String sep = "(";

        for (VariableElement p: e.getParameters()) {

            sb.append(sep);

            sb.append(types.erasure(p.asType()).toString());

            sep = ",";

        }

        sb.append(")");

        return sb.toString();

    }

    /* Warning: Intentional ASCII operation. */

    private static boolean isalnum(char ch) {

        return ch <= 0x7f && /* quick test */

            ((ch >= 'A' && ch <= 'Z') ||

             (ch >= 'a' && ch <= 'z') ||

             (ch >= '0' && ch <= '9'));

    }

    /* Warning: Intentional ASCII operation. */

    private static boolean isprint(char ch) {

        return ch >= 32 && ch <= 126;

    }

}