/*

 * Copyright (c) 2008, 2015, 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 sun.invoke.util;

import java.lang.invoke.MethodType;

import java.util.ArrayList;

import java.util.List;

/**

 * Utility routines for dealing with bytecode-level signatures.

 * @author jrose

 */

public class BytecodeDescriptor {

    private BytecodeDescriptor() { }  // cannot instantiate

    /**

     * @param loader the class loader in which to look up the types (null means

     *               bootstrap class loader)

     */

    public static List<Class<?>> parseMethod(String bytecodeSignature, ClassLoader loader) {

        return parseMethod(bytecodeSignature, 0, bytecodeSignature.length(), loader);

    }

    /**

     * @param loader the class loader in which to look up the types (null means

     *               bootstrap class loader)

     */

    static List<Class<?>> parseMethod(String bytecodeSignature,

            int start, int end, ClassLoader loader) {

        String str = bytecodeSignature;

        int[] i = {start};

        ArrayList<Class<?>> ptypes = new ArrayList<Class<?>>();

        if (i[0] < end && str.charAt(i[0]) == '(') {

            ++i[0];  // skip '('

            while (i[0] < end && str.charAt(i[0]) != ')') {

                Class<?> pt = parseSig(str, i, end, loader);

                if (pt == null || pt == void.class)

                    parseError(str, "bad argument type");

                ptypes.add(pt);

            }

            ++i[0];  // skip ')'

        } else {

            parseError(str, "not a method type");

        }

        Class<?> rtype = parseSig(str, i, end, loader);

        if (rtype == null || i[0] != end)

            parseError(str, "bad return type");

        ptypes.add(rtype);

        return ptypes;

    }

    private static void parseError(String str, String msg) {

        throw new IllegalArgumentException("bad signature: "+str+": "+msg);

    }

    /**

     * @param loader the class loader in which to look up the types (null means

     *               bootstrap class loader)

     */

    private static Class<?> parseSig(String str, int[] i, int end, ClassLoader loader) {

        if (i[0] == end)  return null;

        char c = str.charAt(i[0]++);

        if (c == 'L') {

            int begc = i[0], endc = str.indexOf(';', begc);

            if (endc < 0)  return null;

            i[0] = endc+1;

            String name = str.substring(begc, endc).replace('/', '.');

            try {

                return (loader == null)

                    ? Class.forName(name, false, null)

                    : loader.loadClass(name);

            } catch (ClassNotFoundException ex) {

                throw new TypeNotPresentException(name, ex);

            }

        } else if (c == '[') {

            Class<?> t = parseSig(str, i, end, loader);

            if (t != null)

                t = java.lang.reflect.Array.newInstance(t, 0).getClass();

            return t;

        } else {

            return Wrapper.forBasicType(c).primitiveType();

        }

    }

    public static String unparse(Class<?> type) {

        if (type == Object.class) {

            return "Ljava/lang/Object;";

        } else if (type == int.class) {

            return "I";

        }

        StringBuilder sb = new StringBuilder();

        unparseSig(type, sb);

        return sb.toString();

    }

    public static String unparse(MethodType type) {

        return unparseMethod(type.returnType(), type.parameterArray());

    }

    public static String unparse(Object type) {

        if (type instanceof Class<?>)

            return unparse((Class<?>) type);

        if (type instanceof MethodType)

            return unparse((MethodType) type);

        return (String) type;

    }

    public static String unparseMethod(Class<?> rtype, List<Class<?>> ptypes) {

        StringBuilder sb = new StringBuilder();

        sb.append('(');

        for (Class<?> pt : ptypes)

            unparseSig(pt, sb);

        sb.append(')');

        unparseSig(rtype, sb);

        return sb.toString();

    }

    public static String unparseMethod(Class<?> rtype, Class<?>[] ptypes) {

        StringBuilder sb = new StringBuilder();

        sb.append('(');

        for (Class<?> pt : ptypes)

            unparseSig(pt, sb);

        sb.append(')');

        unparseSig(rtype, sb);

        return sb.toString();

    }

    private static void unparseSig(Class<?> t, StringBuilder sb) {

        char c = Wrapper.forBasicType(t).basicTypeChar();

        if (c != 'L') {

            sb.append(c);

        } else if (t == Object.class) {

            sb.append("Ljava/lang/Object;");

        } else {

            boolean lsemi = (!t.isArray());

            if (lsemi)  sb.append('L');

            sb.append(t.getName().replace('.', '/'));

            if (lsemi)  sb.append(';');

        }

    }

}