/*

 * Copyright (c) 2007, 2016, 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.javap;

import com.sun.tools.classfile.ClassFile;

import com.sun.tools.classfile.ConstantPool;

import com.sun.tools.classfile.ConstantPoolException;

import static com.sun.tools.classfile.ConstantPool.*;

/*

 *  Write a constant pool entry.

 *

 *  <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>

 */

public class ConstantWriter extends BasicWriter {

    public static ConstantWriter instance(Context context) {

        ConstantWriter instance = context.get(ConstantWriter.class);

        if (instance == null)

            instance = new ConstantWriter(context);

        return instance;

    }

    protected ConstantWriter(Context context) {

        super(context);

        context.put(ConstantWriter.class, this);

        classWriter = ClassWriter.instance(context);

        options = Options.instance(context);

    }

    protected void writeConstantPool() {

        ConstantPool constant_pool = classWriter.getClassFile().constant_pool;

        writeConstantPool(constant_pool);

    }

    protected void writeConstantPool(ConstantPool constant_pool) {

        ConstantPool.Visitor<Integer, Void> v = new ConstantPool.Visitor<Integer,Void>() {

            public Integer visitClass(CONSTANT_Class_info info, Void p) {

                print("#" + info.name_index);

                tab();

                println("// " + stringValue(info));

                return 1;

            }

            public Integer visitDouble(CONSTANT_Double_info info, Void p) {

                println(stringValue(info));

                return 2;

            }

            public Integer visitFieldref(CONSTANT_Fieldref_info info, Void p) {

                print("#" + info.class_index + ".#" + info.name_and_type_index);

                tab();

                println("// " + stringValue(info));

                return 1;

            }

            public Integer visitFloat(CONSTANT_Float_info info, Void p) {

                println(stringValue(info));

                return 1;

            }

            public Integer visitInteger(CONSTANT_Integer_info info, Void p) {

                println(stringValue(info));

                return 1;

            }

            public Integer visitInterfaceMethodref(CONSTANT_InterfaceMethodref_info info, Void p) {

                print("#" + info.class_index + ".#" + info.name_and_type_index);

                tab();

                println("// " + stringValue(info));

                return 1;

            }

            public Integer visitInvokeDynamic(CONSTANT_InvokeDynamic_info info, Void p) {

                print("#" + info.bootstrap_method_attr_index + ":#" + info.name_and_type_index);

                tab();

                println("// " + stringValue(info));

                return 1;

            }

            public Integer visitLong(CONSTANT_Long_info info, Void p) {

                println(stringValue(info));

                return 2;

            }

            public Integer visitNameAndType(CONSTANT_NameAndType_info info, Void p) {

                print("#" + info.name_index + ":#" + info.type_index);

                tab();

                println("// " + stringValue(info));

                return 1;

            }

            public Integer visitMethodref(CONSTANT_Methodref_info info, Void p) {

                print("#" + info.class_index + ".#" + info.name_and_type_index);

                tab();

                println("// " + stringValue(info));

                return 1;

            }

            public Integer visitMethodHandle(CONSTANT_MethodHandle_info info, Void p) {

                print(info.reference_kind.tag + ":#" + info.reference_index);

                tab();

                println("// " + stringValue(info));

                return 1;

            }

            public Integer visitMethodType(CONSTANT_MethodType_info info, Void p) {

                print("#" + info.descriptor_index);

                tab();

                println("//  " + stringValue(info));

                return 1;

            }

            public Integer visitString(CONSTANT_String_info info, Void p) {

                print("#" + info.string_index);

                tab();

                println("// " + stringValue(info));

                return 1;

            }

            public Integer visitUtf8(CONSTANT_Utf8_info info, Void p) {

                println(stringValue(info));

                return 1;

            }

        };

        println("Constant pool:");

        indent(+1);

        int width = String.valueOf(constant_pool.size()).length() + 1;

        int cpx = 1;

        while (cpx < constant_pool.size()) {

            print(String.format("%" + width + "s", ("#" + cpx)));

            try {

                CPInfo cpInfo = constant_pool.get(cpx);

                print(String.format(" = %-18s ", cpTagName(cpInfo)));

                cpx += cpInfo.accept(v, null);

            } catch (ConstantPool.InvalidIndex ex) {

                // should not happen

            }

        }

        indent(-1);

    }

    protected void write(int cpx) {

        ClassFile classFile = classWriter.getClassFile();

        if (cpx == 0) {

            print("#0");

            return;

        }

        CPInfo cpInfo;

        try {

            cpInfo = classFile.constant_pool.get(cpx);

        } catch (ConstantPoolException e) {

            print("#" + cpx);

            return;

        }

        int tag = cpInfo.getTag();

        switch (tag) {

            case CONSTANT_Methodref:

            case CONSTANT_InterfaceMethodref:

            case CONSTANT_Fieldref:

                // simplify references within this class

                CPRefInfo ref = (CPRefInfo) cpInfo;

                try {

                    if (ref.class_index == classFile.this_class)

                         cpInfo = classFile.constant_pool.get(ref.name_and_type_index);

                } catch (ConstantPool.InvalidIndex e) {

                    // ignore, for now

                }

        }

        print(tagName(tag) + " " + stringValue(cpInfo));

    }

    String cpTagName(CPInfo cpInfo) {

        String n = cpInfo.getClass().getSimpleName();

        return n.replace("CONSTANT_", "").replace("_info", "");

    }

    String tagName(int tag) {

        switch (tag) {

            case CONSTANT_Utf8:

                return "Utf8";

            case CONSTANT_Integer:

                return "int";

            case CONSTANT_Float:

                return "float";

            case CONSTANT_Long:

                return "long";

            case CONSTANT_Double:

                return "double";

            case CONSTANT_Class:

                return "class";

            case CONSTANT_String:

                return "String";

            case CONSTANT_Fieldref:

                return "Field";

            case CONSTANT_MethodHandle:

                return "MethodHandle";

            case CONSTANT_MethodType:

                return "MethodType";

            case CONSTANT_Methodref:

                return "Method";

            case CONSTANT_InterfaceMethodref:

                return "InterfaceMethod";

            case CONSTANT_InvokeDynamic:

                return "InvokeDynamic";

            case CONSTANT_NameAndType:

                return "NameAndType";

            default:

                return "(unknown tag " + tag + ")";

        }

    }

    String stringValue(int constant_pool_index) {

        ClassFile classFile = classWriter.getClassFile();

        try {

            return stringValue(classFile.constant_pool.get(constant_pool_index));

        } catch (ConstantPool.InvalidIndex e) {

            return report(e);

        }

    }

    String stringValue(CPInfo cpInfo) {

        return stringValueVisitor.visit(cpInfo);

    }

    StringValueVisitor stringValueVisitor = new StringValueVisitor();

    private class StringValueVisitor implements ConstantPool.Visitor<String, Void> {

        public String visit(CPInfo info) {

            return info.accept(this, null);

        }

        public String visitClass(CONSTANT_Class_info info, Void p) {

            return getCheckedName(info);

        }

        String getCheckedName(CONSTANT_Class_info info) {

            try {

                return checkName(info.getName());

            } catch (ConstantPoolException e) {

                return report(e);

            }

        }

        public String visitDouble(CONSTANT_Double_info info, Void p) {

            return info.value + "d";

        }

        public String visitFieldref(CONSTANT_Fieldref_info info, Void p) {

            return visitRef(info, p);

        }

        public String visitFloat(CONSTANT_Float_info info, Void p) {

            return info.value + "f";

        }

        public String visitInteger(CONSTANT_Integer_info info, Void p) {

            return String.valueOf(info.value);

        }

        public String visitInterfaceMethodref(CONSTANT_InterfaceMethodref_info info, Void p) {

            return visitRef(info, p);

        }

        public String visitInvokeDynamic(CONSTANT_InvokeDynamic_info info, Void p) {

            try {

                String callee = stringValue(info.getNameAndTypeInfo());

                return "#" + info.bootstrap_method_attr_index + ":" + callee;

            } catch (ConstantPoolException e) {

                return report(e);

            }

        }

        public String visitLong(CONSTANT_Long_info info, Void p) {

            return info.value + "l";

        }

        public String visitNameAndType(CONSTANT_NameAndType_info info, Void p) {

            return getCheckedName(info) + ":" + getType(info);

        }

        String getCheckedName(CONSTANT_NameAndType_info info) {

            try {

                return checkName(info.getName());

            } catch (ConstantPoolException e) {

                return report(e);

            }

        }

        String getType(CONSTANT_NameAndType_info info) {

            try {

                return info.getType();

            } catch (ConstantPoolException e) {

                return report(e);

            }

        }

        public String visitMethodHandle(CONSTANT_MethodHandle_info info, Void p) {

            try {

                return info.reference_kind + " " + stringValue(info.getCPRefInfo());

            } catch (ConstantPoolException e) {

                return report(e);

            }

        }

        public String visitMethodType(CONSTANT_MethodType_info info, Void p) {

            try {

                return info.getType();

            } catch (ConstantPoolException e) {

                return report(e);

            }

        }

        public String visitMethodref(CONSTANT_Methodref_info info, Void p) {

            return visitRef(info, p);

        }

        public String visitString(CONSTANT_String_info info, Void p) {

            try {

                ClassFile classFile = classWriter.getClassFile();

                int string_index = info.string_index;

                return stringValue(classFile.constant_pool.getUTF8Info(string_index));

            } catch (ConstantPoolException e) {

                return report(e);

            }

        }

        public String visitUtf8(CONSTANT_Utf8_info info, Void p) {

            String s = info.value;

            StringBuilder sb = new StringBuilder();

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

                char c = s.charAt(i);

                switch (c) {

                    case '\t':

                        sb.append('\\').append('t');

                        break;

                    case '\n':

                        sb.append('\\').append('n');

                        break;

                    case '\r':

                        sb.append('\\').append('r');

                        break;

                    case '\b':

                        sb.append('\\').append('b');

                        break;

                    case '\f':

                        sb.append('\\').append('f');

                        break;

                    case '\"':

                        sb.append('\\').append('\"');

                        break;

                    case '\'':

                        sb.append('\\').append('\'');

                        break;

                    case '\\':

                        sb.append('\\').append('\\');

                        break;

                    default:

                        sb.append(c);

                }

            }

            return sb.toString();

        }

        String visitRef(CPRefInfo info, Void p) {

            String cn = getCheckedClassName(info);

            String nat;

            try {

                nat = stringValue(info.getNameAndTypeInfo());

            } catch (ConstantPoolException e) {

                nat = report(e);

            }

            return cn + "." + nat;

        }

        String getCheckedClassName(CPRefInfo info) {

            try {

                return checkName(info.getClassName());

            } catch (ConstantPoolException e) {

                return report(e);

            }

        }

    }

    /* If name is a valid binary name, return it; otherwise quote it. */

    private static String checkName(String name) {

        if (name == null)

            return "null";

        int len = name.length();

        if (len == 0)

            return "\"\"";

        int cc = '/';

        int cp;

        for (int k = 0; k < len; k += Character.charCount(cp)) {

            cp = name.codePointAt(k);

            if ((cc == '/' && !Character.isJavaIdentifierStart(cp))

                    || (cp != '/' && !Character.isJavaIdentifierPart(cp))) {

                return "\"" + addEscapes(name) + "\"";

            }

            cc = cp;

        }

        return name;

    }

    /* If name requires escapes, put them in, so it can be a string body. */

    private static String addEscapes(String name) {

        String esc = "\\\"\n\t";

        String rep = "\\\"nt";

        StringBuilder buf = null;

        int nextk = 0;

        int len = name.length();

        for (int k = 0; k < len; k++) {

            char cp = name.charAt(k);

            int n = esc.indexOf(cp);

            if (n >= 0) {

                if (buf == null)

                    buf = new StringBuilder(len * 2);

                if (nextk < k)

                    buf.append(name, nextk, k);

                buf.append('\\');

                buf.append(rep.charAt(n));

                nextk = k+1;

            }

        }

        if (buf == null)

            return name;

        if (nextk < len)

            buf.append(name, nextk, len);

        return buf.toString();

    }

    private ClassWriter classWriter;

    private Options options;

}