/*

 * Copyright 2009 Sun Microsystems, Inc.  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.

 *

 * 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package com.sun.classanalyzer;

import com.sun.tools.classfile.*;

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

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

/**

 *

 * @author Mandy Chung

 */

public class ConstantPoolParser {

    private final ClassFileParser cfparser;

    private final StringValueVisitor visitor;

    private final ConstantPool cpool;

    ConstantPoolParser(ClassFileParser parser) {

        this.cfparser = parser;

        this.cpool = cfparser.classfile.constant_pool;

        this.visitor = new StringValueVisitor();

    }

    public String stringValue(CPInfo cpInfo) {

        return visitor.visit(cpInfo);

    }

    public String stringValue(int constant_pool_index) {

        try {

            return stringValue(cpool.get(constant_pool_index));

        } catch (ConstantPool.InvalidIndex e) {

            throw new RuntimeException(e);

        }

    }

    public void parseDependency() {

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

            public Integer visitClass(CONSTANT_Class_info info, Void p) {

                try {

                    String classname = cfparser.checkClassName(info.getName());

                    if (classname.isEmpty()) {

                        return 1;

                    }

                    Klass from = cfparser.this_klass;

                    Klass to = Klass.getKlass(classname);

                    ResolutionInfo resInfo = ResolutionInfo.resolvedConstantPool(from, to, info.name_index);

                    from.addDep(to, resInfo);

                    to.addReferrer(from, resInfo);

                } catch (ConstantPoolException ex) {

                    throw new RuntimeException(ex);

                }

                return 1;

            }

            public Integer visitDouble(CONSTANT_Double_info info, Void p) {

                // skip

                return 2;

            }

            public Integer visitFieldref(CONSTANT_Fieldref_info info, Void p) {

                // skip

                return 1;

            }

            public Integer visitFloat(CONSTANT_Float_info info, Void p) {

                // skip

                return 1;

            }

            public Integer visitInteger(CONSTANT_Integer_info info, Void p) {

                // skip

                return 1;

            }

            public Integer visitInterfaceMethodref(CONSTANT_InterfaceMethodref_info info, Void p) {

                // skip

                return 1;

            }

            public Integer visitLong(CONSTANT_Long_info info, Void p) {

                // skip

                return 2;

            }

            public Integer visitNameAndType(CONSTANT_NameAndType_info info, Void p) {

                // skip

                return 1;

            }

            public Integer visitMethodref(CONSTANT_Methodref_info info, Void p) {

                // skip

                return 1;

            }

            public Integer visitString(CONSTANT_String_info info, Void p) {

                // skip

                return 1;

            }

            public Integer visitUtf8(CONSTANT_Utf8_info info, Void p) {

                // skip

                return 1;

            }

        };

        int cpx = 1;

        while (cpx < cpool.size()) {

            try {

                CPInfo cpInfo = cpool.get(cpx);

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

            } catch (ConstantPool.InvalidIndex ex) {

                throw new RuntimeException(ex);

            }

        }

    }

    int getTag(int index) {

        try {

            return cpool.get(index).getTag();

        } catch (ConstantPoolException ex) {

            throw new RuntimeException(ex);

        }

    }

    String getDescriptor(int index) {

        CPInfo cpInfo;

        try {

            cpInfo = cpool.get(index);

        } catch (ConstantPoolException ex) {

            throw new RuntimeException(ex);

        }

        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 {

                    return ref.getNameAndTypeInfo().getType();

                } catch (ConstantPoolException ex) {

                }

        }

        return stringValue(cpInfo);

    }

    String getMethodName(int index) {

        try {

            CPInfo cpInfo = cpool.get(index);

            if (cpInfo.getTag() == CONSTANT_Methodref ||

                    cpInfo.getTag() == CONSTANT_InterfaceMethodref) {

                // simplify references within this class

                CPRefInfo ref = (CPRefInfo) cpInfo;

                String classname;

                if (ref.class_index == cfparser.classfile.this_class) {

                    classname = cfparser.this_klass.getClassName();

                } else {

                    classname = cfparser.checkClassName(ref.getClassName()).replace('/', '.');

                }

                String methodname = ref.getNameAndTypeInfo().getName();

                return classname + "." + methodname;

            } else {

                return null;

            }

        } catch (InvalidIndex ex) {

            throw new RuntimeException(ex);

        } catch (ConstantPoolException ex) {

            throw new RuntimeException(ex);

        }

    }

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

        public StringValueVisitor() {

        }

        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) {

                throw new RuntimeException(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 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) {

                throw new RuntimeException(e);

            }

        }

        String getType(CONSTANT_NameAndType_info info) {

            try {

                return info.getType();

            } catch (ConstantPoolException e) {

                throw new RuntimeException(e);

            }

        }

        public String visitMethodref(CONSTANT_Methodref_info info, Void p) {

            return visitRef(info, p);

        }

        public String visitString(CONSTANT_String_info info, Void p) {

            try {

                int string_index = info.string_index;

                return cpool.getUTF8Info(string_index).accept(this, p);

            } catch (ConstantPoolException e) {

                throw new RuntimeException(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 '\"':

                        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 = info.getNameAndTypeInfo().accept(this, p);

            } catch (ConstantPoolException e) {

                nat = e.getMessage();

            }

            return cn + "." + nat;

        }

        String getCheckedClassName(CPRefInfo info) {

            try {

                return checkName(info.getClassName());

            } catch (ConstantPoolException e) {

                throw new RuntimeException(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 "\"" + name + "\"";

            }

            cc = cp;

        }

        return name;

    }

    String tagName(int index) {

        try {

            int tag = cpool.get(index).getTag();

            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_Methodref:

                    return "Method";

                case CONSTANT_InterfaceMethodref:

                    return "InterfaceMethod";

                case CONSTANT_NameAndType:

                    return "NameAndType";

                default:

                    return "(unknown tag)";

            }

        } catch (InvalidIndex e) {

            throw new RuntimeException(e);

        }

    }

}