/**
 * Copyright 2007 Google Inc.
 *
 * 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.
 */
package com.tonicsystems.jarjar.strings;

import javax.annotation.Nonnegative;
import javax.annotation.Nonnull;
import org.objectweb.asm.AnnotationVisitor;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.FieldVisitor;
import org.objectweb.asm.Handle;
import org.objectweb.asm.Label;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;

public abstract class StringReader extends ClassVisitor {

    private int line = -1;
    private String className;

    public StringReader() {
        super(Opcodes.ASM5);
    }

    public abstract void visitString(@Nonnull String className, @Nonnull String value, @Nonnegative int line);

    private void handleObject(Object value) {
        if (value instanceof String)
            visitString(className, (String) value, line);
    }

    @Override
    public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {
        className = name;
        line = -1;
    }

    @Override
    public FieldVisitor visitField(int access, String name, String desc, String signature, Object value) {
        handleObject(value);
        return new FieldVisitor(Opcodes.ASM5) {
            @Override
            public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
                return StringReader.this.visitAnnotation(desc, visible);
            }
        };
    }

    @Override
    public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
        return new AnnotationVisitor(Opcodes.ASM5) {
            @Override
            public void visit(String name, Object value) {
                handleObject(value);
            }

            @Override
            public void visitEnum(String name, String desc, String value) {
                handleObject(value);
            }

            @Override
            public AnnotationVisitor visitAnnotation(String name, String desc) {
                return this;
            }
        };
    }

    @Override
    public MethodVisitor visitMethod(int access, String name, String desc,
            String signature, String[] exceptions) {
        return new MethodVisitor(Opcodes.ASM5) {
            @Override
            public void visitLdcInsn(Object cst) {
                handleObject(cst);
            }

            @Override
            public void visitLineNumber(int line, Label start) {
                StringReader.this.line = line;
            }

            @Override
            public void visitInvokeDynamicInsn(String name, String desc,
                    Handle bsm, Object... bsmArgs) {
                for (Object bsmArg : bsmArgs)
                    handleObject(bsmArg);
            }

            @Override
            public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
                return StringReader.this.visitAnnotation(desc, visible);
            }

            @Override
            public AnnotationVisitor visitParameterAnnotation(int parameter,
                    String desc, boolean visible) {
                return StringReader.this.visitAnnotation(desc, visible);
            }
        };
    }
}