/*
 * Copyright (c) 2007, 2013, 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.classfile;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Path;

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

See JVMS, section 4.2.
 
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.
/**
 * See JVMS, section 4.2.
 *
 *  <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 ClassFile {
    public static ClassFile read(File file)
            throws IOException, ConstantPoolException {
        return read(file.toPath(), new Attribute.Factory());
    }

    public static ClassFile read(Path input)
            throws IOException, ConstantPoolException {
        return read(input, new Attribute.Factory());
    }

    public static ClassFile read(Path input, Attribute.Factory attributeFactory)
            throws IOException, ConstantPoolException {
        try (InputStream in = Files.newInputStream(input)) {
            return new ClassFile(in, attributeFactory);
        }
    }

    public static ClassFile read(File file, Attribute.Factory attributeFactory)
            throws IOException, ConstantPoolException {
        return read(file.toPath(), attributeFactory);
    }

    public static ClassFile read(InputStream in)
            throws IOException, ConstantPoolException {
        return new ClassFile(in, new Attribute.Factory());
    }

    public static ClassFile read(InputStream in, Attribute.Factory attributeFactory)
            throws IOException, ConstantPoolException {
        return new ClassFile(in, attributeFactory);
    }

    ClassFile(InputStream in, Attribute.Factory attributeFactory) throws IOException, ConstantPoolException {
        ClassReader cr = new ClassReader(this, in, attributeFactory);
        magic = cr.readInt();
        minor_version = cr.readUnsignedShort();
        major_version = cr.readUnsignedShort();
        constant_pool = new ConstantPool(cr);
        access_flags = new AccessFlags(cr);
        this_class = cr.readUnsignedShort();
        super_class = cr.readUnsignedShort();

        int interfaces_count = cr.readUnsignedShort();
        interfaces = new int[interfaces_count];
        for (int i = 0; i < interfaces_count; i++)
            interfaces[i] = cr.readUnsignedShort();

        int fields_count = cr.readUnsignedShort();
        fields = new Field[fields_count];
        for (int i = 0; i < fields_count; i++)
            fields[i] = new Field(cr);

        int methods_count = cr.readUnsignedShort();
        methods = new Method[methods_count];
        for (int i = 0; i < methods_count; i++)
            methods[i] = new Method(cr);

        attributes = new Attributes(cr);
    }

    public ClassFile(int magic, int minor_version, int major_version,
            ConstantPool constant_pool, AccessFlags access_flags,
            int this_class, int super_class, int[] interfaces,
            Field[] fields, Method[] methods, Attributes attributes) {
        this.magic = magic;
        this.minor_version = minor_version;
        this.major_version = major_version;
        this.constant_pool = constant_pool;
        this.access_flags = access_flags;
        this.this_class = this_class;
        this.super_class = super_class;
        this.interfaces = interfaces;
        this.fields = fields;
        this.methods = methods;
        this.attributes = attributes;
    }

    public String getName() throws ConstantPoolException {
        return constant_pool.getClassInfo(this_class).getName();
    }

    public String getSuperclassName() throws ConstantPoolException {
        return constant_pool.getClassInfo(super_class).getName();
    }

    public String getInterfaceName(int i) throws ConstantPoolException {
        return constant_pool.getClassInfo(interfaces[i]).getName();
    }

    public Attribute getAttribute(String name) {
        return attributes.get(name);
    }

    public boolean isClass() {
        return !isInterface();
    }

    public boolean isInterface() {
        return access_flags.is(ACC_INTERFACE);
    }

    public int byteLength() {
        return  4 +     // magic
                2 +     // minor
                2 +     // major
                constant_pool.byteLength() +
                2 +     // access flags
                2 +     // this_class
                2 +     // super_class
                byteLength(interfaces) +
                byteLength(fields) +
                byteLength(methods) +
                attributes.byteLength();
    }

    private int byteLength(int[] indices) {
        return 2 + 2 * indices.length;
    }

    private int byteLength(Field[] fields) {
        int length = 2;
        for (Field f: fields)
            length += f.byteLength();
        return length;
    }

    private int byteLength(Method[] methods) {
        int length = 2;
        for (Method m: methods)
            length += m.byteLength();
        return length;
    }

    public final int magic;
    public final int minor_version;
    public final int major_version;
    public final ConstantPool constant_pool;
    public final AccessFlags access_flags;
    public final int this_class;
    public final int super_class;
    public final int[] interfaces;
    public final Field[] fields;
    public final Method[] methods;
    public final Attributes attributes;
}