/*

 * 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.

 *

 *  <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;

}