/*

 * 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 jdk.internal.module;

import java.lang.module.ModuleDescriptor;

import java.lang.module.ModuleDescriptor.Requires;

import java.lang.module.ModuleDescriptor.Exports;

import java.lang.module.ModuleDescriptor.Provides;

import java.lang.module.ModuleDescriptor.Version;

import java.util.Collections;

import java.util.HashMap;

import java.util.HashSet;

import java.util.Map;

import java.util.Set;

import jdk.internal.org.objectweb.asm.Attribute;

import jdk.internal.org.objectweb.asm.ByteVector;

import jdk.internal.org.objectweb.asm.ClassReader;

import jdk.internal.org.objectweb.asm.ClassWriter;

import jdk.internal.org.objectweb.asm.Label;

import static jdk.internal.module.ClassFileConstants.*;

/**

 * Provides ASM implementations of {@code Attribute} to read and write the

 * class file attributes in a module-info class file.

 */

    private ClassFileAttributes() { }

    /**

     * Module_attribute {

     *   // See lang-vm.html for details.

     * }

     */

        private ModuleDescriptor descriptor;

            super(MODULE);

            this.descriptor = descriptor;

        }

            super(MODULE);

        }

        @Override

        protected Attribute read(ClassReader cr,

                                 int off,

                                 int len,

                                 char[] buf,

                                 int codeOff,

                                 Label[] labels)

        {

            ModuleAttribute attr = new ModuleAttribute();

            // requires_count and requires[requires_count]

            int requires_count = cr.readUnsignedShort(off);

            off += 2;

            for (int i=0; i<requires_count; i++) {

                int flags = cr.readUnsignedShort(off + 2);

                if (flags == 0) {

                    mods = Collections.emptySet();

                } else {

                    mods = new HashSet<>();

                    if ((flags & ACC_SYNTHETIC) != 0)

                    if ((flags & ACC_MANDATED) != 0)

                }

                builder.requires(mods, dn);

                off += 4;

            }

            // exports_count and exports[exports_count]

            int exports_count = cr.readUnsignedShort(off);

            off += 2;

            if (exports_count > 0) {

                for (int i=0; i<exports_count; i++) {

                    String pkg = cr.readUTF8(off, buf).replace('/', '.');

                    if (exports_to_count > 0) {

                        Set<String> targets = new HashSet<>();

                        for (int j=0; j<exports_to_count; j++) {

                            off += 2;

                            targets.add(t);

                        }

                    } else {

                    }

                }

            }

            // uses_count and uses_index[uses_count]

            int uses_count = cr.readUnsignedShort(off);

            off += 2;

            if (uses_count > 0) {

                for (int i=0; i<uses_count; i++) {

                    String sn = cr.readClass(off, buf).replace('/', '.');

                    builder.uses(sn);

                    off += 2;

                }

            }

            // provides_count and provides[provides_count]

            int provides_count = cr.readUnsignedShort(off);

            off += 2;

            if (provides_count > 0) {

                for (int i=0; i<provides_count; i++) {

                }

            }

            attr.descriptor = builder.build();

            return attr;

        }

        @Override

        protected ByteVector write(ClassWriter cw,

                                   byte[] code,

                                   int len,

                                   int maxStack,

                                   int maxLocals)

        {

            assert descriptor != null;

            ByteVector attr = new ByteVector();

            // requires_count

            attr.putShort(descriptor.requires().size());

            // requires[requires_count]

            for (Requires md : descriptor.requires()) {

                String dn = md.name();

                int flags = 0;

                    flags |= ACC_SYNTHETIC;

                    flags |= ACC_MANDATED;

                attr.putShort(index);

                attr.putShort(flags);

            }

            // exports_count and exports[exports_count];

                }

            }

            // uses_count and uses_index[uses_count]

            if (descriptor.uses().isEmpty()) {

                attr.putShort(0);

            } else {

                attr.putShort(descriptor.uses().size());

                for (String s : descriptor.uses()) {

                    String service = s.replace('.', '/');

                    int index = cw.newClass(service);

                    attr.putShort(index);

                }

            }

            // provides_count and provides[provides_count]

            if (descriptor.provides().isEmpty()) {

                attr.putShort(0);

            } else {

                    String service = p.service().replace('.', '/');

                    for (String provider : p.providers()) {

                        attr.putShort(cw.newClass(provider.replace('.', '/')));

                    }

                }

            }

            return attr;

        }

    }

    /**

     *

     * <pre> {@code

     *

     *   // index to CONSTANT_utf8_info structure in constant pool representing

     *   u2 attribute_name_index;

     *   u4 attribute_length;

     *

     *   // the number of entries in the packages table

     *   u2 packages_count;

     *   { // index to CONSTANT_CONSTANT_utf8_info structure with the package name

     *     u2 package_index

     *   } packages[package_count];

     *

     * }</pre>

     */

        private final Set<String> packages;

            this.packages = packages;

        }

            this(null);

        }

        @Override

        protected Attribute read(ClassReader cr,

                                 int off,

                                 int len,

                                 char[] buf,

                                 int codeOff,

                                 Label[] labels)

        {

            // package count

            int package_count = cr.readUnsignedShort(off);

            off += 2;

            // packages

            Set<String> packages = new HashSet<>();

            for (int i=0; i<package_count; i++) {

                String pkg = cr.readUTF8(off, buf).replace('/', '.');

                packages.add(pkg);

                off += 2;

            }

        }

        @Override

        protected ByteVector write(ClassWriter cw,

                                   byte[] code,

                                   int len,

                                   int maxStack,

                                   int maxLocals)

        {

            assert packages != null;

            ByteVector attr = new ByteVector();

            // package_count

            attr.putShort(packages.size());

            // packages

            packages.stream()

                .map(p -> p.replace('.', '/'))

                .forEach(p -> attr.putShort(cw.newUTF8(p)));

            return attr;

        }

    }

    /**

     *

     * <pre> {@code

     *

     *   // index to CONSTANT_utf8_info structure in constant pool representing

     *   u2 attribute_name_index;

     *   u4 attribute_length;

     *

     *   // index to CONSTANT_CONSTANT_utf8_info structure with the version

     *   u2 version_index;

     * }

     *

     * } </pre>

     */

        private final Version version;

            this.version = version;

        }

            this(null);

        }

        @Override

        protected Attribute read(ClassReader cr,

                                 int off,

                                 int len,

                                 char[] buf,

                                 int codeOff,

                                 Label[] labels)

        {

            String value = cr.readUTF8(off, buf);

        }

        @Override

        protected ByteVector write(ClassWriter cw,

                                   byte[] code,

                                   int len,

                                   int maxStack,

                                   int maxLocals)

        {

            ByteVector attr = new ByteVector();

            int index = cw.newUTF8(version.toString());

            attr.putShort(index);

            return attr;

        }

    }

    /**

     *

     * <pre> {@code

     *

     * MainClass_attribute {

     *   // index to CONSTANT_utf8_info structure in constant pool representing

     *   u2 attribute_name_index;

     *   u4 attribute_length;

     *

     *   // index to CONSTANT_Class_info structure with the main class name

     *   u2 main_class_index;

     * }

     *

     * } </pre>

     */

        private final String mainClass;