/*

 * Copyright (c) 2015, 2017, 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 jdk.internal.module;

import java.lang.module.ModuleDescriptor;

import java.lang.module.ModuleDescriptor.Exports;

import java.lang.module.ModuleDescriptor.Opens;

import java.lang.module.ModuleDescriptor.Provides;

import java.lang.module.ModuleDescriptor.Requires;

import java.lang.module.ModuleDescriptor.Version;

import java.util.Collections;

import java.util.List;

import java.util.Set;

import jdk.internal.misc.JavaLangModuleAccess;

import jdk.internal.misc.SharedSecrets;

/**

 * This builder is optimized for reconstituting the {@code ModuleDescriptor}s

 * for system modules.  The validation should be done at jlink time.

 *

 * 1. skip name validation

 * 2. ignores dependency hashes.

 * 3. ModuleDescriptor skips the defensive copy and directly uses the

 *    sets/maps created in this Builder.

 *

 * SystemModules should contain modules for the boot layer.

 */

final class Builder {

    private static final JavaLangModuleAccess JLMA =

        SharedSecrets.getJavaLangModuleAccess();

    // Static cache of the most recently seen Version to cheaply deduplicate

    // most Version objects.  JDK modules have the same version.

    static Version cachedVersion;

    /**

     * Returns a {@link Requires} for a dependence on a module with the given

     * (and possibly empty) set of modifiers, and optionally the version

     * recorded at compile time.

     */

    public static Requires newRequires(Set<Requires.Modifier> mods,

                                       String mn,

                                       String compiledVersion)

    {

        Version version = null;

        if (compiledVersion != null) {

            // use the cached version if the same version string

            Version ver = cachedVersion;

            if (ver != null && compiledVersion.equals(ver.toString())) {

                version = ver;

            } else {

                version = Version.parse(compiledVersion);

            }

        }

        return JLMA.newRequires(mods, mn, version);

    }

    /**

     * Returns a {@link Requires} for a dependence on a module with the given

     * (and possibly empty) set of modifiers, and optionally the version

     * recorded at compile time.

     */

    public static Requires newRequires(Set<Requires.Modifier> mods,

                                       String mn)

    {

        return newRequires(mods, mn, null);

    }

    /**

     * Returns a {@link Exports} for a qualified export, with

     * the given (and possibly empty) set of modifiers,

     * to a set of target modules.

     */

    public static Exports newExports(Set<Exports.Modifier> ms,

                                     String pn,

                                     Set<String> targets) {

        return JLMA.newExports(ms, pn, targets);

    }

    /**

     * Returns an {@link Opens} for an unqualified open with a given set of

     * modifiers.

     */

    public static Opens newOpens(Set<Opens.Modifier> ms, String pn) {

        return JLMA.newOpens(ms, pn);

    }

    /**

     * Returns an {@link Opens} for a qualified opens, with

     * the given (and possibly empty) set of modifiers,

     * to a set of target modules.

     */

    public static Opens newOpens(Set<Opens.Modifier> ms,

                                 String pn,

                                 Set<String> targets) {

        return JLMA.newOpens(ms, pn, targets);

    }

    /**

     * Returns a {@link Exports} for an unqualified export with a given set

     * of modifiers.

     */

    public static Exports newExports(Set<Exports.Modifier> ms, String pn) {

        return JLMA.newExports(ms, pn);

    }

    /**

     * Returns a {@link Provides} for a service with a given list of

     * implementation classes.

     */

    public static Provides newProvides(String st, List<String> pcs) {

        return JLMA.newProvides(st, pcs);

    }

    final String name;

    boolean open, synthetic, mandated;

    Set<Requires> requires;

    Set<Exports> exports;

    Set<Opens> opens;

    Set<String> packages;

    Set<String> uses;

    Set<Provides> provides;

    Version version;

    String mainClass;

    Builder(String name) {

        this.name = name;

        this.requires = Collections.emptySet();

        this.exports = Collections.emptySet();

        this.opens = Collections.emptySet();

        this.provides = Collections.emptySet();

        this.uses = Collections.emptySet();

    }

    Builder open(boolean value) {

        this.open = value;

        return this;

    }

    Builder synthetic(boolean value) {

        this.synthetic = value;

        return this;

    }

    Builder mandated(boolean value) {

        this.mandated = value;

        return this;

    }

    /**

     * Sets module exports.

     */

    public Builder exports(Exports[] exports) {

        this.exports = Set.of(exports);

        return this;

    }

    /**

     * Sets module opens.

     */

    public Builder opens(Opens[] opens) {

        this.opens = Set.of(opens);

        return this;

    }

    /**

     * Sets module requires.

     */

    public Builder requires(Requires[] requires) {

        this.requires = Set.of(requires);

        return this;

    }

    /**

     * Adds a set of (possible empty) packages.

     */

    public Builder packages(Set<String> packages) {

        this.packages = packages;

        return this;

    }

    /**

     * Sets the set of service dependences.

     */

    public Builder uses(Set<String> uses) {

        this.uses = uses;

        return this;

    }

    /**

     * Sets module provides.

     */

    public Builder provides(Provides[] provides) {

        this.provides = Set.of(provides);

        return this;

    }

    /**

     * Sets the module version.

     *

     * @throws IllegalArgumentException if {@code v} is null or cannot be

     *         parsed as a version string

     *

     * @see Version#parse(String)

     */

    public Builder version(String v) {

        Version ver = cachedVersion;

        if (ver != null && v.equals(ver.toString())) {

            version = ver;

        } else {

            cachedVersion = version = Version.parse(v);

        }

        return this;

    }

    /**

     * Sets the module main class.

     */

    public Builder mainClass(String mc) {

        mainClass = mc;

        return this;

    }

    /**

     * Returns an immutable set of the module modifiers derived from the flags.

     */

    private Set<ModuleDescriptor.Modifier> modifiers() {

        int n = 0;

        if (open) n++;

        if (synthetic) n++;

        if (mandated) n++;

        if (n == 0) {

            return Collections.emptySet();

        } else {

            ModuleDescriptor.Modifier[] mods = new ModuleDescriptor.Modifier[n];

            if (open) mods[--n] = ModuleDescriptor.Modifier.OPEN;

            if (synthetic) mods[--n] = ModuleDescriptor.Modifier.SYNTHETIC;

            if (mandated) mods[--n] = ModuleDescriptor.Modifier.MANDATED;

            return Set.of(mods);

        }

    }

    /**

     * Builds a {@code ModuleDescriptor} from the components.

     */

    public ModuleDescriptor build(int hashCode) {

        assert name != null;

        return JLMA.newModuleDescriptor(name,

                                        version,

                                        modifiers(),

                                        requires,

                                        exports,

                                        opens,

                                        uses,

                                        provides,

                                        packages,

                                        mainClass,

                                        hashCode);

    }

}