/*
 * Copyright (C) 2013 The Android Open Source Project
 *
 * 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.android.camera.app;

import com.android.camera.module.ModuleController;

/**
 * The module manager which maintains the
 * {@link ModuleManagerImpl.ModuleAgent}.
 */
public interface ModuleManager {
    public static int MODULE_INDEX_NONE = -1;

    /**
     * The module agent which is responsible for maintaining the static
     * characteristics and the creation of the module.
     */
    public static interface ModuleAgent {

        /**
         * @return The module ID.
         */
        public int getModuleId();

        /**
         * @return Whether the module will request the app for the camera.
         */
        public boolean requestAppForCamera();

        /**
         * Creates the module.
         * @return The module.
         */
        public ModuleController createModule();
    }

    /**
     * Registers a module. A module will be available only if its agent is
     * registered. The registration might fail.
     *
     * @param agent The {@link com.android.camera.app.ModuleManager.ModuleAgent}
     *              of the module.
     * @throws java.lang.NullPointerException if the {@code agent} is null.
     * @throws java.lang.IllegalArgumentException if the module ID is
     * {@code MODULE_INDEX} or another module with the sameID is registered
     * already.
     */
    void registerModule(ModuleAgent agent);

    /**
     * Unregister a module.
     *
     * @param moduleId The module ID.
     * @return Whether the un-registration succeeds.
     */
    boolean unregisterModule(int moduleId);

    /**
     * Sets the default module index. No-op if the module index does not exist.
     *
     * @param moduleId The ID of the default module.
     * @return Whether the {@code moduleId} exists.
     */
    boolean setDefaultModuleIndex(int moduleId);

    /**
     * @return The default module index. {@code MODULE_INDEX_NONE} if not set.
     */
    int getDefaultModuleIndex();

    /**
     * Returns the {@link com.android.camera.app.ModuleManager.ModuleAgent} by
     * the module ID.
     *
     * @param moduleId The module ID.
     * @return The agent.
     */
    ModuleAgent getModuleAgent(int moduleId);
}