// (C) Copyright 2015 Martin Dougiamas
//
// 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.

import { Injectable, Injector } from '@angular/core';
import { CoreCommentsProvider } from '@core/comments/providers/comments';
import { AddonModAssignSubmissionHandler } from '../../../providers/submission-delegate';
import { AddonModAssignSubmissionCommentsComponent } from '../component/comments';
import {
    AddonModAssignAssign, AddonModAssignSubmission, AddonModAssignPlugin
} from '../../../providers/assign';

/**
 * Handler for comments submission plugin.
 */
@Injectable()
export class AddonModAssignSubmissionCommentsHandler implements AddonModAssignSubmissionHandler {
    name = 'AddonModAssignSubmissionCommentsHandler';
    type = 'comments';

    constructor(private commentsProvider: CoreCommentsProvider) { }

    /**
     * Whether the plugin can be edited in offline for existing submissions. In general, this should return false if the
     * plugin uses Moodle filters. The reason is that the app only prefetches filtered data, and the user should edit
     * unfiltered data.
     *
     * @param assign The assignment.
     * @param submission The submission.
     * @param plugin The plugin object.
     * @return Boolean or promise resolved with boolean: whether it can be edited in offline.
     */
    canEditOffline(assign: AddonModAssignAssign, submission: AddonModAssignSubmission,
            plugin: AddonModAssignPlugin): boolean | Promise<boolean> {
        // This plugin is read only, but return true to prevent blocking the edition.
        return true;
    }

    /**
     * Return the Component to use to display the plugin data, either in read or in edit mode.
     * It's recommended to return the class of the component, but you can also return an instance of the component.
     *
     * @param injector Injector.
     * @param plugin The plugin object.
     * @param edit Whether the user is editing.
     * @return The component (or promise resolved with component) to use, undefined if not found.
     */
    getComponent(injector: Injector, plugin: AddonModAssignPlugin, edit?: boolean): any | Promise<any> {
        return edit ? undefined : AddonModAssignSubmissionCommentsComponent;
    }

    /**
     * Whether or not the handler is enabled on a site level.
     *
     * @return True or promise resolved with true if enabled.
     */
    isEnabled(): boolean | Promise<boolean> {
        return true;
    }

    /**
     * Whether or not the handler is enabled for edit on a site level.
     *
     * @return Whether or not the handler is enabled for edit on a site level.
     */
    isEnabledForEdit(): boolean | Promise<boolean> {
        return true;
    }

    /**
     * Prefetch any required data for the plugin.
     * This should NOT prefetch files. Files to be prefetched should be returned by the getPluginFiles function.
     *
     * @param assign The assignment.
     * @param submission The submission.
     * @param plugin The plugin object.
     * @param siteId Site ID. If not defined, current site.
     * @return Promise resolved when done.
     */
    prefetch(assign: AddonModAssignAssign, submission: AddonModAssignSubmission,
            plugin: AddonModAssignPlugin, siteId?: string): Promise<any> {

        return this.commentsProvider.getComments('module', assign.cmid, 'assignsubmission_comments', submission.id,
                'submission_comments', 0, siteId).catch(() => {
            // Fail silently (Moodle < 3.1.1, 3.2)
        });
    }
}