// (C) Copyright 2015 Moodle Pty Ltd.
//
// 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 { Component, OnInit, Optional } from '@angular/core';
import { CoreCourseModuleMainResourceComponent } from '@features/course/classes/main-resource-component';
import { CoreCourseContentsPage } from '@features/course/pages/contents/contents';
import { CoreCourse } from '@features/course/services/course';
import { CoreTextUtils } from '@services/utils/text';
import { CoreUtils } from '@services/utils/utils';
import { AddonModPageProvider, AddonModPagePage, AddonModPage } from '../../services/page';
import { AddonModPageHelper } from '../../services/page-helper';

/**
 * Component that displays a page.
 */
@Component({
    selector: 'addon-mod-page-index',
    templateUrl: 'addon-mod-page-index.html',
    styleUrls: ['index.scss'],
})
export class AddonModPageIndexComponent extends CoreCourseModuleMainResourceComponent implements OnInit {

    component = AddonModPageProvider.COMPONENT;
    contents?: string;
    displayDescription = true;
    displayTimemodified = true;
    timemodified?: number;
    page?: AddonModPagePage;
    warning?: string;

    protected fetchContentDefaultError = 'addon.mod_page.errorwhileloadingthepage';

    constructor(@Optional() courseContentsPage?: CoreCourseContentsPage) {
        super('AddonModPageIndexComponent', courseContentsPage);
    }

    /**
     * Component being initialized.
     */
    async ngOnInit(): Promise<void> {
        super.ngOnInit();

        await this.loadContent();

        try {
            await AddonModPage.logView(this.module.instance, this.module.name);
            CoreCourse.checkModuleCompletion(this.courseId, this.module.completiondata);
        } catch {
            // Ignore errors.
        }
    }

    /**
     * Perform the invalidate content function.
     *
     * @return Resolved when done.
     */
    protected async invalidateContent(): Promise<void> {
        await AddonModPage.invalidateContent(this.module.id, this.courseId);
    }

    /**
     * @inheritdoc
     */
    protected async fetchContent(refresh?: boolean): Promise<void> {
        // Download the resource if it needs to be downloaded.
        const downloadResult = await this.downloadResourceIfNeeded(refresh);

        // Get contents. No need to refresh, it has been done in downloadResourceIfNeeded.
        const contents = await CoreCourse.getModuleContents(this.module);

        const results = await Promise.all([
            this.loadPageData(),
            AddonModPageHelper.getPageHtml(contents, this.module.id),
        ]);

        this.contents = results[1];
        this.warning = downloadResult?.failed ? this.getErrorDownloadingSomeFilesMessage(downloadResult.error!) : '';
    }

    /**
     * Load page data from WS.
     *
     * @return Promise resolved when done.
     */
    protected async loadPageData(): Promise<void> {
        // Get latest title, description and some extra data. Data should've been updated in download.
        this.page = await AddonModPage.getPageData(this.courseId, this.module.id);

        this.description = this.page.intro;
        this.dataRetrieved.emit(this.page);

        // Check if description and timemodified should be displayed.
        if (this.page.displayoptions) {
            const options: Record<string, string | boolean> =
                CoreTextUtils.unserialize(this.page.displayoptions) || {};

            this.displayDescription = options.printintro === undefined ||
                    CoreUtils.isTrueOrOne(options.printintro);
            this.displayTimemodified = options.printlastmodified === undefined ||
                    CoreUtils.isTrueOrOne(options.printlastmodified);
        } else {
            this.displayDescription = true;
            this.displayTimemodified = true;
        }

        this.timemodified = 'timemodified' in this.page ? this.page.timemodified : undefined;
    }

}