// (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 { Injectable } from '@angular/core';
import { CoreSites, CoreSitesCommonWSOptions } from '@services/sites';
import { CoreSite, CoreSiteWSPreSets } from '@classes/site';
import { CoreWSExternalWarning, CoreWSExternalFile } from '@services/ws';
import { makeSingleton, Translate } from '@singletons';
import { CoreConstants } from '@/core/constants';
import { CoreMimetypeUtils } from '@services/utils/mimetype';
import { CoreCourse } from '@features/course/services/course';
import { CoreUtils } from '@services/utils/utils';
import { CoreCourseLogHelper } from '@features/course/services/log-helper';
import { CoreError } from '@classes/errors/error';

const ROOT_CACHE_KEY = 'mmaModUrl:';

/**
 * Service that provides some features for urls.
 */
@Injectable({ providedIn: 'root' })
export class AddonModUrlProvider {

    static readonly COMPONENT = 'mmaModUrl';

    /**
     * Get the final display type for a certain URL. Based on Moodle's url_get_final_display_type.
     *
     * @param url URL data.
     * @return Final display type.
     */
    getFinalDisplayType(url?: AddonModUrlUrl): number {
        if (!url) {
            return -1;
        }

        const extension = CoreMimetypeUtils.guessExtensionFromUrl(url.externalurl);

        // PDFs can be embedded in web, but not in the Mobile app.
        if (url.display == CoreConstants.RESOURCELIB_DISPLAY_EMBED && extension == 'pdf') {
            return CoreConstants.RESOURCELIB_DISPLAY_DOWNLOAD;
        }

        if (url.display != CoreConstants.RESOURCELIB_DISPLAY_AUTO) {
            return url.display;
        }

        // Detect links to local moodle pages.
        const currentSite = CoreSites.getCurrentSite();
        if (currentSite && currentSite.containsUrl(url.externalurl)) {
            if (url.externalurl.indexOf('file.php') == -1 && url.externalurl.indexOf('.php') != -1) {
                // Most probably our moodle page with navigation.
                return CoreConstants.RESOURCELIB_DISPLAY_OPEN;
            }
        }

        const download = ['application/zip', 'application/x-tar', 'application/g-zip', 'application/pdf', 'text/html'];
        let mimetype = CoreMimetypeUtils.getMimeType(extension);

        if (url.externalurl.indexOf('.php') != -1 || url.externalurl.substr(-1) === '/' ||
                (url.externalurl.indexOf('//') != -1 && url.externalurl.match(/\//g)?.length == 2)) {
            // Seems to be a web, use HTML mimetype.
            mimetype = 'text/html';
        }

        if (mimetype && download.indexOf(mimetype) != -1) {
            return CoreConstants.RESOURCELIB_DISPLAY_DOWNLOAD;
        }

        if (extension && CoreMimetypeUtils.canBeEmbedded(extension)) {
            return CoreConstants.RESOURCELIB_DISPLAY_EMBED;
        }

        // Let the browser deal with it somehow.
        return CoreConstants.RESOURCELIB_DISPLAY_OPEN;
    }

    /**
     * Get cache key for url data WS calls.
     *
     * @param courseId Course ID.
     * @return Cache key.
     */
    protected getUrlCacheKey(courseId: number): string {
        return ROOT_CACHE_KEY + 'url:' + courseId;
    }

    /**
     * Get a url data.
     *
     * @param courseId Course ID.
     * @param key Name of the property to check.
     * @param value Value to search.
     * @param options Other options.
     * @return Promise resolved when the url is retrieved.
     */
    protected async getUrlDataByKey(
        courseId: number,
        key: string,
        value: number,
        options: CoreSitesCommonWSOptions = {},
    ): Promise<AddonModUrlUrl> {
        const site = await CoreSites.getSite(options.siteId);

        const params: AddonModUrlGetUrlsByCoursesWSParams = {
            courseids: [courseId],
        };

        const preSets: CoreSiteWSPreSets = {
            cacheKey: this.getUrlCacheKey(courseId),
            updateFrequency: CoreSite.FREQUENCY_RARELY,
            component: AddonModUrlProvider.COMPONENT,
            ...CoreSites.getReadingStrategyPreSets(options.readingStrategy),
        };

        const response = await site.read<AddonModUrlGetUrlsByCoursesResult>('mod_url_get_urls_by_courses', params, preSets);

        const currentUrl = response.urls.find((url) => url[key] == value);
        if (currentUrl) {
            return currentUrl;
        }

        throw new CoreError(Translate.instant('core.course.modulenotfound'));
    }

    /**
     * Get a url by course module ID.
     *
     * @param courseId Course ID.
     * @param cmId Course module ID.
     * @param options Other options.
     * @return Promise resolved when the url is retrieved.
     */
    getUrl(courseId: number, cmId: number, options: CoreSitesCommonWSOptions = {}): Promise<AddonModUrlUrl> {
        return this.getUrlDataByKey(courseId, 'coursemodule', cmId, options);
    }

    /**
     * Guess the icon for a certain URL. Based on Moodle's url_guess_icon.
     *
     * @param url URL to check.
     * @return Icon, empty if it should use the default icon.
     */
    guessIcon(url: string): string {
        url = url || '';

        const matches = url.match(/\//g);
        const extension = CoreMimetypeUtils.getFileExtension(url);

        if (!matches || matches.length < 3 || url.substr(-1) === '/' || extension == 'php') {
            // Use default icon.
            return '';
        }

        const icon = CoreMimetypeUtils.getFileIcon(url);

        // We do not want to return those icon types, the module icon is more appropriate.
        if (icon === CoreMimetypeUtils.getFileIconForType('unknown') ||
            icon === CoreMimetypeUtils.getFileIconForType('html')) {
            return '';
        }

        return icon;
    }

    /**
     * Invalidate the prefetched content.
     *
     * @param moduleId The module ID.
     * @param courseId Course ID of the module.
     * @param siteId Site ID. If not defined, current site.
     * @return Promise resolved when the data is invalidated.
     */
    invalidateContent(moduleId: number, courseId: number, siteId?: string): Promise<void> {
        siteId = siteId || CoreSites.getCurrentSiteId();

        const promises: Promise<void>[] = [];

        promises.push(this.invalidateUrlData(courseId, siteId));
        promises.push(CoreCourse.invalidateModule(moduleId, siteId, 'url'));

        return CoreUtils.allPromises(promises);
    }

    /**
     * Invalidates url data.
     *
     * @param courseid Course ID.
     * @param siteId Site ID. If not defined, current site.
     * @return Promise resolved when the data is invalidated.
     */
    async invalidateUrlData(courseId: number, siteId?: string): Promise<void> {
        const site = await CoreSites.getSite(siteId);

        await site.invalidateWsCacheForKey(this.getUrlCacheKey(courseId));
    }

    /**
     * Report the url as being viewed.
     *
     * @param id Module ID.
     * @param name Name of the assign.
     * @param siteId Site ID. If not defined, current site.
     * @return Promise resolved when the WS call is successful.
     */
    logView(id: number, name?: string, siteId?: string): Promise<void> {
        const params: AddonModUrlViewUrlWSParams = {
            urlid: id,
        };

        return CoreCourseLogHelper.logSingle(
            'mod_url_view_url',
            params,
            AddonModUrlProvider.COMPONENT,
            id,
            name,
            'url',
            {},
            siteId,
        );
    }

}
export const AddonModUrl = makeSingleton(AddonModUrlProvider);

/**
 * Params of mod_url_get_urls_by_courses WS.
 */
type AddonModUrlGetUrlsByCoursesWSParams = {
    courseids?: number[]; // Array of course ids.
};

/**
 * Params of mod_url_view_url WS.
 */
type AddonModUrlViewUrlWSParams = {
    urlid: number; // Url instance id.
};

/**
 * URL returnd by mod_url_get_urls_by_courses.
 */
export type AddonModUrlUrl = {
    id: number; // Module id.
    coursemodule: number; // Course module id.
    course: number; // Course id.
    name: string; // URL name.
    intro: string; // Summary.
    introformat: number; // Intro format (1 = HTML, 0 = MOODLE, 2 = PLAIN or 4 = MARKDOWN).
    introfiles: CoreWSExternalFile[];
    externalurl: string; // External URL.
    display: number; // How to display the url.
    displayoptions: string; // Display options (width, height).
    parameters: string; // Parameters to append to the URL.
    timemodified: number; // Last time the url was modified.
    section: number; // Course section id.
    visible: number; // Module visibility.
    groupmode: number; // Group mode.
    groupingid: number; // Grouping id.
};

/**
 * Result of WS mod_url_get_urls_by_courses.
 */
export type AddonModUrlGetUrlsByCoursesResult = {
    urls: AddonModUrlUrl[];
    warnings?: CoreWSExternalWarning[];
};

/**
 * Url Display options as object.
 */
export type AddonModUrlDisplayOptions = {
    printintro?: boolean;
};