+import * as express from 'express'
+import * as Bluebird from 'bluebird'
+import { buildFileLocale, getDefaultLocale, is18nLocale, POSSIBLE_LOCALES } from '../../shared/models/i18n/i18n'
+import { CONFIG, EMBED_SIZE, CUSTOM_HTML_TAG_COMMENTS, STATIC_PATHS } from '../initializers'
+import { join } from 'path'
+import { escapeHTML, readFileBufferPromise } from '../helpers/core-utils'
+import { VideoModel } from '../models/video/video'
+import * as validator from 'validator'
+import { VideoPrivacy } from '../../shared/models/videos'
+
+export class ClientHtml {
+
+ private static htmlCache: { [path: string]: string } = {}
+
+ static invalidCache () {
+ ClientHtml.htmlCache = {}
+ }
+
+ static async getIndexHTML (req: express.Request, res: express.Response, paramLang?: string) {
+ const path = ClientHtml.getIndexPath(req, res, paramLang)
+ if (ClientHtml.htmlCache[path]) return ClientHtml.htmlCache[path]
+
+ const buffer = await readFileBufferPromise(path)
+
+ let html = buffer.toString()
+
+ html = ClientHtml.addTitleTag(html)
+ html = ClientHtml.addDescriptionTag(html)
+ html = ClientHtml.addCustomCSS(html)
+
+ ClientHtml.htmlCache[path] = html
+
+ return html
+ }
+
+ static async getWatchHTMLPage (videoId: string, req: express.Request, res: express.Response) {
+ let videoPromise: Bluebird<VideoModel>
+
+ // Let Angular application handle errors
+ if (validator.isUUID(videoId, 4)) {
+ videoPromise = VideoModel.loadByUUIDAndPopulateAccountAndServerAndTags(videoId)
+ } else if (validator.isInt(videoId)) {
+ videoPromise = VideoModel.loadAndPopulateAccountAndServerAndTags(+videoId)
+ } else {
+ return ClientHtml.getIndexHTML(req, res)
+ }
+
+ const [ html, video ] = await Promise.all([
+ ClientHtml.getIndexHTML(req, res),
+ videoPromise
+ ])
+
+ // Let Angular application handle errors
+ if (!video || video.privacy === VideoPrivacy.PRIVATE) {
+ return ClientHtml.getIndexHTML(req, res)
+ }
+
+ return ClientHtml.addOpenGraphAndOEmbedTags(html, video)
+ }
+
+ private static getIndexPath (req: express.Request, res: express.Response, paramLang?: string) {
+ let lang: string
+
+ // Check param lang validity
+ if (paramLang && is18nLocale(paramLang)) {
+ lang = paramLang
+
+ // Save locale in cookies
+ res.cookie('clientLanguage', lang, {
+ secure: CONFIG.WEBSERVER.SCHEME === 'https',
+ sameSite: true,
+ maxAge: 1000 * 3600 * 24 * 90 // 3 months
+ })
+
+ } else if (req.cookies.clientLanguage && is18nLocale(req.cookies.clientLanguage)) {
+ lang = req.cookies.clientLanguage
+ } else {
+ lang = req.acceptsLanguages(POSSIBLE_LOCALES) || getDefaultLocale()
+ }
+
+ return join(__dirname, '../../../client/dist/' + buildFileLocale(lang) + '/index.html')
+ }
+
+ private static addTitleTag (htmlStringPage: string) {
+ const titleTag = '<title>' + CONFIG.INSTANCE.NAME + '</title>'
+
+ return htmlStringPage.replace(CUSTOM_HTML_TAG_COMMENTS.TITLE, titleTag)
+ }
+
+ private static addDescriptionTag (htmlStringPage: string) {
+ const descriptionTag = `<meta name="description" content="${CONFIG.INSTANCE.SHORT_DESCRIPTION}" />`
+
+ return htmlStringPage.replace(CUSTOM_HTML_TAG_COMMENTS.DESCRIPTION, descriptionTag)
+ }
+
+ private static addCustomCSS (htmlStringPage: string) {
+ const styleTag = '<style class="custom-css-style">' + CONFIG.INSTANCE.CUSTOMIZATIONS.CSS + '</style>'
+
+ return htmlStringPage.replace(CUSTOM_HTML_TAG_COMMENTS.CUSTOM_CSS, styleTag)
+ }
+
+ private static addOpenGraphAndOEmbedTags (htmlStringPage: string, video: VideoModel) {
+ const previewUrl = CONFIG.WEBSERVER.URL + STATIC_PATHS.PREVIEWS + video.getPreviewName()
+ const videoUrl = CONFIG.WEBSERVER.URL + '/videos/watch/' + video.uuid
+
+ const videoNameEscaped = escapeHTML(video.name)
+ const videoDescriptionEscaped = escapeHTML(video.description)
+ const embedUrl = CONFIG.WEBSERVER.URL + video.getEmbedStaticPath()
+
+ const openGraphMetaTags = {
+ 'og:type': 'video',
+ 'og:title': videoNameEscaped,
+ 'og:image': previewUrl,
+ 'og:url': videoUrl,
+ 'og:description': videoDescriptionEscaped,
+
+ 'og:video:url': embedUrl,
+ 'og:video:secure_url': embedUrl,
+ 'og:video:type': 'text/html',
+ 'og:video:width': EMBED_SIZE.width,
+ 'og:video:height': EMBED_SIZE.height,
+
+ 'name': videoNameEscaped,
+ 'description': videoDescriptionEscaped,
+ 'image': previewUrl,
+
+ 'twitter:card': CONFIG.SERVICES.TWITTER.WHITELISTED ? 'player' : 'summary_large_image',
+ 'twitter:site': CONFIG.SERVICES.TWITTER.USERNAME,
+ 'twitter:title': videoNameEscaped,
+ 'twitter:description': videoDescriptionEscaped,
+ 'twitter:image': previewUrl,
+ 'twitter:player': embedUrl,
+ 'twitter:player:width': EMBED_SIZE.width,
+ 'twitter:player:height': EMBED_SIZE.height
+ }
+
+ const oembedLinkTags = [
+ {
+ type: 'application/json+oembed',
+ href: CONFIG.WEBSERVER.URL + '/services/oembed?url=' + encodeURIComponent(videoUrl),
+ title: videoNameEscaped
+ }
+ ]
+
+ const schemaTags = {
+ '@context': 'http://schema.org',
+ '@type': 'VideoObject',
+ name: videoNameEscaped,
+ description: videoDescriptionEscaped,
+ thumbnailUrl: previewUrl,
+ uploadDate: video.createdAt.toISOString(),
+ duration: video.getActivityStreamDuration(),
+ contentUrl: videoUrl,
+ embedUrl: embedUrl,
+ interactionCount: video.views
+ }
+
+ let tagsString = ''
+
+ // Opengraph
+ Object.keys(openGraphMetaTags).forEach(tagName => {
+ const tagValue = openGraphMetaTags[tagName]
+
+ tagsString += `<meta property="${tagName}" content="${tagValue}" />`
+ })
+
+ // OEmbed
+ for (const oembedLinkTag of oembedLinkTags) {
+ tagsString += `<link rel="alternate" type="${oembedLinkTag.type}" href="${oembedLinkTag.href}" title="${oembedLinkTag.title}" />`
+ }
+
+ // Schema.org
+ tagsString += `<script type="application/ld+json">${JSON.stringify(schemaTags)}</script>`
+
+ // SEO
+ tagsString += `<link rel="canonical" href="${videoUrl}" />`
+
+ return htmlStringPage.replace(CUSTOM_HTML_TAG_COMMENTS.OPENGRAPH_AND_OEMBED, tagsString)
+ }
+}