const express = require('express')
const app = express()
const rateLimit = require('express-rate-limit')
const helmet = require('helmet')
const bp = require('body-parser')
const cookieParser = require('cookie-parser')
const createDOMPurify = require('dompurify')
const { JSDOM } = require('jsdom')
const Controller = require('./source/controller')
const readfile = require('./source/readfile')
const session = require('./source/session')
const logger = require('./source/logger')()
const mime = {
    html: 'text/html',
    txt: 'text/plain',
    css: 'text/css',
    xml: 'text/xml',
    gif: 'image/gif',
    jpg: 'image/jpeg',
    png: 'image/png',
    webp: 'image/webp',
    avif: 'image/avif',
    ico: 'image/ico',
    svg: 'image/svg+xml',
    js: 'application/javascript',
    mp4: 'video/mp4',
    webm: 'video/webm'
}
const assetDir = [
    'js',
    'css',
    'img',
    'vid'
]
const limiter = rateLimit({
    windowMs: 30 * 1000,
    max: 100,
    message: '<h1>Rate Limit Exceeded</h1><p>You have exceeded the allowed number of requests. Please try again later.</p>',
})
require('dotenv').config()
const rss = require('./source/rss')({baseUrl: process.env.baseUrl})

// Handles the routes
class App {
    constructor() {
        this.readfile = new readfile({
            baseUrl: process.env.baseUrl, 
            mime: mime, 
            header: 'header.html', 
            footer: 'footer.html'
        })
        this.controller = new Controller()
    }

    App() {
        app.use(bp.json())
        app.use(cookieParser())
        if (process.env.NODE_ENV === 'prod') {
            app.use(helmet())
            app.use(limiter)
        }

        app.route('*')
            .get(this.#ValidateCookie, this.#Logger, (req, res) => {
                this.controller.Main().then(output => {
                    this.path = {
                        split: req.path.split('/'),
                        string: req.path
                    }

                    if (assetDir.includes(this.path.split[1])) {
                        const data = this.readfile.GetFile(req.path)
                        data.mime.then(output => this.#FileOpen({data: data, mime: output, res: res}))
                    } else {
                        switch (this.path.split[1]) {
                            case 'favicon.ico':
                                this.data = this.readfile.GetFavicon()
                                this.data.mime.then(output => this.#FileOpen({data: this.data, mime: output, res: res}))
                                break
                            case 'robots.txt':
                                this.data = this.readfile.GetRobots()
                                this.data.mime.then(output => this.#FileOpen({data: this.data, mime: output, res: res}))
                                break
                            case 'sitemap.xml':
                                this.data = this.readfile.Sitemap({keys: Array.from(output.keys()), url: process.env.baseUrl})
                                this.data.then(data => {
                                    res.set('Content-Type', mime.xml)
                                    res.send(data)
                                })
                                break
                            case 'rss':
                                res.set('Content-Type', mime.xml)
                                rss.GetFeed({
                                    title: process.env.rssTitle,
                                    description: process.env.rssDescription,
                                    author: process.env.rssAuthor
                                }).then(output => res.send(output))
                                break
                            default:
                                if (this.path.string.endsWith('/') && this.path.string.length > 1) this.path.string = this.path.string.substring(0, this.path.string.length - 1)
                                if (output.has(this.path.string)) {
                                    try {
                                        output.get(this.path.string).then(output => res.send(this.readfile.GetMain(output.meta)))
                                    } catch {
                                        res.send(this.readfile.GetMain(output.get(this.path.string).meta))
                                    }
                                } else {
                                    res.status(404).send(this.readfile.GetMain({title: 'Page not found', description: '', keywords: ''}))
                                }
                                break
                        }
                    }
                })
            })
            .post(this.#Logger, (req, res) => {
                this.path = {
                    split: req.path.split('/'),
                    string: this.#RemoveBaseUrl(req.body.url)
                }

                if (this.path.string.endsWith('/') && this.path.string.length > 1) this.path.string = this.path.string.substring(0, this.path.string.length - 1)
                this.controller.Main(req.body.value).then(output => {
                    if (output.has(this.path.string)) {
                        try {
                            output.get(this.path.string).then(output => {
                                if (output.hasOwnProperty('post') ? output.post : false) {
                                    const DOMPurify = createDOMPurify(new JSDOM('').window)
                                    const clean = DOMPurify.sanitize(output.html)
                                    res.send(JSON.stringify({post: output.post, html: clean, css: output.css, js: output.js}))
                                } else {
                                    const object = {
                                        js: output.assets.js,
                                        css: output.assets.css
                                    }
                                    this.readfile.Create(output.html).then(output => {
                                        const DOMPurify = createDOMPurify(new JSDOM('').window)
                                        const clean = DOMPurify.sanitize(output.layouts.header + output.layouts.data + output.layouts.footer, {
                                            ADD_TAGS: ['iframe'], ADD_ATTR: ['allow', 'allowfullscreen', 'frameborder', 'scrolling']
                                        })
                                        res.send(JSON.stringify({html: clean, css: object.css, js: object.js}))
                                    })
                                }
                            })
                        } catch {
                            const object = {}

                            if (output.get(this.path.string).hasOwnProperty('assets')) {
                                this.assets = output.get(this.path.string).assets
                                object['js'] = this.assets.hasOwnProperty('js') ? this.assets.js : []
                                object['css'] = this.assets.hasOwnProperty('css') ? this.assets.css : []
                            }

                            if (output.hasOwnProperty('post') ? output.post : false) {
                                const DOMPurify = createDOMPurify(new JSDOM('').window)
                                const clean = DOMPurify.sanitize(output.html)
                                res.send(JSON.stringify({post: output.post, html: clean, css: output.css, js: output.js}))
                            } else {
                                this.readfile.Create(output.get(this.path.string).html).then(output => {
                                    const DOMPurify = createDOMPurify(new JSDOM('').window)
                                    const clean = DOMPurify.sanitize(output.layouts.header + output.layouts.data + output.layouts.footer, {
                                        ADD_TAGS: ['iframe'], ADD_ATTR: ['allow', 'allowfullscreen', 'frameborder', 'scrolling']
                                    })
                                    res.send(JSON.stringify({html: clean, css: object.css, js: object.js}))
                                })
                            }
                        }
                    } else {
                        res.send(JSON.stringify({html: this.readfile.NotFound(), css: ['main.css'], js: ['purify.js', '404.js']}))
                    }
                })
            })

        app.listen(3000)
    }

    #Logger(req, res, next) {
        const { cookies } = req
        try {
            logger.Info(`${req.method} ${req.path} from ${req.ip}:${cookies.session_id.replace('session_id', '')}`)
        } catch (err) {
            logger.Info(`${req.method} ${req.path} from ${req.ip}:n/a`)
        }
        next()
    }
    #FileOpen(x) {
        x.res.set('Content-Type', x.mime)
        x.data.file.on('open', () => x.data.file.pipe(x.res)).on('error', () => {
            x.res.set('Content-Type', mime.html)
            x.res.status(404).send('File not found')
        })
    }
    #ValidateCookie(req, res, next) {
        const { cookies } = req
        if ('session_id' in cookies) {
            if (session().Exists(cookies.session_id.replace('session_id', ''))) {
                session().Expired()
            } else {
                res.clearCookie('session_id')
                res.cookie('session_id', session().Create())
            }
        } else res.cookie('session_id', session().Create())
        next()
    }
    #RemoveBaseUrl(x) {
        const object = {
            baseUrlPattern: /^https?:\/\/[a-z\:0-9.]+/,
            result: '',
            url: ''
        }
        const match = object.baseUrlPattern.exec(x)
        if (match !== null) object.result = match[0]
        if (object.result.length > 0) object.result = match[0]
        if (object.result.length > 0) object.url = x.replace(object.result, '')
        return object.url
    }
}
new App().App()