import http from 'http'
import express, { Router } from 'express'
import useragent from 'express-useragent'
import fileUpload from 'express-fileupload'
import * as bodyParser from 'body-parser'
import cookieParser from 'cookie-parser'
import * as mysql from 'mysql2'
import * as ws from 'ws'
import getIP from './extra_modules/getip.js'
import { unsign } from './extra_modules/unsign.js'
import { readFileSync, appendFile } from 'fs'
import { format } from 'util'
import { setup as SETUP_ROUTES } from './routes/setup_all_routes.js'
import { verify as verifyHCaptcha_int } from 'hcaptcha'

import { ensureExists } from './extra_modules/ensureExists.js'

import * as compress from 'compression'
const compression = compress.default

import { fileURLToPath } from 'url'
import { dirname } from 'path'
const __filename = fileURLToPath(import.meta.url)
const __dirname = dirname(__filename)

const config = JSON.parse(readFileSync('server_config.json'))
const time = Date.now()
const original_log = console.log
/**
 * custom logging function
 * @param  {number}     level               importance level if information
 * @param  {any}        info                information to format + log
 * @return {undefined}                      returns nothing
 */
function log_info(level, ...info) {
    let text = info
    if (text === undefined || text.length === 0) {
        text = level
        level = 5
    }
    if (
        config['logs'] &&
        config['logs']['level'] &&
        config['logs']['level'] >= level
    ) {
        let tolog = `[INFO] [${Date.now()}] : ${format(text)} \n`
        original_log(tolog) //still has some nicer colors
        ensureExists(__dirname + '/logs/', function (err) {
            if (err) {
                process.stderr.write(tolog) //just write it to stderr
            } else {
                appendFile(__dirname + '/logs/' + time, tolog, function (err) {
                    if (err) {
                        process.stderr.write(err)
                    }
                })
            }
        })
    }
}
//console.log = log_info;

const hcaptcha_secret = config.hcaptcha_secret
// wrapper for the HCaptcha verify function
function verifyHCaptcha(token) {
    return verifyHCaptcha_int(
        hcaptcha_secret,
        token,
        undefined,
        config.hcaptcha_sitekey
    )
}

const WebSocket = ws.WebSocketServer

const router = Router()
const app = express()
const con = mysql.createPool({
    connectionLimit: config.mysql.connections,
    host: config.mysql.host,
    user: config.mysql.user,
    password: readFileSync(config.mysql.password_file).toString(),
    multipleStatements: true,
    supportBigNumbers: true,
})
const cookiesecret = readFileSync('cookiesecret.txt').toString()

/**
 * custom, bad random number generator
 * @param       {number} seed  seed for the number generator, defaults to current timestamp
 * @constructor
 */
class RNG {
    constructor(seed) {
        if (!seed) seed = Date.now()
        this.seed = seed
        this.random = function (min, max) {
            if (!min) min = 0
            if (!max) {
                max = min
                min = 0
            }
            this.seed += Math.log(Math.abs(Math.sin(this.seed)) * 100)
            return Math.abs(Math.sin(this.seed)) * max + min
        }
        this.rand = function (min, max) {
            return Math.floor(this.random(min, max))
        }
    }
}
const rand = new RNG()
const genstring_characters =
    'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_'
const genstring_charactersLength = genstring_characters.length
/**
 * generates a semi-random string
 * @param  {number} length               length of string to generate
 * @return {string}        semi-random string generated
 */
function genstring(length) {
    let result = ''
    for (let i = 0; i < length; i++) {
        result += genstring_characters.charAt(
            rand.rand(genstring_charactersLength)
        )
    }
    return result
}

var API_CALLS = {}
var API_CALLS_ACCOUNT = {}
var USER_CALLS = {}
var SESSIONS = {}
var REVERSE_SESSIONS = {}
var INDIVIDUAL_CALLS = {}
/**
 * clears current api call list (per IP)
 * @return {undefined} returns nothing
 */
function clear_api_calls() {
    API_CALLS = {}
}
/**
 * clears current api account call list (per account)
 * @return {undefined} returns nothing
 */
function clear_account_api_calls() {
    API_CALLS_ACCOUNT = {}
}
/**
 * clears current user file call list (per IP)
 * @return {undefined} returns nothing
 */
function clear_user_calls() {
    USER_CALLS = {}
}
setInterval(clear_api_calls, config.rate_limits.api.reset_time)
setInterval(clear_account_api_calls, config.rate_limits.api.reset_time)
setInterval(clear_user_calls, config.rate_limits.user.reset_time)
function increaseIndividualCall(url, req) {
    let conf = config['rate_limits']['individual'][url]
    if (!conf) {
        //if(!url.startsWith("/avatars/")) //ignore avatars /* DEBUG: inidividual ratelimiters */
        //console.log(5, "url not in individual ratelimiter", url); /* DEBUG: inidividual ratelimiters */
        return true
    }
    if (!conf['enabled']) return true
    let ip = getIP(req)
    if (INDIVIDUAL_CALLS[ip] === undefined) INDIVIDUAL_CALLS[ip] = {}
    if (INDIVIDUAL_CALLS[ip][url] === undefined) INDIVIDUAL_CALLS[ip][url] = 0
    if (INDIVIDUAL_CALLS[ip][url] === 0) {
        setTimeout(function () {
            INDIVIDUAL_CALLS[ip][url] = 0
        }, conf['reset_time'])
    }
    INDIVIDUAL_CALLS[ip][url]++
    if (INDIVIDUAL_CALLS[ip][url] >= conf['max']) {
        console.log(
            3,
            'ratelimiting someone on',
            url,
            INDIVIDUAL_CALLS[ip][url],
            conf['max'],
            ip
        )
        return false
    }
    return true
}
function increaseAccountAPICall(req, res) {
    let cookie = req.cookies.AUTH_COOKIE
    if (!cookie) {
        return true
    }
    let unsigned = unsign(cookie, req, res)
    if (!unsigned) {
        return true //if there's no account, why not just ignore it
    }
    unsigned = decodeURIComponent(unsigned)
    if (!unsigned) return false
    let values = unsigned.split(' ')
    let username = values[0]
    if (API_CALLS_ACCOUNT[username] === undefined)
        API_CALLS_ACCOUNT[username] = 0
    if (API_CALLS_ACCOUNT[username] >= config.rate_limits.api.max_per_account) {
        res.status(429)
        res.send('You are sending way too many api calls!')
        return false
    }
    return true
}
function increaseAPICall(req, res, next) {
    let ip = getIP(req)
    if (API_CALLS[ip] === undefined) API_CALLS[ip] = 0
    if (API_CALLS[ip] >= config.rate_limits.api.max_without_session) {
        if (
            REVERSE_SESSIONS[ip] &&
            req.cookies.session !== REVERSE_SESSIONS[ip]
        ) {
            //expected a session, but didn't get one
            res.status(429)
            res.send('You are sending way too many api calls!')
            return
        }
        if (!req.cookies.session) {
            let session
            do {
                session = genstring(300)
            } while (SESSIONS[session] !== undefined)
            SESSIONS[session] = ip
            REVERSE_SESSIONS[ip] = session
            setTimeout(function () {
                SESSIONS[session] = undefined
                REVERSE_SESSIONS[ip] = undefined
            }, 50000)
            res.cookie('session', session, {
                maxAge: 100000,
                httpOnly: true,
                secure: true,
            })
            console.log(3, 'sending session to ' + ip)
        }
    }
    if (API_CALLS[ip] >= config.rate_limits.api.max_with_session) {
        res.status(429)
        res.send('You are sending too many api calls!')
        console.log(3, 'rate limiting ' + ip)
        return false
    }
    API_CALLS[ip]++
    if (!increaseAccountAPICall(req, res)) return false //can't forget account-based ratelimits
    if (next) next()
    return true
}
function increaseUSERCall(req, res, next) {
    let ip = getIP(req)
    if (USER_CALLS[ip] === undefined) USER_CALLS[ip] = 0
    if (USER_CALLS[ip] >= config.rate_limits.user.max) {
        res.status(429)
        res.send('You are sending too many requests!')
        console.log(2, 'rate limiting ' + ip)
        return false
    }
    USER_CALLS[ip]++
    if (next) next()
    return true
}
console.log(5, 'loading routes')
app.use(useragent.express())
app.use(
    fileUpload({
        limits: {
            files: 5,
            fileSize: 1_000_000,
        },
    })
)

app.use((_req, res, next) => {
    res.set('x-powered-by', 'ipost')
    res.set('X-Frame-Options', 'DENY')
    res.set('X-XSS-Protection', '1; mode=block')
    res.set('X-Content-Type-Options', 'nosniff')
    res.set('Referrer-Policy', 'no-referrer')

    next()
})

app.use(bodyParser.default.json({ limit: '100mb' }))
app.use(bodyParser.default.urlencoded({ limit: '100mb', extended: true }))
app.use(cookieParser(cookiesecret))
app.use(compression())
let blocked_headers = [
    'HTTP_VIA',
    'HTTP_X_FORWARDED_FOR',
    'HTTP_FORWARDED_FOR',
    'HTTP_X_FORWARDED',
    'HTTP_FORWARDED',
    'HTTP_CLIENT_IP',
    'HTTP_FORWARDED_FOR_IP',
    'VIA',
    'X_FORWARDED_FOR',
    'FORWARDED_FOR',
    'X_FORWARDED',
    'FORWARDED',
    'CLIENT_IP',
    'FORWARDED_FOR_IP',
    'HTTP_PROXY_CONNECTION',
]
if (!config.disallow_proxies_by_headers) {
    blocked_headers = []
}
app.use(function (_req, res, next) {
    res.set('X-XSS-Protection', '1; mode=block')
    next()
})

app.use('/*path', function (req, res, next) {
    for (let i = 0; i < blocked_headers.length; i++) {
        if (req.header(blocked_headers[i]) !== undefined) {
            res.json({ error: "we don't allow proxies on our website." })
            return
        }
    }
    let fullurl = req.baseUrl + req.path
    if (fullurl !== '/') {
        fullurl = fullurl.substring(0, fullurl.length - 1)
    }
    if (!increaseIndividualCall(fullurl, req)) {
        res.status(429)
        res.json({ error: 'you are sending too many requests!' })
        return
    }
    next()
})
console.log(5, 'finished loading user routes, starting with api routes')

/*

START /API/*

*/
var wss
var commonfunctions = {
    increaseAPICall,
    increaseUSERCall,
    increaseAccountAPICall,
    increaseIndividualCall,
    wss,
    genstring,
    ensureExists,
    dirname: __dirname,
    config,
    hcaptcha: {
        verify: verifyHCaptcha,
        sitekey: config.hcaptcha_sitekey,
    },
}

SETUP_ROUTES(router, con, commonfunctions)

router.get('/api/getChannels', function (_req, res) {
    res.set('Access-Control-Allow-Origin', '*')
    let sql = `select post_receiver_name from ipost.posts where post_is_private = '0' group by post_receiver_name;`
    con.query(sql, [], function (err, result) {
        if (err) throw err
        res.json(result)
    })
    /* #swagger.security = [{
        "appTokenAuthHeader": []
    }] */
})
/*

END /API/*

*/

console.log(5, 'finished loading routes')
app.use(router)
const httpServer = http.createServer(app)
httpServer.listen(config['ports']['http'], function () {
    console.log(5, 'HTTP Server is listening')
})

wss = new WebSocket({
    server: httpServer,
    perMessageDeflate: {
        zlibDeflateOptions: {
            chunkSize: 1024,
            memLevel: 7,
            level: 3,
        },
        zlibInflateOptions: {
            chunkSize: 10 * 1024,
        },
        clientNoContextTakeover: true,
        serverNoContextTakeover: true,
        serverMaxWindowBits: 10,
        concurrencyLimit: 10,
        threshold: 1024 * 16,
    },
})
wss.on('connection', function connection(ws) {
    ws.channel = 'everyone'
    console.log(5, 'new connection')
    ws.on('message', function incoming(message) {
        message = JSON.parse(message)
        if (message.id === 'switchChannel') {
            ws.channel = decodeURIComponent(message.data)
        }
    })
})
commonfunctions.wss = wss
console.log(5, 'starting up all services')