const express = require('express');
const app = express();
const path = require('path');
const htmlparser = require('node-html-parser');
const { existsSync, mkdirSync, readFileSync, writeFileSync } = require('fs');
const bodyParser = require('body-parser');
const fs = require('fs/promises')
const crypto = require('crypto')
app.use(express.static(path.join(process.cwd(), 'dist'), {index: false}));
app.use(bodyParser.raw({ limit: 100000000 }));
app.use(bodyParser.json())
const {pipeline} = require('stream/promises')

let password = ''

const savePath = path.join(process.cwd(), "save")
if(!existsSync(savePath)){
    mkdirSync(savePath)
}

const passwordPath = path.join(process.cwd(), 'save', '__password')
if(existsSync(passwordPath)){
    password = readFileSync(passwordPath, 'utf-8')
}
const hexRegex = /^[0-9a-fA-F]+$/;
function isHex(str) {
    return hexRegex.test(str.toUpperCase().trim()) || str === '__password';
}

app.get('/', async (req, res, next) => {
    console.log("connected")
    try {
        const mainIndex = await fs.readFile(path.join(process.cwd(), 'dist', 'index.html'))
        const root = htmlparser.parse(mainIndex)
        const head = root.querySelector('head')
        head.innerHTML = `<script>globalThis.__NODE__ = true</script>` + head.innerHTML
        res.send(root.toString())
    } catch (error) {
        console.log(error)
        next(error)
    }
})

const reverseProxyFunc = async (req, res, next) => {
    const urlParam = req.headers['risu-url'] ? decodeURIComponent(req.headers['risu-url']) : req.query.url;

    if (!urlParam) {
        res.status(400).send({
            error:'URL has no param'
        });
        return;
    }
    const header = req.headers['risu-header'] ? JSON.parse(decodeURIComponent(req.headers['risu-header'])) : req.headers;
    if(!header['x-forwarded-for']){
        header['x-forwarded-for'] = req.ip
    }
    let originalResponse;
    try {
        // make request to original server
        originalResponse = await fetch(urlParam, {
            method: req.method,
            headers: header,
            body: JSON.stringify(req.body)
        });
        // get response body as stream
        const originalBody = originalResponse.body;
        // get response headers
        const head = new Headers(originalResponse.headers);
        head.delete('content-security-policy');
        head.delete('content-security-policy-report-only');
        head.delete('clear-site-data');
        head.delete('Cache-Control');
        head.delete('Content-Encoding');
        const headObj = {};
        for (let [k, v] of head) {
            headObj[k] = v;
        }
        // send response headers to client
        res.header(headObj);
        // send response status to client
        res.status(originalResponse.status);
        // send response body to client
        await pipeline(originalResponse.body, res);


    }
    catch (err) {
        next(err);
        return;
    }
}

app.post('/proxy', reverseProxyFunc);
app.post('/proxy2', reverseProxyFunc);

app.get('/api/password', async(req, res)=> {
    if(password === ''){
        res.send({status: 'unset'})
    }
    else if(req.headers['risu-auth']  === password){
        res.send({status:'correct'})
    }
    else{
        res.send({status:'incorrect'})
    }
})

app.post('/api/crypto', async (req, res) => {
    try {
        const hash = crypto.createHash('sha256')
        hash.update(Buffer.from(req.body.data, 'utf-8'))
        res.send(hash.digest('hex'))
    } catch (error) {
        next(error)
    }
})


app.post('/api/set_password', async (req, res) => {
    if(password === ''){
        password = req.body.password
        writeFileSync(passwordPath, password, 'utf-8')
    }
    res.status(400).send("already set")
})

app.get('/api/read', async (req, res, next) => {
    if(req.headers['risu-auth'].trim() !== password.trim()){
        console.log('incorrect')
        res.status(400).send({
            error:'Password Incorrect'
        });
        return
    }
    const filePath = req.headers['file-path'];
    if (!filePath) {
        console.log('no path')
        res.status(400).send({
            error:'File path required'
        });
        return;
    }

    if(!isHex(filePath)){
        res.status(400).send({
            error:'Invaild Path'
        });
        return;
    }
    try {
        if(!existsSync(path.join(savePath, filePath))){
            res.send();
        }
        else{
            res.setHeader('Content-Type','application/octet-stream');
            res.sendFile(path.join(savePath, filePath));
        }
    } catch (error) {
        next(error);
    }
});

app.get('/api/remove', async (req, res, next) => {
    if(req.headers['risu-auth'].trim() !== password.trim()){
        console.log('incorrect')
        res.status(400).send({
            error:'Password Incorrect'
        });
        return
    }
    const filePath = req.headers['file-path'];
    if (!filePath) {
        res.status(400).send({
            error:'File path required'
        });
        return;
    }
    if(!isHex(filePath)){
        res.status(400).send({
            error:'Invaild Path'
        });
        return;
    }

    try {
        await fs.rm(path.join(savePath, filePath));
        res.send({
            success: true,
        });
    } catch (error) {
        next(error);
    }
});

app.get('/api/list', async (req, res, next) => {
    if(req.headers['risu-auth'].trim() !== password.trim()){
        console.log('incorrect')
        res.status(400).send({
            error:'Password Incorrect'
        });
        return
    }
    try {
        const data = (await fs.readdir(path.join(savePath))).map((v) => {
            return Buffer.from(v, 'hex').toString('utf-8')
        })
        res.send({
            success: true,
            content: data
        });
    } catch (error) {
        next(error);
    }
});

app.post('/api/write', async (req, res, next) => {
    if(req.headers['risu-auth'].trim() !== password.trim()){
        console.log('incorrect')
        res.status(400).send({
            error:'Password Incorrect'
        });
        return
    }
    const filePath = req.headers['file-path'];
    const fileContent = req.body
    if (!filePath || !fileContent) {
        res.status(400).send({
            error:'File path required'
        });
        return;
    }
    if(!isHex(filePath)){
        res.status(400).send({
            error:'Invaild Path'
        });
        return;
    }

    try {
        await fs.writeFile(path.join(savePath, filePath), fileContent);
        res.send({
            success: true
        });
    } catch (error) {
        next(error);
    }
});

app.listen(6001, () => {
    console.log("Server is listening on http://localhost:6001/");
});