import * as path from "path";
import { v4 as uuidv4 } from 'uuid';
import * as fs from 'node:fs';
import * as child_process from 'node:child_process';

export async function sandBox(req:any,res:any,next:any){
    let timeout = req.query.timeout || 60000;
    const code = req.body;

    let name = uuidv4();
    let file = path.join(__dirname,`./${name}.js`);
    console.log(`writing file ${file}`);
    fs.writeFileSync(
        file,
        `
                console.log('entering ${name}');
                const done = async (result)=>{
                    let data = await result
                    console.log('done ${name}');
                    let fs = require('fs');
                    let path = require('path');
                    fs.writeFileSync(path.join(__dirname,'./${name}.child.json'),JSON.stringify({data},null,4));
                    process.exit(0);
                }
                ${code}
                `,
        "utf-8"
    );
    let child_logs: any = {
        start: new Date().toString(),
        timestamp: new Date().toString(),
        end: null,
        success: null,
        value: null,
        stdout: [],
        stderr: [],
        close: null,
        err: null
    };
    let childProc = child_process.exec(`node ${file}`, {
        cwd: __dirname,
    });
    
    childProc.stdout?.on("data", function (data) {
        child_logs.stdout.push(data);
    });
    childProc.stderr?.on("data", function (data) {
        child_logs.stderr.push(data);
    });
    childProc.on("close", function (code) {
        child_logs.success = code == 0;
        child_logs.close = `exit code : ${code}`;
    });
    childProc.on("error", function (err) {
        child_logs.err = err;
    });

    let checkHandle:any;
    let timeoutHandle:any;
    let task = Promise.race([
        new Promise((resolve) => {
            timeoutHandle = setTimeout(() => {
                clearInterval(checkHandle);
                childProc.kill();
                child_logs.end = new Date().toString();
                child_logs.success = false;
                child_logs.value = "timeout";
                fs.writeFileSync(
                    path.join(__dirname,`./${name}.json`),
                    JSON.stringify(child_logs, null, 4)
                );
                resolve("timeout");
            }, timeout);
        }),
        new Promise((resolve) => {
            checkHandle = setInterval(() => {
                child_logs.timestamp = new Date().toString();
                fs.writeFileSync(
                    path.join(__dirname,`./${name}.json`),
                    JSON.stringify(child_logs, null, 4)
                );
                if (child_logs.close) {
                    clearTimeout(timeoutHandle);
                    child_logs.end = new Date().toString();
                    try{
                        child_logs.value = require(path.join(__dirname,`./${name}.child.json`)).data;
                    }catch(e: any){
                        child_logs.value = e.message;
                    }
                    fs.writeFileSync(
                        path.join(__dirname,`./${name}.json`),
                        JSON.stringify(child_logs, null, 4)
                    );
                    resolve("done");
                }
            }, 1000);
        }),
    ]);
        let waitHandle = await task;
        if (waitHandle == "done") {
            res.status(200).send(child_logs);
        } else {
            res.status(500).send(child_logs);
        }
    
}