const express = require('express');
const childProcess = require('child_process');
const fs = require('fs').promises;
const path = require('path');
const async = require('async');
const bodyParser = require('body-parser');

const workingDir = process.env.REPO_DIR ?? "repo";
const buildQueue = async.queue(async (task) => {
    return build(task);
});

const app = express();

app.use(bodyParser.json());

app.post('/build', async (req, res) => {
    try{
        let output = await buildQueue.push(req.body);
        res.status(200);
        res.send(output);
    }catch(e){
        res.status(500);
        res.send(e);
    }
});

app.post('/pull', async (req, res) => {
    try{
        await pull();
        res.status(200);
        res.send("Pulled");
    }catch(e){
        res.status(500);
        res.send(e);
    }
}); 

main();

async function build(body){
    return await make();
}

async function main() {
    await setup();

    app.listen(3000, () => console.log('Server running on port 3000'));

    process.on('SIGINT', async () => {
        console.log("Shutting down");
        process.exit(0);
    });
}

async function pull(){
    await runCommand("git pull");
}

async function make(makeCommand = "make build"){
    try{
        await runCommand(makeCommand);
        let build =  await fs.readFile(path.join(workingDir,"build/bundle.min.lua"), "utf8");
        return build;
    }catch(e){
        console.log("Build failed");
    }finally{
        await runCommand("make clean");
    }
}

async function setup() {
    try {
        await fs.mkdir(workingDir);
    } catch (e) {
        if (e.code !== "EEXIST") {
            throw e;
        }
    }    

    if ((await fs.readdir(workingDir)).length !== 0) {
        return;
    }

    console.log("Setting up repo");
    await runCommand("git clone https://git.kapelle.org/niklas/cc-haxe.git .");
    await runCommand("make deps");
}

function runCommand(cmd) {
    return new Promise((resolve, reject) => {
        childProcess.exec(cmd,{
            cwd: workingDir,
        }, (err, stdout, stderr) => {
            if (err) {
                reject(err);
            }
        
            console.log(stdout);
            console.log(stderr);

            resolve();
        });
    });
}