const fs = require('fs');
const process = require('process');
const pathtools = require('path');
const express = require('express');
const fileUpload = require("express-fileupload");
const { spawn } = require('child_process');
const pug = require('pug');
const unzip = require('unzip');
const app = express();
const port = 8000;
const aisPath = "pytron_run/ai_manager/"
const aisPathOld = "pytron_run/ai_manager_old"

// Create the directories to store the files
try { fs.mkdirSync('pytron_run/ai_manager'); } catch { }
try { fs.mkdirSync('pytron_run/ai_manager_old'); } catch { }

let pythonRunning = false;
let pythonShouldRun = false;

function runPython() {
    process.stdout.write('Requested to run python');
    if (pythonRunning) {
        process.stdout.write(' buy python is already running');
        pythonShouldRun = true;
    } else {
        pythonRunning = true;
    }
    process.stdout.write('\n');

    let p = spawn('python', ['pytron_run/run.py']);
    p.stdout.on('data', (data) => {
        let content = data.toString().split('\n');
        for (let line of content) {
            console.log("run.py: " + line);
        }
    });

    p.stderr.on('data', (data) => {
        let content = data.toString().split('\n');
        for (let line of content) {
            console.log("run.py: " + line);
        }
    });

    p.on('close', (code) => {
        process.stdout.write("Python finished executing");
        if (pythonShouldRun) {
            process.stdout.write(' but another request arrive, so we will relaunch it\n');
            pythonShouldRun = false;
            runPython();
        } else {
            process.stdout.write('\n');
            pythonRunning = false;
        }
    });
}

function parse(data) {
    let content = JSON.parse(data);
    let parsed = {ais: [], battles: {}};
    for (let ai of content.ais) {
        parsed.ais.push({
            name: ai,
            victories: 0,
            defeats: 0,
        });
    }

    for (let key in content.battles) {
        let battlers = key.split('/');
        let ai1 = battlers[0];
        let ai2 = battlers[1];
        parsed.battles[ai1 + '/' + ai2] = Math.floor(100 * content.battles[key]);
        parsed.battles[ai2 + '/' + ai1] = 100 - parsed.battles[ai1 + '/' + ai2];
    }
    parsed.sortedAis = parsed.ais.slice(0);

    parsed.sortedAis.sort((a, b) => {
        if (a.victories < b.victories) {
            return -1;
        } else if (a.victories > b.victories) {
            return 1;
        } else {
            if (a.defeats > b.defeats) {
                return -1;
            } else if (a.defeats < b.defeats) {
                return 1;
            } else {
                return 0;
            }
        }
    });

    return parsed;
}

app.set('view engine', 'pug');
app.use(fileUpload());

app.get('/', (req, res) => {
    fs.readFile('assets/data.json', 'utf-8', (err, data) => {
        if (err != null) {
            console.log(err);
        }
        let parsed = parse(data);
        res.render('index', parsed);
    });
});

app.get('/upload', (req, res) => {
    res.render('upload', {});
});

app.post('/upload-target', (req, res) => {
    let path = pathtools.join(aisPath, req.body.name)

    try {
        if (fs.statSync(path).isDirectory()) {
            // Move it to old
            let version = 0;
            for(;;) {
                let movePath = pathtools.join(aisPathOld, req.body.name + '.' + version);
                try {
                    fs.statSync(movePath);
                    // If the sync succeded, it means that the directory already exists
                    version++;
                } catch {
                    // If we're here, it means that we found the right path. We
                    // will move the old one to the old directories, and save
                    // the new one
                    fs.renameSync(path, movePath);
                    break;
                }
            }
        }
    } catch {
        // Nothing to do here
    }

    fs.mkdirSync(path);

    let zipfile = pathtools.join(path, "archive.zip");
    req.files.archive.mv(zipfile, (err) => {
        console.log(err);
        fs.createReadStream(zipfile)
            .pipe(unzip.Extract({path}))
            .on('close', () => {
                // Trigger python_run
                runPython();
                res.send('yo');
            })
            .on('error', () => {
                res.send('an error occured while extracting the archive')
            });
    });
});

app.use('/static', express.static('static'));

app.listen(port, () => {
    console.log(`Server listening on port ${port}!`)
})