const {Worker, isMainThread, parentPort, workerData} = require("worker_threads");
const readCht = require("./cht");
const { readFileSync } = require("fs");
const ncpu = require("os").availableParallelism();

const loadcheat = (order, serial, title, file) => {
    try {
        const chtfile = readFileSync(file, {encoding: "utf-8"});
        const cheat = readCht(chtfile, { serial }, order);
        return { serial, cheat }
    }
    catch (e) {
        //console.log("bad cheat: %s[order=%d]\n%s", title, order, e.stack)
        return { serial }
    }
}

if( isMainThread ) {
    module.exports = ncpu > 3 ? function(list) {
        const nPerThread = Math.ceil(list.length / ncpu);
        const results = new Array(ncpu);
        let n = 0;
        return new Promise( ok => {
            const workers = new Array(ncpu).fill(0).map( (_,i) => {
                const sublist = list.slice(i * nPerThread, (i+1) * nPerThread);
                const worker = new Worker(__filename, { workerData: sublist });
                worker.once("message", msg => {
                    results[i] = msg;
                    worker.unref();
                    if( ++n == ncpu ) ok(results.flat());
                });
            } );
        });
    } : list => Promise.resolve( list.map( game => {
        const [order, serial, title] = game;
        const file = `./gba/${order}.u8`;
        return loadcheat(order, serial, title ?? order, file);
    } ) );
}
else {
    const list = workerData;
    /*Promise.all( list.map( game => {
        const [order, serial, title] = game;
        const file = `./gba/${order}.u8`;
        return loadcheat(order, serial, title ?? order, file);
    } ) ).then( res => parentPort.postMessage(res) );*/
    parentPort.postMessage(
        list.map( game => {
            const [order, serial, title] = game;
            const file = `./gba/${order}.u8`;
            return loadcheat(order, serial, title ?? order, file);
        })
    );
}