const { readFile, writeFile } = require("fs/promises");
const transform = require("./worker");
const fastly = process.env.OAFCHT_NO_ITER==='1';

const loadlist = async () => {
    const datfile = await readFile("./serial.json");
    const datas = JSON.parse(datfile.toString());
    // 避免使用迭代器方法，减少CPU（已走过performance对比流程）
    // ---------------原来的代码在这里------------------
    if( fastly === false ){
        return Object.entries(datas).filter(n => n[1] != "????");
    }
    // ---------------修改的代码在这里------------------
    const entries = Object.entries(datas);
    const retval = new Array(entries.length);
    let l = 0;
    for( const data of entries ){
        if( data[1] !== "????" ) retval[l++] = data;
    }
    retval.length = l;
    return retval;
    // ---------------修改的代码完结处------------------
}

const format = valid => {
    valid.sort((a, b) => a.serial.localeCompare(b.serial));
    console.info(`valid rom has ${valid.length}`);

    const enc = new TextEncoder();
    //const size = Symbol("length");
    const concatUnit = 10240;
    const align = (n, base) => base * Math.floor((n + base - 1) / base);
    const size = new WeakMap()
    const concat = (a, b) => {
        const sizea = size.get(a);
        let len = (sizea || 0) + b.length;
        if (len > a.length) {
            let n = new (Object.getPrototypeOf(a).constructor)(align(len, concatUnit) * 2);
            n.set(a, 0);
            n.set(b, sizea);
            size.set(n, len);
            return n;
        }
        else {
            a.set(b, sizea);
            size.set(a, len);
            return a;
        }
    }
    // 避免使用迭代器方法，减少CPU（已走过performance对比流程）
    // ---------------原来的代码在这里------------------
    const getnametable = fastly === false ? list => list.reduce((r, { serial, cheat }, idx, arr) => {
        const val = serial.slice(0, -1);
        const size1 = size.get(r[1]);
        if (val != r[4]) {
            if (size1 > 0 && r[2] - r[1].at(size1 - 1) > r[3])
                r[3] = r[2] - r[1].at(size1 - 1);
            r[0] = concat(r[0], enc.encode(val))
            r[1] = concat(r[1], [r[2]]);
            r[4] = val;
        }
        r[2] = r[2] + cheat.length;
        if (idx + 1 == arr.length) {
            if (r[2] - r[1].at(size1 - 1) > r[3])
                r[3] = r[2] - r[1].at(size1 - 1);
            r[1] = concat(r[1], [r[2]]);
        }
        return r;
    }, [concat(new Uint8Array(concatUnit), []), concat(new Uint16Array(concatUnit), []), 0, 0, ""])
    // ---------------修改的代码在这里------------------
    : list => {
        const ret = [concat(new Uint8Array(concatUnit), []), concat(new Uint16Array(concatUnit), []), 0, 0, ""];
        const {length} = list;
        for( let idx=0; idx < length; ++idx ){
            const { serial, cheat } = list[idx];
            const val = serial.slice(0, -1);
            const size1 = size.get(ret[1]);
            if( val != ret[4] ){
                if( size1 > 0 && ret[2] - ret[1].at(size1 - 1) > ret[3] )
                    ret[3] = ret[2] - ret[1].at(size1 - 1);
                ret[0] = concat(ret[0], enc.encode(val))
                ret[1] = concat(ret[1], [ret[2]]);
                ret[4] = val;
            }
            ret[2] = ret[2] + cheat.length;
            if( idx + 1 == length ){
                if( ret[2] - ret[1].at(size1 - 1) > ret[3] )
                    ret[3] = ret[2] - ret[1].at(size1 - 1);
                ret[1] = concat(ret[1], [ret[2]]);
           }
        }
        return ret;
    };
    // ---------------修改的代码完结处------------------


    // 避免使用迭代器方法，减少CPU（已走过performance对比流程）
    // ---------------原来的代码在这里------------------
    const expandcheat = fastly === false ? (list, base) => list.reduce((r, { cheat, serial }) => {
        const val = serial.charCodeAt(3);
        return cheat.reduce((r, { id, bin }) => {
            const off = r[2] + size.get(r[1]);
            r[0] = concat(r[0], [val | (off << 3), id])
            r[1] = concat(r[1], bin);
            return r;
        }, r);
    }, [concat(new Uint32Array(concatUnit), []), concat(new Uint8Array(concatUnit), []), align(base, 32)])
    // ---------------修改的代码在这里------------------
    : (list, base) => {
        const ret = [concat(new Uint32Array(concatUnit), []), concat(new Uint8Array(concatUnit), []), align(base, 32)];
        const {length} = list;
        for( let idx=0; idx < length; ++idx ){
            const { cheat, serial } = list[idx];
            const val = serial.charCodeAt(3);
            for( const { id, bin } of cheat ){
                const off = ret[2] + size.get(ret[1]);
                ret[0] = concat(ret[0], [val | (off << 3), id])
                ret[1] = concat(ret[1], bin);
            }
        }
        return ret;
    };
    // ---------------修改的代码完结处------------------

    const linkbuffer = (arr, ...l) => {
        for (let i of l) {
            const arrBa = arr[i];
            arr[i] = arrBa.slice(0, size.get(arrBa));
        }
        return arr;
    }

    const [sers, offs, chtc, maxl] = linkbuffer(getnametable(valid), 0, 1);
    const [cheats, expanded] = linkbuffer(expandcheat(valid, 8 + sers.length + offs.length * 2 + chtc * 8), 0, 1);
    console.info(`name: ${sers.length} cheats: ${chtc} maxl: ${maxl}`);

    const serialbase = 8;
    const offsetbase = serialbase + sers.length;
    const cheatbase = offsetbase + offs.length * 2;
    const expandbase = align(cheatbase + cheats.length * 4, 32);
    const total = expandbase + expanded.length;

    const output = new ArrayBuffer(total);
    // header: magic number: ACL\1-serial length(u32)
    const writter = new DataView(output);
    writter.setUint8(0, "A".charCodeAt());
    writter.setUint8(1, "C".charCodeAt());
    writter.setUint8(2, "L".charCodeAt());
    writter.setUint8(3, 1);

    const slen = sers.length / 3;
    writter.setUint16(4, slen, true);
    writter.setUint16(6, maxl, true);

    let ret = new Uint8Array(output);
    ret.set(sers, serialbase);
    ret.set(new Uint8Array(offs.buffer), offsetbase);
    ret.set(new Uint8Array(cheats.buffer), cheatbase);
    ret.set(expanded, expandbase);

    return ret;
}

const start = async () => {
    let begin = performance.now();
    let list = await loadlist();
    let roms = await transform(list);
    console.log(`all rom has ${roms.length} and time ${performance.now() - begin}`);
    // 避免使用迭代器方法，减少CPU（已走过performance对比流程）
    // ---------------原来的代码在这里------------------
    if( fastly === false ){
        roms = Object.entries(roms.reduce((r, data) => {
            if (!data) return r;
    
            const { serial, cheat } = data;
            if (!cheat || cheat.length == 0) return r;
            if (serial in r) r[serial] = [...r[serial], ...cheat];
            else r[serial] = cheat;
            return r;
        }, {})).map(([serial, cheat]) => ({ serial, cheat }));
    }
    // ---------------修改的代码在这里------------------
    else
    {
        const res = new Array(10240), idx = {};
        let l = 0;
        for( const data of roms ){
            if( !data ) continue;

            const { serial, cheat } = data;
            if( !cheat || cheat.length == 0 ) continue;

            const cheats = idx[serial] ? idx[serial] : [];
            cheats.push(...cheat);
            if( !idx[serial] ){
                idx[serial] = cheats;
                res[l++] = { serial, cheat: cheats };
            }
        }
        res.length = l;
        roms = res;
    }
    // ---------------修改的代码完结处------------------

    const content = await format( roms );
    await writeFile( "gba.acl", content );
}

start()