wuWxapkg.js

const wu = require("./wuLib.js");
const wuJs = require("./wuJs.js");
const wuCfg = require("./wuConfig.js");
const wuMl = require("./wuWxml.js");
const wuSs = require("./wuWxss.js");
const path = require("path");
const fs = require("fs");

function header(buf) {
    console.log("\nHeader info:");
    let firstMark = buf.readUInt8(0);
    console.log("  firstMark: 0x%s", firstMark.toString(16));
    let unknownInfo = buf.readUInt32BE(1);
    console.log("  unknownInfo: ", unknownInfo);
    let infoListLength = buf.readUInt32BE(5);
    console.log("  infoListLength: ", infoListLength);
    let dataLength = buf.readUInt32BE(9);
    console.log("  dataLength: ", dataLength);
    let lastMark = buf.readUInt8(13);
    console.log("  lastMark: 0x%s", lastMark.toString(16));
    if (firstMark != 0xbe || lastMark != 0xed) throw Error("Magic number is not correct!");
    return [infoListLength, dataLength];
}

function genList(buf) {
    console.log("\nFile list info:");
    let fileCount = buf.readUInt32BE(0);
    console.log("  fileCount: ", fileCount);
    let fileInfo = [], off = 4;
    for (let i = 0; i < fileCount; i++) {
        let info = {};
        let nameLen = buf.readUInt32BE(off);
        off += 4;
        info.name = buf.toString('utf8', off, off + nameLen);
        off += nameLen;
        info.off = buf.readUInt32BE(off);
        off += 4;
        info.size = buf.readUInt32BE(off);
        off += 4;
        fileInfo.push(info);
        console.log(info);
    }
    return fileInfo;
}

function saveFile(dir, buf, list) {
    console.log("Saving files...");
    for (let info of list)
        wu.save(path.resolve(dir, (info.name.startsWith("/") ? "." : "") + info.name), buf.slice(info.off, info.off + info.size));
}

function packDone(dir, cb, order) {
    console.log("Unpack done.");
    let weappEvent = new wu.CntEvent, needDelete = {};
    weappEvent.encount(4);
    weappEvent.add(() => {
        wu.addIO(() => {
            console.log("Split and make up done.");
            if (!order.includes("d")) {
                console.log("Delete files...");
                wu.addIO(() => console.log("Deleted.\n\nFile done."));
                for (let name in needDelete) if (needDelete[name] >= 8) wu.del(name);
            }
            cb();
        });
    });

    function doBack(deletable) {
        for (let key in deletable) {
            if (!needDelete[key]) needDelete[key] = 0;
            needDelete[key] += deletable[key];//all file have score bigger than 8 will be delete.
        }
        weappEvent.decount();
    }

    //This will be the only func running this time, so async is needless.
    if (fs.existsSync(path.resolve(dir, "app-service.js"))) {//weapp
        console.log("Split app-service.js and make up configs & wxss & wxml & wxs...");
        wuCfg.doConfig(path.resolve(dir, "app-config.json"), doBack);
        wuJs.splitJs(path.resolve(dir, "app-service.js"), doBack);
        if (fs.existsSync(path.resolve(dir, "workers.js")))
            wuJs.splitJs(path.resolve(dir, "workers.js"), doBack);
        if (fs.existsSync(path.resolve(dir, "page-frame.html")))
            wuMl.doFrame(path.resolve(dir, "page-frame.html"), doBack, order);
        else if (fs.existsSync(path.resolve(dir, "app-wxss.js"))) {
            wuMl.doFrame(path.resolve(dir, "app-wxss.js"), doBack, order);
            if (!needDelete[path.resolve(dir, "page-frame.js")]) needDelete[path.resolve(dir, "page-frame.js")] = 8;
        } else throw Error("page-frame-like file is not found in the package by auto.");
        wuSs.doWxss(dir, doBack);//Force it run at last, becuase lots of error occured in this part
    } else if (fs.existsSync(path.resolve(dir, "game.js"))) {//wegame
        console.log("Split game.js and rewrite game.json...");
        let gameCfg = path.resolve(dir, "app-config.json");
        wu.get(gameCfg, cfgPlain => {
            let cfg = JSON.parse(cfgPlain);
            if (cfg.subContext) {
                console.log("Found subContext, splitting it...")
                delete cfg.subContext;
                let contextPath = path.resolve(dir, "subContext.js");
                wuJs.splitJs(contextPath, () => wu.del(contextPath));
            }
            wu.save(path.resolve(dir, "game.json"), JSON.stringify(cfg, null, 4));
            wu.del(gameCfg);
        });
        wuJs.splitJs(path.resolve(dir, "game.js"), () => {
            wu.addIO(() => {
                console.log("Split and rewrite done.");
                cb();
            });
        });
    } else throw Error("This package is unrecognizable.\nMay be this package is a subPackage which should be unpacked with -s=<MainDir>.\nOtherwise, please decrypted every type of file by hand.")
}

function doFile(name, cb, order) {
    for (let ord of order) if (ord.startsWith("s=")) global.subPack = ord.slice(3);
    console.log("Unpack file " + name + "...");
    let dir = path.resolve(name, "..", path.basename(name, ".wxapkg"));
    wu.get(name, buf => {
        let [infoListLength, dataLength] = header(buf.slice(0, 14));
        if (order.includes("o")) wu.addIO(console.log.bind(console), "Unpack done.");
        else wu.addIO(packDone, dir, cb, order);
        saveFile(dir, buf, genList(buf.slice(14, infoListLength + 14)));
    }, {});
}

module.exports = {doFile: doFile};
if (require.main === module) {
    wu.commandExecute(doFile, "Unpack a wxapkg file.\n\n[-o] [-d] [-s=<Main Dir>] <files...>\n\n-d Do not delete transformed unpacked files.\n-o Do not execute any operation after unpack.\n-s=<Main Dir> Regard all packages provided as subPackages and\n              regard <Main Dir> as the directory of sources of the main package.\n<files...> wxapkg files to unpack");
}