generate.py

import sys
import os
import struct
import zipfile
import shutil

try:
    set
except NameError:
    from sets import Set as set

def generate_patched(online=True):
    if sys.version_info.major >= 3:
        import urllib.request

        request = urllib.request
        from urllib.request import urlopen
    else:
        import urllib2 as urllib

        request = urllib
        urlopen = urllib.urlopen

    url = "https://clients2.google.com/service/update2/crx?response=redirect&os=cros&arch=x86-64&os_arch=x86-64&nacl_arch=x86-64&prod=chromiumcrx&prodchannel=unknown&prodversion=124.0.0.0&acceptformat=crx2,crx3&x=id%3Daokihcpccmdjjkebakdanncddpdnkfla%26uc"

    # remove old dir
    if os.path.exists("temp"):
        shutil.rmtree("temp")

    if os.path.exists("www"):
        shutil.rmtree("www")

    os.makedirs("temp", exist_ok=True)
    print("Preparing to download extension...")

    print("Downloading extension...")
    furl = urlopen(url)
    size = 0
    with open("temp/extension.crx", "wb") as crx_out:
        chunk = True
        while chunk:
            chunk = furl.read(1024)
            if len(chunk) < 1:
                break
            crx_out.write(chunk)
            size += len(chunk)
        
        crx_out.close()

    print("Extension downloaded")

    print("Decoding extension...")
    with open("temp/extension.crx", "rb") as crx:
        magic_number = crx.read(4)
        magic_number_s = None
        magic_number_s = magic_number.decode("utf-8")
        if magic_number_s != "Cr24":
            print("Invalid extension file. Something went wrong...")
            sys.exit(1)
        
        version = struct.unpack(b"<I", crx.read(4))[0]

        public_key_length = struct.unpack(b"<I", crx.read(4))[0]
        zip_sig = b"\x50\x4b\x03\x04"

        if version <= 2:
            signature_key_length = struct.unpack(b"<I", crx.read(4))[0]
            if signature_key_length > 1024*4/8:
                print("Signature key length larget than normal.", signature_key_length)

            
            crx.seek(public_key_length+signature_key_length, os.SEEK_CUR)

        wrote = 0

        try:
            print("Saving extension zip...")
            with open("temp/extension.zip", "wb") as zip_out:
                buf = " "
                while buf:
                    buf = crx.read(1)
                    if buf:
                        zip_out.write(buf)
                        wrote += 1
                
                zip_out.close()
        except IOError as e:
            print("Error writing extension zip file", e)

        print("Saved extension zip file.")
        crx.close()

    print("Extracting extension...")
    with zipfile.ZipFile("temp/extension.zip", "r") as zip_ref:
        zip_ref.extractall("temp/www")
        zip_ref.close()

    print("Extension extracted.")

    print("Copying patch file...")

    shutil.copy("latealways_patch.js", "temp/www/latealways_patch.js")
    
    if online:
        ff = open("temp/www/latealways_patch.js", "a")
        ff.write("""import TIVarsLib from "./TIVarsLib.js"
window.lib = null;
TIVarsLib().then(result => window.lib = result);""")
        ff.close()

    print("Copied patch file.")

    print("Copying webmanifest...")

    shutil.copy("pwa.webmanifest", "temp/www/pwa.webmanifest")

    print("Copied webmanifest.")

    print("Copying TIVarsLib...")

    shutil.copy("TIVarsLib.js", "temp/www/TIVarsLib.js")
    shutil.copy("TIVarsLib.wasm", "temp/www/TIVarsLib.wasm")

    print("Patching index.html...")

    newhtml = ""
    with open("temp/www/index.html", "r") as index_file:
        newhtml = "<script type=\"module\" src=\"latealways_patch.js\"></script>\n"+(index_file.read().replace("        <title>", '        <link rel="manifest" href="pwa.webmanifest">\n        <title>'))
        index_file.close()

    with open("temp/www/index.html", "w") as index_file:
        index_file.write(newhtml)
        index_file.close()

    print("Patched index.html")

    print("Patching dialog-about")
    dialog_content = None
    with open("temp/www/templates/dialog-about.html", "r") as dialog_file:
        dialog_content = dialog_file.read().replace("../images/TI logo @2x.png", "images/TI logo @2x.png")
        dialog_file.close()

    with open("temp/www/templates/dialog-about.html", "w") as dialog_file:
        dialog_file.write(dialog_content)
        dialog_file.close()

    print("Patched dialog-about")

    print("Patching no-device")

    no_device_content = None
    with open("temp/www/templates/no-device.html", "r") as no_device_file:
        no_device_content = no_device_file.read().replace("Connect a graphing calculator using the USB cable.", "Click here to pair calculator.").replace("class=\"ConnectCalcsHelp\"", "class=\"ConnectCalcsHelp\" onclick=\"latealways_patch.pairDevice()\" style=\"cursor: pointer\"")
        no_device_file.close()

    with open("temp/www/templates/no-device.html", "w") as no_device_file:
        no_device_file.write(no_device_content)
        no_device_file.close()

    print("Patched no-device")

    print("Moving from temp to www...")

    shutil.move("temp/www", "./")

    print("Moved to www")

    print("Generating Service Worker...")

    files_in_www = []
    for root, dirs, files in os.walk("www/"):
        for file in files:
            files_in_www.append(os.path.join(root[4:], file))


    out = "const FILES_TO_CACHE = [\n    \"/\",\n"
    for file in files_in_www:
        if "_metadata" not in file:
            out += '    "'+file.replace("\\", "/")+'",\n'

    out += "];\n"

    out += """
    self.addEventListener('activate', event => {
    event.waitUntil(
        caches.keys().then(cacheNames => {
        return Promise.all(
            cacheNames.map(cacheName => caches.delete(cacheName))
        );
        })
    );
    })

    self.addEventListener('install', event => {
    event.waitUntil(
        caches.open('v1')
        .then(cache => cache.addAll(FILES_TO_CACHE))
    );
    });

    self.addEventListener("fetch", event => {
    event.respondWith(
        caches.match(event.request).then(async response => {
        let response2;
        if(navigator.onLine) {
            response2 = fetch(event.request).then(response => {
            let statuscode = response.status;
            if(statuscode == 200) {
                caches.open('v1').then(cache => {
                    cache.put(event.request, response.clone());
                });
            }
            return response.clone();
            });
        }
        if(response) {
            return response;
        } else {
            return await response2;
        }
        })
    );
    });

    """

    with open("www/sw.js", "w") as f:
        f.write(out)

    print("Cleaning up...")

    shutil.rmtree("temp")

    print("Cleaned up.")

    print("Done.")


if __name__ == "__main__":
    generate_patched()