custominstall.py

#!/usr/bin/env python3

# This file is a part of custom-install.py.
#
# custom-install is copyright (c) 2019-2020 Ian Burgwin
# This file is licensed under The MIT License (MIT).
# You can find the full license text in LICENSE.md in the root of this project.

from argparse import ArgumentParser
from enum import Enum
from glob import glob
import gzip
from os import makedirs, rename, scandir
from os.path import dirname, join, isdir, isfile
from random import randint
from hashlib import sha256
from pprint import pformat
from shutil import copyfile, copy2, rmtree
import sys
from sys import platform, executable
from tempfile import TemporaryDirectory
from traceback import format_exception
from typing import BinaryIO, TYPE_CHECKING
import subprocess

if TYPE_CHECKING:
    from os import PathLike
    from typing import List, Union, Tuple

from events import Events

from pyctr.crypto import CryptoEngine, Keyslot, load_seeddb, get_seed
from pyctr.type.cdn import CDNReader, CDNError
from pyctr.type.cia import CIAReader, CIAError
from pyctr.type.ncch import NCCHSection
from pyctr.type.tmd import TitleMetadataError
from pyctr.util import roundup

if platform == 'msys':
    platform = 'win32'

is_windows = platform == 'win32'

if is_windows:
    from ctypes import c_wchar_p, pointer, c_ulonglong, windll
else:
    from os import statvfs

CI_VERSION = '2.1'

# used to run the save3ds_fuse binary next to the script
frozen = getattr(sys, 'frozen', False)
script_dir: str
if frozen:
    script_dir = dirname(executable)
else:
    script_dir = dirname(__file__)

# missing contents are replaced with 0xFFFFFFFF in the cmd file
CMD_MISSING = b'\xff\xff\xff\xff'

# the size of each file and directory in a title's contents are rounded up to this
TITLE_ALIGN_SIZE = 0x8000

# size to read at a time when copying files
READ_SIZE = 0x200000

# version for cifinish.bin
CIFINISH_VERSION = 3


# Placeholder for SDPathErrors
class SDPathError(Exception):
    pass


class InvalidCIFinishError(Exception):
    pass


class InstallStatus(Enum):
    Waiting = 0
    Starting = 1
    Writing = 2
    Finishing = 3
    Done = 4
    Failed = 5


def get_free_space(path: 'Union[PathLike, bytes, str]'):
    if is_windows:
        lpSectorsPerCluster = c_ulonglong(0)
        lpBytesPerSector = c_ulonglong(0)
        lpNumberOfFreeClusters = c_ulonglong(0)
        lpTotalNumberOfClusters = c_ulonglong(0)
        ret = windll.kernel32.GetDiskFreeSpaceW(c_wchar_p(path), pointer(lpSectorsPerCluster),
                                                pointer(lpBytesPerSector),
                                                pointer(lpNumberOfFreeClusters),
                                                pointer(lpTotalNumberOfClusters))
        if not ret:
            raise WindowsError
        free_blocks = lpNumberOfFreeClusters.value * lpSectorsPerCluster.value
        free_bytes = free_blocks * lpBytesPerSector.value
    else:
        stv = statvfs(path)
        free_bytes = stv.f_bavail * stv.f_frsize
    return free_bytes


def load_cifinish(path: 'Union[PathLike, bytes, str]'):
    try:
        with open(path, 'rb') as f:
            header = f.read(0x10)
            if header[0:8] != b'CIFINISH':
                raise InvalidCIFinishError('CIFINISH magic not found')
            version = int.from_bytes(header[0x8:0xC], 'little')
            count = int.from_bytes(header[0xC:0x10], 'little')
            data = {}
            for _ in range(count):
                if version == 1:
                    # ignoring the titlekey and common key index, since it's not useful in this scenario
                    raw_entry = f.read(0x30)
                    if len(raw_entry) != 0x30:
                        raise InvalidCIFinishError(f'title entry is not 0x30 (version {version})')

                    title_magic = raw_entry[0xA:0x10]
                    title_id = int.from_bytes(raw_entry[0:8], 'little')
                    has_seed = raw_entry[0x9]
                    seed = raw_entry[0x20:0x30]

                elif version == 2:
                    # this is assuming the "wrong" version created by an earlier version of this script
                    # there wasn't a version of custom-install-finalize that really accepted this version
                    raw_entry = f.read(0x20)
                    if len(raw_entry) != 0x20:
                        raise InvalidCIFinishError(f'title entry is not 0x20 (version {version})')

                    title_magic = raw_entry[0:6]
                    title_id = int.from_bytes(raw_entry[0x6:0xE], 'little')
                    has_seed = raw_entry[0xE]
                    seed = raw_entry[0x10:0x20]

                elif version == 3:
                    raw_entry = f.read(0x20)
                    if len(raw_entry) != 0x20:
                        raise InvalidCIFinishError(f'title entry is not 0x20 (version {version})')

                    title_magic = raw_entry[0:6]
                    title_id = int.from_bytes(raw_entry[0x8:0x10], 'little')
                    has_seed = raw_entry[0x6]
                    seed = raw_entry[0x10:0x20]

                else:
                    raise InvalidCIFinishError(f'unknown version {version}')

                if title_magic == b'TITLE\0':
                    data[title_id] = {'seed': seed if has_seed else None}

        return data
    except FileNotFoundError:
        # allow the caller to easily create a new database in the same place where an existing one would be updated
        return {}


def save_cifinish(path: 'Union[PathLike, bytes, str]', data: dict):
    with open(path, 'wb') as out:
        entries = sorted(data.items())

        out.write(b'CIFINISH')
        out.write(CIFINISH_VERSION.to_bytes(4, 'little'))
        out.write(len(entries).to_bytes(4, 'little'))

        for tid, data in entries:
            finalize_entry_data = [
                # magic
                b'TITLE\0',
                # has seed
                bool(data['seed']).to_bytes(1, 'little'),
                # padding
                b'\0',
                # title id
                tid.to_bytes(8, 'little'),
                # seed, if needed
                (data['seed'] if data['seed'] else (b'\0' * 0x10))
            ]

            out.write(b''.join(finalize_entry_data))


def get_install_size(title: 'Union[CIAReader, CDNReader]'):
    sizes = [1] * 5

    if title.tmd.save_size:
        # one for the data directory, one for the 00000001.sav file
        sizes.extend((1, title.tmd.save_size))

    for record in title.content_info:
        sizes.append(record.size)

    # this calculates the size to put in the Title Info Entry
    title_size = sum(roundup(x, TITLE_ALIGN_SIZE) for x in sizes)

    return title_size


class CustomInstall:
    def __init__(self, *, movable, sd, cifinish_out=None, overwrite_saves=False, skip_contents=False,
                 boot9=None, seeddb=None):
        self.event = Events()
        self.log_lines = []  # Stores all info messages for user to view

        self.crypto = CryptoEngine(boot9=boot9)
        self.crypto.setup_sd_key_from_file(movable)
        self.seeddb = seeddb
        self.readers: 'List[Tuple[Union[CDNReader, CIAReader], Union[PathLike, bytes, str]]]' = []
        self.sd = sd
        self.skip_contents = skip_contents
        self.overwrite_saves = overwrite_saves
        self.cifinish_out = cifinish_out
        self.movable = movable

    def copy_with_progress(self, src: BinaryIO, dst: BinaryIO, size: int, path: str, fire_event: bool = True):
        left = size
        cipher = self.crypto.create_ctr_cipher(Keyslot.SD, self.crypto.sd_path_to_iv(path))
        hasher = sha256()
        while left > 0:
            to_read = min(READ_SIZE, left)
            data = src.read(READ_SIZE)
            hasher.update(data)
            dst.write(cipher.encrypt(data))
            left -= to_read
            total_read = size - left
            if fire_event:
                self.event.update_percentage((total_read / size) * 100, total_read / 1048576, size / 1048576)

        return hasher.digest()

    @staticmethod
    def get_reader(path: 'Union[PathLike, bytes, str]'):
        if isdir(path):
            # try the default tmd file
            reader = CDNReader(join(path, 'tmd'))
        else:
            try:
                reader = CIAReader(path)
            except CIAError:
                # if there was an error with parsing the CIA header,
                # the file would be tried in CDNReader next (assuming it's a tmd)
                # any other error should be propagated to the caller
                reader = CDNReader(path)
        return reader

    def prepare_titles(self, paths: 'List[PathLike]'):
        if self.seeddb:
            load_seeddb(self.seeddb)

        readers = []
        for path in paths:
            self.log(f'Reading {path}')
            try:
                reader = self.get_reader(path)
            except (CIAError, CDNError, TitleMetadataError):
                self.log(f"Couldn't read {path}, likely corrupt or not a CIA or CDN title")
                continue
            if reader.tmd.title_id.startswith('00048'):  # DSiWare
                self.log(f'Skipping {reader.tmd.title_id} - DSiWare is not supported')
                continue
            readers.append((reader, path))
        self.readers = readers

    def check_size(self):
        total_size = 0
        for r, _ in self.readers:
            total_size += get_install_size(r)

        free_space = get_free_space(self.sd)
        return total_size, free_space

    def check_for_id0(self):
        sd_path = join(self.sd, 'Nintendo 3DS', self.crypto.id0.hex())
        return isdir(sd_path)

    def start(self):
        if frozen:
            save3ds_fuse_path = join(script_dir, 'bin', 'save3ds_fuse')
        else:
            save3ds_fuse_path = join(script_dir, 'bin', platform, 'save3ds_fuse')
        if is_windows:
            save3ds_fuse_path += '.exe'
        if not isfile(save3ds_fuse_path):
            self.log("Couldn't find " + save3ds_fuse_path, 2)
            return None, False, 0

        crypto = self.crypto
        # TODO: Move a lot of these into their own methods
        self.log("Finding path to install to...")
        [sd_path, id1s] = self.get_sd_path()
        if len(id1s) > 1:
            raise SDPathError(f'There are multiple id1 directories for id0 {crypto.id0.hex()}, '
                              f'please remove extra directories')
        elif len(id1s) == 0:
            raise SDPathError(f'Could not find a suitable id1 directory for id0 {crypto.id0.hex()}')
        id1 = id1s[0]
        sd_path = join(sd_path, id1)

        if self.cifinish_out:
            cifinish_path = self.cifinish_out
        else:
            cifinish_path = join(self.sd, 'cifinish.bin')

        try:
            cifinish_data = load_cifinish(cifinish_path)
        except InvalidCIFinishError as e:
            self.log(f'{type(e).__qualname__}: {e}')
            self.log(f'{cifinish_path} was corrupt!\n'
                     f'This could mean an issue with the SD card or the filesystem. Please check it for errors.\n'
                     f'It is also possible, though less likely, to be an issue with custom-install.\n'
                     f'Exiting now to prevent possible issues. If you want to try again, delete cifinish.bin from the SD card and re-run custom-install.')
            return None, False, 0

        db_path = join(sd_path, 'dbs')
        titledb_path = join(db_path, 'title.db')
        importdb_path = join(db_path, 'import.db')
        if not isfile(titledb_path):
            makedirs(db_path, exist_ok=True)
            with gzip.open(join(script_dir, 'title.db.gz')) as f:
                tdb = f.read()

            self.log(f'Creating title.db...')
            with open(titledb_path, 'wb') as o:
                with self.crypto.create_ctr_io(Keyslot.SD, o, self.crypto.sd_path_to_iv('/dbs/title.db')) as e:
                    e.write(tdb)

                    cmac = crypto.create_cmac_object(Keyslot.CMACSDNAND)
                    cmac_data = [b'CTR-9DB0', 0x2.to_bytes(4, 'little'), tdb[0x100:0x200]]
                    cmac.update(sha256(b''.join(cmac_data)).digest())

                    e.seek(0)
                    e.write(cmac.digest())

            self.log(f'Creating import.db...')
            with open(importdb_path, 'wb') as o:
                with self.crypto.create_ctr_io(Keyslot.SD, o, self.crypto.sd_path_to_iv('/dbs/import.db')) as e:
                    e.write(tdb)

                    cmac = crypto.create_cmac_object(Keyslot.CMACSDNAND)
                    cmac_data = [b'CTR-9DB0', 0x3.to_bytes(4, 'little'), tdb[0x100:0x200]]
                    cmac.update(sha256(b''.join(cmac_data)).digest())

                    e.seek(0)
                    e.write(cmac.digest())

            del tdb

        with TemporaryDirectory(suffix='-custom-install') as tempdir:
            # set up the common arguments for the two times we call save3ds_fuse
            save3ds_fuse_common_args = [
                save3ds_fuse_path,
                '-b', crypto.b9_path,
                '-m', self.movable,
                '--sd', self.sd,
                '--db', 'sdtitle',
                tempdir
            ]

            extra_kwargs = {}
            if is_windows:
                # hide console window
                extra_kwargs['creationflags'] = 0x08000000  # CREATE_NO_WINDOW

            # extract the title database to add our own entry to
            self.log('Extracting Title Database...')
            out = subprocess.run(save3ds_fuse_common_args + ['-x'],
                                 stdout=subprocess.PIPE,
                                 stderr=subprocess.STDOUT,
                                 encoding='utf-8',
                                 **extra_kwargs)
            if out.returncode:
                for l in out.stdout.split('\n'):
                    self.log(l)
                self.log('Command line:')
                for l in pformat(out.args).split('\n'):
                    self.log(l)
                return None, False, 0

            install_state = {'installed': [], 'failed': []}

            # Now loop through all provided cia files
            for idx, info in enumerate(self.readers):
                cia, path = info

                self.event.on_cia_start(idx)
                self.event.update_status(path, InstallStatus.Starting)

                temp_title_root = join(self.sd, f'ci-install-temp-{cia.tmd.title_id}-{randint(0, 0xFFFFFFFF):08x}')
                makedirs(temp_title_root, exist_ok=True)

                tid_parts = (cia.tmd.title_id[0:8], cia.tmd.title_id[8:16])

                try:
                    display_title = f'{cia.contents[0].exefs.icon.get_app_title().short_desc} - {cia.tmd.title_id}'
                except:
                    display_title = cia.tmd.title_id
                self.log(f'Installing {display_title}...')

                title_size = get_install_size(cia)

                # checks if this is dlc, which has some differences
                is_dlc = tid_parts[0] == '0004008c'

                # this checks if it has a manual (index 1) and is not DLC
                has_manual = (not is_dlc) and (1 in cia.contents)

                # this gets the extdata id from the extheader, stored in the storage info area
                try:
                    with cia.contents[0].open_raw_section(NCCHSection.ExtendedHeader) as e:
                        e.seek(0x200 + 0x30)
                        extdata_id = e.read(8)
                except KeyError:
                    # not an executable title
                    extdata_id = b'\0' * 8

                # cmd content id, starts with 1 for non-dlc contents
                cmd_id = len(cia.content_info) if is_dlc else 1
                cmd_filename = f'{cmd_id:08x}.cmd'

                # this is where the final directory will be moved
                tidhigh_root = join(sd_path, 'title', tid_parts[0])

                # get the title root where all the contents will be
                title_root = join(sd_path, 'title', *tid_parts)
                content_root = join(title_root, 'content')
                # generate the path used for the IV
                title_root_cmd = f'/title/{"/".join(tid_parts)}'
                content_root_cmd = title_root_cmd + '/content'

                temp_content_root = join(temp_title_root, 'content')

                if not self.skip_contents:
                    self.event.update_status(path, InstallStatus.Writing)
                    makedirs(join(temp_content_root, 'cmd'), exist_ok=True)
                    if cia.tmd.save_size:
                        makedirs(join(temp_title_root, 'data'), exist_ok=True)
                    if is_dlc:
                        # create the separate directories for every 256 contents
                        for x in range(((len(cia.content_info) - 1) // 256) + 1):
                            makedirs(join(temp_content_root, f'{x:08x}'), exist_ok=True)

                    # maybe this will be changed in the future
                    tmd_id = 0

                    tmd_filename = f'{tmd_id:08x}.tmd'

                    # write the tmd
                    tmd_enc_path = content_root_cmd + '/' + tmd_filename
                    self.log(f'Writing {tmd_enc_path}...')
                    with open(join(temp_content_root, tmd_filename), 'wb') as o:
                        with self.crypto.create_ctr_io(Keyslot.SD, o, self.crypto.sd_path_to_iv(tmd_enc_path)) as e:
                            e.write(bytes(cia.tmd))

                    # in case the contents are corrupted
                    do_continue = False
                    # write each content
                    for co in cia.content_info:
                        content_filename = co.id + '.app'
                        if is_dlc:
                            dir_index = format((co.cindex // 256), '08x')
                            content_enc_path = content_root_cmd + f'/{dir_index}/{content_filename}'
                            content_out_path = join(temp_content_root, dir_index, content_filename)
                        else:
                            content_enc_path = content_root_cmd + '/' + content_filename
                            content_out_path = join(temp_content_root, content_filename)
                        self.log(f'Writing {content_enc_path}...')
                        with cia.open_raw_section(co.cindex) as s, open(content_out_path, 'wb') as o:
                            result_hash = self.copy_with_progress(s, o, co.size, content_enc_path)
                            if result_hash != co.hash:
                                self.log(f'WARNING: Hash does not match for {content_enc_path}!')
                                install_state['failed'].append(display_title)
                                rename(temp_title_root, temp_title_root + '-corrupted')
                                do_continue = True
                                self.event.update_status(path, InstallStatus.Failed)
                                break

                    if do_continue:
                        continue

                    # generate a blank save
                    if cia.tmd.save_size:
                        sav_enc_path = title_root_cmd + '/data/00000001.sav'
                        tmp_sav_out_path = join(temp_title_root, 'data', '00000001.sav')
                        sav_out_path = join(title_root, 'data', '00000001.sav')
                        if self.overwrite_saves or not isfile(sav_out_path):
                            cipher = crypto.create_ctr_cipher(Keyslot.SD, crypto.sd_path_to_iv(sav_enc_path))
                            # in a new save, the first 0x20 are all 00s. the rest can be random
                            data = cipher.encrypt(b'\0' * 0x20)
                            self.log(f'Generating blank save at {sav_enc_path}...')
                            with open(tmp_sav_out_path, 'wb') as o:
                                o.write(data)
                                o.write(b'\0' * (cia.tmd.save_size - 0x20))
                        else:
                            self.log(f'Copying original save file from {sav_enc_path}...')
                            copy2(sav_out_path, tmp_sav_out_path)

                    # generate and write cmd
                    cmd_enc_path = content_root_cmd + '/cmd/' + cmd_filename
                    cmd_out_path = join(temp_content_root, 'cmd', cmd_filename)
                    self.log(f'Generating {cmd_enc_path}')
                    highest_index = 0
                    content_ids = {}

                    for record in cia.content_info:
                        highest_index = record.cindex
                        with cia.open_raw_section(record.cindex) as s:
                            s.seek(0x100)
                            cmac_data = s.read(0x100)

                        id_bytes = bytes.fromhex(record.id)[::-1]
                        cmac_data += record.cindex.to_bytes(4, 'little') + id_bytes

                        cmac_ncch = crypto.create_cmac_object(Keyslot.CMACSDNAND)
                        cmac_ncch.update(sha256(cmac_data).digest())
                        content_ids[record.cindex] = (id_bytes, cmac_ncch.digest())

                    # add content IDs up to the last one
                    ids_by_index = [CMD_MISSING] * (highest_index + 1)
                    installed_ids = []
                    cmacs = []
                    for x in range(len(ids_by_index)):
                        try:
                            info = content_ids[x]
                        except KeyError:
                            # "MISSING CONTENT!"
                            # The 3DS does generate a cmac for missing contents, but I don't know how it works.
                            # It doesn't matter anyway, the title seems to be fully functional.
                            cmacs.append(bytes.fromhex('4D495353494E4720434F4E54454E5421'))
                        else:
                            ids_by_index[x] = info[0]
                            cmacs.append(info[1])
                            installed_ids.append(info[0])
                    installed_ids.sort(key=lambda x: int.from_bytes(x, 'little'))

                    final = (cmd_id.to_bytes(4, 'little')
                             + len(ids_by_index).to_bytes(4, 'little')
                             + len(installed_ids).to_bytes(4, 'little')
                             + (1).to_bytes(4, 'little'))
                    cmac_cmd_header = crypto.create_cmac_object(Keyslot.CMACSDNAND)
                    cmac_cmd_header.update(final)
                    final += cmac_cmd_header.digest()

                    final += b''.join(ids_by_index)
                    final += b''.join(installed_ids)
                    final += b''.join(cmacs)

                    cipher = crypto.create_ctr_cipher(Keyslot.SD, crypto.sd_path_to_iv(cmd_enc_path))
                    self.log(f'Writing {cmd_enc_path}')
                    with open(cmd_out_path, 'wb') as o:
                        o.write(cipher.encrypt(final))

                # this starts building the title info entry
                title_info_entry_data = [
                    # title size
                    title_size.to_bytes(8, 'little'),
                    # title type, seems to usually be 0x40
                    0x40.to_bytes(4, 'little'),
                    # title version
                    int(cia.tmd.title_version).to_bytes(2, 'little'),
                    # ncch version
                    cia.contents[0].version.to_bytes(2, 'little'),
                    # flags_0, only checking if there is a manual
                    (1 if has_manual else 0).to_bytes(4, 'little'),
                    # tmd content id, always starting with 0
                    (0).to_bytes(4, 'little'),
                    # cmd content id
                    cmd_id.to_bytes(4, 'little'),
                    # flags_1, only checking save data
                    (1 if cia.tmd.save_size else 0).to_bytes(4, 'little'),
                    # extdataid low
                    extdata_id[0:4],
                    # reserved
                    b'\0' * 4,
                    # flags_2, only using a common value
                    0x100000000.to_bytes(8, 'little'),
                    # product code
                    cia.contents[0].product_code.encode('ascii').ljust(0x10, b'\0'),
                    # reserved
                    b'\0' * 0x10,
                    # unknown
                    randint(0, 0xFFFFFFFF).to_bytes(4, 'little'),
                    # reserved
                    b'\0' * 0x2c
                ]

                self.event.update_status(path, InstallStatus.Finishing)
                if isdir(title_root):
                    self.log(f'Removing original install at {title_root}...')
                    rmtree(title_root)

                makedirs(tidhigh_root, exist_ok=True)
                rename(temp_title_root, title_root)

                cifinish_data[int(cia.tmd.title_id, 16)] = {'seed': (get_seed(cia.contents[0].program_id) if cia.contents[0].flags.uses_seed else None)}

                # This is saved regardless if any titles were installed, so the file can be upgraded just in case.
                save_cifinish(cifinish_path, cifinish_data)

                with open(join(tempdir, cia.tmd.title_id), 'wb') as o:
                    o.write(b''.join(title_info_entry_data))

                # import the directory, now including our title
                self.log('Importing into Title Database...')
                out = subprocess.run(save3ds_fuse_common_args + ['-i'],
                                     stdout=subprocess.PIPE,
                                     stderr=subprocess.STDOUT,
                                     encoding='utf-8',
                                     **extra_kwargs)
                if out.returncode:
                    for l in out.stdout.split('\n'):
                        self.log(l)
                    self.log('Command line:')
                    for l in pformat(out.args).split('\n'):
                        self.log(l)
                    install_state['failed'].append(display_title)
                    self.event.update_status(path, InstallStatus.Failed)
                else:
                    install_state['installed'].append(display_title)
                    self.event.update_status(path, InstallStatus.Done)

            copied = False
            # launchable applications, not DLC or update data
            application_count = len(glob(join(tempdir, '00040000*')))
            if install_state['installed']:
                if application_count >= 300:
                    self.log(f'{application_count} installed applications were detected.', 1)
                    self.log('The HOME Menu will only show 300 icons.', 1)
                    self.log('Some applications (not updates or DLC) will need to be deleted.', 1)
                finalize_3dsx_orig_path = join(script_dir, 'custom-install-finalize.3dsx')
                hb_dir = join(self.sd, '3ds')
                finalize_3dsx_path = join(hb_dir, 'custom-install-finalize.3dsx')
                if isfile(finalize_3dsx_orig_path):
                    self.log('Copying finalize program to ' + finalize_3dsx_path)
                    makedirs(hb_dir, exist_ok=True)
                    copyfile(finalize_3dsx_orig_path, finalize_3dsx_path)
                    copied = True

                self.log('FINAL STEP:')
                self.log('Run custom-install-finalize through homebrew launcher.')
                self.log('This will install a ticket and seed if required.')
                if copied:
                    self.log('custom-install-finalize has been copied to the SD card.')

            return install_state, copied, application_count

    def get_sd_path(self):
        sd_path = join(self.sd, 'Nintendo 3DS', self.crypto.id0.hex())
        id1s = []
        for d in scandir(sd_path):
            if d.is_dir() and len(d.name) == 32:
                try:
                    # check if the name can be converted to hex
                    # I'm not sure what the 3DS does if there is a folder that is not a 32-char hex string.
                    bytes.fromhex(d.name)
                except ValueError:
                    continue
                else:
                    id1s.append(d.name)
        return [sd_path, id1s]

    def log(self, message, mtype=0, errorname=None, end='\n'):
        """Logs an Message with a type. Format is similar to python errors

        There are 3 types of errors, indexed accordingly
        type 0 = Message
        type 1 = Warning
        type 2 = Error

        optionally, errorname can be a custom name as a string to identify errors easily
        """
        if errorname:
            errorname += ": "
        else:
            # No errorname provided
            errorname = ""
        types = [
            "",  # Type 0
            "Warning: ",  # Type 1
            "Error: "  # Type 2
        ]
        # Example: "Warning: UninformativeError: An error occured, try again.""
        msg_with_type = types[mtype] + errorname + str(message)
        self.log_lines.append(msg_with_type)
        self.event.on_log_msg(msg_with_type, end=end)
        return msg_with_type


if __name__ == "__main__":
    parser = ArgumentParser(description='Install a CIA to the SD card for a Nintendo 3DS system.')
    parser.add_argument('cia', help='CIA files', nargs='+')
    parser.add_argument('-m', '--movable', help='movable.sed file', required=True)
    parser.add_argument('-b', '--boot9', help='boot9 file')
    parser.add_argument('-s', '--seeddb', help='seeddb file')
    parser.add_argument('--sd', help='path to SD root', required=True)
    parser.add_argument('--skip-contents', help="don't add contents, only add title info entry", action='store_true')
    parser.add_argument('--overwrite-saves', help='overwrite existing save files', action='store_true')
    parser.add_argument('--cifinish-out', help='path for cifinish.bin file, defaults to (SD root)/cifinish.bin')

    print(f'custom-install {CI_VERSION} - https://github.com/ihaveamac/custom-install')
    args = parser.parse_args()

    installer = CustomInstall(boot9=args.boot9,
                              seeddb=args.seeddb,
                              movable=args.movable,
                              sd=args.sd,
                              overwrite_saves=args.overwrite_saves,
                              cifinish_out=args.cifinish_out,
                              skip_contents=(args.skip_contents or False))

    def log_handle(msg, end='\n'):
        print(msg, end=end)
    
    def percent_handle(total_percent, total_read, size):
        installer.log(f' {total_percent:>5.1f}%  {total_read:>.1f} MiB / {size:.1f} MiB\r', end='')

    def error(exc):
        for line in format_exception(*exc):
            for line2 in line.split('\n')[:-1]:
                installer.log(line2)

    installer.event.on_log_msg += log_handle
    installer.event.update_percentage += percent_handle
    installer.event.on_error += error

    if not installer.check_for_id0():
        installer.event.on_error(f'Could not find id0 directory {installer.crypto.id0.hex()} '
                                 f'inside Nintendo 3DS directory.')

    installer.prepare_titles(args.cia)

    if not args.skip_contents:
        total_size, free_space = installer.check_size()
        if total_size > free_space:
            installer.event.on_log_msg(f'Not enough free space.\n'
                                       f'Combined title install size: {total_size / (1024 * 1024):0.2f} MiB\n'
                                       f'Free space: {free_space / (1024 * 1024):0.2f} MiB')
            sys.exit(1)

    result, copied_3dsx, application_count = installer.start()
    if result is False:
        # save3ds_fuse failed
        installer.log('NOTE: Once save3ds_fuse is fixed, run the same command again with --skip-contents')
    if application_count >= 300:
        installer.log(f'\n\nWarning: {application_count} installed applications were detected.\n'
                      f'The HOME Menu will only show 300 icons.\n'
                      f'Some applications (not updates or DLC) will need to be deleted.')