# Original work Copyright 2016 Google Inc. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# Modified work Copyright 2022 Michael Gmelin. All Rights Reserved.
# This file, with modifications, is licensed under the above Apache License.
#
# Modified work Copyright 2022 Yubico AB. All Rights Reserved.
# This file, with modifications, is licensed under the above Apache License.

# FreeBSD HID driver.
#
# There are two options to access UHID on FreeBSD:
#
# hidraw(4) - New method, not enabled by default
#             on FreeBSD 13.x and earlier
# uhid(4) - Classic method, default option on
#           FreeBSD 13.x and earlier
#
# To avoid attaching the Yubikey as a keyboard, do:
#
#     usbconfig ugenX.Y add_quirk UQ_KBD_IGNORE
#     usbconfig ugenX.Y reset
#
# The list of available devices is shown using `usbconfig list`
# You can make these changes permanent by altering loader.conf.
#
# Starting from FreeBSD 13 hidraw(4) can be enabled using:
#
#     sysrc kld_list+="hidraw hkbd"
#     cat >>/boot/loader.conf<<EOF
#     hw.usb.usbhid.enable="1"
#     hw.usb.quirk.0="0x1050 0x0010 0 0xffff UQ_KBD_IGNORE"  # YKS_OTP
#     hw.usb.quirk.1="0x1050 0x0110 0 0xffff UQ_KBD_IGNORE"  # NEO_OTP
#     hw.usb.quirk.2="0x1050 0x0111 0 0xffff UQ_KBD_IGNORE"  # NEO_OTP_CCID
#     hw.usb.quirk.3="0x1050 0x0114 0 0xffff UQ_KBD_IGNORE"  # NEO_OTP_FIDO
#     hw.usb.quirk.4="0x1050 0x0116 0 0xffff UQ_KBD_IGNORE"  # NEO_OTP_FIDO_CCID
#     hw.usb.quirk.5="0x1050 0x0401 0 0xffff UQ_KBD_IGNORE"  # YK4_OTP
#     hw.usb.quirk.6="0x1050 0x0403 0 0xffff UQ_KBD_IGNORE"  # YK4_OTP_FIDO
#     hw.usb.quirk.7="0x1050 0x0405 0 0xffff UQ_KBD_IGNORE"  # YK4_OTP_CCID
#     hw.usb.quirk.8="0x1050 0x0407 0 0xffff UQ_KBD_IGNORE"  # YK4_OTP_FIDO_CCID
#     hw.usb.quirk.9="0x1050 0x0410 0 0xffff UQ_KBD_IGNORE"  # YKP_OTP_FIDO
#     EOF
#     reboot
#
import ctypes
import fcntl
import glob
import logging
import os
import re
import struct
import sys
from ctypes.util import find_library

from yubikit.core.otp import OtpConnection

from .base import USAGE_OTP, YUBICO_VID, OtpYubiKeyDevice

# Don't typecheck this file on Windows
assert sys.platform != "win32"  # nosec

logger = logging.getLogger(__name__)

devdir = "/dev/"

# /usr/include/dev/usb/usb_ioctl.h
USB_GET_REPORT = 0xC0205517
USB_SET_REPORT = 0x80205518
USB_GET_REPORT_DESC = 0xC0205515

# /usr/include/dev/hid/hidraw.h>
HIDIOCGRAWINFO = 0x40085520
HIDIOCGRDESC = 0x2000551F
HIDIOCGRDESCSIZE = 0x4004551E
HIDIOCGFEATURE_9 = 0xC0095524
HIDIOCSFEATURE_9 = 0x80095523


class HidrawConnection(OtpConnection):
    """
    hidraw(4) is FreeBSD's modern raw access driver, based on usbhid(4).
    It is available since FreeBSD 13 and can be activated by adding
    `hw.usb.usbhid.enable="1"` to `/boot/loader.conf`. The actual kernel
    module is loaded with `kldload hidraw`.
    """

    def __init__(self, path):
        self.fd = os.open(path, os.O_RDWR)

    def close(self):
        os.close(self.fd)

    def receive(self):
        buf = bytearray(1 + 8)
        fcntl.ioctl(self.fd, HIDIOCGFEATURE_9, buf, True)
        return buf[1:]

    def send(self, data):
        buf = bytes([0]) + data
        fcntl.ioctl(self.fd, HIDIOCSFEATURE_9, buf)

    @staticmethod
    def get_info(dev):
        buf = bytearray(4 + 2 + 2)
        fcntl.ioctl(dev, HIDIOCGRAWINFO, buf, True)
        return struct.unpack("<IHH", buf)

    @staticmethod
    def get_descriptor(dev):
        buf = bytearray(4)
        fcntl.ioctl(dev, HIDIOCGRDESCSIZE, buf, True)
        size = struct.unpack("<I", buf)[0]
        buf += bytearray(size)
        fcntl.ioctl(dev, HIDIOCGRDESC, buf, True)
        return buf[4:]

    @staticmethod
    def get_usage(dev):
        buf = HidrawConnection.get_descriptor(dev)
        usage, usage_page = (None, None)
        while buf:
            head, buf = buf[0], buf[1:]
            typ, size = 0xFC & head, 0x03 & head
            value, buf = buf[:size], buf[size:]
            if typ == 4:  # Usage page
                usage_page = struct.unpack("<I", value.ljust(4, b"\0"))[0]
                if usage is not None:
                    return usage_page, usage
            elif typ == 8:  # Usage
                usage = struct.unpack("<I", value.ljust(4, b"\0"))[0]
                if usage_page is not None:
                    return usage_page, usage

    @staticmethod
    def list_devices():
        devices = []
        for hidraw in glob.glob(devdir + "hidraw?*"):
            try:
                with open(hidraw, "rb") as f:
                    bustype, vid, pid = HidrawConnection.get_info(f)
                    if vid == YUBICO_VID and HidrawConnection.get_usage(f) == USAGE_OTP:
                        devices.append(OtpYubiKeyDevice(hidraw, pid, HidrawConnection))
            except Exception as e:
                logger.debug("Failed opening HID device", exc_info=e)
                continue
        return devices


# For UhidConnection
libc = ctypes.CDLL(find_library("c"))


class usb_gen_descriptor(ctypes.Structure):
    _fields_ = [
        (
            "ugd_data",
            ctypes.c_void_p,
        ),
        ("ugd_lang_id", ctypes.c_uint16),
        ("ugd_maxlen", ctypes.c_uint16),
        ("ugd_actlen", ctypes.c_uint16),
        ("ugd_offset", ctypes.c_uint16),
        ("ugd_config_index", ctypes.c_uint8),
        ("ugd_string_index", ctypes.c_uint8),
        ("ugd_iface_index", ctypes.c_uint8),
        ("ugd_altif_index", ctypes.c_uint8),
        ("ugd_endpt_index", ctypes.c_uint8),
        ("ugd_report_type", ctypes.c_uint8),
        ("reserved", ctypes.c_uint8 * 8),
    ]


class UhidConnection(OtpConnection):
    """
    uhid(4) is FreeBSD's classic USB hid access driver and enabled
    by default in FreeBSD 13.x and earlier.
    """

    def __init__(self, path):
        self.fd = os.open(path, os.O_RDWR)

    def close(self):
        os.close(self.fd)

    def receive(self):
        buf = ctypes.create_string_buffer(9)
        desc = usb_gen_descriptor(
            ugd_data=ctypes.addressof(buf),
            ugd_maxlen=ctypes.sizeof(buf),
            ugd_report_type=3,
        )
        ret = libc.ioctl(self.fd, USB_GET_REPORT, ctypes.pointer(desc))
        if ret != 0:
            raise ValueError("ioctl failed: " + str(ret))
        return buf[:-1]

    def send(self, data):
        buf = ctypes.create_string_buffer(8)
        for i in range(0, len(data)):
            buf[i] = data[i]

        desc = usb_gen_descriptor(
            ugd_data=ctypes.addressof(buf),
            ugd_maxlen=len(buf),
            ugd_report_type=0x3,
        )
        ret = libc.ioctl(self.fd, USB_SET_REPORT, ctypes.pointer(desc))
        if ret != 0:
            raise ValueError("ioctl failed: " + str(ret))

    @staticmethod
    def get_usage(dev):
        c_data = ctypes.create_string_buffer(4096)
        desc = usb_gen_descriptor(
            ugd_data=ctypes.addressof(c_data),
            ugd_maxlen=ctypes.sizeof(c_data),
            ugd_report_type=3,
        )
        ret = libc.ioctl(dev, USB_GET_REPORT_DESC, ctypes.pointer(desc))
        if ret != 0:
            raise ValueError("ioctl failed")

        REPORT_DESCRIPTOR_KEY_MASK = 0xFC
        SIZE_MASK = ~REPORT_DESCRIPTOR_KEY_MASK
        USAGE_PAGE = 0x04
        USAGE = 0x08

        data = c_data.raw
        usage, usage_page = (None, None)
        while data and not (usage and usage_page):
            head, data = struct.unpack_from(">B", data)[0], data[1:]
            key, size = REPORT_DESCRIPTOR_KEY_MASK & head, SIZE_MASK & head
            value = struct.unpack_from("<I", data[:size].ljust(4, b"\0"))[0]
            data = data[size:]
            if key == USAGE_PAGE and not usage_page:
                usage_page = value
            elif key == USAGE and not usage:
                usage = value

        return (usage_page, usage)

    @staticmethod
    def get_info(index):
        vendor_re = re.compile("vendor=(0x[0-9a-fA-F]+)")
        product_re = re.compile("product=(0x[0-9a-fA-F]+)")
        sernum_re = re.compile('sernum="([^"]+)')

        pnpinfo = ("dev.uhid." + index + ".%pnpinfo").encode()

        ovalue = ctypes.create_string_buffer(1024)
        olen = ctypes.c_size_t(ctypes.sizeof(ovalue))
        key = ctypes.c_char_p(pnpinfo)
        retval = libc.sysctlbyname(key, ovalue, ctypes.byref(olen), None, None)
        if retval != 0:
            raise IOError("sysctlbyname failed")

        value = ovalue.value[: olen.value].decode()
        m = vendor_re.search(value)
        vid = int(m.group(1), 16) if m else None
        m = product_re.search(value)
        pid = int(m.group(1), 16) if m else None
        m = sernum_re.search(value)
        serial = m.group(1) if m else None
        return (vid, pid, serial)

    @staticmethod
    def list_devices():
        devices = []
        for uhid in glob.glob(devdir + "uhid?*"):
            index = uhid[len(devdir) + len("uhid") :]
            if not index.isdigit():
                continue

            try:
                (vid, pid, serial) = UhidConnection.get_info(index)
                if vid == YUBICO_VID:
                    with open(uhid, "rb") as f:
                        if UhidConnection.get_usage(f.fileno()) == USAGE_OTP:
                            devices.append(OtpYubiKeyDevice(uhid, pid, UhidConnection))
            except Exception as e:
                logger.debug("Failed opening HID device", exc_info=e)
                continue
        return devices


def list_devices():
    devices = HidrawConnection.list_devices()
    if not devices:
        devices = UhidConnection.list_devices()
    return devices