import datetime
import sys
from typing import Optional, Sequence, Tuple, Union

import click
import cryptography
from cryptography import x509
from cryptography.hazmat.primitives import hashes, serialization
from cryptography.hazmat.primitives._asymmetric import AsymmetricPadding
from cryptography.hazmat.primitives.asymmetric import ec, rsa
from cryptography.hazmat.primitives.asymmetric import utils as asym_utils
from cryptography.hazmat.primitives.asymmetric.padding import PKCS1v15
from cryptography.hazmat.primitives.serialization import Encoding

from pynitrokey.cli.nk3 import nk3
from pynitrokey.helpers import check_experimental_flag, local_critical, local_print
from pynitrokey.tlv import Tlv

# Pyscard does not have wheels for all targets, leading to installation errors
# It is therefore made optional
#
# C901: `TryExcept` is too complex
try:  # noqa: C901
    from pynitrokey.nk3.piv_app import PivApp, find_by_id

    class RsaPivSigner(rsa.RSAPrivateKey):
        _device: PivApp
        _key_reference: int
        _public_key: rsa.RSAPublicKey

        def __init__(
            self, device: PivApp, key_reference: int, public_key: rsa.RSAPublicKey
        ):
            self._device = device
            self._key_reference = key_reference
            self._public_key = public_key

        def public_key(self) -> rsa.RSAPublicKey:
            return self._public_key

        @property
        def key_size(self) -> int:
            return self._public_key.key_size

        def sign(
            self,
            data: bytes,
            padding: AsymmetricPadding,
            algorithm: Union[asym_utils.Prehashed, hashes.HashAlgorithm],
        ) -> bytes:
            assert not isinstance(algorithm, asym_utils.Prehashed)
            assert isinstance(padding, PKCS1v15)
            assert isinstance(algorithm, hashes.SHA256)

            return self._device.sign_rsa2048(data, self._key_reference)

        def decrypt(self, ciphertext: bytes, padding: AsymmetricPadding) -> bytes:
            raise NotImplementedError()

        def private_numbers(self) -> rsa.RSAPrivateNumbers:
            raise NotImplementedError()

        def private_bytes(
            self,
            encoding: serialization.Encoding,
            format: serialization.PrivateFormat,
            encryption_algorithm: serialization.KeySerializationEncryption,
        ) -> bytes:
            raise NotImplementedError()

    class P256PivSigner(ec.EllipticCurvePrivateKey):
        _device: PivApp
        _key_reference: int
        _public_key: ec.EllipticCurvePublicKey

        def __init__(
            self,
            device: PivApp,
            key_reference: int,
            public_key: ec.EllipticCurvePublicKey,
        ):
            self._device = device
            self._key_reference = key_reference
            self._public_key = public_key

        def exchange(
            self, algorithm: ec.ECDH, peer_public_key: ec.EllipticCurvePublicKey
        ) -> bytes:
            raise NotImplementedError()

        def public_key(self) -> ec.EllipticCurvePublicKey:
            return self._public_key

        @property
        def curve(self) -> ec.EllipticCurve:
            return self._public_key.curve

        def private_numbers(self) -> ec.EllipticCurvePrivateNumbers:
            raise NotImplementedError()

        @property
        def key_size(self) -> int:
            return self._public_key.key_size

        def private_bytes(
            self,
            encoding: serialization.Encoding,
            format: serialization.PrivateFormat,
            encryption_algorithm: serialization.KeySerializationEncryption,
        ) -> bytes:
            raise NotImplementedError()

        def sign(
            self, data: bytes, signature_algorithm: ec.EllipticCurveSignatureAlgorithm
        ) -> bytes:
            assert isinstance(signature_algorithm, ec.ECDSA)
            assert isinstance(signature_algorithm.algorithm, hashes.SHA256)

            return self._device.sign_p256(data, self._key_reference)

    @nk3.group()
    @click.option(
        "--experimental",
        default=False,
        is_flag=True,
        help="Allow to execute experimental features",
    )
    def piv(experimental: bool) -> None:
        """Nitrokey PIV App"""
        check_experimental_flag(experimental)
        pass

    @piv.command(help="Authenticate with the admin key.")
    @click.argument(
        "admin-key",
        type=click.STRING,
        default="010203040506070801020304050607080102030405060708",
    )
    def admin_auth(admin_key: str) -> None:
        try:
            admin_key_bytes = bytearray.fromhex(admin_key)
        except ValueError:
            local_critical(
                "Key is expected to be an hexadecimal string",
                support_hint=False,
            )

        device = PivApp()
        device.authenticate_admin(admin_key_bytes)
        local_print("Authenticated successfully")

    @piv.command(help="Initialize the PIV application.")
    @click.argument(
        "admin-key",
        type=click.STRING,
        default="010203040506070801020304050607080102030405060708",
    )
    def init(admin_key: str) -> None:
        try:
            admin_key_bytes = bytearray.fromhex(admin_key)
        except ValueError:
            local_critical(
                "Key is expected to be an hexadecimal string",
                support_hint=False,
            )

        device = PivApp()
        device.authenticate_admin(admin_key_bytes)
        guid = device.init()
        local_print("Device intialized successfully")
        local_print(f"GUID: {guid.hex().upper()}")

    @piv.command(help="Print information about the PIV application.")
    def info() -> None:
        device = PivApp()
        serial_number = device.serial()
        local_print(f"Device: {serial_number}")
        reader = device.reader()
        local_print(f"Reader: {reader}")
        guid = device.guid()
        local_print(f"GUID: {guid.hex().upper()}")

        printed_head = False
        for key, slot in KEY_TO_CERT_OBJ_ID_MAP.items():
            cert = device.cert(bytes(bytearray.fromhex(slot)))
            if cert is not None:
                if not printed_head:
                    local_print("Keys:")
                    printed_head = True
                parsed_cert = x509.load_der_x509_certificate(cert)
                local_print(f"    {key}")
                local_print(
                    f"        algorithm: {parsed_cert.signature_algorithm_oid._name}"
                )
        if not printed_head:
            local_print("No certificate found")
        pass

    @piv.command(help="Change the admin key.")
    @click.option(
        "--current-admin-key",
        type=click.STRING,
        default="010203040506070801020304050607080102030405060708",
        help="Current admin key.",
    )
    @click.argument(
        "new-admin-key",
        type=click.STRING,
    )
    def change_admin_key(current_admin_key: str, new_admin_key: str) -> None:
        try:
            current_admin_key_bytes = bytearray.fromhex(current_admin_key)
            new_admin_key_bytes = bytearray.fromhex(new_admin_key)
        except ValueError:
            local_critical(
                "Key is expected to be an hexadecimal string",
                support_hint=False,
            )

        device = PivApp()
        device.authenticate_admin(current_admin_key_bytes)
        device.set_admin_key(new_admin_key_bytes)
        local_print("Changed key successfully")

    @piv.command(help="Change the PIN.")
    @click.option(
        "--current-pin",
        type=click.STRING,
        prompt="Enter the current PIN",
        hide_input=True,
        help="Current PIN.",
    )
    @click.option(
        "--new-pin",
        type=click.STRING,
        prompt="Enter the new PIN",
        hide_input=True,
        help="New PIN.",
    )
    def change_pin(current_pin: str, new_pin: str) -> None:
        device = PivApp()
        device.change_pin(current_pin, new_pin)
        local_print("Changed pin successfully")

    @piv.command(help="Change the PUK.")
    @click.option(
        "--current-puk",
        type=click.STRING,
        prompt="Enter the current PUK",
        hide_input=True,
        help="Current PUK.",
    )
    @click.option(
        "--new-puk",
        type=click.STRING,
        prompt="Enter the new PUK",
        hide_input=True,
        help="New PUK.",
    )
    def change_puk(current_puk: str, new_puk: str) -> None:
        device = PivApp()
        device.change_puk(current_puk, new_puk)
        local_print("Changed puk successfully")

    @piv.command(help="Reset the retry counter.")
    @click.option(
        "--puk",
        type=click.STRING,
        prompt="Enter the PUK",
        hide_input=True,
        help="Current PUK.",
    )
    @click.option(
        "--new-pin",
        type=click.STRING,
        prompt="Enter the new PIN",
        hide_input=True,
        help="New PIN.",
    )
    def reset_retry_counter(puk: str, new_pin: str) -> None:
        device = PivApp()
        device.reset_retry_counter(puk, new_pin)
        local_print("Unlocked PIN successfully")

    @piv.command(help="Reset the PIV application.")
    def factory_reset() -> None:
        device = PivApp()
        try:
            device.factory_reset()
        except ValueError:
            local_critical(
                "Factory reset could not be performed. You first need to lock the PIN with 3 failed attempts",
                support_hint=False,
            )
        local_print("Factory reset successfully")

    KEY_TO_CERT_OBJ_ID_MAP = {
        "9A": "5FC105",
        "9C": "5FC10A",
        "9D": "5FC10B",
        "9E": "5FC101",
        "82": "5FC10D",
        "83": "5FC10E",
        "84": "5FC10F",
        "85": "5FC110",
        "86": "5FC111",
        "87": "5FC112",
        "88": "5FC113",
        "89": "5FC114",
        "8A": "5FC115",
        "8B": "5FC116",
        "8C": "5FC117",
        "8D": "5FC118",
        "8E": "5FC119",
        "8F": "5FC11A",
        "90": "5FC11B",
        "91": "5FC11C",
        "92": "5FC11D",
        "93": "5FC11E",
        "94": "5FC11F",
        "95": "5FC120",
    }

    @piv.command(help="Generate a new key and certificate signing request.")
    @click.option(
        "--admin-key",
        type=click.STRING,
        default="010203040506070801020304050607080102030405060708",
        help="Current admin key",
    )
    @click.option(
        "--key",
        type=click.Choice(
            [
                "9A",
                "9C",
                "9D",
                "9E",
                "82",
                "83",
                "84",
                "85",
                "86",
                "87",
                "88",
                "89",
                "8A",
                "8B",
                "8C",
                "8D",
                "8E",
                "8F",
                "90",
                "91",
                "92",
                "93",
                "94",
                "95",
            ],
            case_sensitive=False,
        ),
        default="9A",
        help="Key slot for operation.",
    )
    @click.option(
        "--algo",
        type=click.Choice(["rsa2048", "nistp256"], case_sensitive=False),
        default="nistp256",
        help="Algorithm for the key.",
    )
    @click.option(
        "--domain-component",
        type=click.STRING,
        multiple=True,
        help="Domain component for the certificate signing request.",
    )
    @click.option(
        "--subject-name",
        type=click.STRING,
        multiple=True,
        help="Subject name for the certificate signing request.",
    )
    @click.option(
        "--subject-alt-name-upn",
        type=click.STRING,
        help="Subject alternative name (UPN) for the certificate signing request.",
    )
    @click.option(
        "--pin",
        type=click.STRING,
        prompt="Enter the PIN",
        hide_input=True,
        help="Current PIN.",
    )
    @click.option(
        "--path",
        type=click.Path(allow_dash=True),
        default="-",
        help="Write certificate signing request to path.",
    )
    def generate_key(
        admin_key: str,
        key: str,
        algo: str,
        domain_component: Optional[Sequence[str]],
        subject_name: Optional[Sequence[str]],
        subject_alt_name_upn: Optional[str],
        pin: str,
        path: str,
    ) -> None:
        try:
            admin_key_bytes = bytearray.fromhex(admin_key)
        except ValueError:
            local_critical(
                "Key is expected to be an hexadecimal string",
                support_hint=False,
            )
        key_hex = key.upper()
        key_ref = int(key_hex, 16)

        device = PivApp()
        device.authenticate_admin(admin_key_bytes)
        device.login(pin)

        algo = algo.lower()
        if algo == "rsa2048":
            algo_id = b"\x07"
        elif algo == "nistp256":
            algo_id = b"\x11"
        else:
            local_critical("Unimplemented algorithm", support_hint=False)

        body = Tlv.build([(0xAC, Tlv.build([(0x80, algo_id)]))])
        ins = 0x47
        p1 = 0
        p2 = key_ref
        response = device.send_receive(ins, p1, p2, body)

        data = Tlv.parse(response)
        data_tmp = find_by_id(0x7F49, data)
        if data_tmp is None:
            local_critical("Device did not send public key data")
            return

        data = Tlv.parse(data_tmp)

        if algo == "nistp256":
            key_data = find_by_id(0x86, data)
            if key_data is None:
                local_critical("Device did not send public key data")
                return
            key_data = key_data[1:]
            public_x = int.from_bytes(key_data[:32], byteorder="big", signed=False)
            public_y = int.from_bytes(key_data[32:], byteorder="big", signed=False)
            public_numbers_ecc = ec.EllipticCurvePublicNumbers(
                public_x,
                public_y,
                cryptography.hazmat.primitives.asymmetric.ec.SECP256R1(),
            )
            public_key_ecc = public_numbers_ecc.public_key()
        elif algo == "rsa2048":
            modulus_data = find_by_id(0x81, data)
            exponent_data = find_by_id(0x82, data)
            if modulus_data is None or exponent_data is None:
                local_critical("Device did not send public key data")
                return

            modulus = int.from_bytes(modulus_data, byteorder="big", signed=False)
            exponent = int.from_bytes(exponent_data, byteorder="big", signed=False)
            public_numbers_rsa = rsa.RSAPublicNumbers(exponent, modulus)
            public_key_rsa = public_numbers_rsa.public_key()
        else:
            local_critical("Unimplemented algorithm")

        certificate_builder = x509.CertificateBuilder()
        csr_builder = x509.CertificateSigningRequestBuilder()

        if domain_component is None:
            domain_component = []

        if subject_name is None:
            crypto_rdns = x509.Name([])
        else:
            crypto_rdns = x509.Name(
                [
                    x509.RelativeDistinguishedName(
                        [
                            x509.NameAttribute(x509.NameOID.DOMAIN_COMPONENT, subject)
                            for subject in domain_component
                        ]
                    ),
                    x509.RelativeDistinguishedName(
                        [
                            x509.NameAttribute(x509.NameOID.COMMON_NAME, subject)
                            for subject in subject_name
                        ]
                    ),
                ]
            )

        certificate_builder = (
            certificate_builder.subject_name(crypto_rdns)
            .issuer_name(crypto_rdns)
            .not_valid_before(datetime.datetime(2000, 1, 1, 0, 0))
            .not_valid_after(datetime.datetime(2099, 1, 1, 0, 0))
            .serial_number(x509.random_serial_number())
        )
        csr_builder = csr_builder.subject_name(crypto_rdns)

        # SEQUENCE
        # SEQUENCE
        # OBJECT            :aes-256-cbc
        # SEQUENCE
        # OBJECT            :id-aes256-wrap
        # SEQUENCE
        # OBJECT            :aes-192-cbc
        # SEQUENCE
        # OBJECT            :id-aes192-wrap
        # SEQUENCE
        # OBJECT            :aes-128-cbc
        # SEQUENCE
        # OBJECT            :id-aes128-wrap
        # SEQUENCE
        # OBJECT            :des-ede3-cbc
        # SEQUENCE
        # OBJECT            :des-cbc
        # SEQUENCE
        # OBJECT            :rc2-cbc
        # INTEGER           :80
        # SEQUENCE
        # OBJECT            :rc4
        # INTEGER           :0200
        smime_extension = bytes(
            bytearray.fromhex(
                "308183300B060960864801650304012A300B060960864801650304012D300B0609608648016503040116300B0609608648016503040119300B0609608648016503040102300B0609608648016503040105300A06082A864886F70D0307300706052B0E030207300E06082A864886F70D030202020080300E06082A864886F70D030402020200"
            )
        )

        crypto_extensions: Sequence[Tuple[x509.ExtensionType, bool]] = [
            (x509.BasicConstraints(ca=False, path_length=None), True),
            (
                x509.KeyUsage(
                    digital_signature=True,
                    content_commitment=True,
                    key_encipherment=False,
                    data_encipherment=False,
                    key_agreement=False,
                    key_cert_sign=False,
                    crl_sign=False,
                    encipher_only=False,
                    decipher_only=False,
                ),
                True,
            ),
            (
                x509.ExtendedKeyUsage(
                    [
                        x509.oid.ExtendedKeyUsageOID.CLIENT_AUTH,
                        x509.oid.ExtendedKeyUsageOID.SMARTCARD_LOGON,
                    ]
                ),
                False,
            ),
            (
                x509.UnrecognizedExtension(
                    oid=x509.oid.ObjectIdentifier("1.2.840.113549.1.9.15"),
                    value=smime_extension,
                ),
                False,
            ),
        ]

        for ext, critical in crypto_extensions:
            certificate_builder = certificate_builder.add_extension(ext, critical)
            csr_builder = csr_builder.add_extension(ext, critical)

        if subject_alt_name_upn is not None:
            crypto_sujbect_alt_name = x509.SubjectAlternativeName(
                [
                    x509.OtherName(
                        x509.ObjectIdentifier("1.3.6.1.4.1.311.20.2.3"),
                        # bytes, because it's different from bytearray, and tlv because
                        # it expects already DER encoded ASN1
                        bytes(
                            Tlv.build([(0x0C, subject_alt_name_upn.encode("utf-8"))])
                        ),
                    )
                ]
            )
            certificate_builder = certificate_builder.add_extension(
                crypto_sujbect_alt_name, False
            )
            csr_builder = csr_builder.add_extension(crypto_sujbect_alt_name, False)

        if algo == "nistp256":
            csr = csr_builder.sign(
                P256PivSigner(device, key_ref, public_key_ecc), hashes.SHA256()
            )
            certificate = certificate_builder.public_key(public_key_ecc).sign(
                P256PivSigner(device, key_ref, public_key_ecc), hashes.SHA256()
            )
        elif algo == "rsa2048":
            csr = csr_builder.sign(
                RsaPivSigner(device, key_ref, public_key_rsa), hashes.SHA256()
            )
            certificate = certificate_builder.public_key(public_key_rsa).sign(
                RsaPivSigner(device, key_ref, public_key_rsa), hashes.SHA256()
            )
        else:
            local_critical("Unimplemented algorithm")

        with click.open_file(path, mode="wb") as file:
            file.write(csr.public_bytes(Encoding.DER))

        payload = Tlv.build(
            [
                (0x5C, bytes(bytearray.fromhex(KEY_TO_CERT_OBJ_ID_MAP[key_hex]))),
                (
                    0x53,
                    Tlv.build(
                        [
                            (0x70, certificate.public_bytes(Encoding.DER)),
                            (0x71, bytes([0])),
                        ]
                    ),
                ),
            ]
        )

        device.send_receive(0xDB, 0x3F, 0xFF, payload)

    @piv.command(help="Write a certificate to a key slot.")
    @click.argument(
        "admin-key",
        type=click.STRING,
        default="010203040506070801020304050607080102030405060708",
    )
    @click.option(
        "--format",
        type=click.Choice(["DER", "PEM"], case_sensitive=False),
        default="PEM",
        help="Format of certificate.",
    )
    @click.option(
        "--key",
        type=click.Choice(
            [
                "9A",
                "9C",
                "9D",
                "9E",
                "82",
                "83",
                "84",
                "85",
                "86",
                "87",
                "88",
                "89",
                "8A",
                "8B",
                "8C",
                "8D",
                "8E",
                "8F",
                "90",
                "91",
                "92",
                "93",
                "94",
                "95",
            ],
            case_sensitive=False,
        ),
        default="9A",
        help="Key slot for operation.",
    )
    @click.option(
        "--path",
        type=click.Path(allow_dash=True),
        default="-",
        help="Write certificate to path.",
    )
    def write_certificate(admin_key: str, format: str, key: str, path: str) -> None:
        try:
            admin_key_bytes: bytes = bytearray.fromhex(admin_key)
        except ValueError:
            local_critical(
                "Key is expected to be an hexadecimal string",
                support_hint=False,
            )

        device = PivApp()
        device.authenticate_admin(admin_key_bytes)

        with click.open_file(path, mode="rb") as f:
            cert_bytes = f.read()
        format = format.upper()
        if format == "DER":
            cert_serialized = cert_bytes
            cert = x509.load_der_x509_certificate(cert_bytes)
        elif format == "PEM":
            cert = x509.load_pem_x509_certificate(cert_bytes)
            cert_serialized = cert.public_bytes(Encoding.DER)

        payload = Tlv.build(
            [
                (0x5C, bytes(bytearray.fromhex(KEY_TO_CERT_OBJ_ID_MAP[key.upper()]))),
                (0x53, Tlv.build([(0x70, cert_serialized), (0x71, bytes([0]))])),
            ]
        )

        device.send_receive(0xDB, 0x3F, 0xFF, payload)

    @piv.command(help="Read a certificate from a key slot.")
    @click.option(
        "--format",
        type=click.Choice(["DER", "PEM"], case_sensitive=False),
        default="PEM",
        help="Format of certificate.",
    )
    @click.option(
        "--key",
        type=click.Choice(
            [
                "9A",
                "9C",
                "9D",
                "9E",
                "82",
                "83",
                "84",
                "85",
                "86",
                "87",
                "88",
                "89",
                "8A",
                "8B",
                "8C",
                "8D",
                "8E",
                "8F",
                "90",
                "91",
                "92",
                "93",
                "94",
                "95",
            ],
            case_sensitive=False,
        ),
        default="9A",
        help="Key slot for operation.",
    )
    @click.option(
        "--path",
        type=click.Path(allow_dash=True),
        default="-",
        help="Read certificate from path.",
    )
    def read_certificate(format: str, key: str, path: str) -> None:
        device = PivApp()

        value = device.cert(
            bytes(bytearray.fromhex(KEY_TO_CERT_OBJ_ID_MAP[key.upper()]))
        )

        if value is None:
            print("Certificate not found", file=sys.stderr)
            return

        format = format.upper()
        if format == "DER":
            cert_serialized = value
            x509.load_der_x509_certificate(value)
        elif format == "PEM":
            cert = x509.load_der_x509_certificate(value)
            cert_serialized = cert.public_bytes(Encoding.PEM)

        with click.open_file(path, mode="wb") as f:
            f.write(cert_serialized)

except ImportError:
    from pynitrokey.cli.nk3.pcsc_absent import PCSC_ABSENT

    @nk3.group(
        invoke_without_command=True,
        context_settings=dict(
            ignore_unknown_options=True,
        ),
    )
    @click.argument("args", nargs=-1, type=click.UNPROCESSED)
    def piv(args: list[str]) -> None:
        """Nitrokey PIV App"""
        local_critical(PCSC_ABSENT, support_hint=False)
