# Copyright (c) 2015 Yubico AB
# All rights reserved.
#
#   Redistribution and use in source and binary forms, with or
#   without modification, are permitted provided that the following
#   conditions are met:
#
#    1. Redistributions of source code must retain the above copyright
#       notice, this list of conditions and the following disclaimer.
#    2. Redistributions in binary form must reproduce the above
#       copyright notice, this list of conditions and the following
#       disclaimer in the documentation and/or other materials provided
#       with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
# COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.

import functools
import logging
import sys
from collections import OrderedDict
from collections.abc import MutableMapping
from contextlib import contextmanager
from enum import Enum
from threading import Timer
from typing import Optional, Sequence

import click
from cryptography import x509
from cryptography.hazmat.primitives import serialization

from yubikit.core import TRANSPORT, ApplicationNotAvailableError
from yubikit.core.smartcard import ApduError, SmartCardConnection
from yubikit.core.smartcard.scp import KeyRef, Scp11KeyParams, ScpKeyParams, ScpKid
from yubikit.management import CAPABILITY, DeviceInfo
from yubikit.oath import parse_b32_key
from yubikit.securitydomain import SecurityDomainSession

from ..util import parse_certificates

logger = logging.getLogger(__name__)


class _YkmanCommand(click.Command):
    def __init__(self, *args, **kwargs):
        connections = kwargs.pop("connections", None)
        if connections and not isinstance(connections, list):
            connections = [connections]  # Single type
        self.connections = connections

        super().__init__(*args, **kwargs)

    def get_short_help_str(self, limit=45):
        help_str = super().get_short_help_str(limit)
        return help_str[0].lower() + help_str[1:].rstrip(".")

    def get_help_option(self, ctx):
        option = super().get_help_option(ctx)
        option.help = "show this message and exit"
        return option


class _YkmanGroup(_YkmanCommand, click.Group):
    command_class = _YkmanCommand

    def add_command(self, cmd, name=None):
        if not isinstance(cmd, (_YkmanGroup, _YkmanCommand)):
            raise ValueError(
                f"Command {cmd} does not inherit from _YkmanGroup or _YkmanCommand"
            )
        super().add_command(cmd, name)

    def list_commands(self, ctx):
        return sorted(
            self.commands, key=lambda c: (isinstance(self.commands[c], click.Group), c)
        )


_YkmanGroup.group_class = _YkmanGroup


def click_group(*args, connections=None, **kwargs):
    return click.group(
        *args,
        cls=_YkmanGroup,
        connections=connections,
        **kwargs,
    )


def click_command(*args, connections=None, **kwargs):
    return click.command(
        *args,
        cls=_YkmanCommand,
        connections=connections,
        **kwargs,
    )


class EnumChoice(click.Choice):
    """
    Use an enum's member names as the definition for a choice option.

    Enum member names MUST be all uppercase. Options are not case sensitive.
    Underscores in enum names are translated to dashes in the option choice.
    """

    def __init__(self, choices_enum, hidden=[]):
        self.choices_names = [
            v.name.replace("_", "-") for v in choices_enum if v not in hidden
        ]
        super().__init__(
            self.choices_names,
            case_sensitive=False,
        )
        self.hidden = hidden
        self.choices_enum = choices_enum

    def convert(self, value, param, ctx):
        if isinstance(value, self.choices_enum):
            return value

        try:
            # Allow aliases
            self.choices = [
                k.replace("_", "-")
                for k, v in self.choices_enum.__members__.items()
                if v not in self.hidden
            ]
            name = super().convert(value, param, ctx).replace("-", "_")
        finally:
            self.choices = self.choices_names

        return self.choices_enum[name]


class HexIntParamType(click.ParamType):
    name = "integer"

    def convert(self, value, param, ctx):
        if isinstance(value, int):
            return value
        try:
            if value.lower().startswith("0x"):
                return int(value[2:], 16)
            if ":" in value:
                return int(value.replace(":", ""), 16)
            return int(value)
        except ValueError:
            self.fail(f"{value!r} is not a valid integer", param, ctx)


def click_callback(invoke_on_missing=False):
    def wrap(f):
        @functools.wraps(f)
        def inner(ctx, param, val):
            if not invoke_on_missing and not param.required and val is None:
                return None
            try:
                return f(ctx, param, val)
            except ValueError as e:
                ctx.fail(f'Invalid value for "{param.name}": {str(e)}')

        return inner

    return wrap


@click_callback()
def click_parse_format(ctx, param, val):
    if val == "PEM":
        return serialization.Encoding.PEM
    elif val == "DER":
        return serialization.Encoding.DER
    else:
        raise ValueError(val)


click_force_option = click.option(
    "-f", "--force", is_flag=True, help="confirm the action without prompting"
)


click_format_option = click.option(
    "-F",
    "--format",
    type=click.Choice(["PEM", "DER"], case_sensitive=False),
    default="PEM",
    show_default=True,
    help="encoding format",
    callback=click_parse_format,
)


class YkmanContextObject(MutableMapping):
    def __init__(self):
        self._objects = OrderedDict()
        self._resolved = False

    def add_resolver(self, key, f):
        if self._resolved:
            f = f()
        self._objects[key] = f

    def resolve(self):
        if not self._resolved:
            self._resolved = True
            for k, f in self._objects.copy().items():
                self._objects[k] = f()

    def __getitem__(self, key):
        self.resolve()
        return self._objects[key]

    def __setitem__(self, key, value):
        if not self._resolved:
            raise ValueError("BUG: Attempted to set item when unresolved.")
        self._objects[key] = value

    def __delitem__(self, key):
        del self._objects[key]

    def __len__(self):
        return len(self._objects)

    def __iter__(self):
        return iter(self._objects)


def click_postpone_execution(f):
    @functools.wraps(f)
    def inner(*args, **kwargs):
        click.get_current_context().obj.add_resolver(str(f), lambda: f(*args, **kwargs))

    return inner


@click_callback()
def click_parse_b32_key(ctx, param, val):
    return parse_b32_key(val)


def click_prompt(prompt, err=True, **kwargs):
    """Replacement for click.prompt to better work when piping input to the command.

    Note that we change the default of err to be True, since that's how we typically
    use it.
    """
    logger.debug(f"Input requested ({prompt})")
    if not sys.stdin.isatty():  # Piped from stdin, see if there is data
        logger.debug("TTY detected, reading line from stdin...")
        line = sys.stdin.readline()
        if line:
            return line.rstrip("\n")
        logger.debug("No data available on stdin")

    # No piped data, use standard prompt
    logger.debug("Using interactive prompt...")
    return click.prompt(prompt, err=err, **kwargs)


def prompt_for_touch():
    logger.debug("Prompting user to touch YubiKey...")
    try:
        click.echo("Touch your YubiKey...", err=True)
    except Exception:
        sys.stderr.write("Touch your YubiKey...\n")


@contextmanager
def prompt_timeout(timeout=0.5):
    timer = Timer(timeout, prompt_for_touch)
    try:
        timer.start()
        yield None
    finally:
        timer.cancel()


class CliFail(Exception):
    def __init__(self, message, status=1):
        super().__init__(message)
        self.status = status


def pretty_print(value, level: int = 0) -> Sequence[str]:
    """Pretty-prints structured data, as that returned by get_diagnostics.

    Returns a list of strings which can be printed as lines.
    """
    indent = "  " * level
    lines: list[str] = []
    if isinstance(value, list):
        for v in value:
            lines.extend(pretty_print(v, level))
    elif isinstance(value, dict):
        res = []
        mlen = 0
        for k, v in value.items():
            if isinstance(k, Enum):
                k = k.name or str(k)
            p = pretty_print(v, level + 1)
            ml = len(p) > 1 or isinstance(v, (list, dict))
            if not ml:
                mlen = max(mlen, len(k))
            res.append((k, p, ml))
        mlen += len(indent) + 1
        for k, p, ml in res:
            k_line = f"{indent}{k}:".ljust(mlen)
            if ml:
                lines.append(k_line)
                lines.extend(p)
                if lines[-1] != "":
                    lines.append("")
            else:
                lines.append(f"{k_line} {p[0].lstrip()}")
    elif isinstance(value, bytes):
        lines.append(f"{indent}{value.hex()}")
    else:
        lines.append(f"{indent}{value}")
    return lines


def is_yk4_fips(info: DeviceInfo) -> bool:
    return info.version[0] == 4 and info.is_fips


def _fileno(f) -> int:
    try:
        return f.fileno()
    except Exception:
        return -1


def log_or_echo(message: str, log: logging.Logger, *files) -> None:
    fno = _fileno(sys.stdout)
    if any(_fileno(f) == fno for f in files):
        log.info(message)
    else:
        click.echo(f"{message}.")


def find_scp11_params(
    connection: SmartCardConnection, kid: int, kvn: int, ca: Optional[bytes] = None
) -> Scp11KeyParams:
    try:
        scp = SecurityDomainSession(connection)
    except ApplicationNotAvailableError:
        raise ValueError("Security Domain application not available")

    if ca:
        root_ca = parse_certificates(ca, None)[0]
        try:
            ski = root_ca.extensions.get_extension_for_class(x509.SubjectKeyIdentifier)
        except x509.ExtensionNotFound:
            ski = None
    else:
        root_ca = None
        ski = None

    if not kvn:
        if ski:
            # Find by CA
            ca_ski = ski.value.digest
            for ref, ca_check in scp.get_supported_ca_identifiers(klcc=True).items():
                if ca_check == ca_ski:
                    if not kid or ref.kid == kid:
                        kid, kvn = ref
                        break
            else:
                raise ValueError(f"No CA identifier found matching SKI: {ca_ski.hex()}")
        # Find any matching KID
        for ref in scp.get_key_information().keys():
            if ref.kid == kid:
                kvn = ref.kvn
                break
        else:
            raise ValueError(f"No SCP key found matching KID=0x{kid:x}")
    try:
        ref = KeyRef(kid, kvn)
        chain = scp.get_certificate_bundle(ref)
        if not chain:
            raise ValueError(f"No certificate chain stored for {ref}")
        if root_ca:
            logger.debug("Validating KLCC CA using supplied file")
            parent = root_ca
            for cert in chain:
                # Requires cryptography >= 40
                cert.verify_directly_issued_by(parent)
                parent = cert
            logger.info("KLCC CA validated")
        else:
            logger.info("No CA supplied, skipping KLCC CA validation")

        pub_key = chain[-1].public_key()
        return Scp11KeyParams(ref, pub_key)
    except ApduError:
        raise ValueError(f"Unable to get SCP key paramaters ({ref})")


def get_scp_params(
    ctx: click.Context, capability: CAPABILITY, connection: SmartCardConnection
) -> Optional[ScpKeyParams]:
    # Explicit SCP
    resolve = ctx.obj.get("scp")
    if resolve:
        return resolve(connection)

    # Automatic SCP11b if needed
    info = ctx.obj["info"]
    if connection.transport == TRANSPORT.NFC and capability in info.fips_capable:
        logger.debug("Attempt to find SCP11b key")
        try:
            params = find_scp11_params(connection, ScpKid.SCP11b, 0)
            logger.info("SCP11b key found, using for FIPS capable applications")
            return params
        except ValueError:
            logger.debug("No SCP11b key found, not using SCP")

    return None


def organize_scp11_certificates(
    certificates: Sequence[x509.Certificate],
) -> tuple[
    Optional[x509.Certificate], Sequence[x509.Certificate], Optional[x509.Certificate]
]:
    if not certificates:
        return None, [], None

    # Order leaf-last
    ordered, certificates = [certificates[0]], list(certificates[1:])
    while certificates:
        for c in certificates:
            if c.subject == ordered[0].issuer:
                certificates.remove(c)
                ordered.insert(0, c)
                break
            if ordered[-1].subject == c.issuer:
                certificates.remove(c)
                ordered.append(c)
                break
        else:
            raise ValueError("Incomplete chain of certificates")

    ca, leaf = None, None

    # Check if root is self-signed:
    peek = ordered[0]
    if peek.issuer == peek.subject:
        ca = ordered.pop(0)

    # Check if leaf has keyAgreement policy:
    if ordered:
        kue = ordered[-1].extensions.get_extension_for_oid(x509.ExtensionOID.KEY_USAGE)
        if kue.value.key_agreement:
            leaf = ordered.pop()

    return ca, ordered, leaf
