"""NXP ICODE/NTAG5 platform — shared NXP custom commands."""
from __future__ import annotations

import os
import struct

from .frame import RFFrame
from .trace_fmt import decode_15693_nxp
from .type5 import NfcType5Tag

# NXP manufacturer code
NXP_MFG = 0x04

# NXP custom commands per SL2S2602 datasheet
CMD_INVENTORY_READ = 0xA0
CMD_FAST_INVENTORY_READ = 0xA1
CMD_SET_EAS = 0xA2
CMD_RESET_EAS = 0xA3
CMD_LOCK_EAS = 0xA4
CMD_EAS_ALARM = 0xA5
CMD_PASSWORD_PROTECT_EAS_AFI = 0xA6
CMD_WRITE_EAS_ID = 0xA7
CMD_GET_NXP_SYSTEM_INFO = 0xAB
CMD_GET_RANDOM = 0xB2
CMD_SET_PASSWORD = 0xB3
CMD_WRITE_PASSWORD = 0xB4
CMD_LOCK_PASSWORD = 0xB5
CMD_PROTECT_PAGE = 0xB6
CMD_LOCK_PAGE_PROTECTION = 0xB7
CMD_DESTROY = 0xB9
CMD_ENABLE_PRIVACY = 0xBA
CMD_64BIT_PASSWORD_PROTECTION = 0xBB
CMD_STAY_QUIET_PERSISTENT = 0xBC
CMD_READ_SIGNATURE = 0xBD
CMD_READ_CONFIG = 0xC0
CMD_WRITE_CONFIG = 0xC1
CMD_READ_TT = 0xC4


class NxpIcodeTag(NfcType5Tag):
    """NXP ICODE/NTAG5 shared platform features.

    Provides: originality signature, NXP system info, GET_RANDOM, SET_PASSWORD.
    Base for ICODE SLIX, SLIX2, DNA, NTAG 5 Link, etc.
    """
    _uid_prefix = b"\xE0\x04"  # E0 + NXP manufacturer code

    def __init__(self, uid: bytes, signature: bytes | None = None, **kwargs):
        super().__init__(uid=uid, **kwargs)
        # 32-byte ECC originality signature (from factory, read-only)
        self._signature = signature or bytes(32)

    def decode_trace(self, direction: int, payload: bytes) -> str | None:
        return decode_15693_nxp(direction, payload) or super().decode_trace(direction, payload)

    def _handle_custom_command(self, cmd: int, frame: RFFrame) -> RFFrame | None:
        """Handle NXP custom commands (0xA0-0xDF)."""
        # Verify NXP manufacturer code
        if len(frame.data) < 3 or frame.data[2] != NXP_MFG:
            return None

        match cmd:
            case 0xB2:  # GET RANDOM NUMBER
                return self._handle_get_random(frame)
            case 0xB3:  # SET PASSWORD
                return self._nxp_handle_set_password(frame)

        return None

    def _handle_get_nxp_system_info(self, frame: RFFrame) -> RFFrame | None:
        """GET NXP SYSTEM INFO (0xAB): returns PP byte, PP conditions, lock bits, feature flags."""
        # Base implementation — subclasses override with actual PP/feature data
        # Response: flags(1) + PP(1) + PP_cond(1) + lock_bits(1) + feature_flags(4)
        return RFFrame.from_bytes(bytes([0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]))

    def _handle_get_random(self, frame: RFFrame) -> RFFrame | None:
        random_bytes = os.urandom(2)
        return RFFrame.from_bytes(bytes([0x00]) + random_bytes)

    def _handle_read_signature(self, frame: RFFrame) -> RFFrame | None:
        """READ SIGNATURE (0xBD): returns 32-byte ECC originality signature."""
        return RFFrame.from_bytes(bytes([0x00]) + self._signature)

    def _nxp_handle_set_password(self, frame: RFFrame) -> RFFrame | None:
        """Base SET_PASSWORD handler. Override in subclasses for specific password types."""
        return None