# Source code for gpiozero.pins.local

    # vim: set fileencoding=utf-8:
    #
    # GPIO Zero: a library for controlling the Raspberry Pi's GPIO pins
    #
    # Copyright (c) 2016-2023 Dave Jones <dave@waveform.org.uk>
    # Copyright (c) 2020 Fangchen Li <fangchen.li@outlook.com>
    # Copyright (c) 2016 Andrew Scheller <github@loowis.durge.org>
    #
    # SPDX-License-Identifier: BSD-3-Clause

    import io
    import errno
    import struct
    from collections import defaultdict
    from threading import Lock
    from time import monotonic

    try:
        from spidev import SpiDev
    except ImportError:
        SpiDev = None

    from . import SPI
    from .pi import PiFactory, PiPin, SPI_HARDWARE_PINS, spi_port_device
    from .spi import SPISoftware
    from ..devices import Device
    from ..mixins import SharedMixin
    from ..output_devices import OutputDevice
    from ..exc import DeviceClosed, PinUnknownPi, SPIInvalidClockMode

    def get_pi_revision():
        revision = None
        try:
            with io.open('/proc/device-tree/system/linux,revision', 'rb') as f:
                revision = hex(struct.unpack('>L', f.read(4))[0])[2:]
        except IOError as e:
            if e.errno != errno.ENOENT:
                raise e
            with io.open('/proc/cpuinfo', 'r') as f:
                for line in f:
                    if line.startswith('Revision'):
                        revision = line.split(':')[1].strip().lower()
        if revision is not None:
            overvolted = revision.startswith('100')
            if overvolted:
                revision = revision[-4:]
            return int(revision, base=16)
        raise PinUnknownPi(
            'unable to locate Pi revision in /proc/device-tree or /proc/cpuinfo')

    class LocalPiFactory(PiFactory):
        """
        Extends :class:`~gpiozero.pins.pi.PiFactory`. Abstract base class
        representing pins attached locally to a Pi. This forms the base class for
        local-only pin interfaces (:class:`~gpiozero.pins.rpigpio.RPiGPIOPin`,
        :class:`~gpiozero.pins.lgpio.LGPIOPin`, and
        :class:`~gpiozero.pins.native.NativePin`).
        """
        pins = {}
        _reservations = defaultdict(list)
        _res_lock = Lock()

        def __init__(self):
            super().__init__()
            # Override the reservations and pins dict to be this class' attributes.
            # This is a bit of a dirty hack, but ensures that anyone evil enough to
            # mix pin implementations doesn't try and control the same pin with
            # different backends
            self.pins = LocalPiFactory.pins
            self._reservations = LocalPiFactory._reservations
            self._res_lock = LocalPiFactory._res_lock

        def _get_revision(self):
            return get_pi_revision()

        def _get_spi_class(self, shared, hardware):
            return {
                (False, True):  LocalPiHardwareSPI,
                (True,  True):  LocalPiHardwareSPIShared,
                (False, False): LocalPiSoftwareSPI,
                (True,  False): LocalPiSoftwareSPIShared,
                }[shared, hardware]

        @staticmethod
        def ticks():
            return monotonic()

        @staticmethod
        def ticks_diff(later, earlier):
            return later - earlier

    class LocalPiPin(PiPin):
        """
        Extends :class:`~gpiozero.pins.pi.PiPin`. Abstract base class representing
        a multi-function GPIO pin attached to the local Raspberry Pi.
        """
        def _call_when_changed(self, ticks=None, state=None):
            """
            Overridden to provide default ticks from the local Pi factory.

            .. warning::

                The local pin factory uses a seconds-based monotonic value for
                its ticks but you *must not* rely upon this behaviour. Ticks are
                an opaque value that should only be compared with the associated
                :meth:`Factory.ticks_diff` method.
            """
            super()._call_when_changed(
                self._factory.ticks() if ticks is None else ticks,
                self.state if state is None else state)

    class LocalPiHardwareSPI(SPI):
        def __init__(self, clock_pin, mosi_pin, miso_pin, select_pin, pin_factory):
            self._port, self._device = spi_port_device(
                clock_pin, mosi_pin, miso_pin, select_pin)
            self._bus = None
            if SpiDev is None:
                raise ImportError('failed to import spidev')
            super().__init__(pin_factory=pin_factory)
            to_reserve = {clock_pin, select_pin}
            if mosi_pin is not None:
                to_reserve.add(mosi_pin)
            if miso_pin is not None:
                to_reserve.add(miso_pin)
            self.pin_factory.reserve_pins(self, *to_reserve)
            self._bus = SpiDev()
            self._bus.open(self._port, self._device)
            self._bus.max_speed_hz = 500000

        def _conflicts_with(self, other):
            if isinstance(other, LocalPiHardwareSPI):
                return (
                    (self._port == other._port) and
                    (self._device == other._device))
            else:
                return True

        def close(self):
            if self._bus is not None:
                self._bus.close()
            self._bus = None
            self.pin_factory.release_all(self)
            super().close()

        @property
        def closed(self):
            return self._bus is None

        def __repr__(self):
            try:
                self._check_open()
                return 'SPI(port=%d, device=%d)' % (self._port, self._device)
            except DeviceClosed:
                return 'SPI(closed)'

        def transfer(self, data):
            """
            Writes data (a list of integer words where each word is assumed to have
            :attr:`bits_per_word` bits or less) to the SPI interface, and reads an
            equivalent number of words, returning them as a list of integers.
            """
            return self._bus.xfer2(data)

        def _get_clock_mode(self):
            return self._bus.mode

        def _set_clock_mode(self, value):
            self._bus.mode = value

        def _get_lsb_first(self):
            return self._bus.lsbfirst

        def _set_lsb_first(self, value):
            self._bus.lsbfirst = bool(value)

        def _get_select_high(self):
            return self._bus.cshigh

        def _set_select_high(self, value):
            self._bus.cshigh = bool(value)

        def _get_bits_per_word(self):
            return self._bus.bits_per_word

        def _set_bits_per_word(self, value):
            self._bus.bits_per_word = value

        def _get_rate(self):
            return self._bus.max_speed_hz

        def _set_rate(self, value):
            self._bus.max_speed_hz = int(value)

    class LocalPiSoftwareSPI(SPISoftware):
        pass

    class LocalPiHardwareSPIShared(SharedMixin, LocalPiHardwareSPI):
        @classmethod
        def _shared_key(cls, clock_pin, mosi_pin, miso_pin, select_pin,
                        pin_factory):
            return (clock_pin, select_pin)

    class LocalPiSoftwareSPIShared(SharedMixin, LocalPiSoftwareSPI):
        @classmethod
        def _shared_key(cls, clock_pin, mosi_pin, miso_pin, select_pin,
                        pin_factory):
            return (clock_pin, select_pin)