"""
`busio` - Bus protocol support like I2C and SPI
=================================================

See `CircuitPython:busio` in CircuitPython for more details.

* Author(s): cefn
"""

import threading

from adafruit_blinka import Enum, Lockable, agnostic
from adafruit_blinka.agnostic import board_id, detector
import adafruit_platformdetect.board as ap_board

class I2C(Lockable):
    def __init__(self, scl, sda, frequency=400000):
        self.init(scl, sda, frequency)

    def init(self, scl, sda, frequency):
        self.deinit()
        if detector.board.ftdi_ft232h:
            from adafruit_blinka.microcontroller.ft232h.i2c import I2C
            self._i2c = I2C()
            return
        elif detector.board.binho_nova:
            from adafruit_blinka.microcontroller.nova.i2c import I2C
            self._i2c = I2C()
            return
        elif detector.board.any_embedded_linux:
            from adafruit_blinka.microcontroller.generic_linux.i2c import I2C as _I2C
        else:
            from machine import I2C as _I2C
        from microcontroller.pin import i2cPorts
        for portId, portScl, portSda in i2cPorts:
            try:
                if scl == portScl and sda == portSda:
                    self._i2c = _I2C(portId, mode=_I2C.MASTER, baudrate=frequency)
                    break
            except RuntimeError:
                pass
        else:
            raise ValueError(
                "No Hardware I2C on (scl,sda)={}\nValid I2C ports: {}".format((scl, sda), i2cPorts)
            )

        self._lock = threading.RLock()

    def deinit(self):
        try:
            del self._i2c
        except AttributeError:
            pass

    def __enter__(self):
        self._lock.acquire()
        return self

    def __exit__(self, exc_type, exc_value, traceback):
        self._lock.release()
        self.deinit()

    def scan(self):
        return self._i2c.scan()

    def readfrom_into(self, address, buffer, *, start=0, end=None):
        if start is not 0 or end is not None:
            if end is None:
                end = len(buffer)
            buffer = memoryview(buffer)[start:end]
        stop = True  # remove for efficiency later
        return self._i2c.readfrom_into(address, buffer, stop=stop)

    def writeto(self, address, buffer, *, start=0, end=None, stop=True):
        if isinstance(buffer, str):
            buffer = bytes([ord(x) for x in buffer])
        if start is not 0 or end is not None:
            if end is None:
                return self._i2c.writeto(address, memoryview(buffer)[start:], stop=stop)
            else:
                return self._i2c.writeto(address, memoryview(buffer)[start:end], stop=stop)
        return self._i2c.writeto(address, buffer, stop=stop)

    def writeto_then_readfrom(self, address, buffer_out, buffer_in, *, out_start=0, out_end=None, in_start=0, in_end=None, stop=False):
        return self._i2c.writeto_then_readfrom(address, buffer_out, buffer_in,
                                               out_start=out_start, out_end=out_end,
                                               in_start=in_start, in_end=in_end, stop=stop)

class SPI(Lockable):
    def __init__(self, clock, MOSI=None, MISO=None):
        self.deinit()
        if detector.board.ftdi_ft232h:
            from adafruit_blinka.microcontroller.ft232h.spi import SPI as _SPI
            from adafruit_blinka.microcontroller.ft232h.pin import SCK, MOSI, MISO
            self._spi = _SPI()
            self._pins = (SCK, MOSI, MISO)
            return
        elif detector.board.binho_nova:
            from adafruit_blinka.microcontroller.nova.spi import SPI as _SPI
            #from adafruit_blinka.microcontroller.nova.pin import SCK, MOSI, MISO
            self._spi = _SPI()
            #self._pins = (SCK, MOSI, MISO)
            return
        elif detector.board.any_embedded_linux:
            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
        else:
            from machine import SPI as _SPI
        from microcontroller.pin import spiPorts
        for portId, portSck, portMosi, portMiso in spiPorts:
            if ((clock == portSck) and                   # Clock is required!
                (MOSI == portMosi or MOSI == None) and   # But can do with just output
                (MISO == portMiso or MISO == None)):      # Or just input
                self._spi = _SPI(portId)
                self._pins = (portSck, portMosi, portMiso)
                break
        else:
            raise ValueError(
                "No Hardware SPI on (SCLK, MOSI, MISO)={}\nValid SPI ports:{}".
                format((clock, MOSI, MISO), spiPorts))

    def configure(self, baudrate=100000, polarity=0, phase=0, bits=8):
        if detector.board.any_raspberry_pi or detector.board.any_raspberry_pi_40_pin:
            from adafruit_blinka.microcontroller.bcm283x.pin import Pin
            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
        elif detector.board.any_beaglebone:
            from adafruit_blinka.microcontroller.am335x.pin import Pin
            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
        elif board_id == ap_board.ORANGE_PI_PC or board_id == ap_board.ORANGE_PI_R1 or board_id == ap_board.ORANGE_PI_ZERO:
            from adafruit_blinka.microcontroller.allwinner_h3.pin import Pin
            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
        elif board_id == ap_board.GIANT_BOARD:
            from adafruit_blinka.microcontroller.sama5.pin import Pin
            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
        elif board_id == ap_board.CORAL_EDGE_TPU_DEV:
            from adafruit_blinka.microcontroller.nxp_imx8m.pin import Pin
            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
        elif board_id == ap_board.ODROID_C2:
            from adafruit_blinka.microcontroller.amlogic.s905.pin import Pin
            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
        elif board_id == ap_board.DRAGONBOARD_410C:
            from adafruit_blinka.microcontroller.snapdragon.apq8016.pin import Pin
            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
        elif board_id == ap_board.JETSON_NANO:
            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
            from adafruit_blinka.microcontroller.tegra.t210.pin import Pin
        elif board_id == ap_board.JETSON_TX1:
            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
            from adafruit_blinka.microcontroller.tegra.t210.pin import Pin
        elif board_id == ap_board.JETSON_TX2:
            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
            from adafruit_blinka.microcontroller.tegra.t186.pin import Pin
        elif board_id == ap_board.JETSON_XAVIER:
            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
            from adafruit_blinka.microcontroller.tegra.t194.pin import Pin
        elif detector.board.ftdi_ft232h:
            from adafruit_blinka.microcontroller.ft232h.spi import SPI as _SPI
            from adafruit_blinka.microcontroller.ft232h.pin import Pin
        elif detector.board.binho_nova:
            from adafruit_blinka.microcontroller.nova.spi import SPI as _SPI
            from adafruit_blinka.microcontroller.nova.pin import Pin
        else:
            from machine import SPI as _SPI
            from machine import Pin

        if self._locked:
            # TODO check if #init ignores MOSI=None rather than unsetting, to save _pinIds attribute
            self._spi.init(
                baudrate=baudrate,
                polarity=polarity,
                phase=phase,
                bits=bits,
                firstbit=_SPI.MSB,
                sck=Pin(self._pins[0].id),
                mosi=Pin(self._pins[1].id),
                miso=Pin(self._pins[2].id)
            )
        else:
            raise RuntimeError("First call try_lock()")

    def deinit(self):
        self._spi = None
        self._pinIds = None

    @property
    def frequency(self):
        try:
            return self._spi.frequency
        except AttributeError:
            raise NotImplementedError("Frequency attribute not implemented for this platform")

    def write(self, buf, start=0, end=None):
        return self._spi.write(buf, start, end)

    def readinto(self, buf, start=0, end=None, write_value=0):
        return self._spi.readinto(buf, start, end, write_value=write_value)

    def write_readinto(self, buffer_out, buffer_in,  out_start=0, out_end=None, in_start=0, in_end=None):
        return self._spi.write_readinto(buffer_out, buffer_in, out_start, out_end, in_start, in_end)


class UART(Lockable):
    class Parity(Enum):
        pass

    Parity.ODD = Parity()
    Parity.EVEN = Parity()

    def __init__(self,
                 tx,
                 rx,
                 baudrate=9600,
                 bits=8,
                 parity=None,
                 stop=1,
                 timeout=1000,
                 receiver_buffer_size=64,
                 flow=None):
        if detector.board.any_embedded_linux:
            raise RuntimeError('busio.UART not supported on this platform. Please use pyserial instead.')
        else:
            from machine import UART as _UART
        from microcontroller.pin import uartPorts

        self.baudrate = baudrate

        if flow is not None:  # default 0
            raise NotImplementedError(
                "Parameter '{}' unsupported on {}".format(
                    "flow", agnostic.board_id))

        # translate parity flag for Micropython
        if parity is UART.Parity.ODD:
            parity = 1
        elif parity is UART.Parity.EVEN:
            parity = 0
        elif parity is None:
            pass
        else:
            raise ValueError("Invalid parity")

        # check tx and rx have hardware support
        for portId, portTx, portRx in uartPorts:  #
            if portTx == tx and portRx == rx:
                self._uart = _UART(
                    portId,
                    baudrate,
                    bits=bits,
                    parity=parity,
                    stop=stop,
                    timeout=timeout,
                    read_buf_len=receiver_buffer_size
                )
                break
        else:
            raise ValueError(
                "No Hardware UART on (tx,rx)={}\nValid UART ports: {}".format((tx, rx), uartPorts)
            )

    def deinit(self):
        self._uart = None

    def read(self, nbytes=None):
        return self._uart.read(nbytes)

    def readinto(self, buf, nbytes=None):
        return self._uart.readinto(buf, nbytes)

    def readline(self):
        return self._uart.readline()

    def write(self, buf):
        return self._uart.write(buf)