from UniTAP.libs.lib_tsi.tsi import *
from UniTAP.libs.lib_tsi.tsi_io import PortIO

from .fec_shared import FECCounters
from UniTAP.dev.ports.modules.dpcd.dpcd import DPCDRegisters


class FecRx:
    """
    Class `FecRx` allows working with FEC functionality from Sink (RX - receiver) side. You can:
    - Check capable FEC or not `is_capable`.
    - Check enabled FEC or not `is_enabled`.
    - Enable/Disable FEC `enable`.
    - Enable/Disable calculating sum of errors `aggregate_errors`.
    - Get error counters `get_error_counters`.
    - Clear all errors `clear`.
    """
    def __init__(self, port_io: PortIO, dpcd: DPCDRegisters):
        self.__io = port_io
        self.__dpcd = dpcd
        self.__aggregate_error = 0

    def is_enabled(self) -> bool:
        """
        Returns status of FEC, is enabled or not.

        Returns:
            object of `bool` type.
        """
        result = self.__io.get(TSI_DPRX_FEC_STATUS_R, c_int)
        status_fec = ((result[1] & 0x1) != 0)
        return bool(status_fec)

    def is_capable(self) -> bool:
        """
        Returns status of FEC, is capable or not.

        Returns:
            object of `bool` type.
        """
        result = self.__io.get(TSI_DPRX_FEC_CTRL, c_int)
        enabled_fec = (result[1] & 0x1) != 0
        return enabled_fec

    def enable(self, enable: bool):
        """
        Enable/Disable FEC.

        Args:
            enable (bool) - enable (True) or disable (False)
        """
        val = 0x1 if enable else 0x0
        self.__io.set(TSI_DPRX_FEC_CTRL, val)

    def aggregate_errors(self, enable: bool):
        """
        Enable/Disable calculating sum of errors.

        Args:
            enable (bool) - enable (True) or disable (False)
        """
        result = self.__io.get(TSI_DPRX_FEC_CONTROL, c_int)
        val = result[1]
        if enable:
            val |= 0x2
            self.__aggregate_error = 1
        else:
            val &= ~0x2
            self.__aggregate_error = 0
        self.__io.set(TSI_DPRX_FEC_CONTROL, val)

    def get_error_counters(self) -> FECCounters:
        """

        Get current error counters.

        Returns:
            object of `FECCounters` type
        """
        result = FECCounters()
        lane_count = self.__io.get(TSI_R_DPRX_LINK_LANE_COUNT, c_int)[1]
        if lane_count == 4:
            lane_count += 1 if self.__aggregate_error else 0

        dpcd = self.__dpcd.read(0x120, 1).data[0]
        dpcdaggr = bool(dpcd & (1 << 6))

        for i in range(lane_count):
            if i == 0 and dpcdaggr:
                dpcd &= ~(1 << 6)

            if i == 4 and dpcdaggr:
                dpcd |= 1 << 6
            elif i == 4:
                continue

            if i < 4:
                dpcd &= ~(0x3 << 4)
                dpcd |= (i << 4)

            for j in range(1, 6):
                dpcd &= ~(0x7 << 1)
                v = dpcd | (j << 1)
                self.__dpcd.write(0x120, v)
                val = int.from_bytes(self.__dpcd.read(0x281, 2).data, 'little')

                if j == 1:
                    result.uncorrectedBlockErrors[i] = val & 0x7FFF if val & 0x8000 else None
                elif j == 2:
                    result.correctedBlockErrors[i] = val & 0x7FFF if val & 0x8000 else None
                elif j == 3:
                    result.bitErrors[i] = val & 0x7FFF if val & 0x8000 else None
                elif j == 4:
                    result.parityBlockErrors[i] = val & 0x7FFF if val & 0x8000 else None
                elif j == 5:
                    result.parityBitErrors[i] = val & 0x7FFF if val & 0x8000 else None

        return result

    def clear(self):
        """
        Clear all errors.
        """
        address = 0x120
        dpcd = self.__dpcd.read(address, 1).data[0]
        old_fec = dpcd
        fec_ready = dpcd & ~0xE
        dpcd = fec_ready
        self.__dpcd.write(address, dpcd)
        dpcd = old_fec
        self.__dpcd.write(address, dpcd)