import re

class MockSDS1000XEDevice:
    def __init__(self):
        # Mock internal values
        self._channels = [{"AMPL" : None, "VDIV" : None} for i in range(0, 4)]

    def _handleRequest(self, request: str) -> str:
        m = re.search(r"C(?P<channel>\d):(?P<opcode>\w+)\??\s(?P<arg>.+)", request.strip())
        if not m:
            return None
        
        channelIndex = int(m.group("channel")) - 1
        opcode = m.group("opcode")

        if opcode == "PAVA":
            arg = m.group("arg")
            value = self._channels[channelIndex].get(arg)
            unit = "Hz" if arg == "FREQ" else "V"
            
            if value is None:
                return None
            else:
                response = f"C{m.group('channel')}:PAVA {arg},{value:.6E}{unit}"
                return response
        elif opcode == "VDIV":
            arg = float(m.group("arg").rstrip("V"))
            self._channels[channelIndex]["VDIV"] = arg
            return None

        return None

    def setAmplitude(self, channel: int, value: float) -> None:
        self._channels[channel - 1]["AMPL"] = value

    def setPeakToPeak(self, channel: int, value: float) -> None:
        self._channels[channel - 1]["PKPK"] = value

    def setRMS(self, channel: int, value: float) -> None:
        self._channels[channel - 1]["RMS"] = value

    def setFrequency(self, channel: int, value: float) -> None:
        self._channels[channel - 1]["FREQ"] = value

    def getVoltsPerDivision(self, channel: int) -> float:
        return self._channels[channel - 1]["VDIV"]