#! /usr/bin/env python3

import asyncio
import aioserial
import aiomqtt
import pyubx2
import io
import logging
import aioserial
import asyncio
import socket
import signal

from mqtthandler.command import command
from mqtthandler.handler import MQTTConfig, MQTTHandler, task

# The pyubx2 library spams the console with errors that aren't errors.
# I don't care if you failed to parse an incomplete buffer.
logging.getLogger("pyubx2").setLevel(logging.FATAL)


class UBXAsyncParser:
    def __init__(self):
        self.buffer = bytearray()

    def feed(self, data: bytes):
        self.buffer.extend(data)

    def parse(self):
        while True:
            stream = io.BytesIO(self.buffer)
            try:
                ubr = pyubx2.UBXReader(stream, parsing=True)
                raw, parsed = ubr.read()
                if raw is None:
                    return

                consumed = stream.tell()
                del self.buffer[:consumed]
                yield parsed

            except pyubx2.UBXStreamError:
                # incomplete frame
                return


class UBXHandler(MQTTHandler):
    def __init__(
        self,
        mqtt_client: aiomqtt.Client,
        handler_id: str,
        serial_port: aioserial.AioSerial,
    ):
        super().__init__(mqtt_client, handler_id)
        self.serial_port = serial_port

    @task
    async def handle_ubx_messages(self):

        async def read_serial():
            parser = UBXAsyncParser()
            while True:
                chunk = await self.serial_port.read_async(64)
                if not chunk:
                    await asyncio.sleep(0)
                    continue

                parser.feed(chunk)
                for message in parser.parse():
                    yield message

        async for message in read_serial():
            if isinstance(message, pyubx2.UBXMessage):
                for name, value in vars(message).items():
                    # Skip 'private' members
                    if name.startswith("_"):
                        continue

                    topic = f"{self.property_topic}/{message.identity}/{name}"
                    await self.mqtt_client.publish(topic, value, qos=1, retain=True)
            else:
                # print("Unexpected response:", message)
                pass

    @command({"type": "number"}, description="An example command")
    async def example_cmd(self, args):
        print(f"Executing command with args {args}")

    @command(
        {
            "type": "object",
            "properties": {
                "portID": {
                    "type": "integer",
                },
                "baudRate": {
                    "type": "integer",
                    "enum": [
                        110,
                        300,
                        600,
                        1200,
                        2400,
                        4800,
                        9600,
                        14400,
                        19200,
                        38400,
                        57600,
                        115200,
                        230400,
                        460800,
                        921600,
                    ],
                    "default": 9600
                },
            },
            "required": ["portID", "baudRate"],
            "additionalProperties": False,
        },
        description="Reconfigure the serial port for the UBX simulator.",
    )
    async def configure_port(self, args):
        message = pyubx2.UBXMessage(
            "CFG",
            "CFG-PRT",
            pyubx2.ubxtypes_core.SET,
            portID=args["portID"],
            baudRate=args["baudRate"],
        )
        num_bytes = await self.serial_port.write_async(message.serialize())
        return num_bytes

    @command(
        {
            "type": "object",
            "properties": {
                "measRate": {
                    "type": "integer",
                    "minimum": 50,
                    "maximum": 60000,
                    "description": "Measurement period in milliseconds",
                    "default": 1000,
                },
                "navRate": {
                    "type": "integer",
                    "minimum": 1,
                    "maximum": 127,
                    "description": "Number of measurement cycles per navigation solution",
                    "default": 1
                },
                "timeRef": {
                    "type": "integer",
                    "enum": [0, 1],
                    "description": "Time reference (0=UTC, 1=GPS)",
                },
            },
            "required": ["measRate", "navRate", "timeRef"],
            "additionalProperties": False,
        },
        description="Reconfigure the rate properties for the UBX device.",
    )
    async def configure_rate(self, args):
        message = pyubx2.UBXMessage(
            "CFG",
            "CFG-RATE",
            pyubx2.ubxtypes_core.SET,
            measRate=args["measRate"],
            navRate=args["navRate"],
            timeRef=args["timeRef"],
        )
        num_bytes = await self.serial_port.write_async(message.serialize())
        return num_bytes


async def main():
    handler_id = f"example-gps-{socket.gethostname()}"
    mqtt_config = MQTTConfig(host="127.0.0.1", port=1883)

    serial_port = aioserial.AioSerial(
        port="/tmp/ttyV0",
        baudrate=115200,
        timeout=0.05,  # 50 ms
    )

    handler = UBXHandler(mqtt_config, handler_id, serial_port)

    signal.signal(signal.SIGINT, lambda signum, frame: handler.stop())
    await handler.run()


if __name__ == "__main__":
    asyncio.run(main())