"""ROS2 client for fc_network MavCommandLong service (COMMAND_LONG 系列指令)."""

from __future__ import annotations

from dataclasses import dataclass
from typing import Optional
import asyncio

import rclpy
from rclpy.node import Node

from fc_interfaces.srv import MavCommandLong

COMMAND_DO_SET_MODE = 176
COMMAND_NAV_LAND = 21
COMMAND_NAV_TAKEOFF = 22
COMMAND_COMPONENT_ARM_DISARM = 400

DEFAULT_SERVICE_NAME = "/fc_network/vehicle/send_command_long"
DEFAULT_TIMEOUT_SEC = 2.0


@dataclass
class CommandLongResult:
    success: bool
    message: str
    ack_result: int

class CommandLongClient(Node):
    """ROS2 client : 對同一個 send_command_long service 發送各種 MAV_CMD_*。"""

    def __init__(self, service_name: str = DEFAULT_SERVICE_NAME) -> None:
        if not rclpy.ok():
            rclpy.init(args=None)
        super().__init__("fc_command_long_client")
        self._client = self.create_client(MavCommandLong, service_name)

    def wait_for_service(self, timeout_sec: float = 3.0) -> bool:
        return self._client.wait_for_service(timeout_sec=timeout_sec)

    def _send_command_long(
        self,
        *,
        target_sysid: int,
        target_compid: int,
        command: int,
        confirmation: int,
        param1: float,
        param2: float,
        param3: float,
        param4: float,
        param5: float,
        param6: float,
        param7: float,
        timeout_sec: float,
    ) -> CommandLongResult:
        req = MavCommandLong.Request()
        req.target_sysid = target_sysid
        req.target_compid = target_compid
        req.command = command
        req.confirmation = confirmation
        req.param1 = param1
        req.param2 = param2
        req.param3 = param3
        req.param4 = param4
        req.param5 = param5
        req.param6 = param6
        req.param7 = param7
        req.timeout_sec = float(timeout_sec)

        future = self._client.call_async(req)
        rclpy.spin_until_future_complete(self, future, timeout_sec=timeout_sec + 1.0)
        if not future.done() or future.result() is None:
            return CommandLongResult(
                success=False,
                message="Service timeout.",
                ack_result=-1,
            )

        response = future.result()
        return CommandLongResult(
            success=response.success,
            message=response.message,
            ack_result=response.ack_result,
        )

    def change_mode(
        self,
        *,
        target_sysid: int,
        custom_mode: float,
        target_compid: int = 0,
        base_mode: float = 1.0,
        confirmation: int = 0,
        timeout_sec: float = DEFAULT_TIMEOUT_SEC,
    ) -> CommandLongResult:
        return self._send_command_long(
            target_sysid=target_sysid,
            target_compid=target_compid,
            command=COMMAND_DO_SET_MODE,
            confirmation=confirmation,
            param1=float(base_mode),
            param2=float(custom_mode),
            param3=0.0,
            param4=0.0,
            param5=0.0,
            param6=0.0,
            param7=0.0,
            timeout_sec=timeout_sec,
        )

    def takeoff(
        self,
        *,
        target_sysid: int,
        altitude_m: float,
        target_compid: int = 0,
        min_pitch_deg: float = 0.0,
        yaw_deg: float = 0.0,
        latitude: Optional[float] = None,
        longitude: Optional[float] = None,
        timeout_sec: float = DEFAULT_TIMEOUT_SEC,
    ) -> CommandLongResult:
        return self._send_command_long(
            target_sysid=target_sysid,
            target_compid=target_compid,
            command=COMMAND_NAV_TAKEOFF,
            confirmation=0,
            param1=float(min_pitch_deg),
            param2=0.0,
            param3=0.0,
            param4=float(yaw_deg),
            param5=float(latitude) if latitude is not None else 0.0,
            param6=float(longitude) if longitude is not None else 0.0,
            param7=float(altitude_m),
            timeout_sec=timeout_sec,
        )

    def land(
        self,
        *,
        target_sysid: int,
        target_compid: int = 0,
        yaw_deg: float = 0.0,
        latitude: Optional[float] = None,
        longitude: Optional[float] = None,
        altitude_m: float = 0.0,
        timeout_sec: float = DEFAULT_TIMEOUT_SEC,
    ) -> CommandLongResult:
        return self._send_command_long(
            target_sysid=target_sysid,
            target_compid=target_compid,
            command=COMMAND_NAV_LAND,
            confirmation=0,
            param1=0.0,
            param2=0.0,
            param3=0.0,
            param4=float(yaw_deg),
            param5=float(latitude) if latitude is not None else 0.0,
            param6=float(longitude) if longitude is not None else 0.0,
            param7=float(altitude_m),
            timeout_sec=timeout_sec,
        )

    def arm_disarm(
        self,
        *,
        target_sysid: int,
        arm: bool,
        target_compid: int = 0,
        confirmation: int = 0,
        param2: float = 0.0,
        timeout_sec: float = DEFAULT_TIMEOUT_SEC,
    ) -> CommandLongResult:
        return self._send_command_long(
            target_sysid=target_sysid,
            target_compid=target_compid,
            command=COMMAND_COMPONENT_ARM_DISARM,
            confirmation=confirmation,
            param1=1.0 if arm else 0.0,
            param2=float(param2),
            param3=0.0,
            param4=0.0,
            param5=0.0,
            param6=0.0,
            param7=0.0,
            timeout_sec=timeout_sec,
        )

    # ============================================================================
    # 【新增】非阻塞 async 包裝方法（用於 GUI 的非阻塞調用）
    # 這些方法在 ThreadPoolExecutor 中運行同步版本，以避免阻塞事件循環
    # ============================================================================

    async def change_mode_async(
        self,
        *,
        target_sysid: int,
        custom_mode: float,
        target_compid: int = 0,
        base_mode: float = 1.0,
        confirmation: int = 0,
        timeout_sec: float = DEFAULT_TIMEOUT_SEC,
    ) -> CommandLongResult:
        """非阻塞 async 版本的 change_mode（在 ThreadPoolExecutor 中運行）"""
        from concurrent.futures import ThreadPoolExecutor
        loop = asyncio.get_event_loop()
        executor = ThreadPoolExecutor(max_workers=1)
        return await loop.run_in_executor(
            executor,
            lambda: self.change_mode(
                target_sysid=target_sysid,
                custom_mode=custom_mode,
                target_compid=target_compid,
                base_mode=base_mode,
                confirmation=confirmation,
                timeout_sec=timeout_sec,
            )
        )

    async def arm_disarm_async(
        self,
        *,
        target_sysid: int,
        arm: bool,
        target_compid: int = 0,
        confirmation: int = 0,
        param2: float = 0.0,
        timeout_sec: float = DEFAULT_TIMEOUT_SEC,
    ) -> CommandLongResult:
        """非阻塞 async 版本的 arm_disarm（在 ThreadPoolExecutor 中運行）"""
        from concurrent.futures import ThreadPoolExecutor
        loop = asyncio.get_event_loop()
        executor = ThreadPoolExecutor(max_workers=1)
        return await loop.run_in_executor(
            executor,
            lambda: self.arm_disarm(
                target_sysid=target_sysid,
                arm=arm,
                target_compid=target_compid,
                confirmation=confirmation,
                param2=param2,
                timeout_sec=timeout_sec,
            )
        )

    async def takeoff_async(
        self,
        *,
        target_sysid: int,
        altitude_m: float,
        target_compid: int = 0,
        min_pitch_deg: float = 0.0,
        yaw_deg: float = 0.0,
        latitude: Optional[float] = None,
        longitude: Optional[float] = None,
        timeout_sec: float = DEFAULT_TIMEOUT_SEC,
    ) -> CommandLongResult:
        """非阻塞 async 版本的 takeoff（在 ThreadPoolExecutor 中運行）"""
        from concurrent.futures import ThreadPoolExecutor
        loop = asyncio.get_event_loop()
        executor = ThreadPoolExecutor(max_workers=1)
        return await loop.run_in_executor(
            executor,
            lambda: self.takeoff(
                target_sysid=target_sysid,
                altitude_m=altitude_m,
                target_compid=target_compid,
                min_pitch_deg=min_pitch_deg,
                yaw_deg=yaw_deg,
                latitude=latitude,
                longitude=longitude,
                timeout_sec=timeout_sec,
            )
        )

    async def land_async(
        self,
        *,
        target_sysid: int,
        target_compid: int = 0,
        yaw_deg: float = 0.0,
        latitude: Optional[float] = None,
        longitude: Optional[float] = None,
        altitude_m: float = 0.0,
        timeout_sec: float = DEFAULT_TIMEOUT_SEC,
    ) -> CommandLongResult:
        """非阻塞 async 版本的 land（在 ThreadPoolExecutor 中運行）"""
        from concurrent.futures import ThreadPoolExecutor
        loop = asyncio.get_event_loop()
        executor = ThreadPoolExecutor(max_workers=1)
        return await loop.run_in_executor(
            executor,
            lambda: self.land(
                target_sysid=target_sysid,
                target_compid=target_compid,
                yaw_deg=yaw_deg,
                latitude=latitude,
                longitude=longitude,
                altitude_m=altitude_m,
                timeout_sec=timeout_sec,
            )
        )