import asyncio
import time
from collections import deque
from pathlib import Path
import csv

class ValveController:
    def __init__(self):
        self.connected = False
        self.setpoint = 0.0
        self.current_position = 0.0
        self.data_window = deque(maxlen=200)  # 10s at 20Hz

        self.running = False
        self._record_task = None
        self._update_task = None

        self.csv_path = Path("prbs_6_speed.csv")

    async def connect(self):
        self.connected = True
        if not self._update_task:
            self._update_task = asyncio.create_task(self.update_loop())

    async def send_setpoint(self, value: float):
        self.setpoint = value

    async def read_position(self):
        # Simple model: position moves toward setpoint
        self.current_position += 0.1 * (self.setpoint - self.current_position)
        return self.current_position

    # async def update_loop(self):
    #     """Runs continuously to update valve position and data window at 20Hz"""
    #     while True:
    #         pos = await self.read_position()
    #         t = time.time()
    #         self.data_window.append((t, pos, self.setpoint))
    #         await asyncio.sleep(0.05)  # 20Hz

    async def record_loop(self):
        self.running = True
        with self.csv_path.open("w", newline="") as f:
            writer = csv.writer(f)
            writer.writerow(["timestamp", "position", "setpoint"])

            while self.running:
                if self.data_window:
                    t, pos, sp = self.data_window[-1]
                    writer.writerow([t, pos, sp])
                await asyncio.sleep(0.05)  # match 20Hz

    async def stop_recording(self):
        self.running = False
        if self._record_task:
            await self._record_task
            self._record_task = None