import math
import random
from bots.base import BaseBot


# ISO 14644-1 Class 8 limits
ISO8_0_5UM = 3_520_000   # particles/m³ ≥0.5 µm
ISO8_5UM    =    29_300   # particles/m³ ≥5 µm


class ParticleBot(BaseBot):
    """Air quality / particle count sensor — one per room."""

    interval = 60  # publish every 60 s

    def __init__(self, site_id: str, room_id: str) -> None:
        super().__init__()
        self.site_id = site_id
        self.room_id = room_id
        # Normal operating baseline — well below ISO 8
        self._base_0_5 = random.uniform(60_000, 120_000)
        self._base_5   = random.uniform(200, 600)

    def get_topic(self) -> str:
        return f"bms/{self.site_id}/{self.room_id}/particles"

    def get_payload(self) -> dict:
        drift = math.sin(self._scenario_step * 0.05) * 0.1

        p0_5 = self._base_0_5 * (1 + drift) + random.gauss(0, 3_000)
        p5   = self._base_5   * (1 + drift) + random.gauss(0, 20)

        if self._scenario == "PARTICLE_SPIKE":
            spike = min(self._scenario_step * 50_000, ISO8_0_5UM * 1.5)
            p0_5 += spike
            p5   += spike * (ISO8_5UM / ISO8_0_5UM)

        return {
            "particles_0_5um": max(0, round(p0_5)),
            "particles_5um":   max(0, round(p5)),
        }