import asyncio
import random
from typing import Any

_SCROLL_DISTANCES = {"slow": 1500, "normal": 3000, "fast": 5000}


class BehaviorEmulator:
    """Simulates human-like browser interaction. All timings scale with delay_factor."""

    def __init__(
        self,
        human: bool = True,
        delay_factor: float = 1.0,
        scroll_speed: str = "normal",
    ) -> None:
        self.human = human
        self.delay_factor = delay_factor
        self._scroll_base = _SCROLL_DISTANCES.get(scroll_speed, 3000)

    async def human_delay(self, base: float = 2.0, variance: float = 1.0) -> None:
        delay = (
            (base + random.uniform(-variance / 2, variance / 2)) * self.delay_factor
            if self.human
            else 0.3
        )
        await asyncio.sleep(max(0.3, delay))

    async def scroll(self, page: Any, distance: int | None = None) -> None:
        dist = distance if distance is not None else self._scroll_base
        if self.human:
            steps = random.randint(2, 4)
            per_step = dist // steps
            for _ in range(steps):
                jitter = random.randint(-150, 150)
                await page.mouse.wheel(0, per_step + jitter)
                await asyncio.sleep(random.uniform(0.2, 0.7) * self.delay_factor)
        else:
            await page.mouse.wheel(0, dist)

    async def pause_for_reading(self) -> None:
        delay = random.uniform(1.0, 2.5) * self.delay_factor if self.human else 0.2
        await asyncio.sleep(delay)