"""虎牙滑块轨迹生成工具。"""

from __future__ import annotations

import random
import time
from collections.abc import Iterable


def ease_out_expo(sep: float) -> float:
    """缓出曲线，让轨迹更接近人工拖动。"""
    if sep == 1:
        return 1
    return 1 - pow(2, -10 * sep)


def generate_slide_track(distance: int) -> list[list[int]]:
    """生成虎牙滑块验证所需 travel 轨迹。"""
    if not isinstance(distance, int) or distance < 0:
        raise ValueError(f"distance 必须是大于等于 0 的整数: {distance!r}")

    distance = distance + random.randint(10, 40)
    current_time = int(time.time() * 1000) - random.randint(1500, 2000)
    slide_x = random.randint(56, 63)
    slide_y = random.randint(210, 213)
    track = [[slide_x, slide_y, current_time]]

    count = random.randint(40, 60)
    last_x = 0
    for index in range(count):
        x = round(ease_out_expo(index / count) * distance)
        current_time += random.randint(10, 20)
        if x == last_x:
            continue
        y = random.randint(-1, 1)
        track.append([x + slide_x, y + slide_y, current_time])
        last_x = x

    track.append(track[-1])
    return track


def format_track(points: Iterable[Iterable[int]]) -> str:
    """把轨迹点格式化成虎牙 actData.travel 字符串。"""
    return ";".join(f"{x},{y},{t}" for x, y, t in points)