from pathlib import Path
from typing import Union

import numpy as np
import pandas as pd

# 尝试导入 Polars
try:
    import polars as pl
    HAS_POLARS = True
except ImportError:
    HAS_POLARS = False


def read_signal_txt(path: Union[str, Path]) -> np.ndarray:
    """
    Read a txt file and return the first column as a numpy array.

    Args:
        path (str | Path): Path to the txt file.

    Returns:
        np.ndarray: The first column of the txt file as a numpy array.
    """
    path = Path(path)
    if not path.exists():
        raise FileNotFoundError(f"File not found: {path}")

    if HAS_POLARS:
        df = pl.read_csv(path, has_header=False, infer_schema_length=0)
        return df[:, 0].to_numpy()
    else:
        df = pd.read_csv(path, header=None, dtype=float)
        return df.iloc[:, 0].to_numpy()


def read_laebl_csv(path: Union[str, Path]) -> pd.DataFrame:
    """
    Read a CSV file and return it as a pandas DataFrame.

    Args:
        path (str | Path): Path to the CSV file.
    Returns:
        pd.DataFrame: The content of the CSV file as a pandas DataFrame.
    """
    path = Path(path)
    if not path.exists():
        raise FileNotFoundError(f"File not found: {path}")

    # 直接用pandas读取 包含中文 故指定编码
    df = pd.read_csv(path, encoding="gbk")
    df["Start"] = df["Start"].astype(int)
    df["End"] = df["End"].astype(int)
    return df