#!/usr/bin/env python3
import argparse
import csv
import random
from pathlib import Path


def format_one_decimal(value: float) -> str:
    return f"{value:.1f}"


def random_point_in_cube(cx: float, cy: float, cz: float, half_edge: float) -> tuple[float, float, float]:
    return (
        cx + random.uniform(-half_edge, half_edge),
        cy + random.uniform(-half_edge, half_edge),
        cz + random.uniform(-half_edge, half_edge),
    )


def random_point_in_cube_with_z_limits(
    cx: float,
    cy: float,
    cz: float,
    half_edge: float,
    z_min: float,
    z_max: float,
) -> tuple[float, float, float]:
    z_low = max(cz - half_edge, z_min)
    z_high = min(cz + half_edge, z_max)
    if z_low > z_high:
        raise ValueError(f"非法的 Z 采样区间: [{z_low}, {z_high}]")
    return (
        cx + random.uniform(-half_edge, half_edge),
        cy + random.uniform(-half_edge, half_edge),
        random.uniform(z_low, z_high),
    )


def process_file(
    path: Path,
    mode: str,
    edge_cm: float,
    points_per_group: int,
    seed: int | None,
    z_min: float,
    z_max: float,
    extract_centers_every: int,
    output_dir: Path | None = None,
) -> None:
    if seed is not None:
        random.seed(seed)

    half_edge = edge_cm / 2.0

    # 确定输出文件的路径
    if output_dir is None:
        # 原有行为：写临时文件然后替换原文件
        out_path = path.with_suffix(path.suffix + ".tmp")
        replace_original = True
    else:
        # 输出到指定目录，不覆盖原文件
        out_path = output_dir / path.name
        replace_original = False

    with path.open("r", newline="", encoding="utf-8") as src, out_path.open(
        "w", newline="", encoding="utf-8"
    ) as dst:
        reader = csv.DictReader(src)
        fieldnames = reader.fieldnames
        if not fieldnames:
            raise ValueError(f"CSV 表头为空: {path}")
        if not {"X", "Y", "Z"}.issubset(set(fieldnames)):
            raise ValueError(f"缺少 X/Y/Z 列: {path}")

        index_col = fieldnames[0]
        writer = csv.DictWriter(dst, fieldnames=fieldnames, lineterminator="\n")
        writer.writeheader()

        out_index = 1
        in_count = 0
        center_count = 0
        kept_center_count = 0

        for row_idx, row in enumerate(reader):
            in_count += 1

            # 当输入已经是“每组30条”时，仅抽取每组第一条作为中心点
            if mode == "zrange-expand" and extract_centers_every > 1 and (row_idx % extract_centers_every != 0):
                continue

            center_count += 1
            cx = float(row["X"])
            cy = float(row["Y"])
            cz = float(row["Z"])

            if mode == "normalize":
                points = [(cx, cy, cz)]
            elif mode == "expand":
                points = [(cx, cy, cz)]
                for _ in range(points_per_group - 1):
                    points.append(random_point_in_cube(cx, cy, cz, half_edge))
            else:
                # 仅保留 z 在 [z_min, z_max] 的中心点
                if not (z_min <= cz <= z_max):
                    continue
                kept_center_count += 1

                points = [(cx, cy, cz)]
                for _ in range(points_per_group - 1):
                    points.append(
                        random_point_in_cube_with_z_limits(
                            cx=cx,
                            cy=cy,
                            cz=cz,
                            half_edge=half_edge,
                            z_min=z_min,
                            z_max=z_max,
                        )
                    )

            for x, y, z in points:
                new_row = dict(row)
                new_row[index_col] = str(out_index)
                new_row["X"] = format_one_decimal(x)
                new_row["Y"] = format_one_decimal(y)
                new_row["Z"] = format_one_decimal(z)
                writer.writerow(new_row)
                out_index += 1

    if replace_original:
        out_path.replace(path)

    if mode == "zrange-expand":
        print(
            f"{path.name}: in={in_count}, centers={center_count}, kept_centers={kept_center_count}, out={out_index - 1}"
        )
    else:
        print(f"{path.name}: in={in_count}, out={out_index - 1}")


def main() -> None:
    parser = argparse.ArgumentParser(
        description="按立方体随机采样扩增 CSV，或仅格式化/重排索引。"
    )
    parser.add_argument(
        "--dir",
        default="/media/team_data/ML4_team/datasets/smx_sim/original",
        help="输入 CSV 目录路径。",
    )
    parser.add_argument(
        "--mode",
        choices=["expand", "normalize", "zrange-expand"],
        default="zrange-expand",
        help="expand: 每条扩成一组; normalize: 仅重排索引; zrange-expand: 按Z范围筛选中心点后扩增。",
    )
    parser.add_argument(
        "--edge-cm",
        type=float,
        default=30.0,
        help="立方体边长（厘米），默认 30。",
    )
    parser.add_argument(
        "--points-per-group",
        type=int,
        default=30,
        help="每组点数（中心点+随机点），默认 30。",
    )
    parser.add_argument(
        "--seed",
        type=int,
        default=None,
        help="可选随机种子，便于复现。",
    )
    parser.add_argument(
        "--z-min",
        type=float,
        default=60.0,
        help="zrange-expand 模式下，中心点与生成点的最小 Z。",
    )
    parser.add_argument(
        "--z-max",
        type=float,
        default=180.0,
        help="zrange-expand 模式下，中心点与生成点的最大 Z。",
    )
    parser.add_argument(
        "--extract-centers-every",
        type=int,
        default=1,
        help="zrange-expand 模式下，从输入中每 N 条抽取 1 条作为中心点；输入若是旧的30倍数据可设为30。",
    )
    parser.add_argument(
        "--output-dir",
        type=str,
        default="/media/team_data/ML4_team/datasets/smx_sim/30cm",
        help="输出目录，结果将写入该目录，不覆盖原文件。",
    )
    args = parser.parse_args()

    target_dir = Path(args.dir).resolve()
    csv_files = sorted(target_dir.glob("*.csv"))
    if not csv_files:
        raise FileNotFoundError(f"目录下未找到 CSV: {target_dir}")

    if args.mode == "expand" and args.points_per_group < 1:
        raise ValueError("points-per-group 必须 >= 1")
    if args.mode == "zrange-expand":
        if args.points_per_group < 1:
            raise ValueError("points-per-group 必须 >= 1")
        if args.z_min > args.z_max:
            raise ValueError("z-min 不能大于 z-max")
        if args.extract_centers_every < 1:
            raise ValueError("extract-centers-every 必须 >= 1")

    output_dir = Path(args.output_dir).resolve() if args.output_dir else None
    if output_dir and not output_dir.exists():
        output_dir.mkdir(parents=True, exist_ok=True)

    for csv_file in csv_files:
        process_file(
            path=csv_file,
            mode=args.mode,
            edge_cm=args.edge_cm,
            points_per_group=args.points_per_group,
            seed=args.seed,
            z_min=args.z_min,
            z_max=args.z_max,
            extract_centers_every=args.extract_centers_every,
            output_dir=output_dir,
        )


if __name__ == "__main__":
    main()