import torch
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.colors import to_rgba
from matplotlib.lines import Line2D
from mpl_toolkits.mplot3d.art3d import Poly3DCollection
import os
from datetime import datetime
import csv

from core.cylinder import generate_cylinder_n_torch, generate_cylinder_o_torch, snap_to_discrete_values
from core.intersection import center_line_intersections_torch
from core.scoring import cl_score_torch, compute_overlap_ratio_from_cylinder_mask, cl_score_torch_xfr
from imaging.orientation import (azimuth_rotation, analyze_vertebral_tilt_contour,
                                  best_symmetry_plane, best_upper_endplate_plane,
                                  segment_spinous_process)
from utils.helpers import save_with_unique_name

# Volume absorption 渲染（Beer-Lambert）：每 voxel 不透明度 = 1 - exp(-mu * voxel_width)
# 骨頭核心厚度達 70-90 voxel，沿視線堆疊會使任何 per-voxel alpha 累積成不透明。
# 因此以「抽稀 (SUBSAMPLE) 降低堆疊數量」+「低 mu 控制每點吸收」兩項共同調出淡薄 X-ray 陰影，
# 同時保留皮質 / 鬆質的吸收入射差異（mu 比值）。
BONE_MU_CORTICAL = 0.02    # 1/mm  → 每 voxel = 1-exp(-0.02*0.5) ~ 0.010
BONE_MU_TRABECULAR = 0.005 # 1/mm  → 每 voxel = 1-exp(-0.005*0.5) ~ 0.0025
BONE_MARKER_SIZE = 3.0     # 骨骼散點點面積 (pt^2)；略大以補償抽稀後的顆粒感
BONE_SUBSAMPLE = 1         # 每 10 個骨 voxel 畫 1 個，降低堆疊不透明度（1=全畫）

def set_axes_equal_3d(ax):
    """
    Make axes of 3D plot have equal scale so that spheres appear as spheres,
    cubes as cubes, etc.
    """
    x_limits = ax.get_xlim3d()
    y_limits = ax.get_ylim3d()
    z_limits = ax.get_zlim3d()

    x_range = abs(x_limits[1] - x_limits[0])
    x_middle = np.mean(x_limits)
    y_range = abs(y_limits[1] - y_limits[0])
    y_middle = np.mean(y_limits)
    z_range = abs(z_limits[1] - z_limits[0])
    z_middle = np.mean(z_limits)

    plot_radius = 0.5*max([x_range, y_range, z_range])

    ax.set_xlim3d([x_middle - plot_radius, x_middle + plot_radius])
    ax.set_ylim3d([y_middle - plot_radius, y_middle + plot_radius])
    ax.set_zlim3d([z_middle - plot_radius, z_middle + plot_radius])
    
    try:
        ax.set_box_aspect([1, 1, 1])
    except AttributeError:
        pass

def res_plt_2_torch(
    spine_tensor: torch.Tensor,
    cortical_tensor: torch.Tensor,
    image_shape: tuple[int, int, int],
    image2_path: str,
    base_folder: str,
    label_str: str,
    diameter_l: float,
    length_l: float,
    diameter_r: float,
    length_r: float,
    best_position_l: list[float],
    best_position_r: list[float],
    swarm_size: int,
    max_iter: int,
    total_time: float,
    spacing: list[float],
    CBT: bool,
    device: torch.device,
    grid=None
) -> None:
    """
    Same plotting function as before, but it uses torch-based generation 
    and then moves data to CPU for matplotlib 3D scatter.
    """
    cyl_l = generate_cylinder_n_torch(
        diameter_l,
        length_l,
        best_position_l[0],
        best_position_l[1],
        best_position_l[2],
        best_position_l[3],
        best_position_l[4],
        image_shape,
        spacing,
        device,
        grid
    )

    cyl_lo = generate_cylinder_o_torch(
        diameter_l,
        length_l,
        best_position_l[0],
        best_position_l[1],
        best_position_l[2],
        best_position_l[3],
        best_position_l[4],
        image_shape,
        spacing,
        device,
        grid
    )
    cyl_r = generate_cylinder_n_torch(
        diameter_r,
        length_r,
        best_position_r[0],
        best_position_r[1],
        best_position_r[2],
        best_position_r[3],
        best_position_r[4],
        image_shape,
        spacing,
        device,
        grid
    )
    cyl_ro = generate_cylinder_o_torch(
        diameter_r,
        length_r,
        best_position_r[0],
        best_position_r[1],
        best_position_r[2],
        best_position_r[3],
        best_position_r[4],
        image_shape,
        spacing,
        device,
        grid
    )

    intersections_l, line_mask_l = center_line_intersections_torch(
        best_position_l[0],
        best_position_l[1],
        best_position_l[2],
        best_position_l[3],
        best_position_l[4],
        int(length_l),
        spine_tensor,
        spacing,
        device
    )
    loss_l = cl_score_torch(cortical_tensor, spine_tensor, cyl_l, cyl_lo, intersections_l)

    intersections_r, line_mask_r = center_line_intersections_torch(
        best_position_r[0],
        best_position_r[1],
        best_position_r[2],
        best_position_r[3],
        best_position_r[4],
        int(length_r),
        spine_tensor,
        spacing,
        device
    )
    # loss_r = cl_score_torch(cortical_tensor, spine_tensor, cyl_r, cyl_ro, intersections_r)
    loss_r = cl_score_torch_xfr(cortical_tensor, spine_tensor, cyl_r, cyl_ro, intersections_r)

    azi = azimuth_rotation(image2_path)
    res = analyze_vertebral_tilt_contour(image2_path, edge_type='superior', show_plot=False, debug=False)
    alt = res['superior']['tilt_angle_deg']

    # Move data to CPU for plotting
    line_mask_l_cpu = line_mask_l.cpu().numpy()
    line_mask_r_cpu = line_mask_r.cpu().numpy()
    cyl_l_cpu = cyl_l.cpu().numpy()
    cyl_lo_cpu = cyl_lo.cpu().numpy()
    cyl_r_cpu = cyl_r.cpu().numpy()
    cyl_ro_cpu = cyl_ro.cpu().numpy()
    spine_cpu = spine_tensor.cpu().numpy()

    z_lin1, y_lin1, x_lin1 = np.where(line_mask_l_cpu == 1)
    z_lin2, y_lin2, x_lin2 = np.where(line_mask_r_cpu == 1)

    z_cyl_l1, y_cyl_l1, x_cyl_l1 = np.where(cyl_l_cpu == 1)
    z_cyl_l2, y_cyl_l2, x_cyl_l2 = np.where(cyl_lo_cpu == 1)
    z_cyl_r1, y_cyl_r1, x_cyl_r1 = np.where(cyl_r_cpu == 1)
    z_cyl_r2, y_cyl_r2, x_cyl_r2 = np.where(cyl_ro_cpu == 1)

    # 骨頭 voxel 依「體積吸收」分成兩組：皮質（高不透明度）與鬆質（低不透明度）
    cortical_cpu = cortical_tensor.cpu().numpy()
    voxel_mm = float(spacing[0])
    alpha_cortical = 1.0 - np.exp(-BONE_MU_CORTICAL * voxel_mm)
    alpha_trabecular = 1.0 - np.exp(-BONE_MU_TRABECULAR * voxel_mm)
    z_corti, y_corti, x_corti = np.where((spine_cpu == 1) & (cortical_cpu == 1))
    z_trab, y_trab, x_trab = np.where((spine_cpu == 1) & (cortical_cpu == 0))

    # 中矢狀面：骨頭的最佳鏡稱面，一般平面 a·x + b·y + c·z = d（法線方向任意）
    sym = best_symmetry_plane(spine_cpu)

    # 棘突：鏡稱面中線帶（|s|<=w）且在 AP 谷底之後側的骨 voxel，換不同顏色標示
    sp_mask, sp_th, sp_info = segment_spinous_process(spine_cpu, sym)
    if sp_mask is not None and sp_mask.any():
        sp_corti = sp_mask[z_corti, y_corti, x_corti]
        sp_trab = sp_mask[z_trab, y_trab, x_trab]
        sp_n_bone = max(int(spine_cpu.sum()), 1)
        print(f"[SPINOUS] n={sp_info['n_sp']} "
              f"({100.0 * sp_info['n_sp'] / sp_n_bone:.1f}% of bone) "
              f"band=+/-{sp_info['band_w']:.1f} voxel  AP>={sp_info['ap_thresh']:.1f} "
              f"mode={sp_info['mode']}")
    else:
        sp_corti = sp_trab = None

    # X-ray 外觀：骨頭合成一個半透明體積吸收點雲（下方）；
    # 螺絲（中心線 + 圓柱 + 入口軌跡延长）合成一個全不透明點雲，永遠畫在骨頭之上
    def _rgba_block(n, color, a):
        arr = np.empty((n, 4))
        arr[:] = to_rgba(color)
        arr[:, 3] = a
        return arr

    x_bone = np.concatenate([x_corti, x_trab])
    y_bone = np.concatenate([y_corti, y_trab])
    z_bone = np.concatenate([z_corti, z_trab])
    bone_rgba = np.concatenate([
        _rgba_block(len(x_corti), 'lightblue', float(alpha_cortical)),
        _rgba_block(len(x_trab), 'lightblue', float(alpha_trabecular)),
    ])
    bone_size = np.full(len(x_bone), BONE_MARKER_SIZE)

    # 抽稀：降低堆疊不透明度以呈現淡薄 X-ray 陰影
    if BONE_SUBSAMPLE > 1:
        x_bone = x_bone[::BONE_SUBSAMPLE]
        y_bone = y_bone[::BONE_SUBSAMPLE]
        z_bone = z_bone[::BONE_SUBSAMPLE]
        bone_rgba = bone_rgba[::BONE_SUBSAMPLE]
        bone_size = bone_size[::BONE_SUBSAMPLE]
    if sp_corti is not None:
        sp_flag = np.concatenate([sp_corti, sp_trab])
        if BONE_SUBSAMPLE > 1:
            sp_flag = sp_flag[::BONE_SUBSAMPLE]
        bone_rgba[sp_flag] = to_rgba('purple', 0.95)

    x_screw = np.concatenate([x_lin1, x_lin2, x_cyl_l1, x_cyl_l2, x_cyl_r1, x_cyl_r2])
    y_screw = np.concatenate([y_lin1, y_lin2, y_cyl_l1, y_cyl_l2, y_cyl_r1, y_cyl_r2])
    z_screw = np.concatenate([z_lin1, z_lin2, z_cyl_l1, z_cyl_l2, z_cyl_r1, z_cyl_r2])

    _a, _b, _c, _d = sym['plane']
    _n = np.array([_a, _b, _c])
    _u = np.array(sym['u'])
    _v = np.array(sym['v'])
    _p0 = _d * _n                                # 平面上最接近原點的點
    xyz_bone = np.stack([x_bone - _p0[0], y_bone - _p0[1], z_bone - _p0[2]], axis=1)
    _pu = xyz_bone @ _u
    _pv = xyz_bone @ _v
    _U_, _V_ = np.meshgrid(np.linspace(_pu.min(), _pu.max(), 8),
                           np.linspace(_pv.min(), _pv.max(), 8))
    _Xp = _p0[0] + _U_ * _u[0] + _V_ * _v[0]
    _Yp = _p0[1] + _U_ * _u[1] + _V_ * _v[1]
    _Zp = _p0[2] + _U_ * _u[2] + _V_ * _v[2]

    # 上終板平面：RANSAC 擬合骨頭頂面（前側）的最佳 a·x + b·y + c·z = d
    symp = best_upper_endplate_plane(spine_cpu)
    _EX = _EY = _EZ = None
    if symp is not None:
        _ea, _eb, _ec, _ed = symp['plane']
        _en = np.array([_ea, _eb, _ec])
        _eu = np.array(symp['u'])
        _ev = np.array(symp['v'])
        _ep0 = _ed * _en
        xz_ep = np.stack([x_bone - _ep0[0], y_bone - _ep0[1], z_bone - _ep0[2]], axis=1)
        _pu_ep = xz_ep @ _eu
        _pv_ep = xz_ep @ _ev
        _EU, _EV = np.meshgrid(np.linspace(_pu_ep.min(), _pu_ep.max(), 8),
                               np.linspace(_pv_ep.min(), _pv_ep.max(), 8))
        _EX = _ep0[0] + _EU * _eu[0] + _EV * _ev[0]
        _EY = _ep0[1] + _EU * _eu[1] + _EV * _ev[1]
        _EZ = _ep0[2] + _EU * _eu[2] + _EV * _ev[2]
    screw_rgba = np.concatenate([
        _rgba_block(len(x_lin1), 'r', 1.0),
        _rgba_block(len(x_lin2), 'r', 1.0),
        _rgba_block(len(x_cyl_l1), 'darkcyan', 1.0),
        _rgba_block(len(x_cyl_l2), 'pink', 1.0),
        _rgba_block(len(x_cyl_r1), 'blue', 1.0),
        _rgba_block(len(x_cyl_r2), 'pink', 1.0),
    ])
    screw_size = np.concatenate([
        np.full(len(x_lin1), 3), np.full(len(x_lin2), 3),
        np.full(len(x_cyl_l1), 36), np.full(len(x_cyl_l2), 36),
        np.full(len(x_cyl_r1), 36), np.full(len(x_cyl_r2), 36),
    ])

    fig = plt.figure(figsize=(12, 12))

    # 圖例色塊提高到可讀不透明度（實際渲染仍用真實吸收 alpha）
    _leg_alpha_c = max(float(alpha_cortical), 0.35)
    _leg_alpha_t = max(float(alpha_trabecular), 0.2)
    legend_handles = [
        Line2D([], [], marker='o', ls='', ms=5, color=to_rgba('lightblue', _leg_alpha_c), label='Spine (cortical)'),
        Line2D([], [], marker='o', ls='', ms=5, color=to_rgba('lightblue', _leg_alpha_t), label='Spine (trabecular)'),
        Line2D([], [], marker='o', ls='', ms=2, color='r', label='Centerline'),
        Line2D([], [], marker='o', ls='', ms=6, color='darkcyan', label='Cylinder(L)'),
        Line2D([], [], marker='o', ls='', ms=6, color='blue', label='Cylinder(R)'),
        Line2D([], [], marker='o', ls='', ms=6, color='pink', label='Entry track (outer)'),
Line2D([], [], color='orange', lw=2, alpha=0.6,
        label=f"Mirror plane {sym['plane'][0]:+.2f}x {sym['plane'][1]:+.2f}y {sym['plane'][2]:+.2f}z = {sym['plane'][3]:.1f}"),
    ]
    if sp_corti is not None:
        legend_handles.append(Line2D([], [], marker='o', ls='', ms=6, color='purple',
                              label=f"Spinous process (mirror-plane midline, {sp_info['n_sp']} vox)"))
    if symp is not None:
        legend_handles.append(Line2D([], [], color='green', lw=2, alpha=0.7,
                              label=f"Upper endplate plane tilt {symp['tilt_deg']:.1f} deg"))

    def _fill_ax(ax):
        # X-ray 外觀：關閉 mplot3d 依深度自動排序 zorder（否則半透明骨頭會被重繪到
        # 螺絲上方）；改為固定分層：吸收骨頭 zorder=5，全不透明螺絲 zorder=10
        ax.computed_zorder = False
        sc_bone = ax.scatter(x_bone, y_bone, z_bone, c=bone_rgba, s=bone_size, marker='o')
        sc_bone.set_zorder(5)
        sc_screw = ax.scatter(x_screw, y_screw, z_screw, c=screw_rgba, s=screw_size, marker='o')
        sc_screw.set_zorder(10)
        # 中矢狀面（理論左右對稱切分面）：半透明橘色平面 x = x_mid
        # 平面邊緣畫橘色線，讓 axial / 正視（側看時）也能清楚看到切分線
        plane = ax.plot_surface(_Xp, _Yp, _Zp, color='orange', alpha=0.30,
                                linewidth=1.0, edgecolor='orange', rstride=1, cstride=1)
        plane.set_zorder(8)
        # 上終板平面：半透明綠色平面（邊緣綠線）
        if _EX is not None:
            ep = ax.plot_surface(_EX, _EY, _EZ, color='green', alpha=0.35,
                                 linewidth=1.0, edgecolor='green', rstride=1, cstride=1)
            ep.set_zorder(7)

    ax1 = fig.add_subplot(221, projection='3d')
    _fill_ax(ax1)
    ax1.set_xlabel('X-axis'); ax1.set_ylabel('Y-axis'); ax1.set_zlabel('Z-axis')
    set_axes_equal_3d(ax1)

    ax2 = fig.add_subplot(222, projection='3d')
    ax2.view_init(elev=90, azim=-90, roll=0)
    _fill_ax(ax2)
    ax2.set_xlabel('X-axis'); ax2.set_ylabel('Y-axis'); ax2.set_zlabel('Z-axis')
    set_axes_equal_3d(ax2)
    ax2.legend(handles=legend_handles)

    ax3 = fig.add_subplot(223, projection='3d')
    ax3.view_init(elev=0, azim=90, roll=0)
    _fill_ax(ax3)
    ax3.set_xlabel('X-axis'); ax3.set_ylabel('Y-axis'); ax3.set_zlabel('Z-axis')
    set_axes_equal_3d(ax3)

    ax4 = fig.add_subplot(224, projection='3d')
    ax4.view_init(elev=0, azim=0, roll=0)
    _fill_ax(ax4)
    ax4.set_xlabel('X-axis'); ax4.set_ylabel('Y-axis'); ax4.set_zlabel('Z-axis')
    set_axes_equal_3d(ax4)
    
    cyl_points_l = torch.sum(cyl_l).item()
    cyl_points_r = torch.sum(cyl_r).item()

    overlap_l = ((cortical_tensor == 1) & (cyl_l == 1)).sum().item()
    overlap_r = ((cortical_tensor == 1) & (cyl_r == 1)).sum().item()
    overlap_b_l = ((spine_tensor == 1) & (cyl_l == 1)).sum().item()
    overlap_b_r = ((spine_tensor == 1) & (cyl_r == 1)).sum().item()

    overlap_cortical_l = (overlap_l / cyl_points_l) * 100 if cyl_points_l else 0.0
    overlap_cortical_r = (overlap_r / cyl_points_r) * 100 if cyl_points_r else 0.0
    overlap_vertebral_l = (overlap_b_l / cyl_points_l) * 100 if cyl_points_l else 0.0
    overlap_vertebral_r = (overlap_b_r / cyl_points_r) * 100 if cyl_points_r else 0.0
    cb_ratio_l = overlap_cortical_l/overlap_vertebral_l if overlap_vertebral_l else 0.0
    cb_ratio_r = overlap_cortical_r/overlap_vertebral_r if overlap_vertebral_r else 0.0
    user_altitude_l = 90 - best_position_l[4] - alt
    user_altitude_r = 90 - best_position_r[4] - alt
    user_azimuth_l = 90 - best_position_l[3] - azi
    user_azimuth_r = 90 - best_position_r[3] - azi

    date_str = datetime.now().strftime("%Y%m%d")
    patient_id = os.path.basename(os.path.dirname(image2_path))
    output_folder = os.path.join(base_folder, date_str, patient_id)
    os.makedirs(output_folder, exist_ok=True)
    csv_path = os.path.join(output_folder, 'output.csv')
    
    # 檢查檔案是否存在 (決定是否寫入標題)
    file_exists = os.path.isfile(csv_path)

    # 欄位標題 (Header)
    headers = [
        'Label', 'Side', 'Diameter', 'Length', 'Swarm_Size', 'Max_Iter', 
        'Position_XYZ', 'Raw_Azimuth', 'Azimuth_Diff', 'Raw_Altitude', 'Altitude_Diff',
        'Intersections', 'Best_Loss', 'cyl_points', 'Overlap_Cortical', 'Overlap_Bone', 
        'Cortical_Bone_Ratio', 'User_Azimuth', 'User_Altitude', 'Total_Time'
    ]

    try:
        with open(csv_path, 'a', newline='') as csvfile:
            writer = csv.writer(csvfile)
            
            # 如果是新檔案，寫入 Header
            if not file_exists:
                writer.writerow(headers)

            # 寫入 Left 數據
            writer.writerow([
                label_str,
                'L',
                diameter_l,
                length_l,
                swarm_size,
                max_iter,
                # f"({best_position_l[0]:.2f}, {best_position_l[1]:.2f}, {best_position_l[2]:.2f})",
                f"({best_position_l[2]:.2f}, {best_position_l[1]:.2f}, {best_position_l[0]:.2f})",
                f"{best_position_l[3]:.2f}",
                f"{best_position_l[3]-azi:.2f}",
                f"{best_position_l[4]:.2f}",
                f"{best_position_l[4]-alt:.2f}",
                intersections_l,
                f"{loss_l:.2f}",
                cyl_points_l,
                f"{overlap_cortical_l:.2f}",
                f"{overlap_vertebral_l:.2f}",
                f"{(overlap_cortical_l/overlap_vertebral_l if overlap_vertebral_l!=0 else 0):.2f}",
                f"{user_azimuth_l:.2f}",
                f"{user_altitude_l:.2f}",
                f"{total_time:.2f}"
            ])
            
            # 寫入 Right 數據
            writer.writerow([
                label_str,
                'R',
                diameter_r,
                length_r,
                swarm_size,
                max_iter,
                # f"({best_position_r[0]:.2f}, {best_position_r[1]:.2f}, {best_position_r[2]:.2f})",
                f"({best_position_r[2]:.2f}, {best_position_r[1]:.2f}, {best_position_r[0]:.2f})",
                f"{best_position_r[3]:.2f}",
                f"{best_position_r[3]-azi:.2f}",
                f"{best_position_r[4]:.2f}",
                f"{best_position_r[4]-alt:.2f}",
                intersections_r,
                f"{loss_r:.2f}",
                cyl_points_r,
                f"{overlap_cortical_r:.2f}",
                f"{overlap_vertebral_r:.2f}",
                f"{(overlap_cortical_r/overlap_vertebral_r if overlap_vertebral_r!=0 else 0):.2f}",
                f"{user_azimuth_r:.2f}",
                f"{user_altitude_r:.2f}",
                f"{total_time:.2f}"
            ])
        print(f"[CSV Saved] {csv_path}")

    except Exception as e:
        print(f"[Error] Failed to write CSV: {e}")

    fig.text(0.5, 0.98, f'{label_str} Best Position', ha='center', fontsize=15)
    fig.text(
        0.5, 0.44,
        f'L: Diameter = {diameter_l} mm, {length_l} mm, '
        f'R: Diameter = {diameter_r} mm, {length_r} mm, '
        f'Swarm size = {swarm_size}, Iteration = {max_iter}, Total time = {total_time:.2f} s',
        ha='center', fontsize=12
    )
    fig.text(
        0.5, 0.03,
        # f'Left : Position = ({best_position_l[0]:.2f}, {best_position_l[1]:.2f}, {best_position_l[2]:.2f}), '
        f'Left : Position = ({best_position_l[2]:.2f}, {best_position_l[1]:.2f}, {best_position_l[0]:.2f}), '
        f'Azimuth = {user_azimuth_l:.2f}, Altitude = {user_altitude_l:.2f}, '
        f'Intersection = {intersections_l}, Score = {overlap_cortical_l:.2f} / {overlap_vertebral_l:.2f} / {cb_ratio_l:.2f}',
        ha='center', fontsize=9
    )
    fig.text(
        0.5, 0.01,
        # f'Right : Position = ({best_position_r[0]:.2f}, {best_position_r[1]:.2f}, {best_position_r[2]:.2f}), '
        f'Right : Position = ({best_position_r[2]:.2f}, {best_position_r[1]:.2f}, {best_position_r[0]:.2f}), '
        f'Azimuth = {user_azimuth_r:.2f}, Altitude = {user_altitude_r:.2f}, '
        f'Intersection = {intersections_r}, Score = {overlap_cortical_r:.2f} / {overlap_vertebral_r:.2f} / {cb_ratio_r:.2f}',
        ha='center', fontsize=9
    )

    fig.tight_layout()

    date_str = datetime.now().strftime("%Y%m%d")
    file_name = os.path.basename(image2_path) 
    level = file_name.split('_')[0]
    output_folder = os.path.join(base_folder, date_str, patient_id)
    os.makedirs(output_folder, exist_ok=True)

    if CBT == True:
        way = 'CBT'
    
    else:
        way = 'TPS'

    path = save_with_unique_name(output_folder, label_str, way,
                                 diameter_l, length_l, diameter_r, length_r,
                                 swarm_size, max_iter)

    fig.savefig(path, dpi=200, bbox_inches="tight")
    print("[Saved figure]", path)
    plt.close(fig)


def eval_overlap_from_position(
    pos,
    optimize_size: bool,
    spine_tensor: torch.Tensor,
    image_shape,
    spacing,
    device: torch.device,
    grid=None,
    fixed_diameter: float | None = None,
    fixed_length: float | None = None,
):
    """
    根據 position 生成 cylinder mask，再算 overlap ratio
    """

    if optimize_size:
        d, L = snap_to_discrete_values(pos[5], pos[6])
        params_5 = pos[:5]
    else:
        if fixed_diameter is None or fixed_length is None:
            raise ValueError("fixed_diameter and fixed_length must be provided when optimize_size=False")
        d, L = fixed_diameter, fixed_length
        params_5 = pos

    z, y, x, az, alt = params_5

    cyl_mask = generate_cylinder_n_torch(
        d, L,
        z, y, x,
        az, alt,
        image_shape, spacing,
        device=device,
        grid=grid
    )

    overlap = compute_overlap_ratio_from_cylinder_mask(cyl_mask, spine_tensor)
    return overlap, d, L