"""
Visualize GT depth - both reverse and non-reverse versions
Must match exactly with visualize_depth.py sample selection
"""
import os
import sys
import numpy as np
from PIL import Image
import matplotlib.pyplot as plt
import matplotlib
matplotlib.use('Agg')
from tqdm import tqdm

# Dataset paths - MUST match visualize_depth.py
KITTI_BASE = '/home/ywan0794/datasets/eval/moge_style_eval/KITTI'
DDAD_BASE = '/home/ywan0794/datasets/eval/moge_style_eval/DDAD/val'
OUTPUT_DIR = '/home/ywan0794/MoGe/vis_output'


def colorize_depth(depth, cmap='Spectral', reverse=False, mask_invalid=False):
    depth = depth.copy()
    if mask_invalid:
        invalid_mask = depth <= 0
        valid_depth = depth[~invalid_mask]
        if len(valid_depth) > 0:
            vmin = np.percentile(valid_depth, 2)
            vmax = np.percentile(valid_depth, 98)
        else:
            vmin, vmax = 0, 1
    else:
        vmin = np.percentile(depth, 2)
        vmax = np.percentile(depth, 98)

    depth = (depth - vmin) / (vmax - vmin + 1e-8)
    depth = np.clip(depth, 0, 1)

    if reverse:
        depth = 1 - depth

    cm = plt.get_cmap(cmap)
    colored = cm(depth)[:, :, :3]
    colored = (colored * 255).astype(np.uint8)

    if mask_invalid:
        colored[invalid_mask] = 0

    return colored


def load_gt_depth(depth_path):
    depth = np.array(Image.open(depth_path))
    if depth.dtype == np.uint16:
        depth = depth.astype(np.float32) / 256.0
    elif depth.dtype == np.uint8:
        depth = depth.astype(np.float32)
    return depth


def main():
    print("=" * 50, flush=True)
    print("GT Depth Visualization (both versions)", flush=True)
    print("=" * 50, flush=True)

    # Create output directories
    for dataset in ['KITTI', 'DDAD']:
        os.makedirs(os.path.join(OUTPUT_DIR, dataset, 'gt'), exist_ok=True)
        os.makedirs(os.path.join(OUTPUT_DIR, dataset, 'gt_reverse'), exist_ok=True)

    # ============================================
    # KITTI - MUST match visualize_depth.py exactly
    # ============================================
    print("\nCollecting KITTI samples...", flush=True)
    kitti_samples = []
    for drive in os.listdir(KITTI_BASE):
        drive_path = os.path.join(KITTI_BASE, drive, 'image_02')
        if os.path.isdir(drive_path):
            for frame in sorted(os.listdir(drive_path)):
                sample_dir = os.path.join(drive_path, frame)
                img_path = os.path.join(sample_dir, 'image.jpg')
                gt_path = os.path.join(sample_dir, 'depth.png')
                # MUST check both img and gt exist - same as visualize_depth.py
                if os.path.exists(img_path) and os.path.exists(gt_path):
                    kitti_samples.append({
                        'image': img_path,
                        'gt': gt_path,
                        'name': f"{drive}_{frame}"
                    })

    # Same random seed and selection as visualize_depth.py
    np.random.seed(42)
    num_samples = 10  # Must match --num-samples in visualize_depth.py
    kitti_selected = np.random.choice(len(kitti_samples), min(num_samples, len(kitti_samples)), replace=False)

    print(f"Processing {len(kitti_selected)} KITTI GT samples...", flush=True)
    for idx, i in tqdm(enumerate(kitti_selected), total=len(kitti_selected), desc="KITTI GT", file=sys.stdout):
        sample = kitti_samples[i]
        gt_depth = load_gt_depth(sample['gt'])

        # Non-reverse version
        gt_colored = colorize_depth(gt_depth, reverse=False, mask_invalid=True)
        Image.fromarray(gt_colored).save(os.path.join(OUTPUT_DIR, 'KITTI', 'gt', f"{idx:03d}.png"))

        # Reverse version
        gt_colored_rev = colorize_depth(gt_depth, reverse=True, mask_invalid=True)
        Image.fromarray(gt_colored_rev).save(os.path.join(OUTPUT_DIR, 'KITTI', 'gt_reverse', f"{idx:03d}.png"))

    # ============================================
    # DDAD - MUST match visualize_depth.py exactly
    # ============================================
    print("\nCollecting DDAD samples...", flush=True)
    ddad_samples = []
    for scene in sorted(os.listdir(DDAD_BASE)):
        scene_path = os.path.join(DDAD_BASE, scene)
        if os.path.isdir(scene_path):
            for cam in sorted(os.listdir(scene_path)):
                sample_dir = os.path.join(scene_path, cam)
                img_path = os.path.join(sample_dir, 'image.jpg')
                gt_path = os.path.join(sample_dir, 'depth.png')
                # MUST check both img and gt exist - same as visualize_depth.py
                if os.path.exists(img_path) and os.path.exists(gt_path):
                    ddad_samples.append({
                        'image': img_path,
                        'gt': gt_path,
                        'name': f"{scene}_{cam}"
                    })

    # Same random seed and selection as visualize_depth.py
    # Note: seed was already set to 42 above, and kitti_selected consumed some random numbers
    # We need to match the exact sequence
    ddad_selected = np.random.choice(len(ddad_samples), min(num_samples, len(ddad_samples)), replace=False)

    print(f"Processing {len(ddad_selected)} DDAD GT samples...", flush=True)
    for idx, i in tqdm(enumerate(ddad_selected), total=len(ddad_selected), desc="DDAD GT", file=sys.stdout):
        sample = ddad_samples[i]
        gt_depth = load_gt_depth(sample['gt'])

        # Non-reverse version
        gt_colored = colorize_depth(gt_depth, reverse=False, mask_invalid=True)
        Image.fromarray(gt_colored).save(os.path.join(OUTPUT_DIR, 'DDAD', 'gt', f"{idx:03d}.png"))

        # Reverse version
        gt_colored_rev = colorize_depth(gt_depth, reverse=True, mask_invalid=True)
        Image.fromarray(gt_colored_rev).save(os.path.join(OUTPUT_DIR, 'DDAD', 'gt_reverse', f"{idx:03d}.png"))

    print("\n" + "=" * 50, flush=True)
    print("Done!", flush=True)
    print("Output:", flush=True)
    print(f"  {OUTPUT_DIR}/KITTI/gt/         (non-reverse)", flush=True)
    print(f"  {OUTPUT_DIR}/KITTI/gt_reverse/ (reverse)", flush=True)
    print(f"  {OUTPUT_DIR}/DDAD/gt/          (non-reverse)", flush=True)
    print(f"  {OUTPUT_DIR}/DDAD/gt_reverse/  (reverse)", flush=True)
    print("=" * 50, flush=True)


if __name__ == '__main__':
    main()