import os
import random
import sys

import matplotlib.pyplot as plt
from PIL import Image
from pycocotools.coco import COCO

coco_folder = "instance_segmentation/multiannotator_15imgs_coco"
img_folder = "images"

if __name__ == "__main__":
    # Optional user id as argument, otherwise pick a random user
    user_ids = sorted(f[:-len(".json")] for f in os.listdir(coco_folder) if f.endswith(".json"))
    user_id = sys.argv[1] if len(sys.argv) > 1 else random.choice(user_ids)

    coco = COCO(os.path.join(coco_folder, f"{user_id}.json"))
    img_ids = sorted(coco.imgs)
    print(f"User {user_id}: {len(img_ids)} images, {len(coco.anns)} annotations")

    cols = min(3, len(img_ids))
    rows = -(-len(img_ids) // cols)
    fig, axes = plt.subplots(rows, cols, figsize=(6 * cols, 3.6 * rows), squeeze=False)
    for ax in axes.flat:
        ax.axis("off")

    for ax, img_id in zip(axes.flat, img_ids):
        img_info = coco.imgs[img_id]
        anns = coco.loadAnns(coco.getAnnIds(imgIds=img_id))
        ax.imshow(Image.open(os.path.join(img_folder, img_info["file_name"])))
        plt.sca(ax)
        coco.showAnns(anns, draw_bbox=False)
        ax.set_title(f"{img_info['file_name']} ({len(anns)} annotations)", fontsize=9)

    fig.suptitle(f"Annotations of user {user_id}")
    fig.tight_layout()
    fig.savefig("example_user_annotations.png", dpi=100)
    plt.show()