import csv
import os
from PIL import Image

SIZE = (512, 512)
MASK_TYPES = ["inpainting", "outpainting", "random"]


def apply_mask(image1_path, mask_path, size=SIZE):
    """Return GT image: keep image1 pixels where mask=1 (white), black where mask=0."""
    img = Image.open(image1_path).convert("RGB").resize(size)
    mask = Image.open(mask_path).convert("L").resize(size)
    black = Image.new("RGB", size, (0, 0, 0))
    return Image.composite(img, black, mask)


def generate_gt_images(csv_file, output_dir):
    if not os.path.exists(csv_file):
        print(f"Warning: {csv_file} not found, skipping.")
        return

    with open(csv_file, "r", encoding="utf-8") as f:
        rows = list(csv.DictReader(f))

    os.makedirs(output_dir, exist_ok=True)

    for row in rows:
        id_val = row["id"].strip()
        image1_path = row.get("image1_path", "").strip()
        image2_path = row.get("image2_path", "").strip()

        DATA_ROOT = "data"
        image1_path = os.path.join(DATA_ROOT, image1_path)
        image2_path = os.path.join(DATA_ROOT, image2_path)

        img_path = os.path.join(output_dir, f"id_{id_val}.png")

        if image1_path and os.path.exists(image1_path):
            gt = apply_mask(image1_path, image2_path)
            gt.save(img_path)
        else:
            print(f"Skip id={id_val}: image1_path missing or not found ({image1_path!r})")

    print(f"Done: {output_dir}")


if __name__ == "__main__":
    for mask_type in MASK_TYPES:
        generate_gt_images(
            f"metadata/Task_Image_Mask_{mask_type}_metadata.csv",
            output_dir=f"data/Task_Image_Mask/{mask_type}"
        )