import argparse
import glob
import os


def main(args):
    txt_file = open(args.meta_info, "w")
    # sca images
    img_paths_gt = sorted(glob.glob(os.path.join(args.input[0], "*")))
    img_paths_lq = sorted(glob.glob(os.path.join(args.input[1], "*")))

    assert len(img_paths_gt) == len(img_paths_lq), (
        "GT folder and LQ folder should have the same length, but got "
        f"{len(img_paths_gt)} and {len(img_paths_lq)}."
    )

    for img_path_gt, img_path_lq in zip(img_paths_gt, img_paths_lq):
        # get the relative paths
        img_name_gt = os.path.relpath(img_path_gt, args.root[0])
        img_name_lq = os.path.relpath(img_path_lq, args.root[1])
        print(f"{img_name_gt}, {img_name_lq}")
        txt_file.write(f"{img_name_gt}, {img_name_lq}\n")


if __name__ == "__main__":
    """This script is used to generate meta info (txt file) for paired images."""
    parser = argparse.ArgumentParser()
    parser.add_argument(
        "--input",
        nargs="+",
        default=[
            "datasets/DF2K/DIV2K_train_HR_sub",
            "datasets/DF2K/DIV2K_train_LR_bicubic_X4_sub",
        ],
        help="Input folder, should be [gt_folder, lq_folder]",
    )
    parser.add_argument(
        "--root", nargs="+", default=[None, None], help="Folder root, will use the "
    )
    parser.add_argument(
        "--meta_info",
        type=str,
        default="datasets/DF2K/meta_info/meta_info_DIV2K_sub_pair.txt",
        help="txt path for meta info",
    )
    args = parser.parse_args()

    assert (
        len(args.input) == 2
    ), "Input folder should have two elements: gt folder and lq folder"
    assert (
        len(args.root) == 2
    ), "Root path should have two elements: root for gt folder and lq folder"
    os.makedirs(os.path.dirname(args.meta_info), exist_ok=True)
    for i in range(2):
        if args.input[i].endswith("/"):
            args.input[i] = args.input[i][:-1]
        if args.root[i] is None:
            args.root[i] = os.path.dirname(args.input[i])

    main(args)