"""
@author: louisblankemeier
"""
import csv
import os

import pydicom


def find_dicom_files(input_path):
    dicom_series = []
    if not os.path.isdir(input_path):
        dicom_series = [str(os.path.abspath(input_path))]
    else:
        for root, _, files in os.walk(input_path):
            for file in files:
                if file.endswith(".dcm") or file.endswith(".dicom"):
                    dicom_series.append(os.path.join(root, file))
    return dicom_series


def get_dicom_paths_and_num(path):
    """
    Get all paths under a path that contain only dicom files.
    Args:
        path (str): Path to search.
    Returns:
        list: List of paths.
    """
    dicom_paths = []
    for root, _, files in os.walk(path):
        if len(files) > 0:
            if all(file.endswith(".dcm") or file.endswith(".dicom") for file in files):
                dicom_paths.append((root, len(files)))

    if len(dicom_paths) == 0:
        raise ValueError("No scans were found in:\n" + path)

    return dicom_paths


def get_dicom_or_nifti_paths_and_num(path):
    """Get all paths under a path that contain only dicom files or a nifti file.
    Args:
        path (str): Path to search.

    Returns:
        list: List of paths.
    """
    if path.endswith(".nii") or path.endswith(".nii.gz"):
        return [(path, 1)]
    dicom_nifti_paths = []
    for root, dirs, files in os.walk(path):
        if len(files) > 0:
            # if all(file.endswith(".dcm") or file.endswith(".dicom") for file in files):
            dicom_nifti_paths.append((root, len(files)))
            # else:
            #     for file in files:
            #         if file.endswith(".nii") or file.endswith(".nii.gz"):
            #             num_slices = 450
            #             dicom_nifti_paths.append((os.path.join(root, file), num_slices))

    return dicom_nifti_paths


def write_dicom_metadata_to_csv(ds, csv_filename):
    with open(csv_filename, "w", newline="") as csvfile:
        csvwriter = csv.writer(csvfile)
        csvwriter.writerow(["Tag", "Keyword", "Value"])

        for element in ds:
            tag = element.tag
            keyword = pydicom.datadict.keyword_for_tag(tag)
            if keyword == "PixelData":
                continue
            value = str(element.value)
            csvwriter.writerow([tag, keyword, value])