import pandas as pd
from pathlib import Path
import argparse
import sys

# Output of match_owners.py (catalog-media.csv) should be fed in.
# Will also work with the media manifest.

CC_URL = "https://creativecommons.org/"


def get_license_url(license_version):
    """
    Function to generate the appropriate Creative Commons URL for a given license.
    All licenses in the media manifest are "cc-XX", a variation on "publicdomain", or "No known copyright restrictions".

    Parameters:
    -----------
    license_version - String. License (eg., "cc-by-nc 3.0").

    Returns:
    --------
    license_url - String. Creative Commons URL associated with the license_version.

    """
    # First check for version number and isolate it
    if "." in license_version:
        version = license_version.split(sep="-")[-1]
        license_name = license_version.split(sep="-" + version)[0]
    else:
        # No version specified, so default to latest version (4.0)
        license_name = license_version
        version = "4.0"
    # Check which type of license
    if license_name[:5] == "cc-by":
        by_x = license_name.split(sep="cc-")[1]
        license_url = CC_URL + "licenses/" + by_x + "/" + version
    elif (license_name[:4] == "cc-0") or ("public" in license_name):
        license_url = CC_URL + "publicdomain/zero/1.0"
    else:
        # "No known copyright restrictions"
        license_url = None
    return license_url


def main(src_csv, dest_dir):
    # Check CSV compatibility
    try:
        print("Reading CSV")
        df = pd.read_csv(src_csv, low_memory=False)
    except Exception as e:
        sys.exit(e)

    # Check for "License Name" or "license_name" column
    print("Processing data")
    df_cols = list(df.columns)
    if "License Name" not in df_cols:
        if "license_name" not in df_cols:
            sys.exit("Source CSV does not have a column labeled License Name or license_name.")
        license_col = "license_name"
    license_col = "License Name"

    # Check filepath given by user
    dest_dir_path = Path(dest_dir)
    if not dest_dir_path.is_absolute():
        # Use ToL-EDA as reference folder
        base_path = Path(__file__).parent.parent.resolve()
        filepath = base_path / dest_dir_path
    else:
        filepath = dest_dir_path

    filepath.mkdir(parents=True, exist_ok=True)

    # Add links for licenses to catalog manifest
    print("Getting URLs for licenses")
    df["license_link"] = df[license_col].apply(get_license_url)

    # Save license file
    df.to_csv(str(filepath / "licenses.csv"), index=False)

    # Print counts of licenses for which URL was not resolved
    print(
        "Licenses with no URL: \n",
        df.loc[df["license_link"].isna(), license_col].value_counts(),
    )


if __name__ == "__main__":
    parser = argparse.ArgumentParser(
        description="Add license URLs to catalog-media file"
    )
    parser.add_argument("input_file", help="Path to the input CSV file")
    parser.add_argument(
        "--output_path",
        default="data",
        required=False,
        help="Path to the folder for output license file",
    )
    args = parser.parse_args()

    main(args.input_file, args.output_path)