import os
import urllib.request
from datetime import datetime, timedelta

# Base URL for the files
base_url = "https://gws-access.jasmin.ac.uk/public/tamsat/rfe/data_degraded/v3.1/daily/0.25"

# Define the start and end year
start_year = 2003
end_year = 2025

# List of months to loop over (September to January)
months = ["09", "10", "11", "12", "01"]

# Define the output directory
output_dir = "/nird/datalake/NS9853K/kolstad/tamsat"

# Function to download the file
def download_file(file_url, save_path):
    try:
        # Check if the file already exists
        if os.path.exists(save_path):
            print(f"File already exists: {save_path}")
        else:
            print(f"Downloading {file_url}...")
            urllib.request.urlretrieve(file_url, save_path)
            print(f"File saved as {save_path}")
    except Exception as e:
        print(f"Error downloading {file_url}: {e}")

# Loop over the years from start_year to end_year
for year in range(start_year, end_year + 1):
    for month in months:
        # Skip months in the years that fall outside of the range
        if (year == start_year and int(month) < 9) or (year == end_year and int(month) > 1):
            continue

        # Set the correct number of days for the month
        if month in ["09", "04", "06", "09", "11"]:  # Months with 30 days
            days_in_month = 30
        elif month == "02":  # February (Leap year check)
            if (year % 4 == 0 and (year % 100 != 0 or year % 400 == 0)):
                days_in_month = 29  # Leap year
            else:
                days_in_month = 28  # Non-leap year
        else:  # Months with 31 days
            days_in_month = 31

        # Loop through the days of the month
        for day in range(1, days_in_month + 1):
            day_str = f"{day:02d}"
            file_url = f"{base_url}/{year}/{month}/rfe{year}_{month}_{day_str}_0.25.v3.1.nc"
            file_name = f"rfe{year}_{month}_{day_str}_0.25.v3.1.nc"
            save_path = os.path.join(output_dir, file_name)

            # Download the file
            download_file(file_url, save_path)

print("Download complete!")