import csv
import netCDF4
import os
import sys
import datetime
import numpy as np



# Check if the input filename is provided as a command-line argument
if len(sys.argv) < 2:
    print("Please provide the input NetCDF filename as a command-line argument.")
    exit()

# Get the input filename from the command-line argument
input_filename = sys.argv[1]

# Check if the input file exists
if not os.path.isfile(input_filename):
    print("Input file does not exist:", input_filename)
    exit()

# Create the output filename by changing the extension from .nc to .csv
output_filename = os.path.splitext(input_filename)[0] + ".csv"

# Open the NetCDF file
dataset = netCDF4.Dataset(input_filename)

# Get the variables of interest
file_variable = dataset.variables["file"]
lat_variable = dataset.variables["Latitude"]
lon_variable = dataset.variables["Longitude"]
optical_depth_variable = dataset.variables["Optical_Depth_Land_And_Ocean"]
scan_time_variable = dataset.variables["Scan_Start_Time"]
aer_type_variable = dataset.variables["Aerosol_Type_Land"]
deepb_AOD_variable = dataset.variables["Deep_Blue_Aerosol_Optical_Depth_550_Land"]
deepb_Angstrom_variable = dataset.variables["Deep_Blue_Angstrom_Exponent_Land"]
deepb_AOD_variable = dataset.variables["AOD_550_Dark_Target_Deep_Blue_Combined"]

# Get the dimensions of the file variable
dim_file = file_variable.shape[0]  # Dimension size of the file dimension

# Create and open the CSV file in write mode
with open(output_filename, "w", newline="") as csv_file:
    writer = csv.writer(csv_file)

    # Write the header row
    writer.writerow(["File", "Date", "Scan_Start_Time", "Latitude", "Longitude", "Optical_Depth_Land_And_Ocean", "Aerosol_type", "DeepBlue_AOD", "DeepBlue_angstrom", "AOD_Combined"])

    # Loop over the file dimension indices
    for i in range(dim_file):
        # Extract the values at the given index
        file_value = file_variable[i]
        scan_time_value = scan_time_variable[i]
        lat_value = lat_variable[i]
        lon_value = lon_variable[i]
        optical_depth_value = optical_depth_variable[i]
        aer_type_value = aer_type_variable[i] 
        deepb_AOD_value = deepb_AOD_variable[i]
        ddeepb_Angstrom_value = deepb_Angstrom_variable[i]
        deepb_AOD_value = deepb_AOD_variable[i]

        # Convert TAI Time to datetime
        tai_datetime = datetime.datetime(1993, 1, 1) + datetime.timedelta(seconds=int(scan_time_value))

        # Extract year, month, day, hours, and minutes
        #year = tai_datetime.year
        #month = tai_datetime.month
        #ay = tai_datetime.day
        #ours = tai_datetime.hour
        #inutes = tai_datetime.minute

        # Write the values to the CSV file
        writer.writerow([file_value, tai_datetime, scan_time_value, lat_value, lon_value, optical_depth_value,aer_type_value,deepb_AOD_value,ddeepb_Angstrom_value,deepb_AOD_value])

# Close the NetCDF file
dataset.close()

print("Data has been saved to:", output_filename)