import csv

input_file = "../data/passengers.csv"
output_file = "../data/passengers2.csv"

with open(input_file, 'r') as csv_input:
    with open(output_file, 'w', newline='') as csv_output:
        reader = csv.reader(csv_input)
        writer = csv.writer(csv_output)

        # Iterate through each row in the CSV
        for row in reader:
            # Get the last field in the row
            location = row[-1]
            
            # Split the location into two parts if it contains '/' and ','
            if '/' in location and ',' in location:
                location1, location2 = location.split('/')
                
                # Further split location1 into city1 and country1
                city1, country_state1 = location1.split(',', 1)
                
                # Further split location2 into city2 and country2
                city2, country_state2 = location2.split(',', 1)
            elif ',' in location:
                city1, country_state1 = location.split(',', 1)
                # For the second location, set to empty strings
                city2, country_state2 = "", ""
            else:
                # If no city and country details are present
                city1, country_state1, city2, country_state2 = "", "", "", ""
            
            # Now replace the last field with the 4 new fields
            row[-1:] = [city1.strip(), country_state1.strip(), city2.strip(), country_state2.strip()]
                   
            # Write the row into the new csv file
            writer.writerow(row)