import csv
import os
from datetime import datetime
import streamlit as st

def record_attendance_new(present_students: list, subject: str, max_roll_number=26):
    # Automatically get the current date in YYYY-MM-DD format
    date = datetime.now().strftime("%Y-%m-%d")

    # Convert present_students to integers
    present_students = list(map(int, present_students))
    print("Present Students:", present_students)  # Debugging line

    # Get the path of the uploaded CSV file
    csv_file_path = f'{subject}.csv'
    print("CSV File Path:", csv_file_path)  # Debugging line

    # Read the existing CSV file
    if os.path.exists(csv_file_path):
        with open(csv_file_path, 'r', newline='') as csvfile:
            reader = csv.reader(csvfile)
            rows = list(reader)
    else:
        # If file doesn't exist, create a new one with header
        rows = [['Roll Number']]

    # Check if the date column already exists
    if date not in rows[0]:
        rows[0].append(date)

    date_col_index = rows[0].index(date)

    # Update or add attendance for each roll number
    for roll_number in range(1, max_roll_number + 1):
        found = False
        for row in rows[1:]:
            if int(row[0]) == roll_number:
                found = True
                if len(row) < date_col_index + 1:
                    row.extend([''] * (date_col_index - len(row) + 1))
                
                if roll_number in present_students:
                    row[date_col_index] = 'Present'
                    print(f"Updating {roll_number}: Present")  # Debugging line
                else:
                    row[date_col_index] = 'Absent'
                    print(f"Updating {roll_number}: Absent")  # Debugging line
                break
        
        if not found:
            new_row = [str(roll_number)] + [''] * (date_col_index - 1)
            new_row.append('Present' if roll_number in present_students else 'Absent')
            rows.append(new_row)
            print(f"Adding new row for {roll_number}: {'Present' if roll_number in present_students else 'Absent'}")

    # Write the updated data back to the CSV file
    with open(csv_file_path, 'w', newline='') as csvfile:
        writer = csv.writer(csvfile)
        writer.writerows(rows)

    # Create a download button
    with open(csv_file_path, 'r') as file:
        csv_contents = file.read()
    
    st.download_button(
        label="Download updated attendance file",
        data=csv_contents,
        file_name=csv_file_path,
        mime='text/csv'
    )

    print(f"Attendance recorded for {len(present_students)} students on {date} in {subject}.")