import smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from datetime import datetime
import time

# AWS SES SMTP settings
aws_smtp_server = "email-smtp.ap-south-1.amazonaws.com"
aws_smtp_port = 587
aws_smtp_username = "YOUR_SES_SMTP_USERNAME"
aws_smtp_password = "YOUR_SES_SMTP_PASSWORD"

sender_email = "Customer Helpdesk <helpdesk@yourdomain.com>"

# Email subject and body
subject = "Reminder to Complete Registration"

body = """
<html>
<body style="font-family: Arial, sans-serif; font-size: 14px; color: #000;">
<p>Dear Candidate,</p>

<p>
This is a reminder to complete your online registration.
Please complete all required steps before the registration closing date.
</p>

<p>
This is an auto-generated email. Please do not reply to this message.
</p>

<p>
Regards,<br>
<b>Customer Helpdesk</b>
</p>
</body>
</html>
"""

# Output log
output_file = "email_send_status.txt"

# Batch settings
batch_size = 1500
pause_seconds = 60


def send_email(to_email):
    msg = MIMEMultipart()

    msg["From"] = sender_email
    msg["To"] = to_email
    msg["Subject"] = subject

    msg.attach(MIMEText(body, "html"))

    with smtplib.SMTP(
        aws_smtp_server,
        aws_smtp_port
    ) as server:

        server.starttls()

        server.login(
            aws_smtp_username,
            aws_smtp_password
        )

        server.send_message(msg)


# Read email list
with open("list_of_emails.txt", "r") as file:
    all_emails = [
        email.strip()
        for email in file
        if email.strip()
    ]

total_emails = len(all_emails)

print(f"Total emails to send: {total_emails}")


# Send emails in batches
with open(output_file, "a") as output:

    for i in range(0, total_emails, batch_size):

        batch = all_emails[i:i + batch_size]

        batch_number = i // batch_size + 1

        print(
            f"\n--- Sending batch {batch_number} "
            f"({len(batch)} emails) ---"
        )

        for email in batch:

            try:
                send_email(email)

                status = (
                    f"{datetime.now():%Y-%m-%d %H:%M:%S} - "
                    f"Email sent successfully to {email}"
                )

                print(status)
                output.write(status + "\n")

            except Exception as e:

                status = (
                    f"{datetime.now():%Y-%m-%d %H:%M:%S} - "
                    f"Failed to send email to {email}: {e}"
                )

                print(status)
                output.write(status + "\n")

        # Save log after each batch
        output.flush()

        # Wait before the next batch
        if i + batch_size < total_emails:

            print(
                f"Waiting {pause_seconds} seconds "
                f"before next batch..."
            )

            time.sleep(pause_seconds)


print("\nAll emails processed.")
print(f"Check {output_file} for details.")