import pandas as pd
import smtplib
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart
import getpass
from tkinter import Tk
from tkinter.filedialog import askopenfilename

# Open file 
Tk().withdraw() 
file_path = askopenfilename(
    title="Select CSV or XLSX file",
    filetypes=[("CSV files", "*.csv"), ("Excel files", "*.xlsx"), ("All files", "*.*")]
)
if not file_path:
    raise ValueError("No file selected. Exiting.")


if file_path.lower().endswith('.csv'):
    df = pd.read_csv(file_path)
elif file_path.lower().endswith(('.xlsx', '.xls')):
    df = pd.read_excel(file_path)
else:
    raise ValueError("Unsupported file type. Only CSV or XLSX allowed.")

# Recipient column 
print(f"Available columns: {list(df.columns)}")
recipient_col = input("Enter the column name for recipients: ").strip()
if recipient_col not in df.columns:
    raise ValueError(f"Column '{recipient_col}' not found.")


placeholders = {}
while True:
    var_name = input("Enter a placeholder name (e.g., $Variable1) or press Enter to finish: ").strip()
    if not var_name:
        break
    col_name = input(f"Enter the column name to use for {var_name}: ").strip()
    if col_name not in df.columns:
        print(f"Column '{col_name}' not found, try again.")
        continue
    placeholders[var_name] = col_name

sender_email = input("Enter your sender email address: ").strip()


while True:
    smtp_password = getpass.getpass("Enter your email password (hidden): ")
    smtp_server = input("Enter your SMTP server (e.g., smtp.gmail.com): ").strip()
    smtp_port = int(input("Enter your SMTP port (usually 587 for TLS): ").strip())
    try:
        with smtplib.SMTP(smtp_server, smtp_port) as server:
            server.starttls()
            server.login(sender_email, smtp_password)
        print("Login successful!")
        break
    except smtplib.SMTPAuthenticationError:
        print("Authentication failed. Please try again.")
    except Exception as e:
        print(f"SMTP error: {e}. Please try again.")

subject = input("Enter the email subject: ").strip()
print("Enter your email body. Use placeholders like $Variable1, $Variable2.")
print("Type 'END' on a new line to finish:")
lines = []
while True:
    line = input()
    if line.strip().upper() == "END":
        break
    lines.append(line)
body_template = "\n".join(lines)

#  send
with smtplib.SMTP(smtp_server, smtp_port) as server:
    server.starttls()
    server.login(sender_email, smtp_password)
    
    for idx, row in df.iterrows():
        recipient = row[recipient_col]
        body = body_template
        for var, col in placeholders.items():
            body = body.replace(var, str(row[col]))
        
        msg = MIMEMultipart()
        msg['From'] = sender_email
        msg['To'] = recipient
        msg['Subject'] = subject
        msg.attach(MIMEText(body, 'plain'))
        
        try:
            server.send_message(msg)
            print(f"Email sent to {recipient}")
        except Exception as e:
            print(f"Failed to send email to {recipient}: {e}")

print("All emails processed!")