import random
import string
import smtplib
from email.mime.text import MIMEText
import os
import uuid
import config
from werkzeug.utils import secure_filename

UPLOAD_ROOT = os.path.join(os.getcwd(), 'uploads')

def generate_password(length=10):
    characters = string.ascii_letters + string.digits
    return ''.join(random.choice(characters) for _ in range(length))

def send_email(recipient_email, subject, body):
    if config.USE_EXTERNAL_SMTP:
        sender_email = config.SMTP_SENDER_EMAIL
        sender_password = config.SMTP_SENDER_PASSWORD

        msg = MIMEText(body)
        msg['Subject'] = subject
        msg['From'] = sender_email
        msg['To'] = recipient_email

        try:
            with smtplib.SMTP(config.SMTP_SERVER, config.SMTP_PORT) as server:
                if config.SMTP_USE_TLS:
                    server.starttls()
                server.login(sender_email, sender_password)
                server.send_message(msg)
        except Exception as e:
            print(f"Failed to send email via external SMTP: {e}")
    else:
        try:
            process = os.popen(f"/usr/sbin/sendmail -t")
            process.write(f"To: {recipient_email}\n")
            process.write(f"Subject: {subject}\n")
            process.write(f"\n{body}")
            process.close()
        except Exception as e:
            print(f"Failed to send email via local sendmail: {e}")

def is_file_allowed(file):
    return '.' in file.filename and file.filename.rsplit('.', 1)[1].lower() in config.ALLOWED_EXTENSIONS

def save_document(file, subfolder):
    if not is_file_allowed(file):
        raise ValueError("File type not allowed. Only images are permitted.")

    if len(file.read()) > config.MAX_FILE_SIZE:
        raise ValueError("File size exceeds the limit of 5 MB.")

    file.seek(0)

    upload_folder = os.path.join(UPLOAD_ROOT, subfolder)
    os.makedirs(upload_folder, exist_ok=True)
    filename = secure_filename(f"{uuid.uuid4().hex}.{file.filename.rsplit('.', 1)[1].lower()}")
    filepath = os.path.join(upload_folder, filename)
    file.save(filepath)
    return filename