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

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)
            logger.info(f"Email sent successfully via SMTP to {recipient_email}")
        except Exception as e:
            logger.error(f"Failed to send email via SMTP to {recipient_email}: {e}")
    else:
        try:
            process = subprocess.Popen(
                ["/usr/sbin/sendmail", "-t"],
                stdin=subprocess.PIPE,
                stderr=subprocess.PIPE
            )
            email_message = f"To: {recipient_email}\nSubject: {subject}\n\n{body}"
            stdout, stderr = process.communicate(input=email_message.encode())

            if process.returncode != 0:
                logger.error(f"Sendmail error: {stderr.decode().strip()}")
            else:
                logger.info(f"Email sent successfully via sendmail to {recipient_email}")
        except Exception as e:
            logger.error(f"Failed to send email via local sendmail to {recipient_email}: {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