import os
import ssl
import smtplib
from datetime import datetime
from email.message import EmailMessage
from typing import Optional, List, Union
from pydantic import BaseModel, EmailStr, Field

# === ENV SETTINGS ===
EMAIL_SENDER = os.getenv("EMAIL_SENDER", "your@email.com")
EMAIL_PASSWORD = os.getenv("EMAIL_PASSWORD", "yourpassword")
SMTP_SERVER = os.getenv("SMTP_SERVER", "smtp.gmail.com")
SMTP_PORT = int(os.getenv("SMTP_PORT", 465))
USE_SSL = os.getenv("USE_SSL", "true").lower() in ("true", "1", "yes")
EMAIL_TEST_MODE = os.getenv("EMAIL_TEST_MODE", "false").lower() in ("true", "1", "yes")

# === Models ===
class EmailInput(BaseModel):
    to: Union[EmailStr, List[EmailStr]] = Field(..., description="Recipient(s) email address")
    subject: str = Field(..., description="Email subject line")
    body: str = Field(..., description="Plaintext or HTML body")
    html: Optional[bool] = Field(default=False, description="Send as HTML?")
    attachments: Optional[List[str]] = Field(default=None, description="List of file paths to attach")

# === Email Body Generator ===
def generate_email(recipient_name: str, product_name: str, discount: float) -> str:
    return f"""\
Dear {recipient_name},

🎉 Great news! We're offering you an exclusive {discount}% discount on {product_name}.

Visit our site today and don't miss out!

Best regards,  
Your AI Assistant
"""

# === Email Sending Core ===
def send_email(email_input: EmailInput) -> dict:
    msg = EmailMessage()
    msg["From"] = EMAIL_SENDER
    msg["To"] = ", ".join(email_input.to) if isinstance(email_input.to, list) else email_input.to
    msg["Subject"] = email_input.subject

    if email_input.html:
        msg.add_alternative(email_input.body, subtype="html")
    else:
        msg.set_content(email_input.body)

    # Add attachments
    if email_input.attachments:
        for path in email_input.attachments:
            if os.path.exists(path):
                with open(path, "rb") as f:
                    data = f.read()
                    filename = os.path.basename(path)
                    msg.add_attachment(data, maintype="application", subtype="octet-stream", filename=filename)

    # Early exit in test mode
    if EMAIL_TEST_MODE:
        return {
            "status": "✅ TEST MODE — email not actually sent",
            "to": msg["To"],
            "subject": msg["Subject"],
            "timestamp": datetime.utcnow().isoformat()
        }

    # Send email via SMTP
    try:
        if USE_SSL:
            context = ssl.create_default_context()
            with smtplib.SMTP_SSL(SMTP_SERVER, SMTP_PORT, context=context) as smtp:
                smtp.login(EMAIL_SENDER, EMAIL_PASSWORD)
                smtp.send_message(msg)
        else:
            with smtplib.SMTP(SMTP_SERVER, SMTP_PORT) as smtp:
                smtp.ehlo()
                smtp.starttls(context=ssl.create_default_context())
                smtp.ehlo()
                smtp.login(EMAIL_SENDER, EMAIL_PASSWORD)
                smtp.send_message(msg)

        return {
            "status": "✅ Email sent successfully",
            "to": msg["To"],
            "subject": msg["Subject"],
            "timestamp": datetime.utcnow().isoformat()
        }

    except Exception as e:
        return {
            "status": f"❌ Failed to send email: {e}",
            "to": msg["To"],
            "subject": msg["Subject"],
            "timestamp": datetime.utcnow().isoformat()
        }

# === Example usage ===
if __name__ == "__main__":
    email_body = generate_email("Alice", "Super Serum", 25)
    email_data = EmailInput(
        to=["alice@example.com", "bob@example.com"],
        subject="🎁 Special Deal Just For You!",
        body=email_body,
        html=False,
        attachments=["/path/to/brochure.pdf"]
    )
    result = send_email(email_data)
    print(result)