from __future__ import annotations

import json
import logging
import os
import smtplib
from email.message import EmailMessage

from app.config import Settings
from app.models import Alert

logger = logging.getLogger(__name__)


def send_alert_email(settings: Settings, alert: Alert, severity_increased: bool = False) -> bool:
    if alert.severity not in {"warning", "critical"}:
        return False
    if not settings.alerts.email.enabled:
        return False
    host = os.getenv(settings.alerts.email.smtp_host_env)
    to_addr = os.getenv(settings.alerts.email.to_env)
    from_addr = os.getenv(settings.alerts.email.from_env)
    if not host or not to_addr or not from_addr:
        logger.warning("Email alert not sent because SMTP environment is incomplete")
        return False
    msg = EmailMessage()
    msg["Subject"] = f"[DMARC Sentinel] {alert.severity.upper()} {alert.title}"
    msg["From"] = from_addr
    msg["To"] = to_addr
    details = json.dumps(json.loads(alert.details_json or "{}"), indent=2, sort_keys=True)
    msg.set_content(
        "\n".join(
            [
                f"Severity: {alert.severity}",
                f"Domain: {alert.domain}",
                f"Alert type: {alert.type}",
                f"Title: {alert.title}",
                "",
                "Deterministic facts:",
                details,
                "",
                f"LLM summary: {alert.llm_summary or alert.summary}",
                f"LLM risk: {alert.llm_risk or 'Unavailable'}",
                f"LLM recommended action: {alert.llm_recommended_action or 'Review the deterministic facts.'}",
                "",
                f"Dashboard: {settings.app.base_url}/alerts",
                f"Severity increased: {severity_increased}",
            ]
        )
    )
    port = int(os.getenv(settings.alerts.email.smtp_port_env, "587"))
    user = os.getenv(settings.alerts.email.smtp_user_env)
    password = os.getenv(settings.alerts.email.smtp_password_env)
    try:
        with smtplib.SMTP(host, port, timeout=30) as smtp:
            smtp.starttls()
            if user and password:
                smtp.login(user, password)
            smtp.send_message(msg)
        logger.info("Email alert delivered for %s", alert.fingerprint)
        return True
    except Exception as exc:
        logger.warning("Email alert delivery failed for %s: %s", alert.fingerprint, exc)
        return False


def send_digest_email(settings: Settings, subject: str, body: str) -> bool:
    if not settings.alerts.email.enabled:
        return False
    host = os.getenv(settings.alerts.email.smtp_host_env)
    to_addr = os.getenv(settings.alerts.email.to_env)
    from_addr = os.getenv(settings.alerts.email.from_env)
    if not host or not to_addr or not from_addr:
        return False
    msg = EmailMessage()
    msg["Subject"] = subject
    msg["From"] = from_addr
    msg["To"] = to_addr
    msg.set_content(body)
    try:
        with smtplib.SMTP(host, int(os.getenv(settings.alerts.email.smtp_port_env, "587")), timeout=30) as smtp:
            smtp.starttls()
            user = os.getenv(settings.alerts.email.smtp_user_env)
            password = os.getenv(settings.alerts.email.smtp_password_env)
            if user and password:
                smtp.login(user, password)
            smtp.send_message(msg)
        return True
    except Exception as exc:
        logger.warning("Digest email delivery failed: %s", exc)
        return False