"""Service mail simple — envoi HTML via SMTP (Office 365 ou autre relay).

Configuration via Settings > SMTP :
  - smtp_host, smtp_port, smtp_user, smtp_pass, smtp_from, smtp_use_tls

Si SMTP non configuré, send_html_mail retourne {ok:False, msg, html_preview}
pour que l'UI affiche au moins le rendu sans envoi.
"""
import logging
import smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from typing import Iterable

log = logging.getLogger("patchcenter.mail")


def _get(db, key, default=""):
    try:
        from .secrets_service import get_secret
        return (get_secret(db, key) or default).strip()
    except Exception:
        return default


def get_smtp_config(db):
    """Lit la config SMTP depuis app_secrets. Retourne dict ou None si incomplet."""
    host = _get(db, "smtp_host")
    port_str = _get(db, "smtp_port", "587")
    sender = _get(db, "smtp_from")
    user = _get(db, "smtp_user")
    pwd = _get(db, "smtp_pass")
    use_tls = _get(db, "smtp_use_tls", "true").lower() in ("true", "1", "yes", "on")
    if not host or not sender:
        return None
    try:
        port = int(port_str or "587")
    except ValueError:
        port = 587
    return {
        "host": host, "port": port, "from": sender,
        "user": user, "pass": pwd, "use_tls": use_tls,
    }


def send_html_mail(db, to: Iterable[str], subject: str, html: str,
                   cc: Iterable[str] = None, dry_run: bool = False) -> dict:
    """Envoie un mail HTML.
    - to : liste d'adresses (ou string seul)
    - dry_run : si True, ne tente pas l'envoi (juste renvoie le rendu)
    Retourne {ok, msg, sent_to, html_preview, subject_preview, error_kind}.
    """
    if isinstance(to, str):
        to = [to]
    to = [a.strip() for a in to if a and a.strip()]
    if not to:
        return {"ok": False, "msg": "Destinataire(s) vide(s)"}

    cfg = get_smtp_config(db)
    if not cfg:
        return {"ok": False, "msg": "Config SMTP incomplète (Settings > SMTP)",
                "error_kind": "config_missing",
                "html_preview": html, "subject_preview": subject, "sent_to": to}

    if dry_run:
        return {"ok": True, "msg": "Dry-run — pas d'envoi",
                "html_preview": html, "subject_preview": subject, "sent_to": to}

    msg = MIMEMultipart("alternative")
    msg["Subject"] = subject
    msg["From"] = cfg["from"]
    msg["To"] = ", ".join(to)
    if cc:
        cc = [a.strip() for a in cc if a and a.strip()]
        if cc:
            msg["Cc"] = ", ".join(cc)
    msg.attach(MIMEText(html, "html", "utf-8"))

    recipients = list(to) + (list(cc) if cc else [])
    try:
        if cfg["port"] == 465:
            with smtplib.SMTP_SSL(cfg["host"], cfg["port"], timeout=30) as srv:
                if cfg["user"] and cfg["pass"]:
                    srv.login(cfg["user"], cfg["pass"])
                srv.sendmail(cfg["from"], recipients, msg.as_string())
        else:
            with smtplib.SMTP(cfg["host"], cfg["port"], timeout=30) as srv:
                srv.ehlo()
                if cfg["use_tls"]:
                    srv.starttls()
                    srv.ehlo()
                if cfg["user"] and cfg["pass"]:
                    srv.login(cfg["user"], cfg["pass"])
                srv.sendmail(cfg["from"], recipients, msg.as_string())
        log.info(f"Mail envoyé à {to} (subject={subject!r})")
        return {"ok": True, "msg": f"Envoyé à {', '.join(to)}",
                "sent_to": to, "subject_preview": subject}
    except smtplib.SMTPAuthenticationError as e:
        return {"ok": False, "msg": f"Auth SMTP refusée: {e}", "error_kind": "auth"}
    except smtplib.SMTPException as e:
        return {"ok": False, "msg": f"Erreur SMTP: {e}", "error_kind": "smtp"}
    except Exception as e:
        return {"ok": False, "msg": f"{type(e).__name__}: {e}", "error_kind": "other"}