"""Email: Mailjet (HTTPS) → Resend → Brevo SMTP (port 2525) → SMTP fallback."""

import os
import smtplib
import base64
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText


def _build_body(username: str, reset_url: str) -> str:
    return (
        f"Hi {username},\n\n"
        f"We received a request to reset your YapStation password.\n\n"
        f"Open this link (valid for 1 hour):\n{reset_url}\n\n"
        f"If you did not request this, ignore this email.\n\n"
        f"— YapStation"
    )


def _build_msg(mail_from: str, to_email: str, username: str, reset_url: str) -> MIMEMultipart:
    msg = MIMEMultipart()
    msg["Subject"] = "YapStation — reset your password"
    msg["From"] = mail_from
    msg["To"] = to_email
    msg.attach(MIMEText(_build_body(username, reset_url), "plain", "utf-8"))
    return msg


def _send_via_mailjet(to_email: str, username: str, reset_url: str) -> bool:
    api_key = os.environ.get("MAILJET_API_KEY", "").strip()
    secret_key = os.environ.get("MAILJET_SECRET_KEY", "").strip()
    if not api_key or not secret_key:
        return False
    try:
        import httpx
        mail_from = os.environ.get("MAIL_FROM", "yapstation.official@gmail.com").strip()
        resp = httpx.post(
            "https://api.mailjet.com/v3.1/send",
            auth=(api_key, secret_key),
            json={
                "Messages": [{
                    "From": {"Email": mail_from, "Name": "YapStation"},
                    "To": [{"Email": to_email}],
                    "Subject": "YapStation — reset your password",
                    "TextPart": _build_body(username, reset_url),
                }]
            },
            timeout=15,
        )
        if resp.status_code == 200:
            return True
        print(f"[mail] Mailjet error {resp.status_code}: {resp.text}")
        return False
    except Exception as e:
        print(f"[mail] Mailjet failed: {e}")
        return False


def _send_via_resend(to_email: str, username: str, reset_url: str) -> bool:
    api_key = os.environ.get("RESEND_API_KEY", "").strip()
    if not api_key:
        return False
    try:
        import httpx
        mail_from = os.environ.get("MAIL_FROM", "YapStation <onboarding@resend.dev>").strip()
        resp = httpx.post(
            "https://api.resend.com/emails",
            headers={"Authorization": f"Bearer {api_key}", "Content-Type": "application/json"},
            json={"from": mail_from, "to": [to_email], "subject": "YapStation — reset your password", "text": _build_body(username, reset_url)},
            timeout=15,
        )
        if resp.status_code in (200, 201):
            return True
        print(f"[mail] Resend error {resp.status_code}: {resp.text}")
        return False
    except Exception as e:
        print(f"[mail] Resend failed: {e}")
        return False


def _send_via_brevo(to_email: str, username: str, reset_url: str) -> bool:
    smtp_user = os.environ.get("BREVO_SMTP_USER", "").strip().strip('"').strip("'")
    smtp_key = os.environ.get("BREVO_API_KEY", "").strip().strip('"').strip("'").replace(" ", "")
    if not smtp_user or not smtp_key:
        return False
    mail_from = os.environ.get("MAIL_FROM", smtp_user).strip()
    msg = _build_msg(mail_from, to_email, username, reset_url)
    try:
        with smtplib.SMTP("smtp-relay.brevo.com", 2525, timeout=30) as smtp:
            smtp.ehlo(); smtp.starttls(); smtp.ehlo()
            smtp.login(smtp_user, smtp_key)
            smtp.sendmail(mail_from, [to_email], msg.as_string())
        return True
    except Exception as e:
        print(f"[mail] Brevo SMTP failed ({type(e).__name__}): {e}")
        return False


def _send_via_smtp(to_email: str, username: str, reset_url: str) -> bool:
    host = os.environ.get("SMTP_HOST", "").strip()
    if not host or not to_email:
        return False
    port = int(os.environ.get("SMTP_PORT", "587"))
    user = os.environ.get("SMTP_USER", "").strip()
    password = "".join(os.environ.get("SMTP_PASSWORD", "").split()).strip('"').strip("'")
    mail_from = os.environ.get("MAIL_FROM", user or "noreply@localhost").strip()
    msg = _build_msg(mail_from, to_email, username, reset_url)
    try:
        if port == 465:
            with smtplib.SMTP_SSL(host, port, timeout=30) as smtp:
                if user and password: smtp.login(user, password)
                smtp.sendmail(mail_from, [to_email], msg.as_string())
        else:
            with smtplib.SMTP(host, port, timeout=30) as smtp:
                smtp.ehlo(); smtp.starttls(); smtp.ehlo()
                if user and password: smtp.login(user, password)
                smtp.sendmail(mail_from, [to_email], msg.as_string())
        return True
    except Exception as e:
        print(f"[mail] SMTP send failed ({type(e).__name__}): {e}")
        return False


def send_password_reset_email(to_email: str, username: str, reset_url: str) -> bool:
    return _send_via_mailjet(to_email, username, reset_url) or _send_via_resend(to_email, username, reset_url) or _send_via_brevo(to_email, username, reset_url) or _send_via_smtp(to_email, username, reset_url)


def smtp_configured() -> bool:
    return bool(
        os.environ.get("MAILJET_API_KEY", "").strip()
        or os.environ.get("RESEND_API_KEY", "").strip()
        or os.environ.get("BREVO_SMTP_USER", "").strip()
        or os.environ.get("SMTP_HOST", "").strip()
    )