"""Effective notification channel config (DB overrides env)."""

from __future__ import annotations

from dataclasses import dataclass

from sqlalchemy import select
from sqlalchemy.orm import Session

from app.config import get_settings
from app.models.notification_channel import NotificationChannel

VALID_SEVERITIES = frozenset({"info", "warning", "high", "critical"})
CHANNEL_TELEGRAM = "telegram"
CHANNEL_WEBHOOK = "webhook"
CHANNEL_EMAIL = "email"


@dataclass(frozen=True)
class TelegramConfig:
    enabled: bool
    bot_token: str
    chat_id: str
    min_severity: str
    source: str  # env | db

    @property
    def configured(self) -> bool:
        return bool(self.bot_token.strip() and self.chat_id.strip())

    @property
    def active(self) -> bool:
        return self.enabled and self.configured


@dataclass(frozen=True)
class WebhookConfig:
    enabled: bool
    url: str
    secret_header: str
    secret: str
    min_severity: str
    source: str  # env | db

    @property
    def configured(self) -> bool:
        return bool(self.url.strip())

    @property
    def active(self) -> bool:
        return self.enabled and self.configured


@dataclass(frozen=True)
class EmailConfig:
    enabled: bool
    smtp_host: str
    smtp_port: int
    smtp_user: str
    smtp_password: str
    mail_from: str
    mail_to: str
    smtp_starttls: bool
    smtp_ssl: bool
    min_severity: str
    source: str  # env | db

    @property
    def configured(self) -> bool:
        return bool(self.smtp_host.strip() and self.mail_from.strip() and self.mail_to.strip())

    @property
    def active(self) -> bool:
        return self.enabled and self.configured


def _telegram_from_env() -> TelegramConfig:
    settings = get_settings()
    return TelegramConfig(
        enabled=bool(settings.telegram_enabled),
        bot_token=settings.telegram_bot_token.strip(),
        chat_id=settings.telegram_chat_id.strip(),
        min_severity=settings.telegram_min_severity.strip() or "high",
        source="env",
    )


def get_effective_telegram_config(db: Session | None = None) -> TelegramConfig:
    if db is None:
        from app.database import SessionLocal

        session = SessionLocal()
        try:
            return get_effective_telegram_config(session)
        finally:
            session.close()

    row = db.scalar(select(NotificationChannel).where(NotificationChannel.channel == CHANNEL_TELEGRAM))
    env_cfg = _telegram_from_env()
    if row is None:
        return env_cfg

    token = (row.bot_token or "").strip() or env_cfg.bot_token
    chat_id = (row.chat_id or "").strip() or env_cfg.chat_id
    min_sev = (row.min_severity or "").strip() or env_cfg.min_severity
    if min_sev not in VALID_SEVERITIES:
        min_sev = env_cfg.min_severity

    return TelegramConfig(
        enabled=bool(row.enabled),
        bot_token=token,
        chat_id=chat_id,
        min_severity=min_sev,
        source="db",
    )


def upsert_telegram_channel(
    db: Session,
    *,
    enabled: bool | None = None,
    bot_token: str | None = None,
    chat_id: str | None = None,
    min_severity: str | None = None,
) -> TelegramConfig:
    row = db.scalar(select(NotificationChannel).where(NotificationChannel.channel == CHANNEL_TELEGRAM))
    env_cfg = _telegram_from_env()

    if row is None:
        row = NotificationChannel(
            channel=CHANNEL_TELEGRAM,
            enabled=env_cfg.enabled,
            bot_token=env_cfg.bot_token or None,
            chat_id=env_cfg.chat_id or None,
            min_severity=env_cfg.min_severity,
        )
        db.add(row)

    if enabled is not None:
        row.enabled = enabled
    if min_severity is not None:
        if min_severity not in VALID_SEVERITIES:
            raise ValueError(f"invalid min_severity: {min_severity}")
        row.min_severity = min_severity
    if bot_token is not None and bot_token.strip():
        row.bot_token = bot_token.strip()
    if chat_id is not None and chat_id.strip():
        row.chat_id = chat_id.strip()

    db.commit()
    db.refresh(row)
    return get_effective_telegram_config(db)


def _webhook_from_env() -> WebhookConfig:
    settings = get_settings()
    return WebhookConfig(
        enabled=bool(settings.webhook_enabled),
        url=settings.webhook_url.strip(),
        secret_header=settings.webhook_secret_header.strip(),
        secret=settings.webhook_secret.strip(),
        min_severity=settings.webhook_min_severity.strip() or "high",
        source="env",
    )


def get_effective_webhook_config(db: Session | None = None) -> WebhookConfig:
    if db is None:
        from app.database import SessionLocal

        session = SessionLocal()
        try:
            return get_effective_webhook_config(session)
        finally:
            session.close()

    row = db.scalar(select(NotificationChannel).where(NotificationChannel.channel == CHANNEL_WEBHOOK))
    env_cfg = _webhook_from_env()
    if row is None:
        return env_cfg

    url = (row.webhook_url or "").strip() or env_cfg.url
    secret_header = (row.webhook_secret_header or "").strip() or env_cfg.secret_header
    secret = (row.webhook_secret or "").strip() or env_cfg.secret
    min_sev = (row.min_severity or "").strip() or env_cfg.min_severity
    if min_sev not in VALID_SEVERITIES:
        min_sev = env_cfg.min_severity

    return WebhookConfig(
        enabled=bool(row.enabled),
        url=url,
        secret_header=secret_header,
        secret=secret,
        min_severity=min_sev,
        source="db",
    )


def upsert_webhook_channel(
    db: Session,
    *,
    enabled: bool | None = None,
    url: str | None = None,
    secret_header: str | None = None,
    secret: str | None = None,
    min_severity: str | None = None,
) -> WebhookConfig:
    row = db.scalar(select(NotificationChannel).where(NotificationChannel.channel == CHANNEL_WEBHOOK))
    env_cfg = _webhook_from_env()

    if row is None:
        row = NotificationChannel(
            channel=CHANNEL_WEBHOOK,
            enabled=env_cfg.enabled,
            min_severity=env_cfg.min_severity,
            webhook_url=env_cfg.url or None,
            webhook_secret_header=env_cfg.secret_header or None,
            webhook_secret=env_cfg.secret or None,
        )
        db.add(row)

    if enabled is not None:
        row.enabled = enabled
    if min_severity is not None:
        if min_severity not in VALID_SEVERITIES:
            raise ValueError(f"invalid min_severity: {min_severity}")
        row.min_severity = min_severity
    if url is not None and url.strip():
        row.webhook_url = url.strip()
    if secret_header is not None:
        row.webhook_secret_header = secret_header.strip() or None
    if secret is not None and secret.strip():
        row.webhook_secret = secret.strip()

    db.commit()
    db.refresh(row)
    return get_effective_webhook_config(db)


def _email_from_env() -> EmailConfig:
    settings = get_settings()
    return EmailConfig(
        enabled=bool(settings.smtp_enabled),
        smtp_host=settings.smtp_host.strip(),
        smtp_port=int(settings.smtp_port or 587),
        smtp_user=settings.smtp_user.strip(),
        smtp_password=settings.smtp_password,
        mail_from=settings.smtp_from.strip(),
        mail_to=settings.smtp_to.strip(),
        smtp_starttls=bool(settings.smtp_starttls),
        smtp_ssl=bool(settings.smtp_ssl),
        min_severity=settings.smtp_min_severity.strip() or "high",
        source="env",
    )


def get_effective_email_config(db: Session | None = None) -> EmailConfig:
    if db is None:
        from app.database import SessionLocal

        session = SessionLocal()
        try:
            return get_effective_email_config(session)
        finally:
            session.close()

    row = db.scalar(select(NotificationChannel).where(NotificationChannel.channel == CHANNEL_EMAIL))
    env_cfg = _email_from_env()
    if row is None:
        return env_cfg

    host = (row.smtp_host or "").strip() or env_cfg.smtp_host
    port = row.smtp_port if row.smtp_port is not None else env_cfg.smtp_port
    user = (row.smtp_user or "").strip() or env_cfg.smtp_user
    password = (row.smtp_password or "") or env_cfg.smtp_password
    mail_from = (row.mail_from or "").strip() or env_cfg.mail_from
    mail_to = (row.mail_to or "").strip() or env_cfg.mail_to
    min_sev = (row.min_severity or "").strip() or env_cfg.min_severity
    if min_sev not in VALID_SEVERITIES:
        min_sev = env_cfg.min_severity

    return EmailConfig(
        enabled=bool(row.enabled),
        smtp_host=host,
        smtp_port=int(port or 587),
        smtp_user=user,
        smtp_password=password,
        mail_from=mail_from,
        mail_to=mail_to,
        smtp_starttls=bool(row.smtp_starttls),
        smtp_ssl=bool(row.smtp_ssl),
        min_severity=min_sev,
        source="db",
    )


def upsert_email_channel(
    db: Session,
    *,
    enabled: bool | None = None,
    smtp_host: str | None = None,
    smtp_port: int | None = None,
    smtp_user: str | None = None,
    smtp_password: str | None = None,
    mail_from: str | None = None,
    mail_to: str | None = None,
    smtp_starttls: bool | None = None,
    smtp_ssl: bool | None = None,
    min_severity: str | None = None,
) -> EmailConfig:
    row = db.scalar(select(NotificationChannel).where(NotificationChannel.channel == CHANNEL_EMAIL))
    env_cfg = _email_from_env()

    if row is None:
        row = NotificationChannel(
            channel=CHANNEL_EMAIL,
            enabled=env_cfg.enabled,
            min_severity=env_cfg.min_severity,
            smtp_host=env_cfg.smtp_host or None,
            smtp_port=env_cfg.smtp_port,
            smtp_user=env_cfg.smtp_user or None,
            smtp_password=env_cfg.smtp_password or None,
            mail_from=env_cfg.mail_from or None,
            mail_to=env_cfg.mail_to or None,
            smtp_starttls=env_cfg.smtp_starttls,
            smtp_ssl=env_cfg.smtp_ssl,
        )
        db.add(row)

    if enabled is not None:
        row.enabled = enabled
    if min_severity is not None:
        if min_severity not in VALID_SEVERITIES:
            raise ValueError(f"invalid min_severity: {min_severity}")
        row.min_severity = min_severity
    if smtp_host is not None and smtp_host.strip():
        row.smtp_host = smtp_host.strip()
    if smtp_port is not None:
        row.smtp_port = smtp_port
    if smtp_user is not None:
        row.smtp_user = smtp_user.strip() or None
    if smtp_password is not None and smtp_password.strip():
        row.smtp_password = smtp_password
    if mail_from is not None and mail_from.strip():
        row.mail_from = mail_from.strip()
    if mail_to is not None and mail_to.strip():
        row.mail_to = mail_to.strip()
    if smtp_starttls is not None:
        row.smtp_starttls = smtp_starttls
    if smtp_ssl is not None:
        row.smtp_ssl = smtp_ssl

    db.commit()
    db.refresh(row)
    return get_effective_email_config(db)