"""
Connection service — shared profile resolution, Person creation, ntfy dispatch.

SHAREABLE_FIELDS is the single source of truth for which fields can be shared.
"""
import asyncio
import logging
from datetime import date as date_type
from types import SimpleNamespace
from typing import Optional

from sqlalchemy.ext.asyncio import AsyncSession

from app.models.person import Person
from app.models.settings import Settings
from app.models.user import User
from app.services.ntfy import send_ntfy_notification

logger = logging.getLogger(__name__)

# Notification type constants — keep in sync with notifications model CHECK constraint
NOTIF_TYPE_CONNECTION_REQUEST = "connection_request"
NOTIF_TYPE_CONNECTION_ACCEPTED = "connection_accepted"

# Single source of truth — only these fields can be shared via connections
SHAREABLE_FIELDS = frozenset({
    "first_name", "last_name", "preferred_name", "email", "phone", "mobile",
    "birthday", "address", "company", "job_title",
})

# Maps shareable field names to their Settings model column names
_SETTINGS_FIELD_MAP = {
    "first_name": None,   # first_name comes from User model
    "last_name": None,    # last_name comes from User model
    "preferred_name": "preferred_name",
    "email": None,        # email comes from User model
    "phone": "phone",
    "mobile": "mobile",
    "birthday": None,     # birthday comes from User model (date_of_birth)
    "address": "address",
    "company": "company",
    "job_title": "job_title",
}


def resolve_shared_profile(
    user: User,
    settings: Settings,
    overrides: Optional[dict] = None,
) -> dict:
    """
    Merge global sharing defaults with per-connection overrides.
    Returns {field: value} dict of fields the user is sharing.
    Only fields in SHAREABLE_FIELDS are included.
    """
    overrides = overrides or {}
    result = {}

    for field in SHAREABLE_FIELDS:
        # Determine if this field is shared: override wins, else global default
        share_key = f"share_{field}"
        global_share = getattr(settings, share_key, False)
        is_shared = overrides.get(field, global_share)

        if not is_shared:
            continue

        # Resolve the actual value
        if field == "first_name":
            result[field] = user.first_name
        elif field == "last_name":
            result[field] = user.last_name
        elif field == "preferred_name":
            result[field] = settings.preferred_name
        elif field == "email":
            result[field] = user.email
        elif field == "birthday":
            result[field] = str(user.date_of_birth) if user.date_of_birth else None
        elif field in _SETTINGS_FIELD_MAP and _SETTINGS_FIELD_MAP[field]:
            result[field] = getattr(settings, _SETTINGS_FIELD_MAP[field], None)

    return filter_to_shareable(result)


def filter_to_shareable(profile: dict) -> dict:
    """Strip any keys not in SHAREABLE_FIELDS. Defence-in-depth gate."""
    return {k: v for k, v in profile.items() if k in SHAREABLE_FIELDS}


def create_person_from_connection(
    owner_user_id: int,
    connected_user: User,
    connected_settings: Settings,
    shared_profile: dict,
) -> Person:
    """Create a Person record for a new connection. Does NOT add to session — caller does."""
    # Use shared first_name, fall back to preferred_name, then umbral_name
    first_name = shared_profile.get("first_name") or shared_profile.get("preferred_name") or connected_user.umbral_name
    last_name = shared_profile.get("last_name")
    email = shared_profile.get("email")
    phone = shared_profile.get("phone")
    mobile = shared_profile.get("mobile")
    address = shared_profile.get("address")
    company = shared_profile.get("company")
    job_title = shared_profile.get("job_title")
    birthday_str = shared_profile.get("birthday")

    birthday = None
    if birthday_str:
        try:
            birthday = date_type.fromisoformat(birthday_str)
        except (ValueError, TypeError):
            pass

    # Compute display name
    full = ((first_name or '') + ' ' + (last_name or '')).strip()
    display_name = full or connected_user.umbral_name

    return Person(
        user_id=owner_user_id,
        name=display_name,
        first_name=first_name,
        last_name=last_name,
        email=email,
        phone=phone,
        mobile=mobile,
        address=address,
        company=company,
        job_title=job_title,
        birthday=birthday,
        category="Umbral",
        linked_user_id=connected_user.id,
        is_umbral_contact=True,
    )


async def detach_umbral_contact(person: Person) -> None:
    """Convert an umbral contact back to a standard contact. Does NOT commit.

    Preserves all person data (name, email, phone, etc.) so the user does not
    lose contact information when a connection is severed. Only unlinks the
    umbral association — the person becomes a standard contact.
    """
    person.linked_user_id = None
    person.is_umbral_contact = False
    person.category = None

def extract_ntfy_config(settings: Settings) -> dict | None:
    """Extract ntfy config values into a plain dict safe for use after session close."""
    if not settings.ntfy_enabled or not settings.ntfy_connections_enabled:
        return None
    return {
        "ntfy_enabled": True,
        "ntfy_server_url": settings.ntfy_server_url,
        "ntfy_topic": settings.ntfy_topic,
        "ntfy_auth_token": settings.ntfy_auth_token,
        "user_id": settings.user_id,
    }


async def send_connection_ntfy(
    ntfy_config: dict | None,
    sender_name: str,
    event_type: str,
) -> None:
    """Send ntfy push for connection events. Non-blocking with 3s timeout.

    Accepts a plain dict (from extract_ntfy_config) to avoid accessing
    detached SQLAlchemy objects after session close.
    """
    if not ntfy_config:
        return

    title_map = {
        "request_received": "New Connection Request",
        "request_accepted": "Connection Accepted",
    }
    message_map = {
        "request_received": f"{sender_name} wants to connect with you on Umbra",
        "request_accepted": f"{sender_name} accepted your connection request",
    }
    tag_map = {
        "request_received": ["handshake"],
        "request_accepted": ["white_check_mark"],
    }

    title = title_map.get(event_type, "Connection Update")
    message = message_map.get(event_type, f"Connection update from {sender_name}")
    tags = tag_map.get(event_type, ["bell"])

    # Build a settings-like object for send_ntfy_notification (avoids detached SA objects)
    settings_proxy = SimpleNamespace(**ntfy_config)

    try:
        await asyncio.wait_for(
            send_ntfy_notification(
                settings=settings_proxy,
                title=title,
                message=message,
                tags=tags,
                priority=3,
            ),
            timeout=3.0,
        )
    except asyncio.TimeoutError:
        logger.warning("ntfy connection push timed out for user_id=%s", ntfy_config["user_id"])
    except Exception:
        logger.warning("ntfy connection push failed for user_id=%s", ntfy_config["user_id"])