from __future__ import annotations

from datetime import datetime

from sqlalchemy.orm import Session

from db.models import Contact, Conversation, Message


def get_all(db: Session, channel: str | None = None, archived: bool = False) -> list[Conversation]:
    q = db.query(Conversation).filter(Conversation.is_archived == archived)
    if channel:
        q = q.filter(Conversation.channel == channel)
    return q.order_by(Conversation.last_message_at.desc().nullslast()).all()


def get_by_id(db: Session, conv_id: str) -> Conversation | None:
    return db.query(Conversation).filter(Conversation.id == conv_id).first()


def get_by_channel_id(db: Session, channel: str, channel_conversation_id: str) -> Conversation | None:
    return (
        db.query(Conversation)
        .filter(
            Conversation.channel == channel,
            Conversation.channel_conversation_id == channel_conversation_id,
        )
        .first()
    )


def get_or_create(
    db: Session,
    channel: str,
    channel_conversation_id: str,
    contact: Contact,
    title: str | None = None,
) -> Conversation:
    conv = get_by_channel_id(db, channel, channel_conversation_id)
    if not conv:
        conv = Conversation(
            channel=channel,
            channel_conversation_id=channel_conversation_id,
            title=title or contact.name,
        )
        conv.participants.append(contact)
        db.add(conv)
        db.commit()
        db.refresh(conv)
    return conv


def get_messages(
    db: Session, conv_id: str, limit: int = 50, offset: int = 0
) -> list[Message]:
    return (
        db.query(Message)
        .filter(Message.conversation_id == conv_id)
        .order_by(Message.created_at.asc())
        .offset(offset)
        .limit(limit)
        .all()
    )


def unread_count(db: Session, conv_id: str) -> int:
    return (
        db.query(Message)
        .filter(
            Message.conversation_id == conv_id,
            Message.direction == "inbound",
            Message.read_at.is_(None),
        )
        .count()
    )


def mark_all_read(db: Session, conv_id: str) -> None:
    now = datetime.utcnow()
    db.query(Message).filter(
        Message.conversation_id == conv_id,
        Message.direction == "inbound",
        Message.read_at.is_(None),
    ).update({"read_at": now, "status": "read"})
    db.commit()