"""Connection log API — query and stats."""
from datetime import datetime

from fastapi import APIRouter, Depends, Query
from sqlalchemy import select, func, desc, distinct
from sqlalchemy.ext.asyncio import AsyncSession

from ...database import get_db
from ...models.log import ConnectionLog
from ..auth import get_current_admin

router = APIRouter(prefix="/logs", tags=["logs"])


@router.get("")
async def get_logs(
    username: str | None = Query(None),
    channel: str | None = Query(None),
    content_type: str | None = Query(None),
    date_from: str | None = Query(None),
    date_to: str | None = Query(None),
    page: int = Query(1, ge=1),
    limit: int = Query(50, ge=1, le=200),
    db: AsyncSession = Depends(get_db),
    _=Depends(get_current_admin),
):
    q = select(ConnectionLog).order_by(desc(ConnectionLog.started_at))

    if username:
        q = q.where(ConnectionLog.username.ilike(f"%{username}%"))
    if channel:
        q = q.where(ConnectionLog.channel_name.ilike(f"%{channel}%"))
    if content_type:
        q = q.where(ConnectionLog.content_type == content_type)
    if date_from:
        try:
            q = q.where(ConnectionLog.started_at >= datetime.fromisoformat(date_from))
        except ValueError:
            pass
    if date_to:
        try:
            q = q.where(ConnectionLog.started_at <= datetime.fromisoformat(date_to))
        except ValueError:
            pass

    total_result = await db.execute(select(func.count()).select_from(q.subquery()))
    total = total_result.scalar() or 0

    q = q.offset((page - 1) * limit).limit(limit)
    result = await db.execute(q)
    logs = result.scalars().all()

    return {
        "total": total,
        "page": page,
        "limit": limit,
        "items": [_serialize(log) for log in logs],
    }


@router.get("/stats")
async def get_stats(db: AsyncSession = Depends(get_db), _=Depends(get_current_admin)):
    top_users_q = await db.execute(
        select(
            ConnectionLog.username,
            func.count().label("sessions"),
            func.sum(ConnectionLog.bytes_transferred).label("bytes"),
        )
        .group_by(ConnectionLog.username)
        .order_by(desc("sessions"))
        .limit(10)
    )

    top_channels_q = await db.execute(
        select(ConnectionLog.channel_name, func.count().label("sessions"))
        .where(ConnectionLog.channel_name.isnot(None))
        .group_by(ConnectionLog.channel_name)
        .order_by(desc("sessions"))
        .limit(10)
    )

    totals_q = await db.execute(
        select(
            func.count().label("total_sessions"),
            func.sum(ConnectionLog.bytes_transferred).label("total_bytes"),
            func.avg(ConnectionLog.duration_seconds).label("avg_duration"),
            func.count(distinct(ConnectionLog.username)).label("unique_users"),
        )
    )
    t = totals_q.one()

    return {
        "total_sessions": t.total_sessions or 0,
        "total_bytes": t.total_bytes or 0,
        "avg_duration_seconds": round(t.avg_duration or 0),
        "unique_users": t.unique_users or 0,
        "top_users": [
            {"username": r.username, "sessions": r.sessions, "bytes": r.bytes or 0}
            for r in top_users_q
        ],
        "top_channels": [
            {"channel_name": r.channel_name, "sessions": r.sessions}
            for r in top_channels_q
        ],
    }


@router.delete("", status_code=204)
async def clear_logs(db: AsyncSession = Depends(get_db), _=Depends(get_current_admin)):
    """Delete all logs (admin use)."""
    from sqlalchemy import delete
    await db.execute(delete(ConnectionLog))
    await db.commit()


def _serialize(log: ConnectionLog) -> dict:
    return {
        "id": log.id,
        "user_id": log.user_id,
        "username": log.username,
        "channel_id": log.channel_id,
        "channel_name": log.channel_name,
        "content_type": log.content_type,
        "stream_id": log.stream_id,
        "started_at": log.started_at.isoformat() if log.started_at else None,
        "ended_at": log.ended_at.isoformat() if log.ended_at else None,
        "duration_seconds": log.duration_seconds,
        "bytes_transferred": log.bytes_transferred,
        "client_ip": log.client_ip,
    }