"""Feed router — personalized feed, trending, new."""

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

from app.database import get_db
from app.models import User, Shader
from app.schemas import ShaderFeedItem, DwellReport
from app.middleware.auth import get_optional_user, get_current_user

router = APIRouter()


@router.get("", response_model=list[ShaderFeedItem])
async def get_feed(
    limit: int = Query(20, ge=1, le=50),
    cursor: str | None = Query(None),
    db: AsyncSession = Depends(get_db),
    user: User | None = Depends(get_optional_user),
):
    """
    Personalized feed for authenticated users (pgvector taste match).
    Trending/new for anonymous users.
    """
    # TODO: Implement full recommendation engine (Track F)
    # For now: return newest public shaders
    query = (
        select(Shader)
        .where(Shader.is_public == True, Shader.render_status == "ready")
        .order_by(Shader.created_at.desc())
        .limit(limit)
    )
    result = await db.execute(query)
    return result.scalars().all()


@router.get("/trending", response_model=list[ShaderFeedItem])
async def get_trending(
    limit: int = Query(20, ge=1, le=50),
    db: AsyncSession = Depends(get_db),
):
    query = (
        select(Shader)
        .where(Shader.is_public == True, Shader.render_status == "ready")
        .order_by(Shader.score.desc())
        .limit(limit)
    )
    result = await db.execute(query)
    return result.scalars().all()


@router.get("/new", response_model=list[ShaderFeedItem])
async def get_new(
    limit: int = Query(20, ge=1, le=50),
    db: AsyncSession = Depends(get_db),
):
    query = (
        select(Shader)
        .where(Shader.is_public == True, Shader.render_status == "ready")
        .order_by(Shader.created_at.desc())
        .limit(limit)
    )
    result = await db.execute(query)
    return result.scalars().all()


@router.post("/dwell", status_code=204)
async def report_dwell(
    body: DwellReport,
    db: AsyncSession = Depends(get_db),
    user: User | None = Depends(get_optional_user),
):
    """Report dwell time signal for recommendation engine."""
    from app.models import EngagementEvent

    event = EngagementEvent(
        user_id=user.id if user else None,
        session_id=body.session_id,
        shader_id=body.shader_id,
        event_type="dwell",
        dwell_secs=body.dwell_secs,
        metadata={"replayed": body.replayed},
    )
    db.add(event)
    # TODO: Update user taste vector (Track F)