"""
Liderlik tablosu — adım (lifetime), level ve gold sıralamaları.
GET /leaderboard?by=steps|level|gold → top 20 + kendi sıran.
"""
from fastapi import APIRouter, Depends, HTTPException
from pydantic import BaseModel
from sqlalchemy import select, text
from sqlalchemy.ext.asyncio import AsyncSession

from deps import get_current_user
from models import Character, User, get_db

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

ORDER_COLS = {"steps": "step_lifetime", "level": "total_xp", "gold": "gold"}


class LeaderRow(BaseModel):
    rank: int
    name: str
    level: int
    value: int  # sıralama kriterinin değeri
    me: bool


class LeaderboardOut(BaseModel):
    by: str
    rows: list[LeaderRow]
    my_rank: int


@router.get("", response_model=LeaderboardOut)
async def leaderboard(by: str = "steps",
                      user: User = Depends(get_current_user), db: AsyncSession = Depends(get_db)):
    if by not in ORDER_COLS:
        raise HTTPException(400, "by: steps | level | gold")
    col = ORDER_COLS[by]
    char = (await db.execute(select(Character).where(Character.user_id == user.id))).scalar_one_or_none()
    if not char:
        raise HTTPException(404, "Karakter yok")

    rows = (await db.execute(text(f"""
        SELECT rank, name, level, val, id FROM (
            SELECT id, name, level, {col} AS val,
                   RANK() OVER (ORDER BY {col} DESC, id) AS rank
            FROM characters
        ) t WHERE rank <= 20 OR id = :me
        ORDER BY rank
    """), {"me": char.id})).all()

    my_rank = 0
    out: list[LeaderRow] = []
    for r in rows:
        me = r[4] == char.id
        if me:
            my_rank = int(r[0])
        if int(r[0]) <= 20:
            out.append(LeaderRow(rank=int(r[0]), name=r[1], level=int(r[2]), value=int(r[3]), me=me))
    return LeaderboardOut(by=by, rows=out, my_rank=my_rank)