from __future__ import annotations

from fastapi import APIRouter, HTTPException

from web.api import db

router = APIRouter()


def _window(start_date, end_date, tournament_id):
    """Return (where_sql, params) or raise 400 if no filter given."""
    clauses: list[str] = []
    params: list = []
    if tournament_id is not None:
        clauses.append("p.session_id IN (SELECT session_id FROM match_summary WHERE tournament_id = ?)")
        params.append(tournament_id)
    if start_date is not None:
        clauses.append("p.endtime_unix >= ?"); params.append(start_date)
    if end_date is not None:
        clauses.append("p.endtime_unix <= ?"); params.append(end_date)
    if not clauses:
        raise HTTPException(status_code=400, detail={
            "error": "a date window (start_date/end_date) or tournament_id is required",
            "code": "FILTER_REQUIRED"})
    return "WHERE " + " AND ".join(clauses), params


@router.get("/api/tss/leaderboard/players")
async def leaderboard_players(start_date: int | None = None, end_date: int | None = None,
                              tournament_id: int | None = None, limit: int = 100) -> dict:
    where, params = _window(start_date, end_date, tournament_id)
    params.append(max(1, min(limit, 500)))
    rows = await db.query(db.battles_path(), f"""
        SELECT p.UID uid, MAX(p.nick) nick, COUNT(*) battles,
               SUM(CASE WHEN p.victor_bool='Win' THEN 1 ELSE 0 END) wins,
               SUM(p.air_kills+p.ground_kills) kills, SUM(p.deaths) deaths, SUM(p.score) score
        FROM player_games_hist p {where}
        GROUP BY p.UID ORDER BY score DESC LIMIT ?""", tuple(params))
    for r in rows:
        r["uid"] = str(r["uid"])
    return {"players": rows}


@router.get("/api/tss/leaderboard/vehicles")
async def leaderboard_vehicles(start_date: int | None = None, end_date: int | None = None,
                               tournament_id: int | None = None, limit: int = 100) -> dict:
    where, params = _window(start_date, end_date, tournament_id)
    params.append(max(1, min(limit, 500)))
    rows = await db.query(db.battles_path(), f"""
        SELECT p.vehicle_internal, MAX(p.vehicle) vehicle, COUNT(*) battles,
               SUM(p.air_kills+p.ground_kills) kills, SUM(p.deaths) deaths, SUM(p.score) score
        FROM player_games_hist p {where}
        GROUP BY p.vehicle_internal ORDER BY battles DESC LIMIT ?""", tuple(params))
    return {"vehicles": rows}


@router.get("/api/tss/leaderboard/stats")
async def leaderboard_stats(start_date: int | None = None, end_date: int | None = None,
                            tournament_id: int | None = None) -> dict:
    where, params = _window(start_date, end_date, tournament_id)
    totals = await db.query_one(db.battles_path(), f"""
        SELECT COUNT(*) battles, COUNT(DISTINCT p.UID) players,
               SUM(p.air_kills+p.ground_kills) kills, SUM(p.score) score
        FROM player_games_hist p {where}""", tuple(params))
    top = await db.query(db.battles_path(), f"""
        SELECT p.vehicle_internal, MAX(p.vehicle) vehicle, COUNT(*) battles
        FROM player_games_hist p {where}
        GROUP BY p.vehicle_internal ORDER BY battles DESC LIMIT 10""", tuple(params))
    return {"totals": totals or {}, "top_vehicles": top}