import time
from fastapi import APIRouter, Depends
from database import db
from auth import get_current_user, get_current_user_optional

router = APIRouter()

_STATS_SQL = """
    SELECT u.id, u.name, u.avatar_url,
           ROUND(COALESCE(SUM(r.distanz_km), 0), 1)       AS total_km,
           COUNT(DISTINCT r.id)                             AS routen,
           COUNT(DISTINCT p.id)                             AS pois,
           ROUND(COALESCE(SUM(r.distanz_km), 0), 1) * 1
               + COUNT(DISTINCT p.id) * 5
               + COUNT(DISTINCT r.id) * 10                 AS punkte
    FROM users u
    LEFT JOIN routes r ON r.user_id = u.id AND r.is_valid = 1
    LEFT JOIN user_map_pois p ON p.user_id = u.id
    GROUP BY u.id
"""


_pub_cache: dict = {"data": None, "ts": 0.0}
_PUB_TTL = 300  # 5 Minuten


@router.get("/public")
async def public_stats():
    now = time.time()
    if _pub_cache["data"] and now - _pub_cache["ts"] < _PUB_TTL:
        return _pub_cache["data"]
    with db() as conn:
        users = conn.execute("SELECT COUNT(*) FROM users").fetchone()[0]
        dogs  = conn.execute("SELECT COUNT(*) FROM dogs").fetchone()[0]
        km    = conn.execute(
            "SELECT ROUND(COALESCE(SUM(distanz_km),0),0) FROM routes"
        ).fetchone()[0]
        posts = conn.execute("SELECT COUNT(*) FROM forum_posts").fetchone()[0]
        diary = conn.execute("SELECT COUNT(*) FROM diary").fetchone()[0]
    data = {
        "users": users,
        "dogs": dogs,
        "km": int(km or 0),
        "forum_posts": posts,
        "diary_entries": diary,
    }
    _pub_cache["data"] = data
    _pub_cache["ts"] = now
    return data


@router.get("/leaderboard")
async def leaderboard(_user=Depends(get_current_user_optional)):
    with db() as conn:
        rows = conn.execute(f"""
            SELECT * FROM ({_STATS_SQL})
            ORDER BY punkte DESC, total_km DESC
            LIMIT 20
        """).fetchall()
    return [dict(r) for r in rows]


@router.get("/me")
async def my_stats(user=Depends(get_current_user)):
    with db() as conn:
        row = conn.execute(f"""
            SELECT s.*, rank_tbl.rang FROM ({_STATS_SQL}) s
            JOIN (
                SELECT id, ROW_NUMBER() OVER (ORDER BY punkte DESC, total_km DESC) AS rang
                FROM ({_STATS_SQL})
            ) rank_tbl ON rank_tbl.id = s.id
            WHERE s.id = ?
        """, (user["id"],)).fetchone()
    return dict(row) if row else {}