# backend/app/data/store.py
from __future__ import annotations
import json, sqlite3
from datetime import datetime, timezone, timedelta
from typing import Dict, Any, List, Optional
from pathlib import Path

from ..config.settings import settings
from .geo import haversine_km

DB_PATH: Path = settings.REPORTS_DB
# Ensure parent exists & fail early if unwritable
DB_PATH.parent.mkdir(parents=True, exist_ok=True)
try:
    DB_PATH.touch(exist_ok=True)
except Exception as e:
    raise RuntimeError(f"Cannot create DB file at {DB_PATH}: {e}")

_CONN = sqlite3.connect(str(DB_PATH), check_same_thread=False)
_CONN.execute("""
CREATE TABLE IF NOT EXISTS reports (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  lat REAL NOT NULL,
  lon REAL NOT NULL,
  text TEXT NOT NULL,
  props_json TEXT,
  created_at TEXT NOT NULL
)
""")
_CONN.commit()

def _row_to_feature(row: tuple) -> Dict[str, Any]:
    _id, lat, lon, text, props_json, created_at = row
    props = {"type": "user_report", "text": text, "reported_at": created_at}
    if props_json:
        try:
            props.update(json.loads(props_json))
        except Exception:
            props["raw_props"] = props_json
    props.setdefault("rid", str(_id))
    props.setdefault("id", str(_id))
    return {
        "type": "Feature",
        "geometry": {"type": "Point", "coordinates": [lon, lat]},
        "properties": props,
    }

def add_report(lat: float, lon: float, text: str = "User report", props: dict | None = None):
    created_at = datetime.now(timezone.utc).isoformat()
    props = dict(props or {})
    props_json = json.dumps(props)
    cur = _CONN.execute(
        "INSERT INTO reports (lat, lon, text, props_json, created_at) VALUES (?,?,?,?,?)",
        (float(lat), float(lon), text, props_json, created_at)
    )
    _CONN.commit()
    rid = str(cur.lastrowid)

    out_props = {"type": "user_report", "text": text, "reported_at": created_at, **props}
    out_props.setdefault("rid", rid)
    out_props.setdefault("id", rid)

    return {
        "type": "Feature",
        "geometry": {"type": "Point", "coordinates": [float(lon), float(lat)]},
        "properties": out_props,
    }

def get_feature_collection() -> Dict[str, Any]:
    cur = _CONN.execute("SELECT id, lat, lon, text, props_json, created_at FROM reports ORDER BY id DESC")
    feats = [_row_to_feature(r) for r in cur.fetchall()]
    return {"type": "FeatureCollection", "features": feats}

def find_reports_near(
    lat: float,
    lon: float,
    radius_km: float = 10.0,
    limit: int = 20,
    max_age_hours: Optional[int] = None,
) -> List[Dict[str, Any]]:
    params: list[Any] = []
    sql = "SELECT id, lat, lon, text, props_json, created_at FROM reports"
    if max_age_hours is not None:
        cutoff = datetime.now(timezone.utc) - timedelta(hours=int(max_age_hours))
        sql += " WHERE datetime(created_at) >= datetime(?)"
        params.append(cutoff.isoformat())
    sql += " ORDER BY id DESC LIMIT 2000"
    cur = _CONN.execute(sql, params)

    center = (lat, lon)
    cand = []
    for r in cur.fetchall():
        _, lat2, lon2, *_ = r
        d = haversine_km(center, (lat2, lon2))
        if d <= radius_km:
            cand.append((d, r))
    cand.sort(key=lambda x: x[0])
    out = [_row_to_feature(r) for _, r in cand[:max(1, limit)]]
    return out

def clear_reports() -> dict[str, Any]:
    _CONN.execute("DELETE FROM reports")
    _CONN.commit()
    return {"ok": True, "message": "All reports cleared."}