"""BAN YARO — Gassi-Routen"""

import json, math, os, uuid
from fastapi import APIRouter, Depends, HTTPException, UploadFile, File
from pydantic import BaseModel
from typing import Optional, List
from database import db
from auth import get_current_user, get_current_user_optional

router = APIRouter()


def _haversine(lat1: float, lon1: float, lat2: float, lon2: float) -> float:
    R  = 6_371_000
    p1 = math.radians(lat1)
    p2 = math.radians(lat2)
    dp = math.radians(lat2 - lat1)
    dl = math.radians(lon2 - lon1)
    a  = math.sin(dp / 2) ** 2 + math.cos(p1) * math.cos(p2) * math.sin(dl / 2) ** 2
    return 2 * R * math.asin(math.sqrt(a))


# ------------------------------------------------------------------
# Schemas
# ------------------------------------------------------------------
class GPSPoint(BaseModel):
    lat: float
    lon: float

class RouteCreate(BaseModel):
    name:            str
    beschreibung:    Optional[str]         = None
    gps_track:       List[GPSPoint]
    distanz_km:      Optional[float]       = None
    dauer_min:       Optional[int]         = None
    schwierigkeit:   Optional[str]         = "leicht"   # leicht | mittel | anspruchsvoll
    untergrund:      Optional[str]         = None        # wald | asphalt | wiese | mix
    schatten:        Optional[bool]        = None
    leine_empfohlen: Optional[bool]        = None
    is_public:          Optional[bool]     = True
    hunde_tauglichkeit: Optional[str]      = None  # eingeschränkt | gut | sehr_gut | premium

class RouteUpdate(BaseModel):
    name:            Optional[str]  = None
    beschreibung:    Optional[str]  = None
    schwierigkeit:   Optional[str]  = None
    untergrund:      Optional[str]  = None
    schatten:        Optional[bool] = None
    leine_empfohlen: Optional[bool] = None
    is_public:          Optional[bool] = None
    hunde_tauglichkeit: Optional[str]  = None


def _simplify_track(track: list, max_pts: int = 40) -> list:
    """Reduziert GPS-Track auf max_pts Punkte für Vorschau."""
    if len(track) <= max_pts:
        return track
    step = len(track) / max_pts
    return [track[round(i * step)] for i in range(max_pts)]


def _parse(row) -> dict:
    d = dict(row)
    if isinstance(d.get('gps_track'), str):
        d['gps_track'] = json.loads(d['gps_track'])
    for k in ('schatten', 'leine_empfohlen', 'is_public'):
        if d.get(k) is not None:
            d[k] = bool(d[k])
    if isinstance(d.get('foto_urls'), str):
        d['foto_urls'] = json.loads(d['foto_urls'])
    return d


# ------------------------------------------------------------------
# GET /api/routes — Routen (optional: Umkreis vom Startpunkt)
# ------------------------------------------------------------------
@router.get("")
async def list_routes(
    lat:    Optional[float] = None,
    lon:    Optional[float] = None,
    radius: int             = 10000,
    user = Depends(get_current_user_optional),
):
    with db() as conn:
        rows = conn.execute("""
            SELECT r.id, r.user_id, r.name, r.beschreibung,
                   r.distanz_km, r.dauer_min, r.schwierigkeit,
                   r.untergrund, r.schatten, r.leine_empfohlen,
                   r.bewertung, r.anz_bewertungen, r.created_at,
                   r.gps_track, r.is_public, r.hunde_tauglichkeit, r.foto_urls,
                   u.name AS user_name,
                   json_extract(r.gps_track, '$[0].lat') AS start_lat,
                   json_extract(r.gps_track, '$[0].lon') AS start_lon,
                   json_extract(r.gps_track, '$[#-1].lat') AS end_lat,
                   json_extract(r.gps_track, '$[#-1].lon') AS end_lon
            FROM routes r
            LEFT JOIN users u ON u.id = r.user_id
            ORDER BY r.created_at DESC
        """).fetchall()

    result = []
    for row in rows:
        d = dict(row)
        for k in ('schatten', 'leine_empfohlen', 'is_public'):
            if d.get(k) is not None:
                d[k] = bool(d[k])
        if isinstance(d.get('foto_urls'), str):
            d['foto_urls'] = json.loads(d['foto_urls'])
        raw_track = json.loads(d.get('gps_track') or '[]')
        d['preview_track'] = _simplify_track(raw_track, 40)
        del d['gps_track']
        result.append(d)

    if lat is not None and lon is not None:
        result = [
            r for r in result
            if r['start_lat'] and _haversine(lat, lon, r['start_lat'], r['start_lon']) <= radius
        ]

    user_id = user['id'] if user else None
    result = [r for r in result if r.get('is_public', True) or r.get('user_id') == user_id]
    return result


# ------------------------------------------------------------------
# POST /api/routes — neue Route speichern (Login erforderlich)
# ------------------------------------------------------------------
@router.post("", status_code=201)
async def create_route(data: RouteCreate, user=Depends(get_current_user)):
    if len(data.gps_track) < 2:
        raise HTTPException(400, "GPS-Track braucht mindestens 2 Punkte.")

    gps_json = json.dumps([p.model_dump() for p in data.gps_track])

    with db() as conn:
        cur = conn.execute("""
            INSERT INTO routes
                (user_id, name, beschreibung, gps_track, distanz_km, dauer_min,
                 schwierigkeit, untergrund, schatten, leine_empfohlen, is_public, hunde_tauglichkeit)
            VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
        """, (
            user['id'], data.name, data.beschreibung, gps_json,
            data.distanz_km, data.dauer_min, data.schwierigkeit, data.untergrund,
            int(data.schatten)        if data.schatten        is not None else None,
            int(data.leine_empfohlen) if data.leine_empfohlen is not None else None,
            int(data.is_public) if data.is_public is not None else 1,
            data.hunde_tauglichkeit,
        ))
        row = conn.execute("SELECT * FROM routes WHERE id = ?", (cur.lastrowid,)).fetchone()
    return _parse(row)


# ------------------------------------------------------------------
# GET /api/routes/{id} — Route mit vollem GPS-Track
# ------------------------------------------------------------------
@router.get("/{route_id}")
async def get_route(route_id: int):
    with db() as conn:
        row = conn.execute(
            "SELECT r.*, u.name AS user_name FROM routes r LEFT JOIN users u ON u.id = r.user_id WHERE r.id = ?",
            (route_id,)
        ).fetchone()
    if not row:
        raise HTTPException(404, "Route nicht gefunden.")
    return _parse(row)


# ------------------------------------------------------------------
# PATCH /api/routes/{id}
# ------------------------------------------------------------------
@router.patch("/{route_id}")
async def update_route(route_id: int, data: RouteUpdate, user=Depends(get_current_user)):
    with db() as conn:
        row = conn.execute("SELECT * FROM routes WHERE id = ?", (route_id,)).fetchone()
        if not row:
            raise HTTPException(404, "Route nicht gefunden.")
        if row['user_id'] != user['id']:
            raise HTTPException(403, "Nicht berechtigt.")

        updates = data.model_dump(exclude_none=True)
        if updates:
            for key in ('schatten', 'leine_empfohlen', 'is_public'):
                if key in updates:
                    updates[key] = int(updates[key])
            cols = ', '.join(f"{k} = ?" for k in updates)
            conn.execute(f"UPDATE routes SET {cols} WHERE id = ?", [*updates.values(), route_id])

        row = conn.execute("SELECT * FROM routes WHERE id = ?", (route_id,)).fetchone()
    return _parse(row)


# ------------------------------------------------------------------
# DELETE /api/routes/{id}
# ------------------------------------------------------------------
@router.delete("/{route_id}", status_code=204)
async def delete_route(route_id: int, user=Depends(get_current_user)):
    with db() as conn:
        row = conn.execute("SELECT * FROM routes WHERE id = ?", (route_id,)).fetchone()
        if not row:
            raise HTTPException(404, "Route nicht gefunden.")
        if row['user_id'] != user['id']:
            raise HTTPException(403, "Nicht berechtigt.")
        conn.execute("DELETE FROM routes WHERE id = ?", (route_id,))


# ------------------------------------------------------------------
# POST /api/routes/{id}/rate — Bewertung abgeben
# ------------------------------------------------------------------
class RouteRate(BaseModel):
    wertung: float  # 1–5

@router.post("/{route_id}/rate")
async def rate_route(route_id: int, data: RouteRate, user=Depends(get_current_user)):
    if not 1 <= data.wertung <= 5:
        raise HTTPException(400, "Wertung muss zwischen 1 und 5 liegen.")
    with db() as conn:
        row = conn.execute("SELECT * FROM routes WHERE id = ?", (route_id,)).fetchone()
        if not row:
            raise HTTPException(404, "Route nicht gefunden.")
        r = dict(row)
        n = (r['anz_bewertungen'] or 0) + 1
        avg = ((r['bewertung'] or 0) * (n - 1) + data.wertung) / n
        conn.execute(
            "UPDATE routes SET bewertung=?, anz_bewertungen=? WHERE id=?",
            (round(avg, 2), n, route_id)
        )
    return {'bewertung': round(avg, 2), 'anz_bewertungen': n}


# ------------------------------------------------------------------
# POST /api/routes/{id}/photo — Foto hochladen
# ------------------------------------------------------------------
MEDIA_DIR = os.getenv("MEDIA_DIR", "/data/media")

@router.post("/{route_id}/photo", status_code=201)
async def add_route_photo(
    route_id: int,
    file: UploadFile = File(...),
    user = Depends(get_current_user),
):
    with db() as conn:
        row = conn.execute("SELECT * FROM routes WHERE id=?", (route_id,)).fetchone()
    if not row:
        raise HTTPException(404, "Route nicht gefunden.")
    if dict(row)['user_id'] != user['id']:
        raise HTTPException(403, "Nicht berechtigt.")

    ext      = os.path.splitext(file.filename or "")[1] or ".jpg"
    filename = f"route_{route_id}_{uuid.uuid4().hex[:8]}{ext}"
    path     = os.path.join(MEDIA_DIR, "routes", filename)
    os.makedirs(os.path.dirname(path), exist_ok=True)
    with open(path, "wb") as f:
        f.write(await file.read())

    foto_url = f"/media/routes/{filename}"
    with db() as conn:
        row = conn.execute("SELECT foto_urls FROM routes WHERE id=?", (route_id,)).fetchone()
        urls = json.loads(dict(row)['foto_urls'] or '[]')
        urls.append(foto_url)
        conn.execute("UPDATE routes SET foto_urls=? WHERE id=?", (json.dumps(urls), route_id))
    return {'foto_url': foto_url, 'foto_urls': urls}