"""BAN YARO — Tagebuch Routes"""

import os, uuid, json
from fastapi import APIRouter, Depends, HTTPException, UploadFile, File
from pydantic import BaseModel
from typing import Optional
from database import db
from auth import get_current_user
import ki as KI

router    = APIRouter()
MEDIA_DIR = os.getenv("MEDIA_DIR", "/data/media")


class DiaryCreate(BaseModel):
    datum:        Optional[str]       = None   # ISO date, default heute
    typ:          str                 = "eintrag"
    titel:        Optional[str]       = None
    text:         Optional[str]       = None
    tags:         Optional[list]      = None
    gps_lat:      Optional[float]     = None
    gps_lon:      Optional[float]     = None
    is_milestone: bool                = False
    dog_ids:      Optional[list[int]] = None   # alle Hunde inkl. primär; None = nur primary


class DiaryUpdate(BaseModel):
    titel:        Optional[str]       = None
    text:         Optional[str]       = None
    tags:         Optional[list]      = None
    is_milestone: Optional[bool]      = None
    dog_ids:      Optional[list[int]] = None   # wenn gesetzt: Hunde-Zuweisung ersetzen


def _own_dog(dog_id: int, user_id: int, conn):
    dog = conn.execute(
        "SELECT id FROM dogs WHERE id=? AND user_id=?", (dog_id, user_id)
    ).fetchone()
    if not dog:
        raise HTTPException(404, "Hund nicht gefunden.")
    return dog


def _validate_dog_ids(dog_ids: list[int], primary: int, user_id: int, conn) -> list[int]:
    """Stellt sicher dass alle IDs dem User gehören. Gibt die bereinigte Liste zurück."""
    all_ids = list({primary} | set(dog_ids))
    for did in all_ids:
        _own_dog(did, user_id, conn)
    return all_ids


def _fetch_dog_ids(conn, entry_ids: list[int]) -> dict:
    """Gibt {entry_id: [dog_id, ...]} zurück."""
    if not entry_ids:
        return {}
    ph = ",".join("?" * len(entry_ids))
    rows = conn.execute(
        f"SELECT diary_id, dog_id FROM diary_dogs WHERE diary_id IN ({ph})",
        entry_ids
    ).fetchall()
    result = {}
    for r in rows:
        result.setdefault(r["diary_id"], []).append(r["dog_id"])
    return result


def _set_dog_ids(conn, entry_id: int, dog_ids: list[int]):
    conn.execute("DELETE FROM diary_dogs WHERE diary_id=?", (entry_id,))
    for did in dog_ids:
        conn.execute(
            "INSERT OR IGNORE INTO diary_dogs (diary_id, dog_id) VALUES (?,?)",
            (entry_id, did)
        )


def _entry_dict(row, dog_ids_map: dict) -> dict:
    e = dict(row)
    e["tags"]    = json.loads(e["tags"]) if e["tags"] else []
    e["dog_ids"] = dog_ids_map.get(e["id"], [e["dog_id"]])
    return e


@router.get("/{dog_id}/diary")
async def list_diary(dog_id: int, limit: int = 20, offset: int = 0,
                     user=Depends(get_current_user)):
    with db() as conn:
        _own_dog(dog_id, user["id"], conn)
        # Einträge des primären Hundes SOWIE Einträge wo der Hund als weiterer zugeordnet ist
        rows = conn.execute(
            """SELECT DISTINCT d.* FROM diary d
               LEFT JOIN diary_dogs dd ON dd.diary_id = d.id
               WHERE d.dog_id = ? OR dd.dog_id = ?
               ORDER BY d.datum DESC, d.created_at DESC
               LIMIT ? OFFSET ?""",
            (dog_id, dog_id, limit, offset)
        ).fetchall()
        ids = [r["id"] for r in rows]
        dogs_map = _fetch_dog_ids(conn, ids)

    return [_entry_dict(r, dogs_map) for r in rows]


@router.post("/{dog_id}/diary", status_code=201)
async def create_diary(dog_id: int, data: DiaryCreate,
                       user=Depends(get_current_user)):
    tags = data.tags or []

    # KI: Auto-Tags wenn Text vorhanden (lokal, kostenlos)
    if data.text and len(data.text) > 10:
        try:
            ai_tags = await KI.diary_tags(data.text)
            tags = list(set(tags + ai_tags))
        except Exception:
            pass

    with db() as conn:
        _own_dog(dog_id, user["id"], conn)
        all_dogs = _validate_dog_ids(data.dog_ids or [], dog_id, user["id"], conn)

        conn.execute(
            """INSERT INTO diary
               (dog_id, datum, typ, titel, text, tags, gps_lat, gps_lon, is_milestone)
               VALUES (?,
                 COALESCE(?, date('now')),
                 ?,?,?,?,?,?,?)""",
            (dog_id, data.datum, data.typ, data.titel, data.text,
             json.dumps(tags), data.gps_lat, data.gps_lon, int(data.is_milestone))
        )
        entry = conn.execute(
            "SELECT * FROM diary WHERE dog_id=? ORDER BY id DESC LIMIT 1",
            (dog_id,)
        ).fetchone()
        _set_dog_ids(conn, entry["id"], all_dogs)
        dogs_map = _fetch_dog_ids(conn, [entry["id"]])

    return _entry_dict(entry, dogs_map)


@router.get("/{dog_id}/diary/{entry_id}")
async def get_diary(dog_id: int, entry_id: int, user=Depends(get_current_user)):
    with db() as conn:
        _own_dog(dog_id, user["id"], conn)
        row = conn.execute(
            """SELECT DISTINCT d.* FROM diary d
               LEFT JOIN diary_dogs dd ON dd.diary_id = d.id
               WHERE d.id=? AND (d.dog_id=? OR dd.dog_id=?)""",
            (entry_id, dog_id, dog_id)
        ).fetchone()
        if not row:
            raise HTTPException(404, "Eintrag nicht gefunden.")
        dogs_map = _fetch_dog_ids(conn, [entry_id])

    return _entry_dict(row, dogs_map)


@router.patch("/{dog_id}/diary/{entry_id}")
async def update_diary(dog_id: int, entry_id: int, data: DiaryUpdate,
                       user=Depends(get_current_user)):
    with db() as conn:
        _own_dog(dog_id, user["id"], conn)

        # Prüfen ob Eintrag diesem Hund gehört (direkt oder via diary_dogs)
        exists = conn.execute(
            """SELECT 1 FROM diary d
               LEFT JOIN diary_dogs dd ON dd.diary_id = d.id
               WHERE d.id=? AND (d.dog_id=? OR dd.dog_id=?)""",
            (entry_id, dog_id, dog_id)
        ).fetchone()
        if not exists:
            raise HTTPException(404, "Eintrag nicht gefunden.")

        # Felder updaten
        fields = {k: v for k, v in data.model_dump(exclude={"dog_ids"}).items()
                  if v is not None}
        if "tags" in fields:
            fields["tags"] = json.dumps(fields["tags"])
        if fields:
            # primary dog_id für SET-Clause ermitteln (der Eintrag bleibt dem Erstell-Hund)
            set_clause = ", ".join(f"{k}=?" for k in fields)
            conn.execute(
                f"UPDATE diary SET {set_clause} WHERE id=?",
                list(fields.values()) + [entry_id]
            )

        # Hunde-Zuweisung aktualisieren
        if data.dog_ids is not None:
            # primary dog des Eintrags ermitteln
            primary = conn.execute(
                "SELECT dog_id FROM diary WHERE id=?", (entry_id,)
            ).fetchone()["dog_id"]
            all_dogs = _validate_dog_ids(data.dog_ids, primary, user["id"], conn)
            _set_dog_ids(conn, entry_id, all_dogs)

        row      = conn.execute("SELECT * FROM diary WHERE id=?", (entry_id,)).fetchone()
        dogs_map = _fetch_dog_ids(conn, [entry_id])

    return _entry_dict(row, dogs_map)


@router.delete("/{dog_id}/diary/{entry_id}", status_code=204)
async def delete_diary(dog_id: int, entry_id: int, user=Depends(get_current_user)):
    with db() as conn:
        _own_dog(dog_id, user["id"], conn)
        conn.execute(
            "DELETE FROM diary WHERE id=? AND dog_id=?", (entry_id, dog_id)
        )


@router.post("/{dog_id}/diary/{entry_id}/media")
async def upload_media(dog_id: int, entry_id: int,
                       file: UploadFile = File(...),
                       user=Depends(get_current_user)):
    with db() as conn:
        _own_dog(dog_id, user["id"], conn)
        entry = conn.execute(
            """SELECT d.id FROM diary d
               LEFT JOIN diary_dogs dd ON dd.diary_id = d.id
               WHERE d.id=? AND (d.dog_id=? OR dd.dog_id=?)""",
            (entry_id, dog_id, dog_id)
        ).fetchone()
    if not entry:
        raise HTTPException(404, "Eintrag nicht gefunden.")

    ext      = os.path.splitext(file.filename or "")[1] or ".jpg"
    filename = f"diary_{entry_id}_{uuid.uuid4().hex[:8]}{ext}"
    path     = os.path.join(MEDIA_DIR, "diary", filename)
    os.makedirs(os.path.dirname(path), exist_ok=True)

    with open(path, "wb") as f:
        f.write(await file.read())

    media_url = f"/media/diary/{filename}"
    with db() as conn:
        conn.execute("UPDATE diary SET media_url=? WHERE id=?", (media_url, entry_id))

    return {"media_url": media_url}