"""Plex collections: browse mirrored collections + the admin manual-collection editor."""

from fastapi import APIRouter, Depends, HTTPException
from pydantic import BaseModel
from sqlalchemy import func, select
from sqlalchemy.orm import Session

from app.auth import admin_user, current_user
from app.db import get_db
from app.models import (
    PlexCollection,
    PlexLibrary,
    User,
)
from app.plex import sync as plex_sync
from app.plex.client import PlexClient, PlexError, PlexNotConfigured
from app.plex.lookups import by_rating_key
from app.plex.query import like_escape

router = APIRouter(prefix="/api/plex", tags=["plex"])

_STRIP_PROVIDERS = ("imdb", "tmdb", "tvdb", "trakt")


def _collection_source(col: PlexCollection) -> str:
    first = (col.title or "").strip().split(" ", 1)[0].lower()
    if first in _STRIP_PROVIDERS:
        return first
    if col.smart:
        return "smart"
    return "collection"


def _collection_editable(c: PlexCollection) -> bool:
    """Effective editability: the admin marked it editable AND it's a plain manual collection — never
    smart, never an external auto-list (IMDb/TMDb/…), which are managed outside Plex."""
    return bool(c.editable) and not c.smart and _collection_source(c) == "collection"


def _collection_card(c: PlexCollection) -> dict:
    return {
        "id": c.rating_key,
        "title": c.title,
        "summary": c.summary,
        "thumb": f"/api/plex/image/{c.rating_key}" if c.thumb_key else None,
        "child_count": c.child_count,
        "smart": c.smart,
        "source": _collection_source(c),
        "editable": c.editable,
        "can_edit": _collection_editable(
            c
        ),  # whether the edit controls should be offered (admin UI)
    }


@router.get("/collections")
def collections(
    library: str | None = None,
    q: str | None = None,
    user: User = Depends(current_user),
    db: Session = Depends(get_db),
) -> dict:
    """Mirrored collections as cards (most-populated first), optionally name-filtered by `q`. With a
    `library` plex_key → that one library's collections (used by the collection editor). WITHOUT one →
    the UNION across all enabled libraries (the unified-scope sidebar picker, which has no single
    library selected)."""
    if library is not None:
        lib = db.execute(
            select(PlexLibrary).where(PlexLibrary.plex_key == str(library))
        ).scalars().first()
        if lib is None:
            return {"collections": []}
        query = select(PlexCollection).where(PlexCollection.library_id == lib.id)
    else:
        enabled_ids = list(
            db.execute(
                select(PlexLibrary.id).where(
                    PlexLibrary.enabled.is_(True), PlexLibrary.overlay_of.is_(None)
                )
            ).scalars()
        )
        if not enabled_ids:
            return {"collections": []}
        query = select(PlexCollection).where(
            PlexCollection.library_id.in_(enabled_ids)
        )
    term = (q or "").strip()
    if term:
        query = query.where(PlexCollection.title.ilike(f"%{like_escape(term)}%"))
    rows = db.execute(
        query.order_by(
            PlexCollection.child_count.desc().nullslast(),
            func.lower(PlexCollection.title),
        )
    ).scalars().all()
    return {"collections": [_collection_card(c) for c in rows]}


def _editable_collection_or_403(db: Session, rating_key: str) -> PlexCollection:
    col = by_rating_key(db, PlexCollection, rating_key)
    if col is None:
        raise HTTPException(status_code=404, detail="Unknown collection")
    if not _collection_editable(col):
        raise HTTPException(status_code=403, detail="This collection is read-only")
    return col


class CreateCollectionIn(BaseModel):
    library: str = ""
    title: str = ""
    item_rating_key: str = ""


@router.post("/collections")
def create_collection(
    body: CreateCollectionIn,
    _: User = Depends(admin_user),
    db: Session = Depends(get_db),
) -> dict:
    """Create a manual collection (seeded with one item — Plex needs at least one). Editable by default."""
    library = body.library
    title = body.title.strip()
    seed = body.item_rating_key
    if not title or not seed:
        raise HTTPException(
            status_code=400, detail="title and item_rating_key are required"
        )
    lib = db.execute(
        select(PlexLibrary).where(PlexLibrary.plex_key == library)
    ).scalars().first()
    if lib is None:
        raise HTTPException(status_code=404, detail="Unknown library")
    try:
        with PlexClient(db) as plex:
            new = plex.create_collection(lib.plex_key, title, seed)
            col = plex_sync.resync_collection(db, plex, lib, str(new.get("ratingKey")))
            col.editable = True
        db.commit()
    except (PlexError, PlexNotConfigured) as e:
        db.rollback()
        raise HTTPException(status_code=422, detail=f"Plex write failed: {e}")
    return _collection_card(col)


@router.post("/collections/{rating_key}/items/{item_rating_key}")
def collection_add_item(
    rating_key: str,
    item_rating_key: str,
    _: User = Depends(admin_user),
    db: Session = Depends(get_db),
) -> dict:
    col = _editable_collection_or_403(db, rating_key)
    lib = db.get(PlexLibrary, col.library_id)
    try:
        with PlexClient(db) as plex:
            plex.add_collection_item(rating_key, str(item_rating_key))
            col = plex_sync.resync_collection(db, plex, lib, rating_key)
        db.commit()
    except (PlexError, PlexNotConfigured) as e:
        db.rollback()
        raise HTTPException(status_code=422, detail=f"Plex write failed: {e}")
    return _collection_card(col)


@router.delete("/collections/{rating_key}/items/{item_rating_key}")
def collection_remove_item(
    rating_key: str,
    item_rating_key: str,
    _: User = Depends(admin_user),
    db: Session = Depends(get_db),
) -> dict:
    col = _editable_collection_or_403(db, rating_key)
    lib = db.get(PlexLibrary, col.library_id)
    try:
        with PlexClient(db) as plex:
            plex.remove_collection_item(rating_key, str(item_rating_key))
            col = plex_sync.resync_collection(db, plex, lib, rating_key)
        db.commit()
    except (PlexError, PlexNotConfigured) as e:
        db.rollback()
        raise HTTPException(status_code=422, detail=f"Plex write failed: {e}")
    return _collection_card(col)


class CollectionRenameIn(BaseModel):
    title: str = ""


@router.patch("/collections/{rating_key}")
def collection_rename(
    rating_key: str,
    body: CollectionRenameIn,
    _: User = Depends(admin_user),
    db: Session = Depends(get_db),
) -> dict:
    col = _editable_collection_or_403(db, rating_key)
    title = body.title.strip()
    if not title:
        raise HTTPException(status_code=400, detail="title is required")
    lib = db.get(PlexLibrary, col.library_id)
    try:
        with PlexClient(db) as plex:
            plex.rename_collection(lib.plex_key, rating_key, title)
            col = plex_sync.resync_collection(db, plex, lib, rating_key)
        db.commit()
    except (PlexError, PlexNotConfigured) as e:
        db.rollback()
        raise HTTPException(status_code=422, detail=f"Plex write failed: {e}")
    return _collection_card(col)


@router.delete("/collections/{rating_key}")
def collection_delete(
    rating_key: str, _: User = Depends(admin_user), db: Session = Depends(get_db)
) -> dict:
    col = _editable_collection_or_403(db, rating_key)
    lib = db.get(PlexLibrary, col.library_id)
    try:
        with PlexClient(db) as plex:
            plex.delete_collection(rating_key)
        plex_sync.delete_collection_local(db, lib, rating_key)
        db.commit()
    except (PlexError, PlexNotConfigured) as e:
        db.rollback()
        raise HTTPException(status_code=422, detail=f"Plex write failed: {e}")
    return {"deleted": rating_key}


class CollectionEditableIn(BaseModel):
    editable: bool = False


@router.post("/collections/{rating_key}/editable")
def collection_set_editable(
    rating_key: str,
    body: CollectionEditableIn,
    _: User = Depends(admin_user),
    db: Session = Depends(get_db),
) -> dict:
    """Mark an existing Plex collection as 'mine to edit' (or unmark). Smart / auto-list collections
    (IMDb/TMDb/…) can never be made editable — they're regenerated outside Plex."""
    col = by_rating_key(db, PlexCollection, rating_key)
    if col is None:
        raise HTTPException(status_code=404, detail="Unknown collection")
    want = body.editable
    if want and (col.smart or _collection_source(col) != "collection"):
        raise HTTPException(
            status_code=400,
            detail="Smart / auto-list collections can't be made editable",
        )
    col.editable = want
    db.commit()
    return _collection_card(col)