import io
from typing import Annotated

from fastapi import APIRouter, Depends, HTTPException, Request, status
from PIL import Image, UnidentifiedImageError
from sqlalchemy import and_, exists, func, or_, select, true
from starlette.concurrency import run_in_threadpool

from app.blobs import put_bytes
from app.uploads import remove_upload
from app.deps import DB, CurrentUser, has_perm, require
from app.models import Game, GameVersion, User
from app.schemas import GameDetailOut, GameIn, GameOut, GameUpdateIn, VersionOut
from app.translation import version_languages

router = APIRouter(prefix="/api/games", tags=["games"])
Player = Annotated[User, Depends(require("games.play"))]
Uploader = Annotated[User, Depends(require("games.upload"))]

MAX_COVER_BYTES = 20 * 1024 * 1024


def visible_versions_filter(user: User):
    """Versions a user can see: ready published ones (reviewers also see drafts),
    plus their own in any state."""
    if has_perm(user, "versions.manage_any") or has_perm(user, "games.delete"):
        return true()
    ready = GameVersion.status == "ready"
    if not has_perm(user, "versions.publish"):
        ready = and_(ready, GameVersion.visibility == "published")
    return or_(ready, GameVersion.owner_id == user.id)


async def get_game(db: DB, game_id: int) -> Game:
    game = await db.get(Game, game_id)
    if not game:
        raise HTTPException(status.HTTP_404_NOT_FOUND, "Игра не найдена")
    return game


def can_edit_game(user: User, game: Game) -> bool:
    return has_perm(user, "games.edit") or (
        has_perm(user, "games.upload") and game.created_by_id == user.id
    )


@router.get("", response_model=list[GameOut])
async def list_games(user: Player, db: DB, q: str = "", tag: str = "") -> list[dict]:
    stmt = select(Game).order_by(Game.title)
    if q.strip():
        pattern = f"%{q.strip()}%"
        stmt = stmt.where(
            or_(
                Game.title.ilike(pattern),
                Game.description.ilike(pattern),
                Game.tags.any(q.strip().lower()),
            )
        )
    if tag:
        stmt = stmt.where(Game.tags.any(tag.lower()))
    stmt = stmt.where(
        exists().where(GameVersion.game_id == Game.id, visible_versions_filter(user))
        | (Game.created_by_id == user.id)
    )
    games = list((await db.scalars(stmt.limit(500))).all())
    counts: dict[int, dict[str, int]] = {}
    if games:
        rows = await db.execute(
            select(GameVersion.game_id, GameVersion.status, func.count())
            .where(GameVersion.game_id.in_([g.id for g in games]), visible_versions_filter(user))
            .group_by(GameVersion.game_id, GameVersion.status)
        )
        for game_id, st, n in rows:
            key = "ready" if st == "ready" else "failed" if st == "failed" else "pending"
            counts.setdefault(game_id, {}).setdefault(key, 0)
            counts[game_id][key] += n
    return [
        {
            **GameOut.model_validate(g).model_dump(),
            "ready_versions": counts.get(g.id, {}).get("ready", 0),
            "pending_versions": counts.get(g.id, {}).get("pending", 0),
            "failed_versions": counts.get(g.id, {}).get("failed", 0),
        }
        for g in games
    ]


@router.post("", response_model=GameOut, status_code=201)
async def create_game(body: GameIn, user: Uploader, db: DB) -> Game:
    game = Game(
        title=body.title.strip(),
        description=body.description,
        tags=sorted({t.strip().lower() for t in body.tags if t.strip()}),
        created_by_id=user.id,
    )
    db.add(game)
    await db.commit()
    return game


@router.get("/{game_id}", response_model=GameDetailOut)
async def game_detail(game_id: int, user: Player, db: DB) -> dict:
    game = await get_game(db, game_id)
    versions = (
        await db.scalars(
            select(GameVersion)
            .where(GameVersion.game_id == game.id, visible_versions_filter(user))
            .order_by(GameVersion.parent_id.is_not(None), GameVersion.created_at)
        )
    ).all()
    return {**GameOut.model_validate(game).model_dump(),
            "versions": [{**VersionOut.model_validate(v).model_dump(), **version_languages(v.manifest)}
                         for v in versions]}


@router.patch("/{game_id}", response_model=GameOut)
async def update_game(game_id: int, body: GameUpdateIn, user: CurrentUser, db: DB) -> Game:
    game = await get_game(db, game_id)
    if not can_edit_game(user, game):
        raise HTTPException(status.HTTP_403_FORBIDDEN, "Нет прав на редактирование")
    if body.title is not None:
        game.title = body.title.strip()
    if body.description is not None:
        game.description = body.description
    if body.tags is not None:
        game.tags = sorted({t.strip().lower() for t in body.tags if t.strip()})
    await db.commit()
    return game


@router.put("/{game_id}/cover", response_model=GameOut)
async def upload_cover(game_id: int, request: Request, user: CurrentUser, db: DB) -> Game:
    game = await get_game(db, game_id)
    if not can_edit_game(user, game):
        raise HTTPException(status.HTTP_403_FORBIDDEN, "Нет прав на редактирование")
    data = await request.body()
    if len(data) > MAX_COVER_BYTES:
        raise HTTPException(status.HTTP_413_REQUEST_ENTITY_TOO_LARGE, "Слишком большой файл")
    try:
        game.cover_hash = await run_in_threadpool(make_cover, data)
    except (UnidentifiedImageError, OSError):
        raise HTTPException(status.HTTP_400_BAD_REQUEST, "Не удалось прочитать изображение")
    await db.commit()
    return game


@router.delete("/{game_id}", status_code=204)
async def delete_game(game_id: int, _: Annotated[User, Depends(require("games.delete"))],
                      db: DB) -> None:
    game = await get_game(db, game_id)
    version_ids = (await db.scalars(select(GameVersion.id).where(GameVersion.game_id == game.id))).all()
    await db.delete(game)
    await db.commit()
    for vid in version_ids:
        remove_upload(vid)


def make_cover(data: bytes) -> str:
    img = Image.open(io.BytesIO(data))
    img.thumbnail((640, 640))
    if img.mode not in ("RGB", "RGBA"):
        img = img.convert("RGBA")
    out = io.BytesIO()
    img.save(out, "WEBP", quality=85)
    return put_bytes(out.getvalue(), ".webp")[0]