"""Restorer factory: build a Restorer from the app config.

Engines:
- ``deepmosaics``: per-frame generative mosaic removal (image model). Vendored network
  code (``_deepmosaics/``, GPL-3.0) run in-process; user supplies only the weights
  (+ ``mosaic_position.pth`` alongside). Locates the mosaic itself — needs no detections.
- ``deepmosaics_video``: temporal variant (BVDNet) using neighbouring frames for coherence
  — needs the ``clean_*_video.pth`` weights and a contiguous frame sequence.
- ``diffusion``: diffusion-inpaint that *regenerates* masked regions via an external
  diffusion server (SwarmUI). Builds the mask from the YOLO detections, so it **needs
  detections** (see ``restorer_needs_detections``); adds no torch dep (runs out-of-process).

A CUDA GPU is recommended (for DeepMosaics in-process; for diffusion it's the server's GPU).
"""

from __future__ import annotations

from typing import TYPE_CHECKING

from .base import Restorer

if TYPE_CHECKING:  # avoid importing AppConfig at runtime here (not needed)
    from ...config import AppConfig


def build_restorer(name: str = "deepmosaics", config: AppConfig | None = None) -> Restorer:
    if config is None:
        raise ValueError("Для DeepMosaics нужны настройки (config).")
    if name == "deepmosaics":
        from .deepmosaics import DeepMosaicsRestorer

        return DeepMosaicsRestorer(
            config.dm_dir, config.dm_model, config.dm_gpu
        )
    if name == "deepmosaics_video":
        from .deepmosaics import DeepMosaicsVideoRestorer

        return DeepMosaicsVideoRestorer(
            config.dm_dir, config.dm_model, config.dm_gpu,
            feed_restored=getattr(config, "dm_feed_restored", True),
        )
    if name == "diffusion":
        backend_name = (getattr(config, "diff_backend", "swarmui") or "swarmui")
        if backend_name != "swarmui":
            raise ValueError(
                f"Diffusion-бэкенд не поддержан: {backend_name!r} (доступен только swarmui)."
            )
        from .diffusion import DiffusionRestorer, InpaintParams
        from .swarmui import SwarmUIBackend

        backend = SwarmUIBackend(config.diff_url)
        params = InpaintParams(
            prompt=config.diff_prompt,
            negative=config.diff_negative,
            model=config.diff_model,
            steps=config.diff_steps,
            cfg=config.diff_cfg,
            denoise=config.diff_denoise,
            seed=config.diff_seed,
            mask_blur=config.diff_mask_blur,
        )
        return DiffusionRestorer(
            backend, params,
            mask_dilate=config.diff_mask_dilate, mask_blur=config.diff_mask_blur,
        )
    if name == "lada":
        raise ValueError(
            "Движок LADA пока не подключён. Используйте DeepMosaics. См. README."
        )
    raise ValueError(f"Неизвестный режим восстановления: {name!r}")


def restorer_needs_detections(name: str) -> bool:
    """Whether engine ``name`` needs the frame's detections (to build an inpaint mask).

    Lets the UI decide — *without* building the engine — whether to feed real detections
    and whether to require that detection has been computed. Mirrors
    ``Restorer.needs_detections`` for the engines that build lazily on a worker thread.
    """
    return name == "diffusion"