import os
import cv2
import numpy as np
from loguru import logger
from torch.hub import get_dir

from iopaint.plugins.base_plugin import BasePlugin
from iopaint.schema import RunPluginRequest, RemoveBGModel


class RemoveBG(BasePlugin):
    name = "RemoveBG"
    support_gen_mask = True
    support_gen_image = True

    def __init__(self, model_name):
        super().__init__()
        self.model_name = model_name

        hub_dir = get_dir()
        model_dir = os.path.join(hub_dir, "checkpoints")
        os.environ["U2NET_HOME"] = model_dir

        self._init_session(model_name)

    def _init_session(self, model_name: str):
        if model_name == RemoveBGModel.briaai_rmbg_1_4:
            from iopaint.plugins.briarmbg import (
                create_briarmbg_session,
                briarmbg_process,
            )

            self.session = create_briarmbg_session()
            self.remove = briarmbg_process
        else:
            from rembg import new_session, remove

            self.session = new_session(model_name=model_name)
            self.remove = remove

    def switch_model(self, new_model_name):
        if self.model_name == new_model_name:
            return

        logger.info(
            f"Switching removebg model from {self.model_name} to {new_model_name}"
        )
        self._init_session(new_model_name)
        self.model_name = new_model_name

    def gen_image(self, rgb_np_img, req: RunPluginRequest) -> np.ndarray:
        bgr_np_img = cv2.cvtColor(rgb_np_img, cv2.COLOR_RGB2BGR)

        # return BGRA image
        output = self.remove(bgr_np_img, session=self.session)
        return cv2.cvtColor(output, cv2.COLOR_BGRA2RGBA)

    def gen_mask(self, rgb_np_img, req: RunPluginRequest) -> np.ndarray:
        bgr_np_img = cv2.cvtColor(rgb_np_img, cv2.COLOR_RGB2BGR)

        # return BGR image, 255 means foreground, 0 means background
        output = self.remove(bgr_np_img, session=self.session, only_mask=True)
        return output

    def check_dep(self):
        try:
            import rembg
        except ImportError:
            return (
                "RemoveBG is not installed, please install it first. pip install rembg"
            )