# Copyright 2021 Zilliz. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import logging
import numpy
import os
from pathlib import Path

import towhee
from towhee.operator.base import NNOperator, OperatorFlag
from towhee.types.arg import arg, to_image_color
from towhee import register

import torch
from torch import nn
from torchvision import transforms

from PIL import Image as PILImage

import warnings

warnings.filterwarnings('ignore')
log = logging.getLogger()


@register(output_schema=['vec'])
class Swag(NNOperator):
    """
    Pytorch image embedding operator that uses the Pytorch Image Model (timm) collection.
    Args:
        model_name (`str`):
            Which model to use for the embeddings.
        skip_preprocess (`bool = False`):
            Whether skip image transforms.
    """

    def __init__(self, model_name: str, skip_preprocess: bool = False) -> None:
        super().__init__()
        self.device = 'cuda' if torch.cuda.is_available() else 'cpu'

        self.skip_tfms = skip_preprocess
        self.tfms = self.get_transforms(model_name)

        self.model_name = model_name
        self.model = torch.hub.load("facebookresearch/swag", model=model_name)
        self.model.to(self.device)
        self.model.head = None  # To extract features without model head
        self.model.eval()

    @arg(1, to_image_color('RGB'))
    def __call__(self, img: 'towhee.types.Image') -> numpy.ndarray:
        img = PILImage.fromarray(img.astype('uint8'), 'RGB')
        if not self.skip_tfms:
            img = self.tfms(img).unsqueeze(0)
        img = img.to(self.device)
        features = self.model(img)
        if features.dim() == 4:
            global_pool = nn.AdaptiveAvgPool2d(1)
            features = global_pool(features)

        features = features.to('cpu')
        vec = features.flatten().detach().numpy()
        return vec

    def save_model(self, format: str = 'pytorch', path: str = 'default'):
        if path == 'default':
            path = str(Path(__file__).parent)
            name = self.model_name.replace('/', '-')
            path = os.path.join(path, name)
        inputs = torch.ones(1, 3, 224, 224)
        if format == 'pytorch':
            torch.save(self.model, path)
        elif format == 'torchscript':
            path = path + '.pt'
            try:
                try:
                    jit_model = torch.jit.script(self.model)
                except Exception:
                    jit_model = torch.jit.trace(self.model, inputs, strict=False)
                torch.jit.save(jit_model, path)
            except Exception as e:
                log.error(f'Fail to save as torchscript: {e}.')
                raise RuntimeError(f'Fail to save as torchscript: {e}.')
        elif format == 'onxx':
            pass  # todo
        else:
            log.error(f'Save model: unsupported format "{format}".')

    @staticmethod
    def supported_model_names(format: str = None):
        full_list = [
            'vit_h14_in1k',
            'vit_l16_in1k',
            'vit_b16_in1k',
            'regnety_16gf_in1k',
            'regnety_32gf_in1k',
            'regnety_128gf_in1k',
            ]
        full_list.sort()
        if format is None:
            model_list = full_list
        elif format == 'pytorch':
            to_remove = []
            assert set(to_remove).issubset(set(full_list))
            model_list = list(set(full_list) - set(to_remove))
        else:  # todo: format in {'torchscript', 'onnx', 'tensorrt'}
            log.error(f'Invalid format "{format}". Currently supported formats: "pytorch".')
        return model_list

    @staticmethod
    def get_transforms(model_name):
        model_resolution = {
            'vit_h14_in1k': 518,
            'vit_l16_in1k': 512,
            'vit_b16_in1k': 384,
            'regnety_16gf_in1k': 384,
            'regnety_32gf_in1k': 384,
            'regnety_128gf_in1k': 384
        }
        if model_name not in model_resolution.keys():
            log.warning('No transforms specified for model "%s", using resolution 384.', model_name)
            resolution = 384
        else:
            resolution = model_resolution[model_name]
        transform = transforms.Compose([
            transforms.Resize(
                resolution,
                interpolation=transforms.InterpolationMode.BICUBIC,
            ),
            transforms.CenterCrop(resolution),
            transforms.ToTensor(),
            transforms.Normalize(
                mean=[0.485, 0.456, 0.406], std=[0.229, 0.224, 0.225]
            ),
        ])
        return transform


if __name__ == '__main__':
    from towhee import ops

    path = '/Users/mengjiagu/Desktop/models/data/image/animals10/bird.jpg'

    decoder = ops.image_decode.cv2()
    img = decoder(path)
    # op = Swag('vit_b16_in1k')
    op = Swag('regnety_16gf_in1k')
    out = op(img)
    print(out.shape)