#!/usr/bin/env python3

import numpy as np
import os
import sys
from io import BytesIO
from subprocess import run, PIPE, DEVNULL

os.environ["GLOG_minloglevel"] = "2" # seriously :|
import caffe

class NSFWDetector:
    def __init__(self):

        npath = os.path.join(os.path.dirname(__file__), "nsfw_model")
        self.nsfw_net = caffe.Net(os.path.join(npath, "deploy.prototxt"),
                                  os.path.join(npath, "resnet_50_1by2_nsfw.caffemodel"),
                                  caffe.TEST)
        self.caffe_transformer = caffe.io.Transformer({'data': self.nsfw_net.blobs['data'].data.shape})
        self.caffe_transformer.set_transpose('data', (2, 0, 1))  # move image channels to outermost
        self.caffe_transformer.set_mean('data', np.array([104, 117, 123]))  # subtract the dataset-mean value in each channel
        self.caffe_transformer.set_raw_scale('data', 255)  # rescale from [0, 1] to [0, 255]
        self.caffe_transformer.set_channel_swap('data', (2, 1, 0))  # swap channels from RGB to BGR

    def _compute(self, img):
        image = caffe.io.load_image(BytesIO(img))

        H, W, _ = image.shape
        _, _, h, w = self.nsfw_net.blobs["data"].data.shape
        h_off = int(max((H - h) / 2, 0))
        w_off = int(max((W - w) / 2, 0))
        crop = image[h_off:h_off + h, w_off:w_off + w, :]

        transformed_image = self.caffe_transformer.preprocess('data', crop)
        transformed_image.shape = (1,) + transformed_image.shape

        input_name = self.nsfw_net.inputs[0]
        output_layers = ["prob"]
        all_outputs = self.nsfw_net.forward_all(blobs=output_layers,
                    **{input_name: transformed_image})

        outputs = all_outputs[output_layers[0]][0].astype(float)

        return outputs

    def detect(self, fpath):
        try:
            ff = run(["ffmpegthumbnailer", "-m", "-o-", "-s256", "-t50%", "-a", "-cpng", "-i", fpath], stdout=PIPE, stderr=DEVNULL, check=True)
            image_data = ff.stdout
        except:
            return -1.0

        scores = self._compute(image_data)

        return scores[1]

if __name__ == "__main__":
    n = NSFWDetector()

    for inf in sys.argv[1:]:
        score = n.detect(inf)
        print(inf, score)