import os
import sys
import numpy as np



class Accumulator():
    def __init__(self):
        self.dict = dict()

    def update(self, dict):
        for key in dict.keys():
            if key in self.dict.keys():
                self.dict[key].append(dict[key])
            else:
                self.dict[key] = [dict[key]]

    def get(self):
        result = dict()
        for key in self.dict.keys():
            result[key] = np.mean(self.dict[key])
        return result

    def reset(self):
        self.dict = dict()



def mask_faces(F, mask):
    F_mask = np.take(mask, F.reshape(-1), axis=0)
    F_mask = F_mask.reshape((-1, 3)).sum(axis=1) == 3

    V_ind = np.zeros(mask.shape, dtype=np.int32)
    V_ind[mask] = np.arange(mask.sum())
    F_new = np.take(V_ind, F[F_mask, :].reshape(-1), axis=0).reshape((-1, 3))

    return F_new