from glob import glob
import os

class Slides():
    def __init__(self,path):
        if os.path.isdir(path) != True:
            print("PATH is not a dir")
        self.data = "{'type'='diapo', 'value'='%s', 'number'='%d', 'total'='%d'}"
        self.files=sorted(glob("%s/*.png" % path), key=self.key_func)
        for f in range(0,len(self.files)):
            self.files[f] = os.path.abspath(self.files[f])
        self.cur_diapo=0

    def key_func(self,x):
        return int(os.path.split(x)[-1].rsplit('.', 1)[0])

    def cur(self):
        return ( self.data % (self.files[self.cur_diapo], self.cur_diapo+1, len(self.files)))

    def prev(self):
        self.cur_diapo=max(self.cur_diapo-1, 0)
        return self.cur()

    def next(self):
        self.cur_diapo=min(self.cur_diapo+1, len(self.files)-1)
        return self.cur()