#!/usr/bin/env python3
# -*- encoding: utf-8 -*-

import filetype
import shutil
import json
import os

class DownloadedData(object):
    def __init__(self, loadfrom = None):
        self.initialize()
        self.loadfrom(loadfrom)
    def initialize(self):
        self.control = list()
        self.fb = dict()
    def loadfrom(self,loadfrom):
        if loadfrom:
            with open(os.path.join(loadfrom,'meta.json')) as f:
                self.control = json.loads(f.read())
            for ctrl in self.control:
                fnm = ctrl['dname']
                cnt = b''
                with open(os.path.join(loadfrom,fnm),'rb') as f:
                    cnt = f.read()
                self.fb[fnm] = cnt
    def storedLinks(self):
        return [ctrl['link'] for ctrl in self.control]
    def put(self, link, downloaded, ext=None):
        if ext is None:
            try:
                ext = link.rsplit('/',1)[-1].rsplit('.',1)[-1]
                if ext not in ['jpg','png','gif','webp']:
                    raise Exception
            except:
                ext = filetype.guess_extension(downloaded)
                if ext is None:
                    ext = 'unk'
        fnm = '%04d.%s'%(len(self.control),ext)
        self.control.append({
            'dname': fnm,
            'link':link,
            'ext':ext,
        })
        self.fb[fnm] = downloaded
    def into(self, directory):
        directory = os.path.abspath(directory)
        if not os.path.exists(directory):
            os.makedirs(directory)
        try:
            with open(os.path.join(directory,'meta.json'),'w') as f:
                f.write(json.dumps(self.control, sort_keys=True, indent=2))
            for fnm, dtb in self.fb.items():
                with open(os.path.join(directory,fnm),'wb') as f:
                    f.write(dtb)
        except KeyboardInterrupt as e:
            shutil.rmtree(directory)
            raise e
    def merge(self, other):
        for oitem in other.control:
            self.put(oitem['link'], other.fb[oitem['dname']], oitem['ext'])
    def bulk_merge(self, others):
        for other in others:
            self.merge(other)