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

import json
import os
import shutil
import tkinter
from concurrent.futures import ThreadPoolExecutor
from io import BytesIO
from pathlib import Path

import filetype
from PIL import Image, ImageTk


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):
        global rootWindow
        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
        if userWantsPreview and rootWindow is None:
            rootWindow = MainApp()
        if rootWindow is not None and downloaded is not None:
            try:
                rootWindow.update_image(Image.open(BytesIO(downloaded)), link)
            except:
                pass
        if (pth := Path('latest_put_image.file')).exists():
            pth.unlink()
        Path('latest_put_image.url').write_text(link)
        Path('latest_put_image.file').write_bytes(downloaded)
    
    def remove(self, directory):
        directory = os.path.abspath(directory)
        if os.path.exists(directory):
            shutil.rmtree(directory)

    def into(self, directory):
        self.remove(directory)
        directory = os.path.abspath(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 seq, (fnm, dtb) in enumerate(self.fb.items()):
                with open(os.path.join(directory, fnm), 'wb') as f:
                    f.write(dtb)
                print(' '*50, end='', flush=True)
                print('\r', end='', flush=True)
                print(f' `--> Saving image {seq+1} of {len(self.fb)}', end='', flush=True)
                print('\r', end='', flush=True)
        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)


class MainApp(tkinter.Tk):
    def __init__(self):
        super().__init__()
        self.geometry('500x500')
        self.known_width = 500
        self.known_height = 500
        self.resizable(width=True, height=True)
        self.photo = Image.new('RGB', (256,256), (0,0,0))
        self.display_photo = self.photo.copy()
        self.image = ImageTk.PhotoImage(self.display_photo)
        self.frame = tkinter.Frame(self)
        self.frame.pack(fill=tkinter.BOTH, expand=tkinter.YES)
        self.panel = tkinter.Label(self.frame)
        self.panel.pack(fill=tkinter.BOTH, expand=tkinter.YES)
        self.panel.bind('<Configure>', self._resize_image)
        self.panel.configure(image=self.image)
        self.update()
        self._resize_image2()
        self.update()

    def _resize_image(self, event):
        self.known_width = event.width
        self.known_height = event.height
        self._resize_image2()

    def _resize_image2(self):
        size_tuple = (self.known_width, self.known_height)
        self.display_photo = self.photo.copy()
        self.display_photo.thumbnail(size_tuple)
        if self.display_photo is None:
            self.display_photo = self.photo
        self.image = ImageTk.PhotoImage(self.display_photo)
        self.panel.configure(image=self.image)
    
    def update_image(self, image, windowTile=None):
        if windowTile is not None:
            self.winfo_toplevel().title(str(windowTile))
        self.photo = image
        self._resize_image2()
        self.update()


userWantsPreview = False
rootWindow = None

if 'REDDITGETTER_PREVIEW' in os.environ and os.environ['REDDITGETTER_PREVIEW'] != '':
    userWantsPreview = True