# Requires PyCrypto and python-magic
import sys
from pathlib import Path
from urllib.parse import urlparse
import json
import magic

import click
import requests

import database_connection  # noqa: F401
import decrypt_attachment
from matrix_connection import get_download_url
from schema import Message


def download_stem(message, prefer_thumbnails):
    image_url = (message.thumbnail_url if prefer_thumbnails else None) \
        or message.image_url
    return urlparse(image_url).path.lstrip('/')


def run_downloads(messages, download_dir, prefer_thumbnails):
    for msg in messages:
        image_url = (msg.thumbnail_url if prefer_thumbnails else None) or msg.image_url
        download_url = get_download_url(image_url).replace('//bitcointechweekly.com','//matrix.bitcointechweekly.com:8448')
        try:
            res = requests.head(download_url, verify=False)
            assert res.status_code == 200
            print(res.status_code)
            # mtype, subtype = res.headers['content-type'].split('/', 2)
            # if mtype != 'image':
              # print(f"Skipping {download_url}: {res.headers['content-type']}")
              # continue
            res = requests.get(download_url, verify=False)
            # print(res.status_code)
            assert res.status_code == 200

            filename = (download_dir / download_stem(msg, prefer_thumbnails))
            print('Downloading', download_url, '->', filename)

            #Encryption details
            file_meta = msg.content.get('file')
            key_meta = file_meta['key']['k']
            iv = file_meta['iv']
            _hash = file_meta['hashes']['sha256']
            decrypted = decrypt_attachment.decrypt(res.content, key_meta, _hash, iv)
            mtype, subtype = magic.from_buffer(decrypted, mime=True).split('/', 2)

            filename = (download_dir / download_stem(msg, prefer_thumbnails)
                    ).with_suffix('.' + subtype)

            # metadata_file = (download_dir / download_stem(msg, prefer_thumbnails)
                      # ).with_suffix('.metadata')

            with open(filename, 'wb') as fp:
                fp.write(decrypted)
            # with open(metadata_file, 'w') as fp:
                # json.dump(msg.content, fp)
        except:
            e = sys.exc_info()[0]
            print( "<p>Error downloading '%s' : %s</p>" % (download_url, e) )
        # break


@click.command()
@click.option('--thumbnails/--no-thumbnails', default=True)
@click.argument('output', required=False)
def download_images(thumbnails, output):
    """Download thumbnails."""
    noun = 'thumbnails' if thumbnails else 'images'
    download_dir = Path(output or noun)
    messages = [msg for msg in Message.objects
                if msg.content.get('msgtype') == 'm.image']
    download_dir.mkdir(exist_ok=True)
    current_stems = {p.stem for p in download_dir.glob('*')}
    new_messages = [msg for msg in messages
                    if download_stem(msg, thumbnails)
                    not in current_stems]
    # skip_count = len(messages) - len(new_messages)
    # if skip_count:
        # print(f"Skipping {skip_count} already-downloaded {noun}")
    if new_messages:
        print(f"Downloading {len(new_messages)} new {noun}...")
    else:
        print("Nothing to do")
    run_downloads(new_messages, download_dir, prefer_thumbnails=thumbnails)


if __name__ == '__main__':
    download_images()