#!/usr/bin/env python3
"""
Some miscellaneous tools and helper functions. Primarily for quests.
"""
import os
import re
import hashlib

import magic
import requests
from django.conf import settings

IMG_DIR = "/usr/local/www/html/img/"
ALLOWED_MIMES = [
	"image/jpeg",
	"image/png",
	"image/gif",
	"video/webm"
]

def download_img(url):
	"""
	Downloads the requested URL, ensures the mimetype is an acceptable
	type, and saves it to file with the hash as filename. Returns a
	URL to image.
	"""
	# TODO: file size limits
	# https://stackoverflow.com/questions/22346158/
	# TODO: prevent overwriting
	try:
		res = requests.get(url)
		res.raise_for_status()
		mime = magic.from_buffer(res.content, mime=True)
		assert mime in ALLOWED_MIMES
		h = hashlib.sha256()
		h.update(res.content)
		fname = h.hexdigest()
		fname += "." + mime.partition("/")[2]
		with open(os.path.join(IMG_DIR, fname), "wb") as file:
			for chunk in res.iter_content(100000):
				file.write(chunk)
		return settings.IMG_SVR_URL + fname
	except requests.exceptions.RequestException:
		return "INVALID_URL"
	except AssertionError:
		return "INVALID_MIME_TYPE"
	except Exception as e:
		print(e)
		return "UNKNOWN_ERROR"


def handle_img(text, limit=5):
	"""
	Finds all image urls in the given set of text and attempts to handle
	them appropriately. `limit` will limit how many urls are processed.
	The rest will be ignored. If an error occurs during handling, the raw
	(unlinked) url will be inserted.
	"""
	# TODO: handle webms
	urls = re.findall(r"\[img\](.*?)\[/img\]", text)

	for ext_url in urls:
		int_url = download_img(ext_url)
		if int_url in ["INVALID_URL", "INVALID_MIME_TYPE", "UNKNOWN_ERROR"]:
			text = text.replace("[img]" + ext_url + "[/img]", ext_url, 1)
		alt_text = os.path.basename(ext_url)
		img_tag = f'<img src="{int_url}" title="{alt_text}">'

		text = text.replace("[img]" + ext_url + "[/img]", img_tag, 1)

	return text