#!/usr/bin/env python3
"""
Miscellaneous tools and help functions.
"""
import os
import re
import urllib
import hashlib

import magic
import requests

IMG_DIR = "/usr/local/www/html/img"

def sanitize_title(canon_title):
	"""
	Sanitizes the given canonical title for a quest and returns a
	url-friendly version.
	"""
	ident_title = canon_title.lower().replace(" ", "-")
	ident_title = urllib.parse.quote(ident_title)
	return ident_title


def handle_img(post):
	"""
	Handles [img] tags within a quest post appropriately.
	"""
	urls = re.findall(r"\[img\](.*?)\[/img\]", post)
	for url in urls:
		try:
			res = requests.get(url)
			res.raise_for_status()
			mime = magic.from_buffer(res.content, mime=True)
			assert mime in ["image/jpeg", "image/png","image/gif","video/webm"]
			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)
			alt_text = os.path.basename(url)
			img_tag = f'<img src="/img/{fname}" alt="{alt_text}" '
			img_tag += f'title="{alt_text}" />'
		except requests.exceptions:
			img_tag = "INVALID_IMG_URL"
		except assertion:
			img_tag = "INVALID_IMG_MIME_TYPE"
		except:
			img_tag = "UNKNOWN_ERROR"

		post = post.replace("[img]" + url + "[/img]", img_tag)
	return post