mattermost-channels/emoji.py

#!/usr/bin/env python3

import sys
import os
import json
import re

mm_server = os.environ["MM_SERVER"]

with open(sys.argv[1]) as fh:
	custom_emoji = json.load(fh)
with open("./builtin_emoji.json") as fh:
	builtin_emoji = json.load(fh)

def translate_emoji(match_obj):
	emoji_name = match_obj.group(1)
	for emoji in builtin_emoji:
		if emoji_name in emoji["aliases"]:
			return "".join(
				chr(int(unicode_codepoint, 16))
				for unicode_codepoint in emoji["filename"].split("-")
			)
	for emoji in custom_emoji:
		if emoji["name"] == emoji_name:
			return f"<img src='../emoji/images/{emoji_name}' alt=':{emoji_name}:' class='emoji' />"
	return f":{emoji_name}:"

# From https://mattermost.example.org/<team_name>/emoji/add:
# Specify an emoji name that's up to 64 characters. It can contain lowercase letters, numbers, and the symbols '-', '+' and '_'.
print(re.sub(r'(?!<[^>]*):([a-z0-9_+-]{1,64}):', translate_emoji, sys.stdin.read()))