build_pack.py

#!/usr/bin/env python3
"""Build the server emote resource pack from a Discord guild's custom emojis.

Reads every custom emoji in your guild, downloads each as a static PNG, and
builds a Minecraft resource pack whose font maps a private-use codepoint
(U+E000+) to each emote. The server pushes this pack to clients, so even
vanilla players (no mod) see the emotes drawn in chat. Pairs with the
WaveMotes client mod, which bakes the same glyphs in so they render even if
the pack never reaches a player.

Config lives in config.json (copy config.example.json):
    {
      "guild_id":  "your Discord guild id",
      "bot_token": "a bot token that is in that guild",
      "output_dir": "out"
    }

Outputs in <output_dir>/:
    MineWaveEmotes.zip   the resource pack (set as the server resource-pack)
    emote_map.json       name -> {char, codepoint, id, ...}, used by inject_emoticons.py
    SHA1                 the pack's sha1 (server.properties resource-pack-sha1)

Usage:  python build_pack.py
"""
import json
import os
import sys
import urllib.request
import urllib.error
import hashlib
import shutil
import zipfile

HERE = os.path.dirname(os.path.abspath(__file__))


def load_config():
    path = os.path.join(HERE, 'config.json')
    if not os.path.exists(path):
        sys.exit('config.json not found. Copy config.example.json and fill it in.')
    cfg = json.load(open(path, encoding='utf-8'))
    if not cfg.get('guild_id') or not cfg.get('bot_token'):
        sys.exit('config.json needs both "guild_id" and "bot_token".')
    return cfg


def http(url, headers=None):
    h = {'User-Agent': 'DiscordBot (https://w4ve.xyz, 1.0)'}
    if headers:
        h.update(headers)
    req = urllib.request.Request(url, headers=h)
    with urllib.request.urlopen(req, timeout=30) as r:
        return r.read()


def main():
    cfg = load_config()
    guild = str(cfg['guild_id'])
    token = cfg['bot_token']
    work = os.path.join(HERE, cfg.get('output_dir', 'out'))
    pack = os.path.join(work, 'pack')
    texdir = os.path.join(pack, 'assets/minecraft/textures/font/emote')
    fontdir = os.path.join(pack, 'assets/minecraft/font')

    data = json.loads(http('https://discord.com/api/v10/guilds/%s/emojis' % guild,
                           {'Authorization': 'Bot ' + token}))
    print('emojis from guild:', len(data))

    shutil.rmtree(work, ignore_errors=True)
    os.makedirs(texdir)
    os.makedirs(fontdir)

    providers, mapping, fails = [], {}, []
    cp = 0xE000
    for e in sorted(data, key=lambda x: x['name'].lower()):
        name, eid, anim = e['name'], e['id'], bool(e.get('animated'))
        # .png returns a static (first-frame) PNG even for animated emojis; size=64 pre-scales
        url = 'https://cdn.discordapp.com/emojis/%s.png?size=64' % eid
        try:
            raw = http(url)
        except urllib.error.HTTPError as ex:
            fails.append((name, eid, ex.code))
            continue
        if raw[:8] != b'\x89PNG\r\n\x1a\n':
            fails.append((name, eid, 'not-png'))
            continue
        safe = ''.join(c if c.isalnum() or c in '_-' else '_' for c in name)
        open(os.path.join(texdir, safe + '.png'), 'wb').write(raw)
        ch = chr(cp)
        providers.append({"type": "bitmap", "file": "minecraft:font/emote/%s.png" % safe,
                          "ascent": 7, "height": 8, "chars": [ch]})
        mapping[name] = {"char": ch, "codepoint": "U+%04X" % cp, "id": eid,
                         "animated": anim, "file": safe + '.png'}
        cp += 1

    json.dump({"providers": providers}, open(os.path.join(fontdir, 'default.json'), 'w'),
              ensure_ascii=False, indent=2)
    json.dump({"pack": {"pack_format": 34, "description": cfg.get('pack_description', "MineWave Emotes")}},
              open(os.path.join(pack, 'pack.mcmeta'), 'w'), ensure_ascii=False, indent=2)
    json.dump(mapping, open(os.path.join(work, 'emote_map.json'), 'w'), ensure_ascii=False, indent=2)

    zip_path = os.path.join(work, 'MineWaveEmotes.zip')
    with zipfile.ZipFile(zip_path, 'w', zipfile.ZIP_DEFLATED) as z:
        for root, _, files in os.walk(pack):
            for f in files:
                full = os.path.join(root, f)
                z.write(full, os.path.relpath(full, pack))

    sha1 = hashlib.sha1(open(zip_path, 'rb').read()).hexdigest()
    print('ZIP %.1f KB' % (os.path.getsize(zip_path) / 1024))
    print('SHA1:', sha1)
    print('packed:', len(mapping), 'fails:', fails)
    open(os.path.join(work, 'SHA1'), 'w').write(sha1)


if __name__ == '__main__':
    main()