"""Extract local Half-Life assets; never alters the Steam installation."""
import pathlib, struct
from PIL import Image
PROJECT = pathlib.Path(__file__).resolve().parents[1]
SOURCE = pathlib.Path.home()/'.steam/steam/steamapps/common/Half-Life/valve'
out = PROJECT/'assets/textures'
out.mkdir(parents=True, exist_ok=True)
body = bytearray((SOURCE/'models/zombie.mdl').read_bytes())
tex = bytearray((SOURCE/'models/zombiet.mdl').read_bytes())
base = len(body)
count, records, data, refs, families, skins = struct.unpack_from('<6i', tex, 180)
for i in range(count):
    pos = records + i*80
    name, flags, w, h, pixel = struct.unpack_from('<64s4i', tex, pos)
    image = Image.frombytes('P', (w,h), bytes(tex[pixel:pixel+w*h]))
    image.putpalette(bytes(tex[pixel+w*h:pixel+w*h+768]))
    image.convert('RGB').save(out/('zombie_%02d.png'%i))
    struct.pack_into('<i', tex, pos+76, pixel+base)
struct.pack_into('<6i', body, 180, count, records+base, data+base, refs, families, skins+base)
body.extend(tex)
struct.pack_into('<i', body, 72, len(body))
(PROJECT/'assets/zombies/zombie_textured.mdl').write_bytes(body)
wad = (SOURCE/'halflife.wad').read_bytes()
n, directory = struct.unpack_from('<ii',wad,4)
wanted = {'LAB1_W3':'wall.png','C1A0_LABFLR':'floor.png','C1A0_C1':'ceiling.png'}
found = set()
for i in range(n):
    offset, _, _, typ, compression, _, _, raw = struct.unpack_from('<iiiBBBB16s',wad,directory+32*i)
    name = raw.split(b'\0')[0].decode().upper()
    if name not in wanted or compression:
        continue
    _, w,h, a,b,c,d = struct.unpack_from('<16s6I',wad,offset)
    palette_offset = offset+d+(w//8)*(h//8)+2
    image = Image.frombytes('P',(w,h),wad[offset+a:offset+a+w*h])
    image.putpalette(wad[palette_offset:palette_offset+768])
    image.convert('RGB').save(out/wanted[name])
    found.add(name)
    print(name,w,h)
assert found == set(wanted), ('Missing WAD textures',set(wanted)-found)
print('Zombie textures:',count)