"""M3 texel store: parse the game wire's action-0x1a texture uploads into a
handle -> (u_size, v_size, mode, RGB array) dict. Format: header[32] =
{handle, byte_size, u, v, mode, ...}, then v rows of 256 bytes, texels in
0x00BBGGRR little-endian words (bytes R,G,B,0). Verified: decodes to the real
game textures (HUD 'PLAYER n' labels, squadron emblem, panel/terrain art)."""
import struct
import numpy as np


def build_texstore(recs):
    store = {}
    i = 0
    while i < len(recs):
        a, p = recs[i]
        if a == 0x1a and len(p) == 32:
            h = [struct.unpack_from('<I', p, 4 * k)[0] for k in range(8)]
            handle, u, v, mode = h[0], h[2], h[3], h[4]
            rb = b''
            j = i + 1
            while j < len(recs) and recs[j][0] == 0x1a and len(recs[j][1]) == 256:
                rb += bytes(recs[j][1]); j += 1
            n = u * v
            if n and len(rb) >= n * 4:
                arr = np.frombuffer(rb[:n * 4], dtype=np.uint8).reshape(v, u, 4)
                # v-flip (rows arrive bottom-up: 'PLAYER' reads mirrored otherwise)
                store[handle] = (u, v, mode, arr[::-1, :, :3].copy())
            i = j
        else:
            i += 1
    return store