#!/usr/bin/env python3
"""Lay out the LOAD-TIME test: raw container header in, expected results out.

    python3 tools/bench/prep_load.py <in.dlx> [--out tmp/load]

src/player/load.i does on the 68000 what tools/bench/dlxload.py has been doing
host-side since session 1: expand the two codebooks to word-per-pixel form and
pack the 24-bit palette into GGGGGRRRRRBBBBBI with the shared LSB chosen per
entry (ROADMAP P1 and P2).  This writes both halves of that comparison.

  <out>_data.bin    the container's HEADER REGION, byte for byte as it comes
                    off the disc: magic, geometry, the three section offsets,
                    the 768-byte palette, CB1 and CB4.  Nothing is pre-chewed --
                    that is the entire point.  It ends where the frame stream
                    begins, so it is also exactly what a player would have to
                    read before it could draw anything.
  <out>_expect.bin  what dlxload.py says the 68000 must produce: expanded CB1,
                    expanded CB4, then 256 big-endian palette words.
  <out>_meta.lua    sizes, k1/k4, and the expected darkest-entry index.

The expectation is generated by the SAME module the two decode rigs load
through, so this cannot pass by agreeing with a second copy of the maths.
"""
import sys, argparse
sys.path.insert(0, "tools/encoder")
sys.path.insert(0, "tools/bench")
from dlx import DLX
import dlxload as DL

ap = argparse.ArgumentParser()
ap.add_argument("container")
ap.add_argument("--out", default="tmp/load")
a = ap.parse_args()

d = DLX(a.container)
if d.version < 3:
    sys.exit(f"{a.container} is DLX{d.version}: load.i wants DLX3 or DLX4")
if d.idx_bytes != 1:
    sys.exit("2-byte codebook indices: load.i expands one source byte per pixel")

off_frm = int.from_bytes(d.raw[28:32], "big")
raw = d.raw[:off_frm]

cb1, cb4 = DL.expand_codebooks(d)
palb, dark, _ = DL.pack_palette(d)

open(a.out + "_data.bin", "wb").write(raw)
open(a.out + "_expect.bin", "wb").write(cb1.tobytes() + cb4.tobytes() + palb.tobytes())

with open(a.out + "_meta.lua", "w") as fh:
    fh.write("-- generated by tools/bench/prep_load.py -- do not edit\nreturn {\n")
    fh.write(f"  k1={d.k1}, k4={d.k4}, dark={dark},\n")
    fh.write(f"  raw_len={len(raw)}, cb1_len={cb1.nbytes}, cb4_len={cb4.nbytes},\n")
    fh.write(f"  pal_len={palb.nbytes},\n}}\n")

print(f"{a.container}: k1={d.k1} k4={d.k4}, header region {len(raw)} B "
      f"(pal 768 + cb1 {d.k1*16} + cb4 {d.k4*4} + 32)")
print(f"  the 68000 must produce {cb1.nbytes} + {cb4.nbytes} B of expanded "
      f"codebook and {palb.nbytes} B of palette, darkest entry {dark}")