#!/usr/bin/env python3
"""Dump every `.prm` primitive's keyframe group (alpha + time) for a UI build.

The screen-transition fade lives here -- see docs/re/screen-transitions.md.
Usage: PAK=<pak> fade_quads.py [build...]   (default: GP_TITLE, builds 2 4 5 6)"""
import struct, sys, glob, os, zlib
# The monorepo migration left this pointing at /work/Syplheed-Reborn, a path
# that no longer exists -- so the command screen-transitions.md cites as its
# evidence could not be re-run.  Resolve beside this file instead.
_SD = os.path.dirname(os.path.abspath(__file__))
sys.path.insert(0, _SD)
src = open(os.path.join(_SD, "regn_decode.py")).read()
exec(src.split("# ── POF0")[0])

DECL_AT, DECL_ENTRY, KF = 0x20, 60, 40
def be32(b,o): return struct.unpack_from(">I", b, o)[0]

def parse(bundle):
    n = be32(bundle, 0x14)
    names=[]
    for i in range(n):
        o = DECL_AT + i*DECL_ENTRY
        names.append(bundle[o:o+28].split(b"\0")[0].decode("ascii","replace"))
    groups={}
    pos = DECL_AT + n*DECL_ENTRY
    for _ in range(n):
        if pos+8 > len(bundle): break
        idx = be32(bundle,pos); frames = be32(bundle,pos+4)
        if idx>=n or frames==0 or frames>4096: break
        first = pos+12; end = first + frames*KF - 4
        g=[]
        for k in range(frames):
            blk = first + k*KF
            if blk+36 > len(bundle) or blk+36 > end: break
            g.append(dict(fade=be32(bundle,blk), sx=be32(bundle,blk+16), sy=be32(bundle,blk+20),
                          x=struct.unpack_from(">i",bundle,blk+28)[0], y=struct.unpack_from(">i",bundle,blk+32)[0],
                          # A POSE'S TIME PRECEDES IT (ui-keyframe-record-layout.md).
                          # This read `blk+36` -- the NEXT record's time word --
                          # which shifted every time by one slot and left the
                          # last pose untimed. That stale association is what
                          # made screen-transitions.md print a 0.87-4.08 s
                          # fade-in and an untimed fade-out. Corrected 2026-08-30.
                          t=be32(bundle,blk-4)))
        groups[idx]=g; pos=end
    return names, groups

# ...and the default pak pointed at /work/sylph_extract, which the disc mount
# replaced.  $SYLPHEED_DISC is what run-canary and sylpheed-cli both use.
pak = os.environ.get("PAK") or os.path.join(
    os.environ.get("SYLPHEED_DISC", "/disc"), "dat", "GP_TITLE.pak")
E = pak_entries(pak)
E = [b for h,b in E]
# build index -> pak entry index, from `screen list`: 0..9 then 12, 15
BUILDS = {0:0,1:1,2:2,3:3,4:4,5:5,6:6,7:7,8:8,9:9,10:12,11:15}
# An argument may be a BUILD ordinal (mapped through BUILDS) or, prefixed with
# `e`, a raw PAK ENTRY -- the splashes are entries 10/11 and are NOT screen
# builds, so no build ordinal addresses them. Writing `e10` says which index
# space is meant, which is the whole lesson of build-ordinal-vs-entry.md.
want = sys.argv[1:] or ["2","4","5","6"]
for arg in want:
    if str(arg).startswith("e"):
        idx = int(str(arg)[1:]); label = f"entry {idx}"
    else:
        idx = BUILDS[int(arg)]; label = f"build {arg} (entry {idx})"
    names, groups = parse(E[idx])
    print(f"=== {label} ===")
    for i,nm in enumerate(names):
        if not nm.endswith(".prm"): continue
        g = groups.get(i, [])
        print(f"  [{i}] {nm}  {len(g)} kf")
        for k in g:
            a=(k['fade']>>24)&0xff
            print(f"      t={str(k['t']):>5}  fade=0x{k['fade']:08x} (alpha {a:3d})  scale={k['sx']}x{k['sy']}  pos=({k['x']},{k['y']})")