#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""W7 (rehearsal 2026-10-20): the linked banner clears the console AND its scroll-back before it paints, so the spent
pairing code is no longer readable above it. Pure file read (runs on the BusyBox CI runner).
RED-PROOF: remove the ESC[3J printf from print_bound_banner → FAIL.
Run: python3 scripts/iso/test/test_bound_banner_clears.py"""
import os
import re
import sys

HERE = os.path.dirname(os.path.abspath(__file__))
SCRIPT = os.path.join(os.path.dirname(HERE), "felhom-bootstrap.sh")


def banner_body(text):
    m = re.search(r"^print_bound_banner\(\) \{\n(.*?)^\}", text, re.S | re.M)
    return m.group(1) if m else ""


def main():
    body = banner_body(open(SCRIPT, encoding="utf-8").read())
    if not body:
        print("FAIL: print_bound_banner not found")
        return 1
    first = re.search(r"printf\s+'([^']*)'", body)
    if not first or "\\033[3J" not in first.group(1) or "\\033[2J" not in first.group(1):
        print("FAIL: the first thing the linked banner prints must clear the screen and its scroll-back (\\033[3J ... \\033[2J)")
        return 1
    # control: the decoy without the clear is refused
    if "\\033[3J" in banner_body("print_bound_banner() {\n    printf 'x'\n}\n"):
        print("FAIL: control")
        return 1
    print("OK: the linked banner clears the console and its scroll-back first")
    return 0


if __name__ == "__main__":
    sys.exit(main())