#!/usr/bin/env python3
"""
TM-T88V paper width NV fix — attempt 2.
Tries multiple memory switch group/value combinations.
Writes directly to /dev/usb/lp0.
"""
import sys, time

ESC = b'\x1b'
GS  = b'\x1d'

INIT   = ESC + b'\x40'
FONT_A = ESC + b'\x4d\x00'
CUT    = GS  + b'\x56\x00'
DEV    = "/dev/usb/lp0"

RULER = "123456789|123456789|123456789|123456789|12"

def write_dev(data: bytes):
    with open(DEV, "wb") as f:
        f.write(data)

def gs_e(fn: int, data: bytes) -> bytes:
    """Build GS ( E pL pH fn [data]"""
    payload = bytes([fn]) + data
    pL = len(payload) & 0xFF
    pH = (len(payload) >> 8) & 0xFF
    return GS + b'\x28\x45' + bytes([pL, pH]) + payload

def strip(label: str, nv_cmd: bytes):
    body = (
        f"\n[{label}]\n"
        f"{RULER}\n"
    ).encode("ascii")
    write_dev(INIT + nv_cmd + INIT + FONT_A + body + b"\n\n" + CUT)
    time.sleep(4)

# ── Memory switch (fn=3): GS ( E 03 00 03 <group> <value> ──────────────────
# group 1-8 control different settings; one of them holds paper width.
# Trying both 0x00 (all bits clear = 80mm) and 0x80 (bit7 = 80mm candidate).
MSW_TESTS = [
    # (label, group, value)
    ("fn3 grp1 val=0x00", 3, 1, 0x00),
    ("fn3 grp2 val=0x00", 3, 2, 0x00),
    ("fn3 grp3 val=0x00", 3, 3, 0x00),
    ("fn3 grp4 val=0x00", 3, 4, 0x00),
    ("fn3 grp5 val=0x00", 3, 5, 0x00),
    ("fn3 grp6 val=0x00", 3, 6, 0x00),
    ("fn3 grp7 val=0x00", 3, 7, 0x00),
    ("fn3 grp8 val=0x00", 3, 8, 0x00),
    # Same groups, value=0x80 in case the width bit is bit 7
    ("fn3 grp6 val=0x80", 3, 6, 0x80),
    ("fn3 grp7 val=0x80", 3, 7, 0x80),
    # Customized values (fn=5): GS ( E 03 00 05 <id> <value>
    ("fn5 id=0x01 val=0",  5, 0x01, 0x00),
    ("fn5 id=0x02 val=0",  5, 0x02, 0x00),
    ("fn5 id=0x03 val=0",  5, 0x03, 0x00),
    ("fn5 id=0x04 val=0",  5, 0x04, 0x00),
]

if __name__ == "__main__":
    print("Sending NV test strips. Watch for the first one that prints 42 chars wide.")
    print("Each strip has its label printed on it. Power-cycle after the winning one.\n")
    for entry in MSW_TESTS:
        label, fn, param, val = entry
        nv = gs_e(fn, bytes([param, val]))
        print(f"  Trying: {label}")
        strip(label, nv)
    print("\nDone. Tell me which label was the first to print 42 chars wide.")
    print("If none worked, all strips will be 30 chars and we need a different approach.")