#!/usr/bin/env python3
"""CUPS filter for TA 3505ci - injects department account code into PostScript stream."""
import sys


def parse_options(options_str):
    options = {}
    for token in options_str.split():
        if '=' in token:
            k, v = token.split('=', 1)
            options[k] = v
        else:
            options[token] = 'true'
    return options


def get_account_code(options):
    km = options.get('KmManagment', 'Default')
    if km == 'Default' or not km.startswith('MG'):
        return None
    code = km[2:]
    if not code.isdigit():
        return None
    return code.zfill(8)


def process_stream(lines, account_code):
    if not account_code:
        yield from lines
        return

    inject = f"({account_code}) statusdict /setmanagementnumber get exec\n".encode()
    injected = False

    for line in lines:
        stripped = line.rstrip(b'\r\n')
        if not injected and (stripped.rstrip() == b'%%EndSetup' or stripped.startswith(b'%%Page:')):
            yield inject
            injected = True
        yield line

    if not injected:
        sys.stderr.write("kyofilter: WARNING: no injection point found in PostScript stream\n")


if __name__ == '__main__':
    pass