# pylint: disable=E0602
Import("env")  # noqa

# Remove forced scanf linkage to allow garbage collection of unused code
#
# The ESP8266 Arduino framework unconditionally adds:
#   -u _printf_float -u _scanf_float
#
# The -u flag forces symbols to be linked even if unreferenced, which pulls
# in the entire scanf family (~7-8KB). ESPHome doesn't use scanf at all
# (verified by CI check in PR #13657), so this is pure dead weight.
#
# By removing -u _scanf_float, --gc-sections can eliminate:
#   - scanf family functions (~7KB)
#   - _strtod_l (~3.7KB)
#   - Related parsing infrastructure
#
# We keep -u _printf_float because components still use %f in logging.


def remove_scanf_float_flag(source, target, env):
    """Remove -u _scanf_float from linker flags.

    This is called as a pre-action before the link step, after the
    Arduino framework has added its default flags.
    """
    linkflags = env.get("LINKFLAGS", [])
    new_linkflags = []
    i = 0

    while i < len(linkflags):
        flag = linkflags[i]
        if flag == "-u" and i + 1 < len(linkflags):
            next_flag = linkflags[i + 1]
            if next_flag == "_scanf_float":
                print("ESPHome: Removing _scanf_float (saves ~8KB flash)")
                i += 2  # Skip both -u and the symbol
                continue
        new_linkflags.append(flag)
        i += 1

    env.Replace(LINKFLAGS=new_linkflags)


# Register the callback to run before the link step
env.AddPreAction("$BUILD_DIR/${PROGNAME}.elf", remove_scanf_float_flag)