from collections.abc import Sequence
from typing import Final, Protocol

from ear.fileio.adm.elements import FormatDefinition, Frequency

LFE_LOWPASS_HZ: Final = 120.0


class _Frequency(Protocol):
    lowPass: float | None
    highPass: float | None


class _ChannelFormat(Protocol):
    id: str
    audioChannelFormatName: str
    frequency: _Frequency


class _StreamFormat(Protocol):
    id: str
    format: object
    audioChannelFormat: object | None
    audioPackFormat: object | None


class _Adm(Protocol):
    @property
    def audioChannelFormats(self) -> Sequence[_ChannelFormat]: ...

    @property
    def audioStreamFormats(self) -> Sequence[_StreamFormat]: ...


# Python mirrors of EAT's fix_dolby.json pre-fixes (ebu/ebu-adm-toolbox
# src/eat/process/misc.cpp), applied to the parsed EAR ADM instead of
# re-writing the file. Real Dolby ADM Profile masters need both before
# adm.validate() passes. The third fix_dolby process, fix_block_durations, is
# covered by EAR's own timing_fixes.check_blockFormat_timings(adm, fix=True).


def fix_ds_frequency(adm: _Adm) -> tuple[str, ...]:
    # EAT: every audioChannelFormat whose name contains "LFE" gets lowPass=120.
    # EAR's ADM also holds the common-definitions channels (EAT operates on the
    # axml document alone), so skip channels that already carry a lowPass —
    # same outcome, and no-op fixes are not reported.
    fixed_channel_format_ids = []
    for channel_format in adm.audioChannelFormats:
        if "LFE" in channel_format.audioChannelFormatName and channel_format.frequency.lowPass is None:
            # Set only the missing lowPass; preserve any existing highPass.
            channel_format.frequency = Frequency(
                lowPass=LFE_LOWPASS_HZ,
                highPass=channel_format.frequency.highPass,
            )
            fixed_channel_format_ids.append(channel_format.id)

    return tuple(fixed_channel_format_ids)


def fix_stream_pack_refs(adm: _Adm) -> tuple[str, ...]:
    # EAT: PCM audioStreamFormats that reference an audioChannelFormat drop
    # their audioPackFormat reference (Dolby writes both; BS.2076 allows one)
    fixed_stream_format_ids = []
    for stream_format in adm.audioStreamFormats:
        if (
            stream_format.format == FormatDefinition.PCM
            and stream_format.audioChannelFormat is not None
            and stream_format.audioPackFormat is not None
        ):
            stream_format.audioPackFormat = None
            fixed_stream_format_ids.append(stream_format.id)

    return tuple(fixed_stream_format_ids)